Procedure for Conducting Polarized Electron Reflection Measurements on One Magnetization Direction

The purpose of this procedure is to measure the electron arrival rates at both channeltrons of the Mott polarimeter, with the order in which the two channeltrons are measured varying, to protect against drift effects.

1. The sample was placed, according to the procedure in appendix A.1, in a position that had previously been determined (section 5.4) to direct the specularly reflected electron beam into the polarimeter.
2. One channeltron was chosen, connected to the data acquisition apparatus (chapter 3,) and switched on (table A.1.) If the procedure being described here had been performed previously, the channeltron chosen was the one that had not been chosen at the same stage in the preceding performance of this procedure. Otherwise, a channeltron was chosen at random.
   

   Table A.1: The Voltages, Relative to Earth, on the Electrodes of the Mott Polarimeter, During the Polarized Electron Reflection Experiment

   Electrode	Voltage
   Front grids	$(-100\pm{}1)\,\mathrm{V}-\frac{E_b}{e}$
   First lens	$(1.7\pm{}0.005)\,\mathrm{kV}$
   Second lens	$(1\pm{}0.005)\,\mathrm{kV}$
   Thorium foil	$(20.5\pm{}0.00725)\,\mathrm{kV}-\frac{E_b}{e}$
   Focus electrodes	$(1.5\pm{}0.005)\,\mathrm{kV}$
   Retarding grids	$(-200\pm{}1)\,\mathrm{V}-\frac{E_b}{e}$
   Channeltron front ends	$(0\pm{}1)\,\mathrm{V}$
   Channeltron anodes	$(2.2\pm{}0.005)\,\mathrm{kV}$

   
   
3. A series of electron arrival rate measurements was taken, according to the procedure in appendix A.2.2.
4. The other channeltron was connected to the data acquisition apparatus (chapter 3) and switched on (table A.1.)
5. A series of electron arrival rate measurements was taken, according to the procedure in appendix A.2.2.