TWIST Technote 62

Positron Energy Scale Calibration

Andrei Gaponenko, March 2002

This note discusses a systematic uncertainty caused by an error in the positron energy scale. Sensitivities of all the four Michel parameters to the energy scale are obtained from fits to a generated 2-d spectrum. Stabilities of the sensitivities with respect to a choice of the fit region are shown. A method of determining an energy scale is described and a statistical part of the energy scale uncertainty is obtained.

Most of the results have been shown before. A new piece of information is a study of the dependence of the sensitivities on a fit region.