First complete test measurements of the AGATA Core _ Pulser Assembly . • AGATA Core Pulser, Segments Bulk Capacitances (First measurements of the Pulser Core / Segment Ratio) • Real transfer function measurements of the AGATA Pulser_Core and Segments preamplifiers • Core recovery from saturation ( with SHD_C ON / OFF ) • Pulser dynamic range and intrinsic pulser energy resolution for core & segments • Conclusion, hints to improve the characteristic. • G. Pascovici on behalf of preamplifier & detector teams Cologne, March 16, 2006
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First complete test measurements of the AGATA Core _ Pulser Assembly
First complete test measurements of the AGATA Core _ Pulser Assembly. AGATA Core Pulser, Segments Bulk Capacitances (First measurements of the Pulser Core / Segment Ratio) Real transfer function measurements of the AGATA - PowerPoint PPT Presentation
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First complete test measurements of the AGATA Core _ Pulser Assembly
.
• AGATA Core Pulser, Segments Bulk Capacitances (First measurements of the Pulser Core / Segment Ratio) • Real transfer function measurements of the AGATA Pulser_Core and Segments preamplifiers
• Core recovery from saturation ( with SHD_C ON / OFF )
• Pulser dynamic range and intrinsic pulser energy resolution for core & segments
• Conclusion, hints to improve the characteristic.
• G. Pascovici on behalf of preamplifier & detector teams
Cologne, March 16, 2006
CSPs for the first AGATA_Detector Core Tests
Specs IKP-Cologne(a) (FET_BF862)
IKP-Cologne(b) (FET_IF1320)
IKP-Cologne(Miniball - FET_IF1320)
Sensitivity( mV / MeV)
~ 100 mV/MeV
( differential )
~ 100 mV/MeV
( differential )
~ 175 mV/MeV
( single ended )
Resolution(Cd= 0pF; cold FET) ~ 600 eV ~ 600 eV ~ 600 eV
Slope( + eV/ pF) [Cd]
< 10 eV / pF
(cold FET)< 10 eV / pF (cold FET)
< 10 eV / pF (cold FET)
Rise time *)(Cd= 0pF); *[Amplit.]
< 12 ns ( warm FET)
~ 15 ns
( cold FET)
~ 15 ns
( cold FET)
Slope( + ns/ pF) [Cd]
~ 0.25 ns
( ~ 23 ns / 45 pF )
~ 0.25 ns( ~ 26.5 ns / 45 pF )
~ 0.3 ns( ~ 25 ns / 33 pF )
U(out) @ [100 Ohm] / Power [mW]
~ 2.0V*/ ~290 mW(LM-6171; *AD-8057)
~ 2.0V*/~ 290 mW(AD-8057; LMV-6723)
~ 4.5V*/~ 450 mW ( + /- 12V) (LM-6172)
Saturation of
the 1st stage @
equiv. ~ 90 MeV (@ ~20 mW_ jFET)
equiv. ~100 MeV (@ ~60mW_ jFET)
equiv. ~100 MeV(@ ~60mW_ jFET)
Open Loop Gain > 80,000 ~ 20,000 ~ 20,000
One-wire test pulse for all segmentsOne-wire test pulse for all segments
From From anan idea available in literature idea available in literature
1 . 8
H V
P u l s e r s i g n a l
W a r m p a r tC o l d p a r t
C o r e p r e a m p l i f i e r + p u l s e r C o r e p r e a m p l i f i e r + p u l s e r
4 7
C o l d p a r t W a r m p a r t
S e g m e n t p r e a m p l i f i e r S e g m e n t p r e a m p l i f i e r
H P G e c r y s t a l ( 3 6 + 1 s e g m e n t s ) H P G e c r y s t a l ( 3 6 + 1 s e g m e n t s )
9 c m
A.Pullia, presented at AGATA week, GSI, Feb.2005
also: “Test of a new low-noise preamplifier with the MARS segmented detector and extraction of physical data from the noise measurements” presented at EDAQ meeting, Padova, Sept. 19-20, 2002
• we have to understand the equivalent “transfer function” of the pulser signals for core and segments !
core
segment
core
segment
•Both core and segments preamplifiers bench adjusted for fastest transfer function with no ringing for pulser signals with tr > 10 ns and/or for core_pulser tr > 65 ns
• Pulser Exponential Pulseform (decay time 100µs) (+) normal (-) supressed 20:1
Pulser(-)
X_Pb
Pulser(-)
122 keV
136 keV
1173 keVPulser
(+) 1332keV
Intrinsic Core resolution in AGATA Triple Cryostat (01)
• with NO Pulser 1.3 keV• with Pulser ON 1.5 keV
Structure of Core Resolutionin Coincidence with Segments Rings
1 2 3 4 5 6
Peak
Position (1332,...) keV
.285
keV
.166
keV
.353
keV
.535
keV
.543
keV
.495
keV
Resolution
FWHM
( keV )2.37 2.38 2.27 2.22 2.24 2.34
Nigel Warr, “AGATA core resolution with gate on segment
Cryostat Wirering_Cableling
• Segments: - two detectors self made “flat band” cable, one individual Cu(Be) wires - one GND_0 / detector, no twisted cable• Core: - twisted cable for D and FB signals at GND_0 (in the case of only one detector), - if all three detectors at common GND then large crosstalk (due to the superposition of Return_GND(i) signals) - Core return GND on the segments cold motherboard!• Pulser: - Pulser coaxial PTFE, 0.9 mm external diameter with individual GND_1• Warm Core_CSP: - common GND for Pulser & CSP > most probable has to be changed ?! - on board separation between A_GND and D_GND, but only one GND to the F_ADCs (as decided by Infrastructure Group, Feb. 2005) - differential outputs, with the same polarity as Segments, as well as the INH_C and SHD_C signals functionality identical to the INH_A(B) and SHD_A(B), respectively.
• Triple Cryostat Wirering: - has to be decided, as soon as possible !
Conclusions
• Test demonstrated that a pulser with a very good energy resolution (< 1keV @ segments , < 1.5keV @
core) with a rather good very long time stability and fast rise time (< 35 ns) can be obtained,
• Further developments of core_pulser assembly is mandatory (to reduce the core CSP noise with pulser ,
to optimize pulser rise time if “in situ” transfer function measurements are foreseen),
• Solution to improve the wirering in the triple cryostat have been presented by A.Pullia at the AGATA week, Strasbourg, Nov. 2005 (next two slides),
(milestones for the above mentioned tasks has to be decided)
A.Pullia, AGATA week, Nov. 2005
A.Pullia, AGATA week, Nov.2005
Position of cold preamps for nearest neighbours event