Page History

H4/SPS Daily meetings

September

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15

Status: First day of beam. We were supposed to have the beam at midnight, we got it at 3PM. The timing was looked at, the calorimeter  signal is now coming earlier with respect to the tracker as compared to PS.  BT 5 configutation with cal/tkr in the middle of the trigger window at SPS is now the baseline.The calibration of the calorimeter (cross pattern) at 100 GeV was started then interrupted to let the experts optimize the beam tuning at the highest energies. Many interruptions due to machine problems.

Program: completion of the 100 GeV calibration runs, ACD calibration with protrons+pions, switch to 200 GeV, scanning of different  (X,Y, theta) configurations 

September 7

Status: The beam is now much more stable. Calorimeter calibration completed, ACD calibration completed, scanning of 200 GeV configurations almost completed. Some runs were repeated after it was found that 4 scintillators used for the beam tuning were still in and be moved out. The pressure in the 2 Cerenkovs (1.2 bars so far) was set to 0. The dependence of the calorimeter measured energy as a function of rate has been investigated ("baseline restoration" problem). The effect is clearly visible. We decide to limit the rate to 400 Hz.

Program: switch to 280 GeV and repeat same configurations. Specific BT configuration files will be prepared by Luca and Carmelo to study the FHE efficiency using the SPS timing settings. As proposed by Anders, the TEM diagnostics will be on by default (BT 6 which is now the baseline).   

We could only run part of the night, until about 4:00 AM. Beam expected at 8:30 PM . CAL calibration with 20 GeV pions completed.
Two configurations suggested by Leon tested as well (with 150 GeV pions).

Program: 10 GeV electrons (limited number of configurations). We will stop tomorrow at 7:00 AM. The area must be cleared by 8:00 AM. 

September 14

Status: Program with 20 GeV protons completed (center of tower 2: 0,45,180 deg +1 position at 90 deg 100k events). Different configurations with 200 GeV electrons used for the FIFO full issue. As of today, we are in "democratc mode", so we have lost the capability to run at the highest energies (>250 GeV). To do list related to dismantling and shipping  Configurations still to do

Program: 10 GeV electrons. Completion of the scan with 20 GeV pions.

Analysis: Dave Smith looked a little at position measurements in CAL single crystals, here. Benoit had a look at the 20 GeV pion run used for CAL calibrations. There is a very good agreement between the reconstructed energy of the MIP peak and that predicted by the MC, demonstrating that pedestals or light yields/gains have not significantly drifted over time.    

September 11

Status:  Smooth operation most of the time, except for 3 hours in the morning. Program of different geometrical configurations completed at 20 GeV. New configurations proposed by Philippe at different energies (200,100,50,20 GeV) to study the crack effects + direct contributions from the beam almost done.

Program: Different electronic configurations to investigate the FIFO full issue. Switch to 20 GeV (10 GeV?) protons.

Analysis:  Luis presented the first comparison between MC and data for the ACD distributions. The agreement seems reasonable.   

September 10

Status:  Smooth operation most of the time. Program of different geometrical configurations completed at 50 GeV, well along at 20 GeV. Runs with different trigger engines (internal trigger for physical events: 1 range readout, 0-suppress, external trigger for random events: 4 range readout, non 0-suppress) performed successfully to study the pedestal drift issue.

Program: Completion of 20 GeV program. Dedicated runs near cracks at 200 GeV. Switch to protons+pions tomorrow morning, when the experts are around.

Analysis: Preliminary results of the "pedestal-drift" runs (Benoit). The expected effect is clearly visible, although this is still very qualitative.

September 9

Status:  Smooth operation most of the time, but for a long interruption from 4:30 to 9 AM. Program of different geometrical configurations completed at 100 GeV. Specific configurations proposed by Leon (45 deg, with particles entering the tracker sideways within the thick-converter layers) were used as well. 

Program: Specific studies for the "baseline restoration" (aka "pedestal drift") problem using LATTE's muti-engine capabilities (configuration files provided by Jim Panetta). CAL pedestals, internal trigger runs. Switch to 50 GeV.

Analysis: A look at the deposited-energy distributionsmeasured in the different CAL layers (Benoit): a factor close to 90%, dependent on the layer and the bombarding energy has to be applied to the data to get a good match with the data. It is not clear if this effect is only due to non-linearity in the extrapolation of the cosmic-muon calibration to the highest energy range.   Philippe showed the dependence of the measured energy on the distance to the log edge. David P. has studied the beam width, found to be much narrower in the data than in the existing simulation runs. Jan and Niklas showed results on the FHE efficiency at 200 GeV. Since the deposited energy per layer is so high, there are only few events below threshold. The measurement must be repeated at lower energy.    

September 8

Status:  Smooth operation most of the time. Program of different geometrical configurations completed at 280 GeV.  FHE tests completed at 280 GeV (theshold=0.5 GeV-2 GeV) at 2 different positions.  Cerenkov counters have been checked (there was connection problems), and are now working, although the efficiency is low.

Program: Specific studies for the "baseline restoration" (aka "pedestal drift") problem (waiting for Ric's help to implement muti-engine capabilities). CAL pedestals, internal trigger runs. Switch to 100 GeV.

September 7

Status: The beam is now much more stable. Calorimeter calibration completed, ACD calibration completed, scanning of 200 GeV configurations almost completed. Some runs were repeated after it was found that 4 scintillators used for the beam tuning were still in and be moved out. The pressure in the 2 Cerenkovs (1.2 bars 

so far) was set to 0. The dependence of the calorimeter measured energy as a function of rate has been investigated ("baseline restoration" problem). The effect is clearly visible. We decide to limit the rate to 400 Hz for the rest of the run. The time of the daily meeting will be moved to 5 PM to enable people on the previous night shift to attend.  

Program: switch to 280 GeV and repeat  the same configurations. Specific BT configuration files will be prepared by Luca and Carmelo to study the FHE efficiency using the SPS timing settings. As proposed by Anders, the TEM diagnostics will be on by default (BT 6 which is now the baseline).

Analysis: the first quick comparison with the MC simulations at 100 GeV shows a reasonable agreement for the tracker hit multiplicity (the multiplicity is larger for the data) and the energy deposited per layer in the calorimeter.  No comparison is available for the ACD yet.  More simulations are needed.   

September 6

Status: First day of beam. We were supposed to have the beam at midnight, we got it at 3PM. The timing was looked at, the calorimeter  signal is now coming earlier with respect to the tracker as compared to PS.  BT 5 configutation with cal/tkr in the middle of the trigger window at SPS is now the baseline.The calibration of the calorimeter (cross pattern) at 100 GeV was started then interrupted to let the experts optimize the beam tuning at the highest energies. Many interruptions due to machine problems. Benoit attended the weekly users' meeting (moved from Thursadt to Wednesday as tomorrow is a holiday in Switzerland): there will be machine development (no beam)  from next Tuesday 8 AM to Wednesday 4 PM. A threat on our running with the "0 mrd" configuration (allowing us to get the highest rate at high energy)  was mentioned during the meeting, as the H2 users (sharing the same target) would like a less detrimental configuration for them. Finally, a way around was found and we wil keep this configuration at least until Monday. 

Program: completion of the 100 GeV calibration runs, ACD calibration with protrons+pions, switch to 200 GeV, scanning of different  (X,Y, theta) configurations 

T9/PS run Daily Briefings - 3PM

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