HCAL 1 Status 2003 Oleg Gavrishchuk JINR Dubna

HCAL 1 Status 2003 Oleg Gavrishchuk, JINR, Dubna 1. HCAL 1 performance 2003 • General design • High Voltage system • LED monitoring 2. Tests in muon halo beam (June 2003) 3. On-line reference plots 4. On-line LED monitoring plots 5. End of Run muon test (September 2003) 6. Stability control 7. Conclusions Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting

HCAL 1 Status 2003 HCAL 1 general view in frame • Matrix setup of 28 v 20 cells • 480 cells 150 x 150 mm**2 • Total size: 4200 x 3000 mm**2 • Window size: 1200 x 600 mm**2 (8 x 4 cells) • Total Weight: 83 tonn • Moving range: +/-2. 5 m Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 2

HCAL 1 Status 2003 High Voltage layout • H/V interface is controlled by pccofe 03 • 100 m flat cable (50 pairs) transfer the commands from H/V interface to receiver in the CAMAC crate • Receiver distribute the commands to 7 Data and 1 -Chip-select boards • Power suppliers: +100 V DC, load current 140 m. A per 480 PM +6 V DC, load current 8 A (6 A for 480 PM) -6 V DC, load current 3 A Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 3

HCAL 1 Status 2003 LED monitoring layout • Blue LED (470 nm) high (ultra bright) luminosity used for 480 HCAL 1 Photomultipliers PM-84 • Light intensity controlled by avalanche PIN diode • Led generator pulsed out of Spill with frequency selected before start of Run Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 4

HCAL 1 Status 2003 Muon tests 02. 06. 2003 1. HCAL 1 was tested in muon halo beam with VO 1 trigger in. Calorimeter was moved left and right on 1. 5 m to obtain statistics in edges. Total statistic is equal about 3 millons events (500 spills). 2. 480 HCAL 1 cells were adjusted: muon peak should be in 58 ADC channel 3. Total muon HCAL 1 spectra is feted to Mean=57. 6 ADC ch. 4. Statistics X-Y distribution is shown on bi-plot. Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 5

HCAL 1 Status 2003 Muon HCAL 1 cells spectra , column 19 , row from 0 to 19. 02. 06. 2003. Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 6

HCAL 1 Status 2003 ON-Line Reference Plots: 1. Hits distribution. 2. Amplitude vs channels. 3. Amplitude distribution. 4. Noise distribution 5. All events histogram 6. Frequency vs HCAL 1 560 channels (matrix 28 x 20) 7. Total HCAL 1 amplitude 8. Hits for events with amplitude cut of 20 ADC channels. Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 7

HCAL 1 Status 2003 LED reference plots. 1. Sum HCAL 1 Led amplitude histogram 2. Pin Diode amplitude histogram LED amplitude vs HCAL 1 560 channels (matrix 28 x 20) X-Y amplitude be- plot 3. 4. Sum_LED Pin Diode_amp Ampl. VS N_chann Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 8

HCAL 1 Status 2003 Muon tests 22. 09. 2003 1. Total muon ADC spectra in ADC channels (Mean=53. 6) 2. Total muon spectra in Energy scale. Mean=1. 68 Ge. V 3. Individual ADC spectra for cell: X=18, Y=8 4. Statistics distribution, X-Y plot Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 9

HCAL 1 Status 2003 Muon HCAL 1 cells spectra , column 19 , row from 0 to 19. 02. 06. 2003. Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 10

HCAL 1 Status 2003 Muon HCAL 1 cells spectra , column 19 , row from 0 to 19. Measurement of 22. 09. 2003. Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 11

HCAL 1 Status 2003 LED amplitude behavior in data taking periods P 1 A_P 1 H 1. Pin diode amplitude 2. HCAL 1 corrected on PIN 3. HCAL 1 LED with-out PIN corrections 4. LED monitoring system indicate: 5. HCAL 1 amplitude decrease on 8% from P 1 A to P 1 H data taking periods. 6. HCAL 1 amplitude is practically stable Lisbon, September 1 -3, 2003 O. Gavrishchuk, COMPASS Collaboration Meeting 12

HCAL 1 Status 2003 CONCLUSIONS: 1. HCAL 1 signals are rather stable from June 02 to September 21 2. It is difference about 7% in total HCAL 1 amplitude from Start and End of Run 3. It is in agreement with LED monitoring behavior. 4. HCAL 1 energy calibration can be corrected according to LED monitoring references. Start of Run 2003: Mean A=57. 6 Lisbon, September 1 -3, 2003 End of Run 2003 Mean A=53. 6 O. Gavrishchuk, COMPASS Collaboration Meeting 13