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    User name K. Aniol

    Log entry time 21:38:44 on December 16,1999

    Entry number 31235

    keyword=revised elastic normalization point

    Revised elastic cross section normalization points. The point we measured at Q2=10.08( runs 1365 and 1366) has a rate 15 times smaller than estimated. This is perhaps due to the uncertainty in the form factor at the minimum, although in Amroun's paper the minimum should not come until 12 /fm2. I recommend making the elastic measurement at the 2nd maximum, Q2 = 15.00 /fm2. The estimates for the rates for density = 0.056 g/cm3, 6.7msr, z_tgt=5.8cm, an 85% reduction at 70uA, are:

    E Q2(/fm2) th_e p_e (fm2/sr) rate@ 70uA run time
    842 15.00 57.94 738.59 1.77e-9 3/s 2 hrs
    842 19.39 68.45 708.15 3.13e-10 0.5/s 7 hrs
    4045 19.39 12.54 3911.16 2.05e-8 33/s 0.5 hrs
    2903 15.00 15.41 2799.5 4.48e-8 72/s 0.5 hrs