Tokamak runs for 29 hours - Page 1
Forum section: electronics / general

author: G7PSK
author_rank: Super Contributor
timestamp: July 09, 2015, 04:04:39 pm
content: A tokamak has been run in Oxford for 29 hours so is fusion going to be here within the 30 years. I hope so as fusion is the only real hope to meet our future energy needs.http://www.tokamakenergy.co.uk/about-us/

author: LabSpokane
author_rank: Super Contributor
timestamp: July 09, 2015, 04:21:15 pm
content: I'm reading that as they ran high-temperature superconducting magnets for 29 hours. I don't think they're claiming to fuse atoms for 29 hours, or are they?

author: Mechanical Menace
author_rank: Super Contributor
timestamp: July 09, 2015, 04:24:55 pm
content: Not to belittle the achievement but given the lack of fanfare I'm guessing it wasn't self sustaining?EDIT: Actually having finally noticed the tweet I'll second LabSpokane's question and also ask how progress on harnessing the energy is coming on?

author: con-f-use
author_rank: Unknown
timestamp: July 09, 2015, 05:00:40 pm
content: The current position is that even ITER is too small to sustain fusion at break-even. Even if we had a working break-even now, it would take at least 40 years to design, build and implement fusion reactors, that are commercially viable. The technology is very complicated an expensive. As a physicist I don't expect to see it in my lifetime. Sorry to crush your hopes.

author: Artlav
author_rank: Frequent Contributor
timestamp: July 10, 2015, 09:08:05 am
content: Quote from: con-f-use on July 09, 2015, 05:00:40 pmAnd then comes the plasma wakefield accelerator, and a 7.5 billion euro, country-spanning LHC gets shrunk to a car-priced tabletop device.I suspect it's just a matter of finding a way how to make a reactor, rather than trying to build that hugely complex and expensive thing.

author: free_electron
author_rank: Super Contributor
timestamp: July 10, 2015, 10:08:31 am
content: Quote from: mojo-chan on July 10, 2015, 09:41:40 amzero maintenance and a 1 million year warranty ...The problem is that 'the powers that be' don't like the idea of everyone using this fre eenergy. they want to bill you for it.

author: rolycat
author_rank: Super Contributor
timestamp: July 10, 2015, 10:13:50 am
content: Quote from: mojo-chan on July 10, 2015, 09:41:40 amOnly(!) 174 petawatts actually arrives on Earth, though.So you could say it 'wastes' 2.2 billion times as much energy as it delivers.If you were feeling energetically geocentric.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 10:38:54 am
content: Fusion will be more costly than solar for quiet some time in the future. If anything a fusion-reactor is useful during night time as a supplement to renewable energies.

author: tom66
author_rank: Super Contributor
timestamp: July 10, 2015, 10:43:20 am
content: I wonder if fusion will be easily throttleable, or if it will be like nuclear, and will generate energy continuously? If it's the latter, then it could create problems for grid stability that will require extra storage to be built out.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 10:49:29 am
content: Here is a nice interactiveoutreach primer(~250MB) on fusion in general and its commercial application. It was made by the "European Consortium for the Development of Fusion Energy" and is scientifically sound. Even they state, it won't be until 2050 that we have commercial fusion. Since they are mostly scientists and politicians, I'd say they are overly optimistic, but not by much. One of the biggest problems is funding. ITER was build as a ~6m fusion camber. The initial recommendations from the science side of things were 8mminimum. That would have made for a nice break-even and sensible science to be done. Politicians essentially said, they're only going to fund the smaller version. So they ended up building another one (DEMO) and setting the science back a few years. All just because someone was a cheap bastard.

author: coppice
author_rank: Super Contributor
timestamp: July 10, 2015, 10:53:34 am
content: Quote from: tom66 on July 10, 2015, 10:43:20 amAll the techniques tried so far for fusion are very controllable. Fuel is fed into the reactor as it is needed. Stop the flow of fuel, and you stop the reactor with very little lag.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 10:59:57 am
content: Quote from: G7PSK on July 09, 2015, 04:04:39 pmAnd in 400 years the oceans boil. Simple thermodynamics of a black-body radiator such as the earth, coupled with current rate of increase of energy usage. If you magically assume that all energy use becomes 100% efficient, then the oceans will boil in 440 years.Seehttp://physics.ucsd.edu/do-the-math/2011/07/can-economic-growth-last/for full discussion; the above isveryabbreviated!

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 11:01:36 am
content: Well yes, its mostly throtteable with a few minor quirks. You have effects like the H-modes that need certain conditions to reach a high efficiency, but you could switch between those and actually but net energy into your plasma in the mean time. It's nothing you're keen on doing, but it would work.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 11:04:07 am
content: Quote from: tggzzz on July 10, 2015, 10:59:57 amAssuming we haven't found a way to cool or leave earth by than. Radiating energy into space or putting up large reflectors over especially hot spots or the like. People usually find a way to prolong their suffering, if it really need be. I know he cautions against believing technology cures everything, but I strongly belief humans can solve their problems, if really really hard pressed to the brink of extinction. At great costs of course.

author: John Coloccia
author_rank: Super Contributor
timestamp: July 10, 2015, 11:41:20 am
content: What we need are fusion roadways.

author: Artlav
author_rank: Frequent Contributor
timestamp: July 10, 2015, 12:07:41 pm
content: Quote from: John Coloccia on July 10, 2015, 11:41:20 amWell, there were the Radium roadways in the 40s...

author: LordNobady
author_rank: Contributor
timestamp: July 10, 2015, 12:16:30 pm
content: Quote from: John Coloccia on July 10, 2015, 11:41:20 amSounds like a kickstarter. how much GW* do you think you can get per square meter. When will you start, I like to see Dave debunk it.* I mean if a solar pannel can claim KW fusion must make GW don't you think.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 12:48:11 pm
content: Quote from: con-f-use on July 10, 2015, 11:04:07 amPlease do the arithmetic and physics; his points are pretty fundamental.What is your suggested way for cooling the earth? Have you considered, for example, that a reflector will keep heatinas well as a little sunlight out?The historical evidence that "humans can solve their problems...extinction" is theydon'tand do go extinct. You don't even have to cross the water to see it: go south into Mexico and the Andes! It is very unwise to bet on a change in human nature.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 02:04:35 pm
content: Good point, but let me ask you: If you really think we are irredeemably doomed for extinction, why aren't you more of a dick? I'm assuming, you don't rape, steal and constantly live off of other people (even in situations, where you think, you'd never be caught). I'm asking because that or catatonia would be the ultimate response to such a dire expectation.Of course putting reflectors up is a silly plan (but they do keep much more heat out, than they hold in). You missed my point there. I wasn't seriously suggesting that exact means to solve the issue. Neither was I doubting the numbers or advocating a "the problem will solve itself" attitude. I'm merely remarking that people become very ingenious, when they have to. I just had the pleasure of listening to a member of the Manhattan Project lecture about it. Even they didn't belief they could do it. Yes, we'll have to put effort into it, and yes countless people will suffer, but I really don't think, we'll go extinct. And one final point: Other civilisations went extinct because of war or some dispersed into a more powerful one. You are talking about humans actively intending for the others to vanish, not about us being inactive and impassive as a whole species. It is in human nature that the latter will likely not happen.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: July 10, 2015, 02:15:07 pm
content: Quote from: mojo-chan on July 10, 2015, 02:10:52 pmWouldn't work. A Dyson swarm might.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 02:18:09 pm
content: And the thread needs to go back on track... Fusion is nice, but won't cure everything and certainly not overnight.

author: LabSpokane
author_rank: Super Contributor
timestamp: July 10, 2015, 03:13:39 pm
content: Quote from: tom66 on July 10, 2015, 10:43:20 amWhere are you getting this information? France has been load following with their reactors for years. Running reactors as base load only is a combination of design and regulatory issues.How far one is able to turn down the reactor (or any thermal plant) is driven substantially by the plant's ability to provide proper steam quality. If the steam becomes wet, it will erode the turbine blades. A coal or wood-fired boiler would have similar constraints.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 03:16:02 pm
content: Quote from: con-f-use on July 10, 2015, 02:04:35 pmThat's true in some cases, but false in others. The classic clear-cut example is the Easter Islanders, who had a flourishing civilisation until they cut down all their trees - and couldn't even make boats to escape.There are many other examples in all continents (except Antartica!) where thecauseof their demise was over-use of their local environment weakened them significantly - which allowed other people to overrun them.Unlimited fusion power would cause as many problems as it solves.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 03:40:19 pm
content: Quote from: LabSpokane on July 10, 2015, 03:13:39 pmTrue, but an over-simplification. Many plants "dislike" simple thermal cycling. There is the concept of "dispatch", which is more immediately applicable to renewables, and is discussed in this good paper:http://www.templar.co.uk/downloads/Renewable%20Energy%20Limitations.pdf

author: edavid
author_rank: Super Contributor
timestamp: July 10, 2015, 03:53:05 pm
content: Quote from: tggzzz on July 10, 2015, 10:59:57 amIt's a very silly paper. Why would energy usage continue to increase at the current rate? What would people do with that much energy?

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 04:18:38 pm
content: Quote from: edavid on July 10, 2015, 03:53:05 pmQuite right. After all, there's only a market for 7 computers (TJ Watson, head of IBM early 50s) and nobody will ever want a computer in their home (Ken Olsen, head of Digital Equipment Corporation late 70s).More seriously, you need to understand where the energy is used; it might not be where you think. I suggest starting withhttp://withouthotair.com/

author: edavid
author_rank: Super Contributor
timestamp: July 10, 2015, 04:46:51 pm
content: Quote from: tggzzz on July 10, 2015, 04:18:38 pmAnd that means I have some need for 100X as many computers as I have now?Anyway, one of the commenters pointed out:QuoteSo, as I said, the paper is silly.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 04:54:37 pm
content: Quote from: edavid on July 10, 2015, 04:46:51 pmDon't be silly and make points worthy of a troll. For example, the number of computers in my household has increased from 1 in the late 70s to probably around 100. I expect yours is the same.QuoteHow exceedingly parochial, even for an American. All that matters is the global energy usage.Besides, you neglect that a significant amount of the US (and UK for that matter) energy usage has been exported to China and similar place.

author: apis
author_rank: Super Contributor
timestamp: July 10, 2015, 04:54:56 pm
content: Quote from: con-f-use on July 10, 2015, 10:49:29 amHmm, in my mind any estimate >=30 years is physicist speak for "we don't have a clue when, but not any time soon". From what I hear there isn't even viable materials that would work in a commercial reactor. Lots of things that have to be fixed and invented first.For now the best option appears to be a mix of fission power and renewables. Meanwhile most of the world seems hellbent on switching to even more coal or gas.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 05:00:05 pm
content: Quote from: apis on July 10, 2015, 04:54:56 pmJust so, on both counts.Fusion has been 30 years in the future for the last 60 years. It means "after my career is over and there's no longer any personal penalty for being wrong"Just like any prediction from a marketeer/pundit/rent-a-quote that predicts a sudden uptake in 2 years time - by that time they will have moved on.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: July 10, 2015, 05:07:27 pm
content: Quote from: tggzzz on July 10, 2015, 05:00:05 pmAnd if it wasn't for the amount of money and people all the Allies threw into the Manhattan Project and the "mines bigger than yours" cold war stuff between parties on all sides of the iron curtain fission would probably be in the same position. I bet less money has been put into fusion research over the last 60 years than has been put into nuclear weapons by just the US in the last 10.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: July 10, 2015, 05:18:08 pm
content: I went to see JET under construction at Culham when I was a teenager.Nuclear fusion will never be commercially viable. A demo reactor perhaps, but it will be a white elephant.The Manhattan example is very misleading; not everything is possible to achieve however much money and effort is thrown at it. Better examples are perhaps Concorde, Apollo. While these great technical projects can be done, without sufficient economic return they don't sustain.

author: Marco
author_rank: Super Contributor
timestamp: July 10, 2015, 05:36:09 pm
content: Quote from: Artlav on July 10, 2015, 09:08:05 amAchieving high enough temperatures is not the problem, so this doesn't really help AFAICS.

author: abebarker
author_rank: Contributor
timestamp: July 10, 2015, 05:40:02 pm
content: Fission, fusion, cold fusion are all simple sources of heat. They all drive a heat engine. The heat engine is the underlying technology. Improve the heat engine and every form of energy input is worth more.That brings up the question of what is the energy going to be used for? Is it going to be used to play more hours of XBox? Is it going to be used to power the lights in an office complex so more busy work can be done? Is it going to be used to make more laws or fund more police to make things that were previously legal now illegal?What good is it going to do? Is it going to be used to teach or is it going to be used to sell you more things you don't need.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 05:49:16 pm
content: Quote from: abebarker on July 10, 2015, 05:40:02 pmNot as much as you might like in the face of exponential growth. Magically making everything100% efficient buys you a few decadesQuoteAgriculture/fertiliser and air conditioning

author: LabSpokane
author_rank: Super Contributor
timestamp: July 10, 2015, 05:52:25 pm
content: Quote from: tggzzz on July 10, 2015, 03:40:19 pm?Dispatching a thermal power plant from warm/hot standby has even a greater thermal cycle range than load following.The argument put forth was, in essence: "nuclear fission power plants can only run at MCR (maximum continuous rating)." That is not correct. The problem isn't on the fission side, it's on the steam generator / turbine side.Is thermal cycling hard on equipment, heat exchangers in particular? Of course it is. But, nuclear fission plants run at varying loads right now, just not in US and UK commercial power plants due to design and regulations. I refer you to your nearest nuclear submarine as evidence.It's hard to correct some of the misconceptions posted on here if I have to publish a copy of B&W's Steam and B&V's Power Plant Engineering just to answer a question to your persnickety satisfaction.

author: abebarker
author_rank: Contributor
timestamp: July 10, 2015, 05:57:22 pm
content: Quote from: tggzzz on July 10, 2015, 05:49:16 pmWhat happens when the entire face of the earth is covered with human being all squeezed together shoulder to shoulder? Or did you not state something that is so obvious that everyone already knows it?

author: apis
author_rank: Super Contributor
timestamp: July 10, 2015, 06:29:38 pm
content: Quote from: abebarker on July 10, 2015, 05:57:22 pmBut that's not what's happening. According to world census data, the world population won't exceed 10 billion according to current trends.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 10, 2015, 06:53:56 pm
content: Lot's of mixed information here. For those who are adherents of exponential growth, get the models or read the books. There is no danger of the oceans boiling because civilization collapse for other reasons much sooner.For those wishing to ignore the US energy consumption curves. Yes, it is only one small segment of the world. But it is the segment with the highest per capita energy consumption, and the country with some of the weakest legislative limits on energy use, and the country with some of the lowest energy pricing in the world. Doesn't say exponential growth is wrong, but might say that older estimates of doubling time for energy were significantly wrong. Might be an indicator of what will happen as the rest of the world develops. Really should say China and India. The rest of us hardly matter.For those arguing human extinction, it seems highly unlikely (but remotely possible). Extinction of our civilization is so close to assured that it isn't even worth discussing. Why should our civilization be the only one of hundreds that didn't die eventually. Many people seem to conflate civilization death with human extinction, perhaps because for the vast majority of individuals there is no difference.And fusion. We all know the old joke, and it remains true today and always will be.

author: apis
author_rank: Super Contributor
timestamp: July 10, 2015, 06:56:20 pm
content: Quote from: LabSpokane on July 10, 2015, 06:43:53 pm10B is less than 50% increase and a whole lot better than "entire earth covered with people shoulder to shoulder" and it's based on empirical data which helps a lot. Carrying capacity isn't 1B? Where did you get that figure? It's commonly said Americans use (on average) about 5x what's sustainable, Europeans about 3x and China India about 2x. So problem is getting consumption levels down to 1x long term which can be done either through using less or being more efficient.

author: abebarker
author_rank: Contributor
timestamp: July 10, 2015, 07:02:38 pm
content: Quote from: apis on July 10, 2015, 06:29:38 pmLife expectancy increase and reproduction rate decrease are consequences of education.Perhaps the global population wont exceed 10 billion, but that is because it simply can't with the technology we are using today. What if a technology were discovered that would enable the population to exceed 10 billion? Should it take advantage of the technology? Could the least educated be stopped from reproducing to fill every available space?As they say; Life is hard, life is harder when you're stupid.

author: abebarker
author_rank: Contributor
timestamp: July 10, 2015, 07:13:45 pm
content: Don't get me wrong, I love technology. I want the best technology. In fact, I want my flying car.It has become painfully obvious to me that I can not have what I want when I am surrounded by stupid people.I guess my question should be; What to do with all these stupid people? (Unfortunately, I can not ask that question around stupid people.)

author: apis
author_rank: Super Contributor
timestamp: July 10, 2015, 07:25:55 pm
content: Quote from: abebarker on July 10, 2015, 07:02:38 pmYes, by reducing poverty and increasing education. This website might help give a brighter perspective on things:http://www.gapminder.org/Quote from: abebarker on July 10, 2015, 07:13:45 pmyeah, but it helps remembering we are all pretty stupid in the end...

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 07:33:35 pm
content: Quote from: CatalinaWOW on July 10, 2015, 06:53:56 pmQuite true, of course. Hence exponentially increasing energy generation (e.g. from fusion) will cause "problems" muchsoonerthan 400 years.

author: con-f-use
author_rank: Unknown
timestamp: July 10, 2015, 08:28:07 pm
content: Quote from: apis on July 10, 2015, 04:54:56 pmI said, I find the 2050 overly optimistic, didn't I?Quote from: abebarker on July 10, 2015, 05:40:02 pmNope, you could extract energy from a fusion reactor via induction, so directly electrical.Quote from: Mechanical Menace on July 10, 2015, 05:07:27 pmAs I said, It has. ITER's biggest problem was cheap politicians.Quote from: apis on July 10, 2015, 04:54:56 pmDepends on what you would define viable. The reflectors are difficult to manufacture making them expensive. They and part of the inner assembly get activated and need to be replaced very frequently. That would be costly in a commercial reactor, but if you don't have coal, oil or gas as an alternative and mass produce the parts, all of a sudden they become not that expensive. Before someone asks, the activated parts loose their radioactivity fairly quickly.

author: LukeW
author_rank: Frequent Contributor
timestamp: July 11, 2015, 02:32:19 am
content: Quote from: LabSpokane on July 10, 2015, 05:52:25 pmYou can load-follow and throttle a fission power plant if you want to.If a nuclear submariner wants to quickly throttle up and get moving in a hurry, they're able to do so.There are some nuclear phenomena such as xenon poisoning that may be relevant, but those limitations and what can and cannot be worked around are well understood by nuclear engineers.Typical commercial nuclear power plants are run at full power all the time not because that's technically mandatory but because it's most economical - you've got a large up-front capital investment but your fuel cost and operating cost is minimal, (unlike something like a natural gas turbine where the fuel cost is a significant portion of the overall cost). So it makes the most money to keep it running.As far as the spherical tokamak mentioned in the original post is concerned, I wonder exactly what type of "high temperature" superconductor this is, what the current and the field strength is and what the temperature is?High-temperature oxide superconductor materials such as YBCO typically have very limited critical fields, which limits their usefulness for engineering superconducting magnets. There are also challenges with the fabrication of these materials into wires or tapes, in a reliable and scalable way.Most superconducting magnets, as used in NMR/MRI, particle accelerators, ITER etc are all low-temperature systems, cooled by liquid helium, and made of materials such as niobium-titanium or niobium-tin alloys which are high-critical-field superconductors.

author: abebarker
author_rank: Contributor
timestamp: July 11, 2015, 03:34:29 am
content: Quote from: con-f-use on July 10, 2015, 08:28:07 pmI stand corrected. Thank you. Now I am curious. I must look into that.

author: miguelvp
author_rank: Super Contributor
timestamp: July 11, 2015, 05:01:35 am
content: Quote from: LukeW on July 11, 2015, 02:32:19 amIn their other youtube videos they mention the superconductor material is between 50K and 60K so just a mere -213C at it's highest temperature. But they also mention that the housing is at room temperature.And they do use liquid helium to cool them.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: July 11, 2015, 03:38:14 pm
content: Quote from: con-f-use on July 10, 2015, 08:28:07 pmI thought the people working on the ICF approach were planning on somehow directly using the heat?And probably a stupid question but any fusion reactor is going to be a massive neutron source isn't it? I know we probably wouldn't see it anywhere in my lifetime but could they be used to breed fissionable materials?

author: zapta
author_rank: Super Contributor
timestamp: July 11, 2015, 04:44:51 pm
content: "Tokamak Energy is seeking additional investment to accelerate the plans."It's a commercial company that needs to create buzz to raise more money, like many others start ups and the probability of their technology becoming successful products is slim.Considering the up side, if they had a significant breakthrough, big money would already flow in.

author: Marco
author_rank: Super Contributor
timestamp: July 11, 2015, 07:56:53 pm
content: Quote from: apis on July 10, 2015, 06:29:38 pmTechnical analysis is bullshit ... secularism and Malthusian pressure has slowed growth down, secularism seems to me to be in a retreat.

author: con-f-use
author_rank: Unknown
timestamp: July 11, 2015, 08:40:11 pm
content: Quote from: Mechanical Menace on July 11, 2015, 03:38:14 pmAt least, they activate the Carbon reflectors inside, so yes. As for breading fissionable material, no. We do have great neutron sources available and still use centrifuges for isotope separation, because just shooting neutrons at a nucleus, doesn't magically turn it into Uranium. You could theoretically do produce higher isotopes directly via fusion, but that is technically impossible because plasma containment already becomes very difficult with (comparably) small Li-contaminant. For now, we'll have to leave fissionable material to super-novae and by-products of higher element decay.

author: LukeW
author_rank: Frequent Contributor
timestamp: July 12, 2015, 10:51:36 am
content: Quote from: Mechanical Menace on July 11, 2015, 03:38:14 pmIt is plausible, yes. Although fusion neutrons tend to be very energetic, on the order of 10 MeV, which is fast by the standards of a lot of the work and nuclear reactions/physics typically done with fission reactors.The fission-fusion hybrid reactor has been seriously proposed and studied before.Hans Bethe published a little review article on the subject in Physics Today in 1979.http://large.stanford.edu/publications/coal/references/docs/bethe.pdf

author: apis
author_rank: Super Contributor
timestamp: July 12, 2015, 03:56:03 pm
content: Quote from: con-f-use on July 10, 2015, 08:28:07 pmYes but also: "I'd say they are overly optimistic,but not by much." ;-) There seems to be many ifs involved (including cheap politicians!) :-/QuoteThere is usually a limited budget for publicly funded science (way to little if you ask me) and that money is divided between projects so if fusion gets more e.g. battery and solar get less, etc. If it were up to me they would throw money at both but that's not the way it is sadly. But it was stupid to only pay for another too small test reactor, will likely be more expensive in the log run.QuoteWhy not begin in that end then? Develop necessary materials, manufacturing processes (likely will have benefits in other fields as well) etc and make sure it would be possible to make something that would be economically realistic before building huge and very expensive experimental test reactors? Seems like we could have gotten super batteries and cheaper high efficiency solar by now if all that money would have gone into that field instead? But it's hard to predict what will pay off in the long run of course.

author: con-f-use
author_rank: Unknown
timestamp: July 12, 2015, 05:11:29 pm
content: Quote from: apis on July 12, 2015, 03:56:03 pmSure, but if your scientists say, the project is almost worthless, if we don't get just 10% more and if they also say, you are going end up building the expensive one any way, then why not just make it right from the start?

author: apis
author_rank: Super Contributor
timestamp: July 12, 2015, 06:35:13 pm
content: Quote from: con-f-use on July 12, 2015, 05:11:29 pmYes, as I said, that's stupid. The fusion physicists need something to keep themselves occupied with so the competence isn't lost I suppose. But it's hard to understand why they didn't go the extra 10% of the way in that case.

author: EEMarc
author_rank: Regular Contributor
timestamp: July 12, 2015, 08:25:22 pm
content: The problem with fusion energy is that the fundamentals are missing.Lets start with what works, fission. The fundamental of a fission reactor is that a U235 splits most of the time when it's nucleus is hit with a neutron. Each fission averages significantly more than 1 neutron which can in turn cause at least another fission. The fundamentals are solved. It is only a matter of getting the technical details around it to work to get a fission reactor. It is so simple, natural reactors have formed from a relatively small amount of uranium. At this point, controlling the reaction by either slowing the neutrons to increase the reaction or using neutron absorption to reduce the reaction is all that is needed to control an artificial reactor. The fundamental is that a nucleus of a U235 isotope does not resist a neutron. The only factor at play is the ability of the nucleus to capture the neutron using the strong nuclear force. The slower the neutron, the larger the target needed to be hit in order for the nucleus to capture it.The fundamental of fusion is a different story. Two protons are repulsed by the electrostatic force, which is significantly stronger than the strongest magnetic field achieved. If two hydrogen atoms are shot at each other, there is a tiny target required to be hit for their two nucleus to capture each other with the nuclear strong force. The vast majority of the time, they miss and shoot away from each other at high speed. On the unusual occasion that fusion does occur, it tends to scatter the fuel apart making future fusion less likely to occur. This scattering after fusion is how stars regulate their rate of fusion. They tend to expand when more fusion occurs, thus reducing the rate of fusion. When fusion slows down, they tend to contract and increase the fusion rate. The rate of fusion of a star is ultimately controlled by the star's mass. A Tokamak doesn't release enough energy from fusion to create another. Not by a long shot. It is fundamentally broken.Humans have only created conditions for useful fusion for very short periods of time. The atomic bomb creates such conditions for a tiny fraction of a second. With clever design, materials that cause fusion are put in the right place that are at the pressures and temperatures to cause fusion. After a very short period of time, the conditions fail and fusion stops. The conditions required to create fusion destroy the device that caused it to occur in the first place.Fusion energy is similar to perpetual motion. Their arguments for super cheap energy are the same. A lot of effort is being put into solving the technical details around it, but the fundamentals behind it are broken.