Beam Time Request

 

In the December 1993 proposal we requested a total of 164 d (3940 h) of beam time to complete measurements of forward and backward asymmetries in the range GeV². Of this time, the 46 d (1100 h) for commissioning was approved. At this time we request that 46 d of commissioning time again be approved. We plan to return to the PAC for approval of the first physics measurement in the near future.

The commissioning plan envisioned in 1993 is essentially unchanged. We anticipate breaking the time into two runs of approximately 3 weeks or about 6 calendar weeks each (running with the fully instrumented spectrometer and the liquid hydrogen target). The details of the measurements for the two runs are as follows:

1. Run 1
   • check spectrometer optics (shape of constant locus at focal surface, etc.): 3 days
   • backgrounds: external shielding, set field to low value to investigate neutrons and 's: 4 d
   • detector efficiencies, ADC and TDC spectra, overall device symmetry: 2 d
   • begin to establish procedure for centering beam with respect to target and detector: 2 d
   • studies of beam polarization (current dependence of polarization): 1 d
   • begin measurement of correlated parameter derivatives (yield with respect to beam position, etc.): 2 d
   • first asymmetries: 5 d
   • empty target (background, symmetry, etc.): 2 d
2. Run 2
   • more background studies: 4 d
   • final procedure for centering: 3d
   • final correlated parameter derivative study: 4 d
   • asymmetry test: 10 d