Abstract for CEBAF Technical Note 93-059

The feasibility of using Moller scattering to measure the absolute value of the beam energy to ~10^-4 is discussed. The small emission angles typical in Moller scattering of high energy beams imply the need for very precise measurement of the particle angles. One of the primary limitations of this method arises from the effect of motion of the bound target electrons which distorts the shape of the angular distribution. Estimates of the size of this effect for iron and hydrogen targets are carried out. It is concluded that even for hydrogen the influence on the opening angle due to atomic binding is more than one order of magnitude larger than the angular accuracy requirement. Although, in principle, these effects can be calculated for hydrogen, it seems unlikely that the accuracy goal of 10^-4 can be achieved.

Go to the Hall A Technical Notes Home Page