Why does the burst last for just a second even when excess heat is produced after the radiation burst?
On Fri, Mar 11, 2016 at 4:25 PM, <mix...@bigpond.com> wrote: > In reply to Bob Cook's message of Fri, 11 Mar 2016 09:34:55 -0800: > Hi, > [snip] >>The effectiveness of the SS can at stopping any high energy electrons that >>cause Bremsstrahlung would depend upon the thickness of the can (or alumina) >>and the energy of the incident electrons. I think the loss of energy per >>scattering event is proportional to Z ^2 for the nucleus that is doing the >>scattering. Al at Z=13 and with Fe at Z=26 the intensity of the >>Bremsstrahlung signal would be about a factor of 4 different. The mean >>length of the path of an electron is a good parameter to know for any given >>substance (basically its density) vs the incident energy of the electron. >>Shielding engineering curves provide this information I believe. Iron being >>significantly more dense than Al2O3 would be much better at slowing electrons >>and thus producing Bremsstrahlung IMHO. > > Shielding is based primarily on the electrons of an atom being ionized. > Bremsstrahlung is created when a fast particle interacts with a nucleus. > Most fast electrons impinging on solid matter will create ionization, i.e. > they > get stopped by other electrons. AFAIK Only about 1% get through to the nucleus > and create Bremsstrahlung. I think that both nuclear charge and number of > nuclei > per unit volume would be important for Bremsstrahlung production. Mass of a > nucleus not so much, because even a single proton is already about 2000 times > more massive than an electron. When it comes to collisions, it makes little > difference whether the nucleus is light or heavy. In short any nucleus is > effectively an "immovable object" as far as an electron is concerned. > > BTW if MeV level electrons are stopped by Aluminium foil, then the can would > have to be very thin not to stop them. > > Has anyone considered the possibility that some (little) bremsstrahlung might > be > caused by fast protons impacting on heavier nuclei? > > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/project.html >
