1 / 10

MEG Commissioning & Engineering Run 2007 Review - Achievements, Constraints, and Organization

This review discusses the achievements, constraints, and organization of the MEG Commissioning & Engineering Run in 2007, with a focus on beam time goals and constraints faced during the run. It also highlights the organization structure and tools used for smooth experimental running and monitoring.

eblalock
Download Presentation

MEG Commissioning & Engineering Run 2007 Review - Achievements, Constraints, and Organization

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MEG Commissioning&Engineering Run 2007 MEG Review February 2008

  2. Beam Time Goals & Constraints • Engineering Run Goals: • all parts of the Detector Operational • Read-out/Data-taking Chain tested • all Triggers implemented + Rate Check • full set of Calibration & Test Data • contribute to “Long-term” Goal of • understanding our Detector • Constraints: • Experiment Change-over - • Kottmann et al. beam time • - in total 2 weeks extra beam time given to them!!! • - 3-4 weeks for -beamline installation + BTS cool- down after Kottmann et al. • Calorimeter Cryostat delivery + seal problem • LXe HV feed through problem optimal either Beginning or End of a Period  Only 3 Months available for Beam !!! Calo. Delay Feed through problem but many task could Progress in parallel MEG Review February 2008

  3. COMMISSIONING Parasitic Run Beam optimization in parallel with Debug, Tune & Calibrate Full Run Full Trigger Implementation DAQ/Readout chain tested Calibration & Test Data + CEX LED, , C-W Cosmics & Michel e+ Commissioning & Engineering Run With 3 months to achieve proposed goals needed “rigid” organization & planning but flexibility to implement changes • Run Coordindation group formed: • 6 beam coordinators + 1 offline coordinator •  • Split time into 2 overlapping parts: 2 x 12 Hrs Only detector Experts nights • to allow for flexibility + continuity: • Coordinators each 2 weeks • Daily Run Meetings (on-site) • Weekly Video Meeting (Calloboration) - strategy • Web-based schedule + shift list + on-call list 3 x 8 Hrs Shift leader + 1 crew MEG Review February 2008

  4. Organization In Practice • Information Access • “How to” information database for shift • crews on MEGWiki – grew with time Example • Continuity + Schooling • staggered + overlapping shifts • basic 3 days/person shift-block • detector experts start as shift • leaders MEG Review February 2008

  5. O2sensor Experimental Conditions – Beam Line • (1) Improved COBRA He-environment: monitoring with O2-sensors ~ (97±1)% • - but air doping was needed for DCs • (2) Target found to be • slightly misaligned! • target made for = 21° • but due to DC support • could only be 13° inclined • expect only ~ 75% of s • to hit target for 2007 !!! Laser check (estimate)!!! slant angle =(12.5±0.5)° vertical misalignment  =(22.8  5.0) mr shift of Laser cross SHIFT =(5.51.0) mm • (3) New degrader needed (air doping + range-curve) • 300 m Mylar (old 480m CH2) • Now can transmit 1108 +/s to COBRA centre with Degrader (2mA Ip) • For Run used: • Ultra-low Intensity ~ 5106 -stops/s • Nominal Intensity ~ 3107 -stops/s MEG Review February 2008

  6. Detectors etc. TCs DCs • TCs: • late arrival APD power • supplies + DAQ problems Full complement of detectors • DCs: • external HV problem in • pure He air-doping needed • Calo: • initial problems with HV • feedthroughs – noise + • splitter input-stage damaged • Liquid purification success • 70l/hr ~ 250 hrs for  > 3m • C-W: • proved v. successful • Li (17.6, 14.6 MeV) • + B (4.4, 11.7, 16.1 MeV) • targets – Energy + Timing • NaI: • automated mover • temp. contolled APDs • E/E ~5-6% () Calo. C-W NaI MEG Review February 2008

  7. lcmeg05 lcmeg04 lcmeg03 lcmeg02 lcmeg01 Trigger + DAQ Online Cluster Megonxx Trigger + Splitters • Staged trigger implementation: • Single detectors + Michel trigger • Coincidence detectors e.g. DC+CR • TC+LXe rad.-decay, 11B C-W (narrow t=20 ns) • TC+DC • Direction matching  e (planned TC fibres) • too slow  XEC PMT-index + TC-bar(index,z) • where z from bar charge-ratio • 24 Trigger types introduced (max. 32) • Multiple triggers with prescaling  Read-out • Trig. Monitoring (cyclic-buffers) Works nicely DRS v2 DRS3 – tested improved (clock signals, temp eff. Etc.) • Limits: • DAQ/DRS readout limited by VME (83MB/s) • ~ 30 events/s full waveforms (threading) • Online (backend) 1.2TB storage • Offline (lcmeg) 64 CPUs + 50TB disk • “Lazylogger” autocopy Online Offline • factor 2 compression Offline Cluster lcmeg MEG Review February 2008

  8. MEG Monitoring Tools SCS2000 controller • In order to ensure smooth • experimental running • !!! monitoring essential !!! • SLOW-CONTROL: • MSCB-submaster+ SCS2000 + dedicated LabView control software • Midas history virtually all equipment monitored & logged Midas History MSCB Area Network • ONLINE: • Data Quality using Argus MEGanalyzer with Event Display digital oscilloscope for all channels LXe, TCs, DCs, NaI, Trig., DRS included • Midas Voice Alarm system MEGanalyzer MEG Review February 2008

  9. Eg 170o 175o q 54.9MeV 82.9MeV 1.3MeV for q>170o 0.3MeV for q>175o H~ 8.5 mm fully contained V~ 7.5 mm Eg CEX – Calorimeter 0-Calibration After Data-taking with  e trigger still time for planned “reduced” CEX Run: LH2-target setup/testing in // with muon data-taking outside zone NaI ~ 5 days Data-taking 450 Runs ~ 2.2 M events • Setup • -Beam > 1.4 MHz of 70.5 MeV/c - • LH2-Target + Control & Stabilization System • LHe supply (dewars) • 9-Crystal NaI array + Pb/Scintillator as Tag • LXe Calorimeter LH2-target MEG Review February 2008

  10. Summary • Due to the “Great Effort” by All – we were able • to meet our goals for the Engineering Run • having tested ALL Detector Parts • implemented all Trigger Chains & checked Rates • full set of Calibration & “Physics” Data taken In Total 9974 Runs taken amounting to ~ 29.5 TB of Data Analysis is in progress !!! RunData Data transferred TB Chronology MEG Review February 2008

More Related