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Update on LS1 Activities W.Baldini, N. Bondar, O.Maev, B. Schmidt Muon Meeting Mar. 13-th 2014

Update on LS1 Activities

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Update on LS1 Activities. W.Baldini , N. Bondar , O.Maev , B. Schmidt . Muon Meeting Mar. 13-th 2014 . Present Status. A-Side commissioning activities: Connectivity test is ongoing: Q1 done - PowerPoint PPT Presentation

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Page 1: Update on LS1 Activities

Update on LS1 Activities

W.Baldini, N. Bondar, O.Maev, B. Schmidt

Muon Meeting Mar. 13-th 2014

Page 2: Update on LS1 Activities

Present Status• A-Side commissioning activities:

– Connectivity test is ongoing: • Q1 done• Q2: M4 all regions, M5R2, M5R3, M5R4 still to be tested. Hopefully in the next 4-5 days it

will be done. • So far we found just a few cables (~10) to be checked for swappings or bad connections

• Chamber conditioning in progress: – Conditioning of problematic chambers on A side essentially done, ready to move to C side – Reconditioning of M4R4 finished (96ch)

• HV: – PNPI doubling: The hardware part is done, Giovanni will work on the update of the ECS

at the end of the month– CAEN: trying to switch ON but on A-side muhva02w-opc is dead (online guys are

working on that), and on C-side there is a problem with the ECS project after the migration, HW seems OK.

• Analysis of the thr. Scan data: ongoing, checking data consistency, ENC, offsets, thresholds… 2

Page 3: Update on LS1 Activities

Next Steps• The next comm. Week#5: March 17-21

– New thr. Scan, after fixing some bad connections – Noise runs: standard (data taking) and low thresholds – Global run

• Around March 20 praparation for the nacelle installation on C-side: – Open C-side stations – Move nacelles as soon as the CALOs can be closed on both sides for a few days

• For more details as usual you can refer to the e-log: http://lblogbook.cern.ch/MUON/

3

Page 4: Update on LS1 Activities

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Feb. 2014 Threshold Scan • Checked consistency of data (ENC values for all stations-regions) w.r.t.

expected values OK (just for myself, to get acquainted with all the machinery..).

• Offsets: – A side ~OK – C side there is a clear indication that in some areas the LV is probably too low (see next

slides).

• Thresholds: – still few things I do not quite understand, talk to Davide after the meeting. – My impression is that now the thresholds are a little too low (~ 1-2 r.u. in average) but

(at least on the test stand) 1 r.u. is often enough to reduce the noise rate by a factor 2….– I think at some point we should dedicate a muon meeting to see if the present method

can be somehow improved.

• Effects of the grounding/consolidation activities on M2 Cside

Page 5: Update on LS1 Activities

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Offset:Offset

Measured rate vs thr. Plot: “cusp” plot due to hysteresis of the discriminator

Ideal rate vs thr. Plot, if thr. could go down to 0 (no hysteresis of the discriminator)

The offset is an intrinsic feature of the differential discriminator, we expect it to be randomly distributed

Page 6: Update on LS1 Activities

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Offsets Distributions: A-Side

M2R1 M2R2

M2R3 M2R3

Expected a Gaussian distribution of the offsets if the LV is OK

Tail on lower side, it might indicate that the LV is not enough in some areas (voltage drop in the cables)

~OK ~OK

Page 7: Update on LS1 Activities

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Offsets Distributions: C-Side

M2R1 M2R2

M2R3 M2R4

On C side is rather clear that LV should be tuned..

Page 8: Update on LS1 Activities

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Offsets Distributions: summary

• M1: ~OK, large distributions in R1, both sides • M2: A-side ~ OK, C-side to be tuned, all regions • M3: A-side~OK, C-side large distribution in R1• M4: OK both sides, maybe slightly high tail • M5: as M4

See the appendix for all the plots

Page 9: Update on LS1 Activities

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First Effects of Detector Intervention

• Grounding has been improved (wire-connection among the 4 gaps grounds, otherwise rely only on the brass spacers that get loose with time)

• All M2/M3 R1/R2 chambers are affected by this issue

• Tested and, if needed, changing noisy FEBS

• On M2 C-Side the FRONT chambers have been modified while the BACK ones are still untouched

• In the next slides there is the comparison FRONT/BACK for the most noise-sensitive parameter: the ENC (RMS of the rate-vs-threshold gaussian)

Page 10: Update on LS1 Activities

10

First Effects of Detector Intervention

Small (but visible) effects, we expect the FEBs to be more stable and insensitive to external noise during data taking

Improved Improved

Not improved Not improved

Better separation between anode and Cathode FEBs, and “more gaussian shaped”

Less Channels with errors in the fitting procedure

Page 11: Update on LS1 Activities

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Appendix

Page 12: Update on LS1 Activities

Offset M1

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A Side C Side

~ OK: M1AR1,M1CR1 larger distributions…

Page 13: Update on LS1 Activities

Offset M2

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A Side C Side

A Side ~ OK, C Side to be tuned

Page 14: Update on LS1 Activities

Offset M3

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A Side C Side

A Side ~ OK, C Side M3R1 to be tuned

Page 15: Update on LS1 Activities

Offset M4

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A Side C Side

~ OK both sides, maybe some tail on the high side

Page 16: Update on LS1 Activities

Offset M5

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A Side C Side

~ OK both sides