A possible way for removing instrumental asymmetries in spin resolved photoemission with unpolarized light

We introduce a new method, a linear subtraction, to eliminate instrumental asymmetries in spin resolved photoemission with excitation by unpolarized light. The new method is applied successfully to analyze the spin polarizations in the valence band and 4d core level photoemission, excited with unpolarized light from a nonmagnetic Pt crystal. It is also tested in the spin analysis of the 2p core level photoemission, generated with circularly polarized X-rays from magnetic Fe. Even though the new method of linear subtraction is applicable for limited cases, it is a very valuable method for removing instrumental asymmetries especially when the helicity flipping, magnetization flipping, and even geometry flipping in spin resolved photoemission experiment are not possible.