10 facts about getting a PhD

I write about this work I'm doing all the time, but I have never written anything about what really constitutes a PhD, so I thought this week you'll get 10 FACTS about how to get a PhD:

1. After you get a master's degree, you can continue with a PhD
2. The actual PhD work is 3 years, but many of us also have 25% teaching so that we have the job for 4 years in total (the teaching is normally done during the time you also work on the degree)
3. To be admitted to the PhD program at the University of Oslo, you have to have quite good grades; B as an average on the courses in your master's degree, and at least B on your master thesis
4. Most of the PhD degree is research, but you also have to take one semester (in total) with courses (one of the courses is a mandatory ethics course - which sounds like a good idea, but when I took the course, I thought it wasn't a particularly good course...:/ )
5. My courses were the ethics course, one called "Communicating Scientific Research", a statistics course (STK9900), and a nuclear structure course ("advanced nuclear structure and reactions")
6. The main part of the PhD is research; you have to do stuff that is new, and the results must be of such a quality that it's published in serious, peer reviewed joournals (if your work isn't worthy publishing, well, then that's too bad for you - no PhD!)
7. The actual "thesis" is a collection of the articles you write (often it's something like three), and an "introduction" where you sort of sow everything together (which can be challenging when you feel like your articles have almost nothing in common), and write in detail about the methods you've used, and experimental setup, and theory and stuff (for example, I write about nuclear power in general, nuclear reactions that are interesting and important for nuclear reactors, simulations of nuclear fuel, and the Oslo Cyclotron Laboratory, and of course there is some kind of conclusion after the articles :) )
8. When everything is finished (your research, your article writing, your thesis writing, and your funding), the entire thing will be sent to a committee (experts in the field, of course ;) ) that will read everything carefully and decide whether the thesis is worthy of defending, or not. (If they decide it's not at all worthy, you don't get a chance to make it better, and all your work is worthless for the degree - if still you want to get a PhD then, you have to start ALL.OVER.AGAIN.)
9. After the committee says the thesis is ok, you'll get the date for the thesis defence, and two weeks before this, you get the title of you trial lecture that you have to prepare for the thesis defence. This could be almost anything (is my impression), but it's normally related to your research
10. The last part is the day of the thesis defence: it starts with the trial lecture, and if this is approved, then you get to actually defend your thesis. The defence happens later the same day; first you give a short presentation of the work, and the two opponents will ask all kinds of questions about it and discuss with you. After they've finished, people in the audience can ask questions. All of this is public. At the end of the day, after the committee (hopefully) approves of your work, you have to have a dinner with the opponents and your supervisor, and maybe your friends and family <3

I guess you can say I've finished points 1-5, and more or less number 6, and now I'm mostly working on the rest of point number 6, and 7.

not sure which one is most correct for me, but I'm leaning towards the first...:P

 

This week my supervisor from Paris, Jon, is coming, and my goals for the work with him is to make a draft of an article about prompt fission gamma rays, discuss my thesis draft, finish my article about uranium-234 and send it off to all the co-authors. Really (!) hope we/I manage all this...!

10 facts about nuclear physcis

A normal misconception about nuclear physics is that it's all about nuclear power and/or atomic bombs, and that that's it. This is far from the truth, and therefore I think 10 facts about nuclear physics is a good idea today :)

1. nuclear physics is  all about the atomic nucleus - discovered by accident by Ernest Rutherford a century ago, when he was bombarding a thin gold foil with alpha particles
2. there's so much we don't know about the heart of the atom - the nucleus; and that's why we are a lot of people around the world still spending all of our lives to study it, and try to understand the nucleus and the nuclear force that holds it all together (how does it really work, and why, and how big can a nucleus actually get?)
3. all atoms have a nucleus - nuclear physics is as much about the non-radioactive nuclei (stable gold, stable oxygen, stable iron), as the radioactive ones (thorium, uranium, plutonium) 
4. the "applied part" of my phd thesis is about nuclear power, which is of course also one part of nuclear physics - how to produce energy from big nuclei that splits in two (you get heat and you can boil water and you get steam and then you can generate electricity)
5. I don't want to lie; atomic bombs is also something that some people (not in Norway) study - knowledge about nuclear physics can be used in such a destructive way. As can most knowledge if I think of it...
6. knowledge about nuclear physics tells us about the creation of the elements - what happens in the sun and similar stars; how do they get their energy, and what happens there? In stars like our sun, elements all the way up to iron are produced
7. no elements that are heavier than iron can be produced in stars/the sun, but we know they exist  so they must have been created somehow (we know gold exist, we know thorium exist, we know there is lead - to give some examples), but not where they came from. Creation of these heavy elements is actually one of the great mysteries, and we think they are made in explosions or collisions in space. We use nuclear physics to try to figure out how and where all these elements are created.
8. one of the really nice applications of nuclear physics is radiation therapy. Atomic radiation may cause cancer, but it may also cure cancer <3
9. if you've ever had a CT scan, you've experienced applied nuclear physics. Think about it: it's kind of awesome that we can actually look inside the body, and get really great images of the inside, without even cutting it open...!
10. PET, which is short for positron electron tomography is another imaging technique in the nuclear medicine, where you actually detect gamma radiation from an electron that meets its anti particle, the positron (awesome, seriously!). And from this you can create beautiful three dimensional images of for example a tumour inside the body

Nuclear physics is seriously awesome <3<3<3

10 differences of the RBMK and a PWR

Since it was 30 years since the Chernobyl accident on Tuesday, I was thinking it would be a good idea with 10 facts related to that as a little "comeback" of Friday Facts (so sorry that I don't manage to make these facts every week, it's just that lately I've either been travelling, or really busy with my PhD, which I sort of have to prioritize sometimes ;) ). Or, not just ten facts, but ten differences between the Chernobyl type RBMK reactor ("reaktor bolshoy moshchnosty kanalny", meaning high-power channel reactor), and the standard pressurized water reactor (PWR). 

Ready? 

Let's go!

1. PWR is the most common type of reactor in the world operated in countries like USA,  Belgium, Brazil, China, Finland, France, Germany, India, Japan (the Fuksuhima reactor was not a PWR, though), Russia, Spain, and Sweden, and several more. The RBMK was a Soviet develloped design - only built in the former Soviet Union.
2. the PWR uses water as both moderator (for slowing down all the neutrons from really high energies, to really low energy - which is what we want <3 ) and as cooling medium, but the RBMK uses graphite as moderator, and water as cooling medium. Normally we say that the PWR is light water (light water is what we normally just call "water", instead of heavy water) moderated and cooled, and the RBMK is graphite moderated and light water cooled.
3. the RBMK was designed with a positive void coefficient; I'll don't go in detail on that now (if you want me to, I can make a separate blogpost about what this means), but in short it is the reason why the RBMK is unstable under certain conditions
4. the tip of the control rods of the RBMK actually didn't control the reactor/absorb the neutrons -it was made out of graphite that speeds up the fission process, instead of a material that actually shuts it down
5. the control rods of the RBMK could be withdrawn completely from the reactor - even if it wasn't allowed (no one should EVER be able to overrun safety systems, like it was done the night of the accident)
6. it took almost half a minute to insert the control rods into the RBMK reactor; on a PWR it takes around a second or so
7. a PWR needs fuel which is enriched to 5% uranium-235, but the RBMK only needed 2% - so it was economical with the fuel
8. the RBMK could have its fuel changed while it was running. This, together with the low enrichment (no 7) made it ideal as a producer of weapons plutonium 
9. a PWR is passively safe, but the RBMK definitely wasn't
10. the Chernobyl reactor didn't have any outer barrier; meaning the reactor was placed more or less in a warehouse rather than a full containment building. Therefore, when the reactor actually exploded, the radioactive inside of it could get out, and fresh air (oxygen...!) could get in, making a strong fire that lasted for days

These are just the first ten big differences I could think of, but there are even more. 

When I, or other nuclear scientists, say that Chernobyl could never happen in a modern, Western reactor, it's not because we just don't want to see reality or something silly like that, but it's because of these facts listet above - which makes that accident physically impossible in, for example a PWR...!

testing of reactor grade concrete - the concrete stays intact, as the plane is just disintegrated (plane vs concrete: plane 0, concrete 1)

PS: There are still some RBMKs operating in the world today, but major modifications have been made to these reactors.

Ten facts about depleted uranium

As we were approaching the Tenerife airport yesterday, I suddenly remembered something... 

The thing is, I have this weird fascination for accidents and catastrophes (Titanic, bombings of Hiroshima and Nagasaki, the Chernobyl accident, and more or less all accidents from "air crash investigation ") - which is probably one of the main reasons I was interested in nuclear physics in the first place. If you're like me, you might know which thing, or accident, I came to think about as we were approaching the airport? It was of course the Tenerife accident of March 1977, involving two Boeing-747, that crashed at the runway, killing close to 600 people. If you're weird like me, you probably don't think I'm completely crazy for googling the accident. (If you're not like me, you might think I'm insane for reading all I could find about the deadliest air crash ever, just before I'm about to go on a six hours flight :v )

First I found a very interesting and well written article, but after I had read this, and still wanted more, I kept scrolling, and suddenly I saw the two words depleted uranium. I don't think it was from the most serious web page ever, but I was inspired by it to make ten facts about this mysterious material - check fact number 10 for why the Tenerife air crash and depleted uranium have anything to do with each other:

1. depleted uranium is what you get when you take natural uranium, and you enrich it to get enriched uranium for nuclear fuel - the "waste" from this process is the depleted uranium (natural uranium minus enriched uranium equals depleted uranium, to sort of make into an equation <3) reason why it's called "depleted" is that it's depleted in the fissile uranium-235 
2. natural uranium is made by uranium-238, uranium-235, and uranium-234. The uranium-238 isotope makes up 99.275%, uranium-235 is 0.72%, and uranium-234 is just 0.0054%. Depleted uranium is made up by typically 99.799% uranium-238, 0.2% uranium-235, and 0.001% uranium-234
3. depleted uranium is often called just DU
4. it's the least radioactive kind of uranium: depleted uranium is less radioactive than natural uranium - meaning it's close to not radioactive at all. Uranium-238 has an activity of 12 445 Bequerels per gram, uranium-235: 80 011 Bequerels per gram, and uranium-234: 231 million Bequerels per gram. The total activity of natural uranium is therefore: 25 280 Bequerel from 1 gram (meaning that 25 280 atoms of the uranium - either 234, 235, or 238 is changed into another atom every second :D), and the activity of depleted uranium is about half the activity: typically 14 600 Bequerels per second. (Don't be fooled by long halflifes - the longer the halflife, the less radioactivity... Activity/radioactivity sort of tells us how fast a material is turning into something stable: if the radioactivity is very high, the halflife is short. If it's very very low, the halflife is long. Uranium-238 has a halflife of 4.5 billion years, and is not at all very radioactive.)  
5. the gamma dose rate from a 30 mm DU-bullet (of 271 grams) at a distance of 1 m is 7 nano sieverts per hours, which is almost not distinguishable from the normal background radiation of typically 100 nano sieverts per hour. If you take 10 kg of DU and disperse it over 1000 m² the result is a gamma dose rate of 4 micro sieverts per year (the average background radiation from gamma in Norway is 0.5 milli sieverts)
6. DU is extremely dense, and therefore very heavy. Natural uranium is already a metal of high density, with 18.9 g/cm³, and DU is even more dense: 19.1 g/cm³ - making it almost 70% denser than lead 
7. because of the extreme density, it's used as ammunition; since a projectile made from DU has a bigger kinetic energy than if it were made by lead, and therefore it will penetrate or destroy almost anything. Also, if a DU bullet hits a tank, all the energy that it's carrying will turn it into dust, and the heat generated will make it burn. If you're in a tank that's hit by a DU projectile - it's not exactly the radioactivity you should fear...
8. DU is actually the best kind of shielding you can make to protect yourself against gamma- or X-rays. It's even better than lead, since uranium has 92 protons in the nucleus, compared to only 82 in lead. (You could also shield with natural uranium, but since natural uranium has more of the uranium-235 isotope than depleted uranium, and 235 is more radioactive than 238 and DU, you would rather use DU than natural uranium)
9. uranium (thus also depleted uranium) is a heavy metal, like lead, and this fact is the main reason it's not very healthy - not the radioactivity. You take natural uranium, and make into something that's about half as radioactive as it already was. It's not like you make a new radioactive material. 
10. depleted uranium is also used as counterweight in airplanes like the Boeing-747; that carries around 250 kg of DU. I didn't know this until I started reading all I could find about the 1977 Tenerifie aircrash. I definitely learned something new, and now I want to learn more about counterweights :)

Luckily we got home safely after a great week of vacation, and I think I'm ready for a couple of very busy months. I've made a nice plan for this week, that includes talking about cold fusion on the radio tomorrow. Sorry I haven't been "here" last week, but I needed the vacation, and Alexandra needed her mother to be there, on vacation with her, and not on the cell or the computer all the time...:)

Friday FACTS: cosmic radiation

Friday Facts on a Sunday again - I'm starting to think I should just call it "facts"... Well, I'll try a little bit more, and see if I manage to get back on track with actually having FRIDAY facts on FRIDAYS again :P

Anyway: this day started super super early; the alarm rung at 3:15, and at 7 we took off from Gardermoen airport, with Tenerife as our destination. I feel almost silly to have one week of vacation now, just after Easter, but it just had to be this way this time. Since we've been flying today, I thought the perfect theme for facts is cosmic radiation...:

1. 1. cosmic radiation is a mixture of particles, like protons, neutrons, alphas, and electrons, and gamma- and X-rays. Most of it comes from outside our solar system, and a small part comes from the sun 
   2. when the solar activity is high, there is more radiation coming towards the earth (since the small part that comes from the sun becomes larger :) )
   3. our atmosphere works as a radiation shield for us; the cosmic rays come into it and interact, so that the rays/particles are either stopped completely, or at least lose their energy - which is a good thing for us here on Earth :)
   4. the intensity of the cosmic radiation changes with altitude - which is sort of logic, since you move “closer to space” if you climb up on a high mountain, or you get on a plane, so that there’s less atmosphere to stop whatever rays that are coming towards us from outer space. When you go from sea level to around 1600 meters above sea level, the intensity of the cosmic radiation doubles. If you go to 5000 meters, the radiation is 8 to 10 times more intense than at sea level, and if you’re on a plane, at 8500 meters above sea level,  the level of radiation is 40 times higher than at the ground 
   5. pilots and air attendants are actually classified as radiation workers; even though I work in a nuclear physics lab, with the cyclotron (that produces ionizing radiation), and with actual radioactive substances, they receive a higher dose each year than I have ever received 
   6. there are four factors that decides how big of a dose you will receive: solar activity (more activity from the sun means more particles bombarding Earth), time (if you spend a lot of time in a plane, 10 000 meters above sea level, you will of course receive a larger dose than if you spend little time at these altitudes), altitude (the higher you go, the more radiation - see point number 4), latitude (the shielding is better around equator that towards the poles - at typical flight altitudes, the difference between the cosmic ray dose rates at the equator and high latitudes is about a factor of two to three) 
   7. normal, average annul dose from cosmic radiation is 0.35 milli Sievert (this is not much - in Norway, we receive around 2 milli Sivert from radon gas, 0.6 from medical use, 0.55 from external gamma radiation, 0.35 from internal gamma radiation, and then just 0.35 from cosmic ;) )
   8. the annual dose for pilots and air attendants is somewhere between 2 and 3 milli Sivert per year; which means that if you work on a plane, your dose is well below the normal annual limit for radiation workers that is 20 milli Sievert, but more than the general public is allowed to receive (still not much - it just means that the dose limits for “members of the public” is really really strict ;) )
   9. the dose you receive on a long distance flight (like Oslo-Tokyo back and forth) is four times bigger than the total dose the average Norwegian receives from fallout from the Chernobyl accident in April 1986, from that year and 50 years into the future. (This does NOT mean that you receive a big dose from being on a plane, but that the dose we get from Chernobyl in Norway is small.)
   10. flying to the Mediterranean will get you an extra dose from cosmic radiation, equal to one meal of reindeer meat with a radioactivity of 10 000 Bq/kg. A pilot receives something equal to 100 such meals every year. If you have been scared into believing it's dangerous to eat Norwegian reindeer meat because of the radioactive downfall from Chernobyl 30 years ago, then you definitely shouldn't fly… (hint: fly as much as you want to, and eat the reindeer you want to - it's not doses that are dangerous to you; they might even be positive :) )
   
   
   
   
   
   
   Back and forth to Tenerife is about 13 hours on a plane, in roughly 10 000 meters altitude. This means that when we get back to Oslo, we've all received an extra dose of radiation of 0.065 milli Sieverts (this is just a very rough average estimate, since I haven’t really taken into account where we are flying, or where in it 11-year cycle the sun is just now - I actually have no idea of that , but maybe some of you guys know? :P ).
   
   
   PS: I didn't manage all my goals, but at least I did "finish" my article draft, and I sent it off to supervisor Jon on Friday. Also, I'm planning on plotting some stuff while I'm here - not exactly working, but sort of maintenance ;) 

Ten facts about neutrinos

Friday again - facts again <3

You know the drill, say no more:

1. a neutrino is a en elementary particle
2. a neutrino is not a neutron - neutrons are made up of quarks, and are thus not elementary particles
3. there are three types of neutrinos: they're called electron neutrino, muon neutrino, and tau neutrino (they all also have an antiparticle)
4. the name neutrino actually means "little neutron", but I have to tell that story another time...;) (In short: Pauli proposed that there should be a particle called a neutron, before the actual neutron was discovered. Then, what we know today as a neutron was discovered before the neutrino, and by that time the term neutron was taken, and this particle became a neutrino).
5. neutrinos don't have any electric charge (so they are not at all affected by the electromagnetic force), and they're almost massless - but only almost...! They do have a tiny tiny tiny mass: the heaviest one is more than 4 million times lighter than the electron (the next lightest particle). Since they are so light, neutrinos move at a speed more than 80% of the speed of light at room temperature
6. neutrinos are created in radioactive decay (like beta-decay), nuclear reactions (like in a reactor when a heavy nucleus fission, or in the sun when light nuclei fuse), when cosmic rays hit atoms, and in supernovae. Most of the neutrinos here on Earth come from the nuclear reactions that take place in the Sun <3
7. every second, a trillion trillion neutrinos pass through your body, and since they do have (a tiiiiiny) mass, this means that there's a constant flow of matter through your body ALL THE TIME. Since their mass is so small, they don't add up to much mass - about 0.0000000000001 kg of neutrinos will pass through your body in a lifetime :D (If you add up the mass of all neutrinos that have passed through every single person who ever lived, over everyone's total lifetime, the sum is 0.15 kg)
8. neutrinos are extremely difficult to detect, so you need really huge detectors if you want to try... For example, the OPERA detector (a good neutrino detector) consists of 1000 tonnes of mass to try to catch a neutrino, but even if this detector was a block of lead a light-year in length, you'd only have a 50% chance of stopping a neutrino!
9. they are often called ghost particles, since they can actually change from being one kind to being another - an electron neutrino changing into being a muon neutrino changing into being a tau neutrino (this is weird: like if you went into a Mercedes and drove for a while, and then suddenly the car changed into being a BMW, and then when you arrived at your destination you were driving and Audi. W. E. I. R. D.)
10. in 2011 neutrinos were sort of detected to move faster than light - which shouldn't be possible. Of course it turned out to be an experimental mistake, and we are still very very certain that Einstein's theory of special relativity is true <3

Bonus facts: According to my colleague, Cecilie, neutrinos fabulous :D Happy Friday!

Friday FACTS: Black holes

Happy Friday!

I'm at Anders (not my Anders, but my good friend) and Charlotte's fantastic cabin at Nordseter (Sjusjøen). We just had a nice dinner, we're drinking wine, talking, and there's a fire in the fireplace <3 I'm about to put away my laptop for the weekend, but before I do that, what could fit better now than ten facts about black holes? Close to nothing :D Here goes:

1. Black holes are called “black” because they swallow all light, and no light (or anything) can ever escape it
2. Black holes are made when stars die and collapse (*sad*)
3. Black holes are super super super dense, and NOTHING have a higher density than a black hole
4. It's not really like what people think of as a hole, but maybe more like what we would normally think of as a sphere. But then again, it has the "traplike" properties of a hole (since you can fall into is, as if it was a hole in the ground), so you can probably think about it as a three dimensional hole ;)
5. A black hole with the size of a sugar cube weighs the same as the entire earth: 1000000000000000000000000kg (24 zeros!) - 1 septillion kilos :D
6. We know nothing about what happens inside black holes
7. If a black hole came into our solar system it would swallow the earth. This is extremely unlikely, but it’s still more likely than for example winning the lottery ten times in a row (but less likely than being struck by lightening)
8. Black holes have a horizon (or really an "event horizon", which is the boarder of the black hole) where time stands still (at least it looks like it’s standing still if we are looking at a person who is falling into it) this horizon is the point of no return, where it's absolutely impossible to escape falling into the hole. It's really just like as a a clock runs a bit slower closer to sea level than up on a space station, a clock run really slow near black holes, and this all have to do with gravity 
9. If you fall into a black hole you would be stretched (to death) like spaghetti, since whatever part of your body that reaches the horizon first will feel soooo much more gravity (since the hole is so dense and heavy) than the rest of the body that's outside the horizon
10. When black holes collide, they make gravitational waves - which were discovered last Thursday!

By the way: today I managed to finally make this figure I was talking about yesterday, so then I'm one step closer to a new article. Next week I want to finish the rest of the figures to the article, and then I'm suddenly quite close to finishing the thing.

PS. This week I just have to give you a sort of fact number 11: we don't believe that inside black holes you find book shelves. (Hint: "Interstellar")

Fuel on a Friday - 10 Facts

I can’t believe it’s Friday already. 

This week has just gone by so fast. It started with Alexandra still being sick on Monday, and then on Tuesday I went to Stavanger, and spent around 50 hours there - giving two talks, and talking to so many interesting people. (I think I’ll have to write about some of my thoughts about the Norwegian oil industry - just not right now.) Yesterday I got home, and the evening was spent with Anders; we shared a bottle of wine, he worked on his code and I scanned all my receipts from the trip, and sorted them into the right folders (not fun doing, but it feels GREAT when you’re done, especially when you realise you’ve spent roughly 9000NOK on travelling, that you of course want, and will get, back ;)). Then we made the working your ass off thai chili, and around that time I got a migraine…:/ 

However, today is Friday, and luckily I woke up this morning feeling great again - hopefully there'll be many months before I get another migraine attack!

So Friday is luckily NOT equal to migraine, but it IS equal to FACTS! It's finally time for ten Friday Facts about Fuel - nuclear fuel, of course:

1. the fuel in a nuclear power plant is placed inside the reactor core. Mostly all the fuel soaked in water because water is great for cooling the fuel, which is the same as removing the heat - which is exactly what we want; we want water to be heated so that we can produce steam and thus generate electricity with a turbine <3
2. we often call it "burning" the fuel, but it's no real burning going on - the fuel is the place where the fission chain reaction happens (the energy from nuclear power comes from fission of nuclei inside the fuel :) ), so when I talk about (nuclear) fuel I mean material where there’s a chain reaction going on.
3. nuclear fuel is made out of slightly radioactive elements; it can either be uranium, plutonium, or thorium
4. a small part of the fuel has to be fissile; meaning it has to have a really big chance of splitting if it's hit by a neutron. The fissile material can be either uranium-233, uranium-235, or plutonium-239
5. thorium is NOT fissile, so thorium must be mixed with something that is. This means that in thorium based fuels it is actually not the nuclei of the thorium atoms itself that fissions - thorium is first transformed into uranium-233, and then this uranium nucleus is the one that fissions and releases energy :D
6. the fissile part of the fuel is typically just 5% of the total of the fuel. The rest of the fuel (so, the majority of the fuel, really) is either thorium-232 or uranium-238.
7. the "flame" in nuclear fuel is the neutron. There is of course no real flame, and there is also no burning (see point number 2.), but I think that calling the neutron "the flame" is a nice analogy, since the neutron is what makes the nucleus fission and then release all the energy <3
8. the most common nuclear fuel is called UOX, which is for uranium oxide, meaning that it’s not pure metallic uranium (uranium as an element is a metal), but uranium and oxygen ( the oxides are used rather than the metals themselves because the oxide melting point is much higher than that of the metal and because it cannot actually burn, since it's already in the oxidized state.)
9. used fuel can (and should, in my opinion!) be recycled, since it has a lot of material that is really useful (actually: typically only half a percent of all the fuel fissions during the years it's in the reactor, so if you throw away all that's left after a couple of years, you throw away A LOT of resources). If you recycle these materials - which can be uranium-235 that just hasn't fissioned yet, or plutonium-239 that has been made during the time the fuel was in the reactor - you have to mix them with fresh fissile material, and when you do this the fuel is called MOX. MOX is short for Mixed Oxides :D
10. if you get really got at recycling, and you have the kind of reactors that are optimized for this type of MOX fuel (see point number 9.), you can actually end up getting 200 times more energy from the fuel than you normally get today!

- my fuel when I got to Stavanger airport yesterday: Chablis and Cæsar salad - as I started going through all the receipts (a lot!) rom just two days travelling -

10 facts about neutrons

Hi sweeties <3 Alexandra's been sick since Wednesday, poor girl, so I've spent most of the time taking care of her and comfort her. Therefore, again (!), this week's Friday Facts blogpost comes on a Sunday. Hope you understand...
This time I feel the need of giving you ten facts about my favourite particle - the neutron:

1. neutrons are radioactive if they are "free" (alone, and not part of the nucleus of an atom)
2. neutrons have no charge - they are neutral, and can therefore "sneak" into another nucleus, and for example make it fission :D
3. the recipe for a neutron is: 2 down quarks and 1 up quark (opposite to the proton that is made up of 2 ups and 1 down)
4. the half-life of a (free) neutron is about 10.2 minutes, and then it turns into a proton, and electron, and an anti neutrino. Meaning it beta decays :D
5. the neutron was discovered by James Chadwick in 1932
6. neutrons have a mass, which is almost equal to the proton, but the neutron is a little bit heavier. Actually the mass of the neutron is 1.674927471×10⁻²⁷ kg (or 0.00000000000000000000000000164927471 kg), and that's the same as 2.5 electron masses (electrons weigh really little) more than a proton
7. neutrons can make stuff radioactive - which is called neutron activation; so a normal, stable gold nucleus can for example be activated by a neutron and go from gold-197 (stable) into gold-198 (un stable) and then decay into mercury-198, which is stable
8. you can't make a nucleus entirely out of neutrons - you have to have at least one proton too, and then you have deuteron, or heavy hydrogen
9. number 8 is actually just sort of true; you can go to an extreme, and calculate how many neutrons you need to make a "nucleus" entirely out of neutrons (since neutrons have no charge, they don't repel each other, like protons do, but they don't stick together either - a little bit like two pieces of paper; if you put them together they will just fall apart), and since they do have a mass they will attract each other because of gravity between them. This means that if you have enough neutrons, you will make something that won't just fall apart; and that number is . Not exactly nuclear size...:P (Read more about that HERE)
10. when neutrons hit you, they will give you a dose that is dependant on their energy. The highest dose from a neutron comes when it has an energy of 1 million electron volts. If the neutron has lower or higher energy, the dose from it will be lower. 

For some reason I imagine neutrons to be white :P How do you imagine the neutron to look?

Friday Facts - gamma radiation

Friday again, darlings, and we know by now what day (normally) means: Friday Facts! This week I want to tell you about gamma radiation, since most of my (professional) life orbits around this kind of radiation these days.

1. gamma rays, or gamma radiation, is the same kind of radiation as light (both are "just" electromagnetic radiation) - it's just really really intense, and comes from the atomic nucleus. A gamma ray carries at least 10 000 times more energy than "normal" visible light ray
2. it doesn't have any mass or charge - as opposed to for example alpha or beta radiation
3. gamma radiation travels with the speed of light - maybe not a big surprise, since I say in number 1 that it's really the same kind of radiation as light ;)
4. gamma rays can be used to kill cancer cells, but it's not the standard for radiation treatment in Norway - where we use X-rays (when it comes to killing cells there's really no big difference between using gamma or X-rays )
5. gamma rays are kind of waves, with very high energy, and very short wavelength - of less than ten trillionths of a meter
6. gamma radiation goes through "everything" - at least compared to alpha and beat radiation, which are easily stopped. If you want to shield something from gamma radiation (and I often want to do just that), you (or I) use something very dense, like lead or actually depleted uranium is even better 
7. a nucleus will very often emit a gamma ray at the same time as it emits an alpha or beta particle; this happens because after emitting the alpha/beta, the nucleus has a lot of extra energy, which is called being excited, and to get rid of this extra energy (called "de-excite") it emits gamma radiation
8. measuring the gamma rays can be used to identify all kinds of different nuclei, since the different energies of the gamma rays sort of works like an id, or fingerprint, for one specific nucleus. For example we know for sure that oxygen-17 emits a gamma ray with an energy of 870 kilo-electron volts, and if we measure this we know that we have measured that exact oxygen isotope
9. we (people) emit gamma radiation: A person that weighs 70 kg emits 500 gamma rays that come from potassium-40 every second. Potassium is the main reason why humans are radioactive, and that's completely normal :)
10. I think it's so funny that we call a nucleus that has extra energy excited...I mean, this is me when I'm excited :D When I'm excited I don't emit more gamma rays than normal :P

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Now I have to run for our nuclear physics group meeting - but maybe I'll talk to you later today. Have a great Friday and soon weekend sweeties!

Friday Facts is back!

After this week, when North Korea decided to do what they did, what else could be the theme for Friday facts than the hydrogen bomb?

1. the hydrogen bomb is also called the H-bomb, a fusion weapon/bomb, or a thermonuclear weapon
2. the point of a "real" hydrogen bomb is to get hydrogen to fuse, and to get a large portion of energy released from this reaction
3. to get the hydrogen to fuse you have to make it hot enough (you try to recreate what happens in the sun) so that light nuclei will fuse and release even more energy than in a "normal" atomic bomb/nuclear weapon - the word thermonuclear means that the fusion takes place when the temperature is extremely high
4. a hydrogen bomb is also an atomic bomb/nuclear weapon, but it was developed some years after the fission bombs ("normal" atomic bombs) that were used in 1945, on Hiroshima and Nagasaki - the only time nuclear weapons have been used (a hydrogen bomb has never been used - only tested)
5. the first step of a hydrogen bomb is a fission bomb, which makes the temperature so extreme that fusion may start
6. I don't understand this mushroom cloud from the North Korean bomb test on Wednesday, since they did it under ground... I think they've either had fun with photo shop, or they just "borrowed" the pictures of the cloud from somewhere else (maybe Kim Jong Un really loves mushroom clouds?)
7. in addition to a real fusion bomb (where most of the energy released comes from fusion reactions), you could make a fission bomb that is boosted with hydrogen - this means that there will be some hydrogen in the weapon that fuses, and from these fusion reactions you get more neutrons so that even more of the fissile material will fission. Almost of all the energy released in such a weapon comes from fission, so therefore it's called a boosted fission bomb
8. there is in theory no limits for how big a hydrogen bomb can be; you can just put more and more fusion material in it - I state that the real hydrogen bomb is the deadliest weapon ever made, and the biggest ever bomb test was the Tsar Bomba, which had an explosive power of 50 million tons of TNT (around 1500 times the total explosive power of both Hiroshima and Nagasaki combined)
9. the first hydrogen bomb was tested in 1952, by the USA - today there are at least five countries that have these types of weapons (USA, Russia, UK, France, and China)
10. this book is about the hydrogen bomb, and I got it from my sweet colleague, Gry, and now I'm going to read it <3

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Happy weekend from Rose castle - we are going to watch West Wing and share a bottle of wine now :)

(I'm a frog :D)

Merry Christmas!

First of all, the most important message to day is: MERRY CHRISTMAS to all my wonderful, fantastic readers - I love you all!

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To follow up on the last blog post about stars, here are two more facts about stars that I think suits the theme of this day (my favourite day of the year):

1) There is no “Star of Bethlehem”, or "Christmas star". What the wise men probably saw on their way to meet baby Jesus, was Halley's comet (there are other theories as well, but I like the comet theory :) ), which was visible 11 or 12 years BC.

We told Alexandra this the other day, and she replied by instructing us to change the word "star" into "comet" in the songs :D (For the record: I have no trouble singing "star" - this was her choice...)

2) The most poetic fact is that we are all made of star dust (or we can call it starstuff), and Carl Sagan said it so beautifully and fantastic, I will just finish this holiday blog post with his words:

Facts on a Friday - Beta radiation

Hi everyone, sorry I've been quiet since Sunday! I was planning to share my plan of the week on Monday, but then the day just sort of disappeared, and I really don't know what happened to the rest of the week either (I know that yesterday disappeared since I was in charge of the nuclear physics group's christmas party, and this weekend, including today, I'm at Trysil, but Monday, Tuesday, and Wednesday I really don't know...:/)

Anyway, here are 10 facts about Beta radiation, since today is Friday and it's rime for facts (read about Alpha radiation HERE):

1. beta radiation consists of particles - you can call it betas, beta particles or beta radiation.
2. beta particles (or betas or beta radiation) is just exactly the same as electrons - beta particles are free electrons.
3. you can have either beta plus or beta minus radiation (so it's actually not exactly true that beta particles are electrons, because if they're beta plus particles, then they're positrons, and if they're beta minus, then they're electrons).
4. I think beta decay (the process where a nucleus emits a beta particle) is really weird: I mean, a neutron actually changes into a proton (or a proton changes into a neutron, if it's a beta plus).
5. beta minus decay is also called electron emission, and beta plus decay is called positron emission.
6. when a nucleus emits (sends out) a beta particle, it transforms into a nucleus that has a higher proton number (hydrogen would for example turn into a helium nucleus, since helium has one more proton than hydrogen) - this also means, that, yes, you can make gold from platinum, that has one less proton than gold.
7. beta particle a are sometimes relativistic - that means that they move with a speed that's close to the speed of light, and that makes them seriously difficult to deal with (for instance theoretical calculations).
8. if the beta particle is emitted in air, it usually moves a few meters before it is stopped (it has a range of a couple of meters in air). In water it moves only a few centimeters. This means they're quite easy to shield yourself from...
9. most fission products emit beta (minus) radiation.
10. beta radiation can cause actual "burns" on your skin; you can see (and feel) that your skin turns red, if you're very close to an intense source of beat radiation.

Friday Facts - Alpha radiation

We just finished this week's experiment, where we used alphas to learn more about zirkonium, and therefore I thought that today I have to give you 10 Friday Facts about ALPHA RADIATION (a couple of weeks ago I wrote about radiation in general, you can read that blogpost HERE):

2 proton (p) + 2 neutrons (n) = alpha particle = helium nucleus

1. Alpha radiation is one of the types of particle radiation - alpha radiation is like a stream of alpha particles (I change all the time between calling it just alphas, alpha particles, or alpha radiation - they're all the same :) )
2. An alpha particle is exactly the same as a helium nucleus (so, a helium atom stripped of its electrons)
3. A helium nucleus consists of 2 protons and 2 neutrons - meaning that an alpha particle consists of two protons and two neutrons
4. Alpha particles/radiation have a very short range - meaning they can't move very far; for example they only get a couple of centimetres in air
5. Since the alpha particles have such a short range, it means that they are very easy to shield yourself, or protect yourself, from 
6. If you get something (a source) in your body that emits alpha particles, this can be quite bad, since basically none of the alphas will get out of your body, and all their energy will be deposited inside your body
7. Radon is an example of a radioactive gas that emits alpha radiation
8. As long as whatever material that emits alphas is on the outside of your body, it can't hurt you (if the only problem with this material is that it emits alphas, of course)
9. If I hold some material that emits alpha radiation in my hand, I won't get any dose (from radiation) to my hand (except from the part of my skin which is already dead, but I don't really care about whether or not my dead skin cells are exposed to a radiation dose ;))
10. Heavy, unstable nuclei can emit an alpha particle to become a little bit lighter, and therefore more stable - ie, it's a little bit like "chopping" off a small part of the nucleus (like you have an apple, and you take a knife and you chop off a small part, then you have a little smaller apple and a piece of the apple)

helium atom: alpha particle + 2 electrons <3

Friday Facts (or something): Top 10 places to visit...

Today's Friday Facts are not really facts (they are just highly my opinion...;) ), but my list of the top ten places to visit around the world, as a nuclear/reactor physicist. I'm not sure about the order, so that's quite random (except I think to me Chernobyl really is number one - I can't believe we didn't manage to go there when we were in Kiev two years ago).

1. Chernobyl - Ukraine
2. La Hague - France
3. Sellafield - UK
4. Olympic Dam - Australia
5. Olkiluoto - Finland
6. Fukushima - Japan
7. Three Mile Island - USA
8. Los Alamos - USA
9. Hirsohima - Japan
10. CERN - Switzerland

Now you know where to go when you're planning your next vacation ;)

 

The only place I can cross off the list is Hirsohima. I went there when we made Sushi and Nuclear last year. It was actually quite emotional to go there - it felt a little bit like a continuous punch in the stomach, to walk around the A-bomb Dome, which they left as it was after the bombing.

So, do you agree on my list? Or should some of the places be replaced?

Facts on a Friday: 10 reasons why neutrons are really cool

Today I just wanted to tell you a little bit about neutrons, and why I think they're the coolest. You know, in a way they're like a Chanel purse - classical, and never out of style ;)

speaking of Chanel: I've been thinking that I should buy a black Chanel purse as a gift for my self when I have finished my PhD, but maybe I should consider the pink one instead...?

So here are my ten reasons why I think neutrons are really cool:

1. Neutrons have no charge
2. They decide if an atom is stable or radioactive
3. A single neutron can sneak its way into a nucleus and make fission <3
4. It's an unstable particle with a half life of a little bit more than 10 minutes
5. I sort of envision them as white dots, or tiny billiard balls...
6. A free neutron turns into hydrogen (meaning that the neutron is actually a radioactive particle - radioactivity is just soooo fascinating :D )
7. Neutrons are the "flame" in the fuel of a nuclear reactor
8. Neutrons gives different doses (of radiation) depending on their  energy 
9. You can make a neutron from a proton and a proton from a neutron (almost sounds like witchcraft, or something)
10. If neutrons have the right energy, they can do quite a lot of damage - but you can just use normal water as a shield, and you're fine ;)

I just love them - neutrons are without doubt my favorite. They're fabulous ✨

Do you have a favorite particle?

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PS: I am working on Question of the month (which is actually not a nuclear physics one this first time) - the plan was to publish it yesterday, but since I (unfortunately? :P ) have another job than just being a blogger, I haven't been able to finish it yet , and I'm really sorry :/ However, I'm still inside my own "limits", since I said it would come this week, and even though it's Friday, it's not the end of the week just yet ;)

Force on a Friday

Hi there, Friday!

Last week there were no FACTS on FRIDAY, but this week we're back on track again :D Today I think it's time to talk about the force - the nuclear force: 10 facts about the nuclear force, here you go!

1. the nuclear force is the force that holds, or binds, a nucleus (of an atom) together, even though all the protons in it are being pushed apart by another force - the protons are like extremely strong magnets with the same pole; they repel each other
2. without the nuclear force, there wouldn't be any nuclei; without nuclei there wouldn't be atoms, and without atoms there wouldn't be molecules; without the nuclear force there would be no life - no nothing, really, and you couldn't exist...!
3. it is the strongest of the four fundamental forces, and it's really strong (the three others are electromagnetic force, gravity, and weak force); for example it is 137 times stronger than the elctromagnetic force, and compared to gravity, it is a 1000 million million million million million million (1000000000000000000000000000000000000000) times stronger!
4. the nuclear force has a very short range - meaning that it only works when a particle "touches" a nucleus; or, in other words: if you get 0.000000000000001 meters from the center of a nucleus, you can't feel it anymore. This distance is called femtometer
5. when you fission a heavy nucleus, you release some of the force that holds this nucleus together, and since it is so strong, you get soooo much energy from fission
6. "strong force" is another word for the nuclear force (in Norwegian: "sterk kjernekraft")
7. when you fuse two light nuclei (make a new nucleus by putting two nuclei together), you also release some of the nuclear force - and therefore you can get energy from fusion, like the sun does it :)
8. it was after Chadwick discovered that there were neutrons (with no electric charge) inside the nucleus, in 1932, that the physicists discovered the nuclear force - neutrons don't feel the elctromagnetic force, like protons (or electrons, that have electric charge) do, and therefore it had to be something else that was holding the nucleus together...
9. the nuclear force doesn't really care if a particle has a charge or not; the force between two protons, two neutrons, or a proton and a neutron are nearly the same <3
10. we still don't understand everything about the nuclear force, even though has been worked on for eight decades...

Don't forget about "Question of the month" next week; I already have some very nice questions, but please, ask more!

Ok, I think that's it for now - I have to go back to my figures and my tables, and then there is the weekly nuclear physics group meeting... Bon weekend, and may the force be with you <3

Ten facts about nuclear weapons and the "Megatons to Megawatts" program

Friday again!

This week that means Bergen, and as (almost) always that means FACTS. This week I want to give you ten facts about nuclear weapons and the "Megatons to Megawatts" project - a little "taster" of what my talk tomorrow will be about (I don't know if there will be a live stream yet, but at least the entire confernce will be filmed, and go on-line later - I will of course share the link when it's ready ;) )

1. nuclear weapons have been used against humans two times; Hiroshima August 6th and Nagasaki August 9th, 1945 - hopefully NEVER again
2. both "Little Boy" and "Fat Man" were fission bombs (getting their energy from fission); "Little Boy" was made of highly enriched uranium (uranium-235), and "Fat Man" was made of plutonium(-239)
3. after WWII a nuclear arms race begun between the US and the Sovjet Union, and at one time there were more than 60 000 nuclear weapons in the world
4. a nuclear weapon is ugly, but by mixing the fissile material in it with uranium or thorium, it can be changed into beautiful nuclear fuel (100% normal nuclear fuel for normal reactors) <3
5. the "Megatons to Megawatts" program was an agreement between US and Sovjet/Russia that lasted from 1993 to 2013, where Sovjet made fuel out of their weapons (unfortunately not all of them) and US bought it
6. during those 20 years (1993-2013), 500 tonnes of highly enriched uranium, from 20 000 Russian nuclear weapons have been converted into nuclear fuel and "burned" in reactors (more than 2 weapons destroyed every day!)
7. the electricity generated from these weapons is the same amount as all the electricity in the US in two years(!)
8. weapons uranium (highly enriched uranium) could be mixed with natural uranium to make fuel (as has been done in the program) - or, even better, with thorium
9. if you mix weapons uranium with thorium, you can also recycle the spent fuel; this means that not only do you get rid of horrible weapons, you also get rid of a lot of nuclear waste (WIN WIN :D )
10. today there are around 16 000 nuclear weapons in the world - much better than 65 000 (or whatever the peak number was), but still that's definitely 16 000 too many...:/

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(I bite my lip when I concentrate - haha)

 Now I'm soon off to NHH, where the conference tomorrow will be held, for sound check, and just "feel" the stage. And when I come back to the hotel again, Anders will be here! I'm so incredibly happy he could join me here in Bergen this weekend!!! We're here until Sunday afternoon, so hopefully we'll have time to actually experience something while we're here - any recommendations from my readers?

Anyway: happy weekend to everyone <3

Fusion on a Friday

TGIF, since that means 10 more facts. This week I just have to tell you little bit about fusion - Fusion on a Friday ;) Hope you enjoy it!

1. Fusion is when two (light) nuclei merge (fuse) together to form a heavier nucleus - it's the opposite of fission. (Read more about fission HERE and HERE)
2. When very light (atomic) nuclei, like for example hydrogen and hydrogen, or helium and helium, or hydrogen and helium, fuse, they produce energy :D :D
3. The sun (and all other stars in the universe) get their energy from nuclei that are fusing (like hydrogen and hydrogen, or helium and helium, or hydrogen and helium - or other nuclei)
4. The different elements in the periodic table (up to iron) are made from fusion in stars/suns (but the heavier ones, like gold, or thorium, or uranium, for example are made in the big explosions in space)
5. If you check the mass of the nuclei you start out with, and the mass of the nucleus you get after the fusion (so, checking how much they weigh, that is), it weighs less after the fusion than before - this extra mass that suddenly is "gone" hasn't really disappeared, but it is released as energy <3 E=mc2 <3
6. It would be really really cool if we could produce energy from fusion, like the sun is doing - but so far we can't do it...:/ (We manage to get nuclei to fuse, but we use more energy than what we get out.)
7. Since nuclei is made out of protons and neutrons, they have a positive charge, and therefore they REALLY don't want to get so close to each other that they fuse - it's like trying to push the same pole of two extremely strong magnets together; it doesn't work (but it does work in the sun, since it's very hot and very high pressure, so there the nuclei just fuse all the time :D)
8. I think it's really fascinating, and a little weird, that you get all this energy from two opposite reactions - either by fusing light nuclei, or splitting heavy ones... <3 nature <3
9. If you managed to make a fusion power plant, you wouldn't have the problem with radioactive waste, that you get from a fission power plant (a normal nuclear power plant) - so that's very nice...
10. ...however, fusion is hard :/ We don't manage to do it (without putting more energy in than we get out) yet; but who knows what will happen in the future...? ;)

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Yesterday was date night with my Handsome - we went to Champagneria at Mathallen (our favourite place these days, I think), snacked tapas and drank their delicious self imported Cava (nom nom nom) <3 

He just left for a cabin trip with a friend, and Alexandra and me already miss him...but we will have nice weekend together too, and it will be even better to see him again on Sunday <3<3<3

Happy weekend everyone!

Fission on a Friday - 10 facts

It’s been a long time since I did a “10 facts” blog post (last one was about heavy water) - too long, I think, so it’s about time I do it again now ;)

I can’t promise there’ll one every week (I’ve tried those every week kind of blog posts before, and there’s always some reason - like my PhD work - why it’s difficult to see it through ), but it would have been fun if 10 facts could be like a Friday thing. Anyway, we’ll see how it goes, but today is Fission Friday; here are ten facts about fission:

1. fission is when a (heavy) nucleus splits into two (lighter) nuclei
2. an example of fission is when uranium-235 is hit by one neutron and becomes barium-144, krypton-90, and 2 free neutrons (same number of particles before and after fission: 1+235 = 144+90+2 = 236 :D)
3. the light nuclei (like barium and krypton) are called fission products
4. fission can be induced, which means that it happens because a neutron hits the nucleus (like in the picture) - a little bit like the neutron is a knife that cuts the nucleus into two pieces <3
5. fission can be spontaneous, which means it just happens - no neutron or other particle hitting the nucleus - the nucleus just suddenly splits
6. fission is my favourite decay mode (I think) <3<3<3
7. a nucleus that will fission when it’s hit by a neutron is called (a) fissile (nucleus)
8. the energy that is released in fission (when one nucleus splits) is 200 mega electron volts - which is the same as if 50 million carbon atoms burns and produces CO2 (yes, 1 versus 50 million to get the same amount of energy!)
9. most of the energy released in fission comes from kineticc energy of the fission products - which is energy from motion of the fission products (they are moving fast away from each other)
10. I think the energy release in fission is really really fascinating

If you think it's a good idea to do more "10 facts" blog posts, please tell me what you what you want to read about <3

 

Ok, I gotta run now, to catch my flight back to Oslo - since I've been giving a talk about motivation for science in Bodø today. If you follow me on Snapchat (sunnivarose), you can see the super cool LEGO rose i got after the talk (the talk was for First Lego League, so it was 100% right to get a rose made out of LEGO :D).