A sample of He + ions is prepared at a temperature of 298 K and a density of 2.0 # 1010 cm-3 . Because these are ions, magnetic ields may be used to trap those ions with kinetic energy less than some threshold value et . he faster-moving ions escape the trap and are lost. Our sample is placed in such a trap with a threshold energy et = 1.00#10-20 J, the fast ions are lost, and the sample is allowed to return to equilibrium (so the temperature is well-deined again). Write an expression for the new temperature of the sample