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

13

Characteristation and Scanning

Line 12

Line

11 Line

10

Line

16

Line

15

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

Line

17

Azimuth 3

Azimuth 4

Azimuth 1

Azimuth 2

0o

Line

18

• √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