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User name D. Parno
Log entry time 18:47:48 on February16,2009
Entry number 261532
keyword=LHRS electron rates as expected for L90 kinematic
We did a full replay of Run 20223, the last run at the L90 kinematic. Fig. 1 shows E/P for good electrons (after Cerenkov cuts, a cut on having a good track, and a cut on E/P to cut out the remaining pions). (Fig. 2 shows E/P without the Cerenkov cut, for comparison).
We see 490 good electrons in Fig. 1. According to the end of run post, the run lasted 57.734 minutes. The electron rate thus becomes 8.5 electrons/minute or 0.14 Hz. This is a little over a factor of two higher than the expected value of 0.06 Hz. (Question: is this value computed for a 15 uA current?) All 490 electrons probably aren't "good", though -- our cuts could be more stringent -- which will reduce our rate toward the expected value.