(a) A neutron of mass mn and kinetic energy K makes a head-on elastic collision with a stationary atom of mass m. Show that the fractional kinetic energy loss of the neutron is given by

Find (K/K for each of the following acting as the stationary atom:
(b) Hydrogen,
(c) Deuterium,
(d) Carbon, and
(e) Lead.
(f ) If K = 1.00 MeV initially, how many such head-on collisions would it take to reduce the neutron's kinetic energy to a thermal value (0.025 eV) if the stationary atoms it collides with are deuterium, a commonly used moderator? (In actual moderators, most collisions are not head-on.)

Transcribed Image Text:

AK Amm ΔΚ K (m m)