May 26, 1995 Zvi and I took a look at the kaon yield in the HEUB at 14 GeV/c. We ran high voltage plateaus on the three beam cerenkovs, and ran a pressure curve on C1. Settings: C1 3000 9 psig F12, C1 has a x2 dc amplifier-- CHECK FOR DRIFT!!! C2 2500 0 psig air C3 3000 0 psig air PRESSURE CURVE FOR C1: Define 's' as s from the top of the MPS 'light' as s*C2*C3 'pi1' as light*C1 'heavy' as (s)*(/C2)*(/C3) 'k1' as heavy*C1 The hardware for these defintions is set up in the fast trailer See trigger notebook 3 for details. The pressure in C1 was gradually lowered from approximately 9 psig, and several rates --including those listed above -- were recorded. The expected thresholds for 14 GeV particles in F-12 are: pi threshold = -82 kPa (-100 kPa = vacuum, 0 kPa = 1 atmosphere) k threshold ~ -42 kPa Pressure curves of pi1/light and k1/heavy were plotted as a function of pressure. In the ideal case, the pi curve should show a sharp knee at approximately -82 kPa, and the k curve a knee at -42 kPa. To see the pressure curves click here The data covers the range -55 kPa to +61 kPa and shows a strong knee in the k pressure curve at the correct pressure. There is no doubt that we are seeing kaons at 14 GeV/c. Our operating pressure at 9 psig corresponds to approximately 61 kPa -- well onto the "pressure plateau". The AGS went to "studies" and ended our data taking before we could explore pressures below -60 kPa, so we did not get data in the region of the pi knee. However it is evident from the graph that we are well up on the "pressure plateau" for the pi's and that C1 is highly eficient for pi's. FRACTION OF K's IN BEAM: The ratio of k1/s is approximately 0.73%. The ratio of k1*pretrig/pretrig is somewhat larger at approximately 1.12%. To see pressure curves of these ratios click here. HIGH VOLTAGE PLATEAUS: To see the HV plateaus of C1, C2 and C3 click here. JPD
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