Jacques

Something like this

Thanks Roger very interesting! My first idea was more the reverse and more of a beam-target configuration. The ion are injected in the center and accelerated outwardly and colliding into a wall of solid boron... I need to confirm some point before eleborating more on that. 1- What is the probability that a H+ ion accelerated to 580 keV hitting a solid boron piece fuse (do the fusion) ? 2- Is it possible to create an electric potential between the center of a sphere and its inside surface? Like having +500 kV at the center and 0 V at the inside surface . Thanks

Yes a similar manner ! Thanks for the link. I don't understand why they use pyroelectric cristal to get the potential... Must not be a very effetive way to get potential. Why not use a simple tranformer ? Thanks for your answer

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I was thinking of using a fixed target of boron so no need to strip any electron from boron. So I repeat: Magnetic fields are used to curve the path of particle and use up a lot of energy. For the acceleration an electric field is used. And my question is about a kind of linear accelerator. The big problem in current fusion experiment is the high temperature which necessitate the use of magnetic field for confinement. I am trying to figure a way to get fusion without the high temperature. I imagine that having particle with the proper energy would not create these high temperature if the reaction is spreadout on a larger surface. Description of the reactor: A source of ionized hydrogen (proton) injected in the center of a vacuum chamber a few meter in diameter. The potential between the center and the wall of the chamber is around 1 MV. A sheet of boron near the wall react with the accelerated proton. A lot of little fussion will occured at the surface of the boron. The reaction happen in a continuous way over a large area, so no high temperature generated. Do it make some sense ? Thanks

To overcome the energy barrier in let say p-Boron is Am I right if I say that to accelerate a proton to an energy of 580 keV you need to have 580 kVolt potential ?

That reconfort me ! On what do you base that ?

But the more I read the more I am concerned about the environment impact of the fussion technology. We were told that fusion doesn't produce radioactive waste, that the only product is helium an inert gas... But reading about the reaction, there is these fast neutrons that can contaminate the machine. How much secondary radioactivity will be produced ? Why no research on cleaner fuel like the p-Boron reaction ? From post #7 Of these two articles, what estimate of Q is the good one.

More like designing a fusion device using accelerator technology. Why ? Because with thermofusion the temperature needed is very hight because the particles energy is randomly distributed. The beam-beam fusion would not necessitate hard to confine plasma. I did a little google and found that: Colliding Beam Fusion Reactor I am not the first to think about that ! But searching more I found: Feasibility of a Colliding Beam Fusion Reactor The first article give a Q of 2.7 but the other a Q of .02

How much ? You need to overcome the protons repulsion up to the distance where the nuclear force is greater than the electrostatic force. I don't know the math but Wiki It is not that much when we think that the top accerator are in the range of TeV. They tell nothing more about beam-beam fusion... That is where I am getting lost... Does the cross section of beam-beam fusion too small to give subtantial output ? Can we use a magnetic field to pinch the two beam to increase the cross section ? Thanks

Does fusion have been observe in accelerator collision ? If I collide protons with enought energy will they fuse ? If yes wouldn't it take less energy than trying to confine a plasma to high temperatur ?

Your spinning will produce half galaxies will be redshift and half the galaxies will be blueshift. Can you see that? What we observe is that most of the galaxies are redshifted. Only a small number in our local group are blueshifted.

Not enzyme, but catalyst. Enzyme would be detroyed at these temperature.

Here in Quebec we use calcium chloride and can melt donw to 0F. There are other deicing salt. Take a look at this site for more info. http://www.askthebuilder.com/251_Deicing_Salts_and_Concrete.shtml Using fertiliser (NH4NO3) is not recomended because of damage it can cause on concrete and asphalte

Not sure but if I remember correctly y=1/2 gt^t Let assume that the faucet drip at a constant rate. Let say for example that the drip is 1 drop per second Let take 3 drop at t0=0 t1=1 and t2=2 Let take g 10 m/s^2 t0=> 0 t1=> 5 t2=> 20 So the space between drop increase until terminal volocity is achived Merry Chrismass!

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How do you use spoiler ?

A few years ago, I met many time someone who belived in that alien thing. He was having a very elaborate thinking scenario and the mains points were that life is common in the galaxie and that there was plenty of time for different civilisations to conquer the galaxie. He was a brilliant person but was having a paranoiac tendency. He was often giving me some reference on the internet and specialy a figure of authority (don't remember the name). He was so convinced that it was true, and was considering other that didn't belived in that has brain washed idiot by the establishment. I was interested in what he was saying and when he was seeing me, he would stick to me and wouldn't let me go. My interest in speaking to him was not what he was thinking it was. I was simply curious of how an intelligent person could think it was true. He needed attention because no body else would take time to listen to him. Anyway one day is paranoia went agains me and it made me very angry about him and I told him. I never meet him again after that. I think some people need some kind of gods to be able to live. I also think that he was to much consuming marijuanna and was to lonely and that the main contact whith the world was throught internet.

OK I made a mistake in my first postulate. Inside a gravitating system the expansion is not the same, like Fred said. If every thing is scaling then we cannot observe the red shift: a meter expanding at the same rate as the wave lenght of the photon emited cannot give shift in the specter. With that we are back to the bigbang... Unless there are other redshift explaination. That bring me to an other question: At what scale do we stop expanding? From Fred answer I would say at the QM scales. And for big structure I would say galaxys cluster. That bring me to an other question: is dark energy real ? Will the big rip happen ???

atheist "space is expanding" like galaxy recession. In the galaxie level, that expansion is not mesurable and even less at the atomic level. The QM rule are the same in the pass as today. Only when you fix a reference frame in time you can see that there was an expansion of space. Expansion of space mean that the space itself expand: 1 meter today is the same as 1 meter yesterday, but if you look today at yesterday meter you will see it smaller. Atheist Yes elementary particle that are point likeAtheist No new "matter-points". Let say that it take 5 billions years of expansion to "double" the volume. 5 billion years ago one of our ancestor sealed a 1 cubic meter box with in it 1 mole of hydrogene. You found that box and you mesured it. It is still 1 cubic meter and as 1 mole of hydrogene in it. But you saw in your scope an alien doing the same thing on an other planet 5 billion light year away and you mesure it only to be half a cubic meter. That is because you are taking a mesurement in the pass with today's instrument. Also, astronomer can see galaxies something like 13 billion light years away: did they observed a change of density ? fred56 That make sense but not everybody think the same. Look at the big rip Finally, the scientific principle that the phisic law are the same no matter where you are in the universe can be extented to the 4th dimention time, everywhere and anytime... I know that it look strange that why I put that post in the speculation thread

Speculation Postulate 1: space is expanding everywhere (between galaxies as well as inside atoms) Postulate 2: matter is composed of point like particle If every thing scale with time, the density of the universe is constant. Looking back in time, a meter stick seem to contract, but if you go back in time, a meter stick will look the same, everything had contracted. Do you see what I mean ? Thanks in advence for your comments

I don't know what you mean... Please explain Thanks

Thanks for the links. I can read that h is the slope of the stopping potential as a function of frequency, mutiplied by the electron charge. h=e(V2-V1)/(f2-f1) Why does the electron charge putted in the equation ? I tried to check if this expression give the good unit of measure. The unit of V is m2·kg·s-3·A-1 The unit of f is s-1 The unit of e is s·A so the unit of h is m2·kg·s-1 The unit of J is m2·kg·s-2 So the unit of h is J·s or m2·kg·s-1 which is consitent I was surprise to see that ampere (A) was a SI base units. I was expecting something more fundamental like the Coulomb © and that A would be a derived unit C·s-1

Hi I am just a layman and what I can read on it is that it is anything but simple... What I can understand from that is only that this 'mathematical structure' (E8) describe well the world. Remind me a little bit of the epicicle: It doesn't fit ? And more dimension... Do I need to know QM to appreciate the simplicity ?

Isn't it a little bit circular ??? photon-photon use virtual fermions. fermion-fermion use virtual photon. See what I mean ?