Radioactivity and temperature

[Jacques]

Hi

I have a small question:

Does temperature influence radioactivity?

Uranium 238 have a half-life of around 4.5 billion years.

If I heat some U238 to 1,000,000 degre K does the half-life change. My guest is yes more collision will increase the chance of the atom to emit an alpha particule.

 

My next question would be is it possible to heat a stable element like lead so it will become radioactive ?

 

Thanks for your answer

[insane_alien]

Radio activity isn't normally affected by heat but if the temperature is such that the nuclei are actually hitting each other then its a nuclear reaction (most probably fusion)

for a heavy element such as uranium this would take more energy than it makes.

a stable isotope would also have to fuse before becoming radioactive. but maybe if you could prevent fusion then it could be possible by having the nucleons vibrate enough to escape the strong force(which would be a HUGELY MASSIVE temperature)

[J.C.MacSwell]

There should be an almost negligible time dilation/increased lifespan caused by the increased velocities and accelerations, if no other effects overwhelm it.

[Martin]

There should be an almost negligible time dilation/increased lifespan caused by the increased velocities and accelerations, if no other effects overwhelm it.

 

Jacques, we should both look at what JC is telling us. it's interesting.

I would like to amplify JC response. Look at these NIST equivalents:

 

click on the "energy conversion factors" here

http://physics.nist.gov/cuu/Constants/index.html

 

or print out the PDF energy conversion table

http://physics.nist.gov/cuu/Constants/energy.html

 

one atomic mass unit is a billion (E9) eV

so the uranium 238 nucleus you are talking about has a mass of

238E9 eV

 

and the temp you mention is 100 eV

because look at the same NIST and see that one eV temp is E4 kelvin.

 

so the "gamma" factor which is the ratio of the total energy to the rest energy is one plus a tiny negligible one over 238E7

 

so the time dilation for this whizzing U238 nucleus is roughly one part per billion.

 

it's halflife for spontaneous radioactive decay would be lengthened by one ppb, for an observer in the lab. that is, on the order of one year longer halflife.

 

(I am being careless and only making a rough order-magnitude estimate.

please correct me anybody who sees a bad mistake)

 

it is absurd, but there is this ridiculous small effect.

we do not know about collision because we do not know how dense the plasma is. we only know temp---in other words kinetic energy.

[Jacques]

Thanks for your answers

Yes I understand that will be a ridiculous small relativist effect.

For the density let say that it is at the center of a star. I think like insane answered that the reaction will be more a fussion one than a fission one.

[H2SO4]

From what ive read, radioactivity is not infuenced by pressure, heat, being extremely cold, irradiation, or gravity.

[swansont]

From what ive read, radioactivity is not infuenced by pressure, heat, being extremely cold, irradiation, or gravity.

 

Electron capture has a small dependence on pressure, which affects the shape of the electron orbitals.

 

"Hensley et al. (1973) demonstrated that the electron capture decay of 7Be to 7Li is increased by 0.59% when BeO is subjected to 270 " 10 kbars pressure in a diamond anvil." (from this link)

[insane_alien]

i was assuming that at the high temperatures it would be a plasma where the nucleus (sp? it just looks wrong but for the life of me i can't think why just now) and electrons were seperated. It never occured to me that the electrons would hit the nuclei. Anyway the radiation wouldn't increase unless there is a direct effect on the nucleus that turns it into something else which is either fission or fusion.

[H2SO4]

All this makes me want to buy a digital geiger counter. I wonder if you can connct those to your laptop.