User name Mack
Log entry time 15:33:09 on March 27,2001
Entry number 34924
keyword=HMS tracking efficiency should be okayThe tracking efficiency was significantly non-zero last nite at midnite and was up to 90% by 8am. ((Figure 1) I think when you come up again you'll find the tracking efficiency is nominal. In fact, extrapolating linearly, the efficiency should have been 110% by 9:30 am. (Just kidding.) You can check the tracking efficiency in hms####.txt.
Questions any reasonable person would ask:
1. Why was the WC gas off? Because the air-conditioner was down and no work could be done on it under conditions which you well know. (No air flow means no WC gas or clean power.)
2. Why was recovery so slow? Bill Vulcan worked out the numbers. With a combined chamber volume of 240 liters, at a rate of .6 liters/minute, one exchange volume takes 6.7 hours. It looks like it took roughly 3 exchange volumes to get the efficiency up to 90%. We (I?) broke a window once trying to fast-flush a chamber before (on the SOS) so that is not a popular method in Hall C. (The flow meter acts as a current source with foldback at a "voltage" of 15 psi - so if the gas can't get out of the chambers fast enough there is more than enough pressure available to eventually pop the windows.)
Lessons learned: We should reduce the impedance of the WC gas exit line so we can flsu
FIGURE 1
