TWiki> LHCb Web>OTrAgeing (revision 2)EditAttachPDF
-- BarbaraStoraci - 12 Mar 2009

Outer Tracker Scanning System in Situ

The performance of the detector modules is monitored at various stages of the commissioning and operation of the detector. Before and after irradiations reference measurements are performed with a scanning system of two 74 MBq 90Sr sources transported by a step motor.

Scanning System in Situ

Main Elements:

  • Scanning Frame


  • 2 90Sr sources of 74MBq, moved by a step motor


  • Current-meter and Safety Garage


Schematic of the scanning source:



The analysis is typically carried out comparing the current behavior after and before an irradiation step. The ratio plot produced by this comparison is normalised using the average value obtained inside a region where the source is not present. A zone around the source, “source region”, is selected to study in details the effect of the irradiation. Two quantities are proposed to estimate the ageing effects: the average of the two absolute minima in the source region and the “region factor” quatified summing the deviation from 1 of all the cells inside the source region and dividing by the number of cells considered. If there are no gain changes in the irradiated area these two quantities must be 1 and 0 respectively.

How To Run it

  • Connect to the plus node with "ot_oper" user

  • Run the script: [-t -n -f -m -s] #module
    • -t list of irradiation hours (useful only if you enable "trend_plot" function in the option file)
    • -n installation setup ('cern' for first monolayer, 'cern2' for second monolayer)
    • -m detector part scanned ('L_half' for the lower part of the monolayer, 'U_half' for the upper part of the monolayer, 'all' for the entire detector)
    • -f force to set new input file for the analysis
    • -s run single scan analysis

  • Output save in: /scratch/everyone/ot_oper/SrScan/# module/output/plots
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg current_meter.JPG r1 manage 51.3 K 2009-03-12 - 14:18 BarbaraStoraci Current-meter
JPEGjpg scanning_system.JPG r1 manage 152.3 K 2009-03-12 - 14:21 BarbaraStoraci Scanning System in Situ
JPEGjpg schematic.jpg r1 manage 15.9 K 2009-03-12 - 16:11 BarbaraStoraci Schematic of the source system
JPEGjpg sources.JPG r1 manage 39.4 K 2009-03-12 - 16:08 BarbaraStoraci Scanning Sources
Edit | Attach | Watch | Print version | History: r6 | r4 < r3 < r2 < r1 | Backlinks | Raw View | Raw edit | More topic actions...
Topic revision: r2 - 2009-03-12 - BarbaraStoraci
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    LHCb All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback