Digital Electronic Tests at JYFL

• Introduction• Synchronisation Tests / TDR Integration• Phase I Detector Tests• Clover Tests

Pete Jones, University of JyväskyläSAGE / LISA Kick-Off Meeting

Daresbury Laboratory, 2nd September 2005

TNT2

TNT2

Synchronisation

• TNT uses 100MHz clock, but currently cannot be used as a ”slave”– Use sync pulses from TDR metronome– Use pseudo-random pulse generator into both TDR

and TNT– Merge / Time differences offline

Syncronisation Results• Pseudo-random generator shows 0.6x10-6 cannot be corellated

• TNT ”dead-time” ~1.8% (10kHz input) : < 4us pulses

• Dead time possible in both systems

In Beam Tests

• Idea : Test both analogue and digital electronics in real situation

• Test effects of counting rates

• Performance more realistic than with sources (multiplicity)

• Idea of what kind of gamma-ray array need would be for the future

• 107,109Ag(36Ar,2p2n)139Eu

• 160MeV β~2.5%• Ib=5 – 50 pnA• Ge count rate 10-100kHz• RITU Gas counter 1-10kHz

Test Reaction

Phase 1 Tests

Ge 1

Ge 2

BGO 1

BGO 2

SYNC/RESYNC

Threshold of Digital vs Analogue

Lower threshold Higher Background(veto)

..but...

Analogue : Effect of Rate(pileup)

10kHz

100kHz

50kHz

Phase 1 : Analogue

Phase 1 : Analogue

Phase 1 : Digital

Phase 1 : Digital

Phase 1 Tests : Summary

• Analogue limited by pileup & resolution

• Digital offers lower energy thresholds

• Veto handling in digital needs some work, as does marking of data

• Digital solution improves counting rate up to 40-50kHz

Clover Tests

Angle 1 : 69.2o EUROGAM II = 75.5o

Angle 2 : 117.5o EUROGAM II = 104.5o

Target – detector distance same as in EUROGAM IIDetector Resolution ~2.5 keV

Clover

Ge44

Clover

Ge44

Angle 1 : 69.2o

Clover

Ge23

Clover

Ge23

Angle 2 : 117.5o

n=2

n=1

Unsuppress

”clean”

Suppression, Sum & Fold

E1+3

E3

E1

”clean”

Diagonal Crystals 4 13 2

sum

Clover

Ph 1

g713

g554

g323

γ-γ coincidence matrix

50kHz

20kHz

10kHz

70kHz

40kHz

Digital Data…

Summary

• Instrument Digital Electonics into TDR : Need some ”TDR” compatability

• Digital electronics : – seems work well with phase 1, and improves counting capability– Offer lower thresholds– Need some work on veto / data

• Clover detector gives as good performance as phase 1– More efficient– Digital problems need to be solved