Stern-Gerlach splittings of atomic beams are small and require either large magnetic field gradients or long magnets for their observation. For a beam of atoms with zero orbital angular momentum, such as H or Ag, the deflection is given by
x =
±(
μBL2/4
EK)d
B/d
z, where
μB is the Bohr magneton,
L is the length of the magnet,
EK is the average kinetic energy of the atoms in the beam, and d
B/d
z is the magnetic field gradient across the beam.
(a) Use the Maxwell-Boltzmann velocity distribution to show that the average translational kinetic energy of the atoms emerging as a beam from a pinhole in an oven at temperature
T is 2
kT. (Do this on paper. Your instructor may ask you to turn in this work.)
(b) Calculate the magnetic field gradient required to produce a splitting of
1.27 mm in a beam of Ag atoms from an oven at 1000. K with a magnet of length
42 cm.
(No Response)
T m
−1