PS/SPD final cosmic results

PS/SPD final cosmic results • Calibration of PMTs with masks • Cosmic results Commissioning meeting, CERN

PMT calibration with masks • During the cosmic data taking there were few PMT calibrations done using blue and green LEDs. Pixel gain coefficients obtained during different calibration runs show good reproducibility and stability of the setup. • Also to study the effect of pixel uniformity two masks was used : • 02-05-2006: mask with one hole d=1.5 mm on pixel • 06-07-2006: real mask with two holes from CF Commissioning meeting, CERN

1-hole mask Light (ph.el.) measured on each of 64 pixels with and without mask for each PMT is shown on figure. Mask effects mainly the first and the last 8 pixel rows. Also the non-uniformity (read-out) appears to be significant. Q.E. is measured for PMT1-4: 12.%, 10.8%,11.8%, 12.2%. For data analysis for PMT2-4 is taken value of CF 10.7% 11.53% 12.6%. Commissioning meeting, CERN

Real mask with 2 holes (CF) On the right figure: Light (in phel) on pixels of PMT2: 1-h mask, no mask, CF mask. The difference between masks is ~20%, mainly on 1-st and last 8 pixels. On the left figure: Ratio of gain coefficients for PMT2 pixels with/without mask : 1-h mask and CF mask. Effect of masks is about +-10%. Commissioning meeting, CERN

PS uniformity There are 100 optical cables connect PS modules to the PMTs, usually 4 PS elements (64 cells) per PMT. Uniformity of detector response within single PMT is important. On the figure the result for modules p51, p57, p71, p127 is shown as an example of data presentation. On the top plot the light yield for each module is plotted in ph.el. The red lines indicates +-20% corridor. On the bottom the histogram of responses normalized over PMT. The file with all data is attached to the agenda of this meeting. Commissioning meeting, CERN

PS uniformity Variation of the detector response for single PMT is shown on figure. Inside the window [0.8:1.2] there is 95% of cells, inside [0.7:1.3] is more than 99%. The variation of the response within each PS element (16 channel = small optical connector) is about 6%. Commissioning meeting, CERN

PS light yield All low signals from Load5, PMT2, adc ch. #9 (pixel # 63) -> deffect of measurement? Distribution of the light yield (ph.el.) in PS cells. Commissioning meeting, CERN

Calibration coefficients PMT2 Gain of this pixel was changed ~2 times. Probably, due to extra illumination with LED during run with Load5. Commissioning meeting, CERN

Average light yield for single PMT Distribution of the average light yield (ph.el.) for each PS PMT. Commissioning meeting, CERN

SPD light yield Distribution of the light yield (ph.el.) in SPD cells. Commissioning meeting, CERN

SPD uniformity Variation of response in SPD cells is shown for each detector element and for each PMT. On the bottom plots there are integral probability curves are shown. Width of distribution within detector element is 5.7% (sigma). Commissioning meeting, CERN

Average light yield for single PMT (SPD) Distribution of the average light yield (ph.el.) for each SPD PMT. Commissioning meeting, CERN

Backup slides • Distribution of responses normalized for PMTs: separately for each PS SM. • Distribution of responses normalized for PMTs: separately for each SPD SM. • “Bad” modules and channels with low LY: example. Commissioning meeting, CERN

Loads logbook Totals: 212+164+104+272=752 groups (12032 cells) “BAD” modules (average l.y. ~14 (15) ph.el.): s71(11), p163, p166, p168, s81(2), s169(7), s170(6) p172(8),s23, s39, s41, s56, s101 p13(3), p73(4) % Loads: SMs and PMTs in cosmic stand Load2={'SPD1''SPD2''PS5''SPD4'}; Load3={'SPD6''PS6''PS2''PS7'}; Load4={'SPD8''SPD7''PS1''PS8'}; Load5={'SPD5''PS4''SPD3''PS3'}; PMT 1: SPD1, SPD5, SPD6, SPD8 PMT 2: SPD2, SPD7 PMT 3: SPD3 PMT 4: SPD4 PMT 2: PS4, PS6 PMT 3: PS1, PS2, PS5 PMT 4: PS3, PS7, PS8 Commissioning meeting, CERN

PS uniformity - 1 PMT 2: PS4, PS6 PMT 3: PS1, PS2, PS5 PMT 4: PS3, PS7, PS8 Commissioning meeting, CERN

PS uniformity - 2 Commissioning meeting, CERN

SPD uniformity - 1 PMT 1: SPD1, SPD5, SPD6, SPD8 PMT 2: SPD2, SPD7 PMT 3: SPD3 PMT 4: SPD4 Commissioning meeting, CERN

SPD uniformity - 2 Commissioning meeting, CERN

Load2: modules (<17 phel) and channels with low LY (<13 phel) Commissioning meeting, CERN

Load3: modules with low LY <17 phel Commissioning meeting, CERN

Load3: channels with low LY <13 phel Commissioning meeting, CERN

PS/SPD final cosmic results