Characterisation Status -...
Transcript of Characterisation Status -...
Characterisation Status
• 4 presentations
– Liverpool System, A Boston
– The GSI System, J Gerl
– The Orsay System, H Ha
– Effective size of the segmentation lines of an
AGATA detector, Dino Bazzacco
Pulse Shape Analysis
• 5 Presentations:
– Comparison of MGS & scan data, M Dimmock
– Comparison of JASS & scan data, M Schlarb
– A FEM based Ge detector modelling program , J.
Ljungvall
– Automated optimisation of detector simulations to fit
scan data, B. Bruyneel
– Recursive subtraction for event characterisation, F
Crespi
– Improvements in double hit resolution, M. Schlarb
Liverpool Scanning
• Between Feb – Nov 2006 singles and
coincidence scans completed for s002 & s003
detectors.
• Time frame:
– Test detector (3 weeks)
– Singles scan (1 week)
– Coincidence scan (2 months)
• http://ns.ph.liv.ac.uk/AGATA (MTsort)• http://www-csnsm.in2p3.fr/groupes/strucnuc/Agata/database.html
(Root)
FE
D C B
A
Prototype Detector Scanning
3 Symmetric prototypes produced (, , )
Precision scanning in the x-y plane
1GBq Cs-137 source (E = 662keV)
Cartesian grid in 1mm steps
1mm injection collimator, 120mm long
S002 and S003 prototypes have been scanned in this way
Incident photons
Tapered Side Scan
52s per position
Front Face Scan
1 minute per position
Incident
photons
Partial
crystal width
S002 SCANS:
S002 & S003 Coincidence measurements
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Characteristation and Scanning
Line 12
Line
11 Line
10
Line
16
Line
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Line
14
Line 1
Line 5
Line 13
A
B
C
D
E
F
Line 9
Line 6Line 2Line 3
Line 4
Line 7
Line 8
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Azimuth 3
Azimuth 4
Azimuth 1
Azimuth 2
0o
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• √r, grid adopted
• 1200 positions
Coincidence measurements cont …
• 16 radial scans + 4 azimuthal scans
Azimuthal detector sensitivity
A1
B1
C1
D1
E1
F1
r = 24mm
z = 7.3mm
= 171.9o
0o
PSA Algorithms
Are these PSA algorithms performing to the physically achievable limits?
Given that simulated pulse shapes have yet to be thoroughly validated against
real pulses...
Does the simulated pulse comparison approach significantly improve the
detector’s tracking capability ?
Can a comparable result be achieved by using a spatial calibration based on
pulse shape parameterisations of a scanned detector?
This would imply:
No need for basis dataset generation
Simplification of online event processing -> Increased processing speed
Azimuthal Position Information Image Charge
Asymmetry (ICA) clockwiseiseanticlockw
clockwiseiseanticlockw
AA
AAICA
Radial Position Information
Rise Time Asymmetry (RTA)
Lattice effect is reduced 3090
3090
TT
TTRTA
Depth Information
Vertical Image Charge
Asymmetry
belowabove
belowabove
AA
AAICA
Sectors C and D Sectors C and D
Back
view
Asymmetric scan proposal
• 241Am front face & side scan
– Detector alignment
– Location of segment boundaries
• 137Cs front face & side scan
• Coincidence scan (i) front & (ii) side
• Analysis programs ready (see Matt’s talk)
• System is ready for data collection
• Have to resolve bias shutdown issue.
AGATA Characterisation group Future Work
• Plan for 2007:– Coincidence scan of the first asymmetric detector
[Liverpool March – June 2007]. delayed
– Compare results between Liverpool, Orsay and GSI scanning systems. delayed
• Compare and correct the experimental/simulated signals with MGS (Matt), other codes (Joa/M Schlarb).
In progress