Question

One way to look for oil deposits under ground is to lower a source of neutrons and detect how many are reflected back by the surroundings as the neutron source is lowered (not many neutrons reflected implies oil in the surroundings that are absorbing the neutrons.) The decay that produces the neutron is 13Be  12Be + n. The respective atomic masses are 13Be: 13.036135; 12Be: 12.0269221. The rest mass of the neutron and the conversion from atomic mass unit (amu) to MeV/c2 are 939.5653 MeV/c2 and 1 amu =931.494 MeV/c2. Note that 13Be and 12Be both have 4 electrons, so you need not subtract 4*0.511 MeV/c2 since both sides of the reaction (the starting 13Be and the ending 12Be have the same 4 electrons.)

a.)  Ignoring the kinetic energy of the 12Be (a good approximation since it is much more massive than the neutron), what is the total energy of the emitted neutron?

b.) what is the kinetic energy of the emitted neutron?

c.)  What is the velocity, u, of the neutron?

Answer 1