Is this a way to stimulate an alpha emitter?

[Spinnor]

Say we can create a high energy particle beam of radioactive alpha emitting nuclei (all the same kind). Let the particle beam have an energy such that if an alpha particle is emitted in the direction opposite to the beam direction the alpha particle will appear in the lab frame to be almost at rest. Now have this high energy particle beam be directed at a meter cubed volume of liquid helium-4 which is so cold that nearly all of the helium is in the ground state. Does the liquid helium-4 in this situation stimulate the alpha emitting nuclei to emit an alpha particle as they pass through the liquid helium even if only a small amount? Reading Feynman's lectures on bose particles (https://www.feynmanlectures.caltech.edu/III_04.html) I might naively think there would be a factor of N enhancement of alpha emission (in the direction opposite the beam direction) while the nuclei passed through the liquid helium where N is the number of helium-4 atoms in the Bose-Einstein condensate, which for a meter cubed volume of liquid helium-4 is a large number, but I'm not sure that is correct for this situation. I know Quantum Mechanics always gets it right as long as you analyse the problem properly.

Thanks for any help.

 

[mfb]

I don't think there will be any effect. Among other problems, alpha particles are helium nuclei while your superfluid helium consists of atoms.

Even if there is an effect it would be completely negligible.

• The phase space of alpha decay is really large compared to the phase space of the liquid helium.
• Making a beam with just the right energy needs applied magic.
• The first scattering process - still within the container walls - will ruin your magic beam.
• Further scattering process in the helium will ruin the liquid helium

 

[Spinnor]

• The phase space of alpha decay is really large compared to the phase space of the liquid helium.
• Making a beam with just the right energy needs applied magic.
• The first scattering process - still within the container walls - will ruin your magic beam.
• Further scattering process in the helium will ruin the liquid helium

I get the first bullet point. In a proper calculation though would the number of ground state helium-4 atoms in the meter cubed target volume be used, if so that is quite an enhancement factor?

Is there a quantum limit on how precise particles can be accelerated? I practice can we get close to that limit?

I am interested in how quantum mechanics or quantum field theory is properly applied to this thought experiment.

Thanks.

 

[mfb]

on though would the number of ground state helium-4 atoms in the meter cubed target volume be used, if so that is quite an enhancement factor?

No.
In particular, there is nothing special about a cubic meter.

Is there a quantum limit on how precise particles can be accelerated? I practice can we get close to that limit?

Momentum can be very sharp if the position is spread out, but accelerators are nowhere near such a limit. Beams are "hot".