Procedure for Conducting Polarized Electron Reflection Measurements on One Film

The purpose of this procedure is to examine the sample's magnetic properties with each of two opposite magnetization directions, with the order in which the magnetizations are examined varying, to protect against drift effects.

1. The vacuum chamber's ion pump (figure 4.1) was isolated from the chamber using a gate valve, and switched off, to protect the polarimeter from noise from the ion pump.
2. The vacuum chamber's ion gauge (figure 4.1) was switched off, to protect the polarimeter from noise from the ion gauge.
3. The sample was magnetized, according to the procedure in appendix A.2. If the procedure being described here had been performed previously, then the direction chosen for the magnetization was opposite to that chosen, at the same stage, in the preceding performance of this procedure. Otherwise, a direction was chosen at random.
4. Polarized electron reflection measurements, as a function of incident electron energy and incident beam current, were taken, according to the procedure in appendix A.2.1.
5. The sample was magnetized, according to the procedure in appendix A.2, in the opposite direction from that chosen at the earlier stage in this procedure.
6. Polarized electron reflection measurements were taken, according to the procedure in appendix A.2.1.
7. The ion gauge was switched on.
8. The ion pump was switched on.
9. The valve between the ion pump and the chamber was opened.