Revision as of 16:28, 13 June 2010

General GEM Information

NIM Papers
- GEM: A new concept for electron amplification in gas detectors, F. Sauli
- Performance of triple GEM tracking detectors in the COMPASS experiment, Ketzer et al.
PDG Accelerator Detector Review (See Section 28.6.3)
Super BigBite CDR

Presentations

http://www.jlab.org/~cisbani/SBS_Tracker.pdf

GEM Detectors for PREX

Configuration

The GEMs were mounted in an XY XY XY XY configuation on April 14. Our best guess at positions (from Dustin) in the rotated coordinate system are:

Detector	Orientation	z (m)
Bottom UVA	XY	1.15
Top UVA	XY	1.15
Bottom INFN	XY	1.4
Top INFN	XY	1.4

Chambers are placed orthogonal to the z axis.

HV Adjustment

Individual chamber HV is controlled through a CAEN N1471 NIM module. It can be remotely controled through minicom on ahut. The channel mapping is

http://www.jlab.org/~adaq/halog/html/1004_archive/100414225720.html

Channel	Cable	Detector
0	7	Top UVA
1	8	Bottom UVA
2	FPP7	Top INFN
3	FPP6	Bottom INFN

Gas configuration

The gas is presently a 80-20 Argon/CO2 mix (or 70/30?).

Replaying Data and Software

Replaying data can be done on any of the adaq machines. Simply do

goprex
analyzer prex_gem_L.C

and enter in the run number and number of events you would like to analyze. The database for the GEMs is in the $DB_DIR directory. This replay uses the TreeSearch-GEM library for GEM decoding, clustering, and tracking maintained by Ole Hansen.

Replayed files go in the rootfiles directory and are named

prex_gem_L_xxxxx.root

GEM class variables

Tree :T : Hall A Analyzer Output DST *
Entries : 50874 : Total = 2404513729 bytes File Size = 204721823 *
: : Tree compression factor = 11.77 *
Br 0 :T.gem.x1.hit.adc : data[Ndata.T.gem.x1.hit.adc]/D *
Entries : 50874 : Total Size= 417941 bytes File Size = 247905 *
Baskets : 20 : Basket Size= 32000 bytes Compression= 1.68 *
............................................................................*
Br 1 :T.gem.x1.hit.pos : data[Ndata.T.gem.x1.hit.pos]/D *
Entries : 50874 : Total Size= 417941 bytes File Size = 173593 *
Baskets : 20 : Basket Size= 32000 bytes Compression= 2.40 *
............................................................................*
Br 2 :T.gem.x1.hit.size : data[Ndata.T.gem.x1.hit.size]/D *
Entries : 50874 : Total Size= 417966 bytes File Size = 64792 *
Baskets : 20 : Basket Size= 32000 bytes Compression= 6.44 *
............................................................................*
Br 3 :T.gem.x1.hit.type : data[Ndata.T.gem.x1.hit.type]/D *
Entries : 50874 : Total Size= 417966 bytes File Size = 41224 *
Baskets : 20 : Basket Size= 32000 bytes Compression= 10.12 *
............................................................................*
Br 4 :T.gem.x1.strip.adc : data[Ndata.T.gem.x1.strip.adc]/D *
Entries : 50874 : Total Size= 98231855 bytes File Size = 17749252 *
Baskets : 3180 : Basket Size= 32000 bytes Compression= 5.53 *
............................................................................*
Br 5 :T.gem.x1.strip.adc_p : data[Ndata.T.gem.x1.strip.adc_p]/D *
Entries : 50874 : Total Size= 98238225 bytes File Size = 69205992 *
Baskets : 3180 : Basket Size= 32000 bytes Compression= 1.42 *
............................................................................*
Br 6 :T.gem.x1.nhits : T.gem.x1.nhits/D *
Entries : 50874 : Total Size= 417522 bytes File Size = 43319 *
Baskets : 104 : Basket Size= 4000 bytes Compression= 9.58 *
............................................................................*
Br 7 :T.gem.x1.noise : T.gem.x1.noise/D *
Entries : 50874 : Total Size= 417522 bytes File Size = 341742 *
Baskets : 104 : Basket Size= 4000 bytes Compression= 1.21 *
............................................................................*
Br 8 :T.gem.x1.nstrips : T.gem.x1.nstrips/D *
Entries : 50874 : Total Size= 417838 bytes File Size = 49291 *
Baskets : 105 : Basket Size= 4000 bytes Compression= 8.43 *
............................................................................*

To plot amplitude for each strip :

T->Draw("T.gem.x1.strip.adc:Iteration$");

To look at amplitude ( total energy deposition )

T->Draw("T.gem.x1.hit.adc","T.gem.x1.hit.size>1");

Run List

PREX GEM Runs

Work to Do/Main issues

HV Scan
- GEM HV Scan Runplan

Pedestal analysis (Francesco Cusanno)
- Stability
- Event-by-event corrections algorithm
- Higher order event-by-event corrections
- HV/Rate dependence
- Pedestal value/widths to find bad channels

Cluster Analysis
- Multiple cluster propagation across planes
- Clusters energy association between planes, noise evaluation

Position Resolution (Ozgur Ates)
- Evaluate plane resolution
- Different ways to utilize energy information to maximize resolution(?)

Efficiency/Gain Analysis (Kiad)
- Evaluate hit efficiency vs. ADC cuts
- Efficiency, gain vs. strip
- Efficiency, gain vs. HV
- Gain differences in readout planes

Tracking (Ole + Kiad)
- Quantify X-Y hit association techniques

Bad Channels Handling (Ole)
- List to ignore in software
- How they affect clustering/energy weighting

Commissioning Meeting Summary

Analysis status, April 19, 2010

Listed projects that need to be finished for GEM tracking and divided among students/postdocs/staff.

Seamus' HALOG post on status:

http://www.jlab.org/~adaq/halog/html/1004_archive/100416175501.html

Analysis status, April 26, 2010

GEM Meeting, April 26, 2010

Source runs, April 27, 2010

http://www.jlab.org/~adaq/halog/html/1004_archive/100427134612.html

Beam data, May 5th, 2010

Run 27605 to 27610

http://www.jlab.org/~adaq/halog/html/1005_archive/100507142643.html

UVA bottom 3600 V UVA top 3750 V

Meeting , May 17th, 2010

Megan's plots

Beam data , May 19th, 2010

HV

http://www.jlab.org/~adaq/halog/html/1005_archive/100519220407.html

UVA Bottom 3550 V UVA Top 3600 V

INFN Bottom 4000 V UVA Top 3600 V

http://www.jlab.org/~adaq/halog/html/1005_archive/100519221308.html

27692 pedestal

27696 Spot++ with T5 on lead 2

27697 Qsq lead 2

27698 Qsq lead 2

27699 Qsq lead 2

27700 Qsq lead 2

27701 Qsq lead 3

VDC Projection

http://www.jlab.org/~adaq/halog/html/1005_archive/100520164442.html

Beam data , June 11th, 2010

Run from 27792 to 27844 have the GEM in the datastream and with HV on

UVA Bottom 3650 V UVA Top 3700 V

INFN Bottom 4100 V UVA Top 3600 V

Pedestal run 27792

Pedestal check run 27793

Run # Target Ch0 (V) Ch1 (V) Ch2 (V) Ch3 (V) Current (uA) P0 (GeV) Comment

27792 No Target 3700 3650 3600 4100 0.03 1.063 Pedestal

27793 No Target 3700 3650 3600 4100 0.03 1.063 Pedestal Check

27795 Thin C12 3700 3650 3600 4100 0.03 1.063 Qsq

27796 Thin C12 3700 3650 3600 4100 0.03 1.063 Qsq

27797 Thick C12 3700 3650 3600 4100 0.03 1.063 Qsq

27798 Thin Pb 3700 3650 3600 4050 0.03 1.063 Qsq

27800 Thin Pb 3750 3650 3600 4050 0.03 1.063 Qsq

27801 Thin Pb 3800 3700 3600 3650 0.03 1.063 Qsq

27804 Thin C12 3800 3700 3600 3650 0.005 1.063 Qsq

27805 Thick C12 3800 3700 3600 3650 0.005 1.063 Qsq

27825 Thin Pb 3800 3700 3600 3650 0.005 1.063 Qsq

27826 Thin Pb 3800 3700 3600 3650 0.005 1.063 Qsq

27827 Thin Pb 3800 3700 3600 3650 0.05 1.063 Qsq

27828 Thin Pb 3800 3700 3600 3650 0.05 1.063 Qsq

27829 Thin Pb 3800 3700 3600 3650 0.05 1.063 Qsq

27830 Thin Pb 3800 3700 3600 3650 0.05 1.063 Qsq (0x00)

27831 Thin Pb 3800 3700 3600 3650 0.05 1.063 Qsq(0x8)

27832 Thin Pb 3800 3700 3600 3650 0.05 1.073 Qsq(0x10)

27833 Thin Pb 3800 3700 3600 3650 0.05 1.083 Qsq(0x18)

27834 Thin Pb 3800 3700 3600 3650 0.05 1.083 Qsq(0x1c)

27835 Thin Pb 3800 3700 3600 3650 0.05 1.083 Qsq

27836 Thin Pb 3800 3700 3600 3650 0.05 1.073 Qsq

27837 Thin Pb 3800 3700 3600 3650 0.05 1.084 Qsq

27838 Thin Pb 3800 3700 3600 3650 0.05 1.1 Qsq

27839 Thin Pb 3800 3700 3600 3650 0.05 1.13 Qsq

27840 Thin Pb 3800 3700 3600 3650 0.05 1.13 Qsq

27841 Thin Pb 3800 3700 3600 3650 0.05 1.168 Qsq

27842 Thin Pb 3800 3700 3600 3650 0.05 1.122 Qsq

27843 Thin Pb 3800 3700 3600 3650 0.05 1.121 Qsq

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