Matthew Dimmock (mrd@ns.ph.liv.ac.uk)

Matthew Dimmock (mrd@ns.ph.liv.ac.uk)Matthew Dimmock (mrd@ns.ph.liv.ac.uk)

AGATAS002 and S003

Coincidence Scans

Overview

• Issues with MGS

• Experimental versus MGS

• S002 versus S003

• Ongoing work

• AGATA symmetric geometry

2mm Isolant No Isolant

• Passivation reduces surface currents

Some issues with MGS

Some issues with MGS• Potential mapping

2mm Isolant No Isolant

• Back region where all charges are collected

due to deformed potential surface

Some issues with MGS

• Electron drift velocity

2mm Isolant No Isolant

• Regions of unsaturated velocity

Some issues with MGS

• Electron drift – not a problem with

calculations but consequence of model

2mm Isolant No Isolant

r = 20mm = 290o

z = 85mm

r = 20mm = 290o

z = 65mm

Some issues with MGS

• “Charge sharing”

Experimental centre contact pulses

Test experimental alignment

Experimental segment 15 (C3) & 33 (F3) pulses

x

y

B3

A3

F3

E3

C1

D3

• Line 1

• T1 aligned

• Good agreement

MGS and experimental centre contact pulses

Experimental versus MGS

MGS and experimental segment 15 (C3) & 33 (F3) pulses

x

y

B3

A3

F3

E3

C1

D3

• Line 1 – real charge

pulses

Experimental versus MGSx

y

B3

A3

F3

E3

C1

D3

• Line 1 – Upper / Lower

ICs

Experimental and MGS segment C4 and F4 image charges

Experimental and MGS segment C2 and F2 image charges

Experimental versus MGSx

y

B3

A3

F3

E3

C1

D3

19mm Experimental and MGS segment F4 image charges

19mm Experimental and MGS segment F2 image charges

Exp, z = 34mm

MGS, z = 34mm

MGS, z = 34mm

Exp, z = 34mm

• Vary MGS to fit experimental

data

MGS and Experimental core pulses

Experimental versus MGSx

y

B3

A3

F3

E3

C1

D3

• Line 2, 7.5o clockwise

B/C

• T1 aligned

• Good agreementMGS and Experimental segment F3 (33) pulses

Experimental versus MGSx

y

B3

A3

F3

E3

C1

D3

Segment E3 (Left) Image Charge Pulse

Segment A3 (Right) Image Charge Pulses

• Line 1 – Upper / Lower

ICs

Experimental versus MGS

• Sum of squares difference for experimental

and MGS data

Experimental versus MGS

• Is sum of squares difference a result of poor

time alignment

S002 Versus S003• Quantify detector twist

Conclusions

• MGS R5.02 is has been used to generate

latest data

• Two MGS data sets will be generated. The

S003 set will factor in twist.

• Basis sets have been partially generated to

produce 3D chi squared difference to see

where MGS fails

• Bart and Benedikt code will be used to find

best parameters.