Presentation on theme: "Detector Characterisation Group"— Presentation transcript:
1 Detector Characterisation Group Boston and the Liverpool groupCCLRC Daresbury LaboratoryCharacterisation GroupPreliminary report on AGATA detector #1Full characterisation of prototype crystalDetailed source scansCoincidence measurementDetector Characterisation Group
3 AGATA data analysis summary A number of measurements have been made:Analogue energy resolution resultsA 370kBq 60Co source was placed near the detector.An Ortec 671 Spectroscopy amplifier was used with 6us of shaping to produce energy resolutions.The count rate was <1000cps.The core energy resolution was measured to be 2.6 keV.Efficiency measurementDigital electronicsEnergy resolutionScattering / AddbackSingles scanCoincidence scanDetector Characterisation Group
4 AGATA detector scanning Detector scansMRD26 connector blocksDetector Characterisation Group
5 AGATA detector measurements Detector Characterisation GroupPerformance tests of the AGATA prototype detector.Fitted with GANIL differential preamplifiersCWC differential to single ended converters (manufactured at TU Munich) used to provide single ended signal to electronics.GRT4 digital electronics cards
6 AGATA detector – segment labelling Back faceA5A1A2A3A4A5A6B4B3B2B1B6B5C3C2C1C6C5C4D2D1D6D5D4D3E1E6E5E4E3E2F6F5F4F3F2F1654321A4A2A1A B C D E FDetector Characterisation GroupFront faceThe above plot shows the labelling of the segments on the first AGATA prototype module.Note the confusing scheme (all segs offset by 1)!Errors on can labelling are indicated in red.Our cabling philosophy shown in green.
7 AGATA cabling scheme Back Front AGATA detector connected to CWC modules through 7 MRD cable cables.37 BNC > SMA cables connect to GRT4 modules.The cabling scheme groups segments in rings:1-6 ring 17-12 ring 2 etc.The core is channel 37.Detector Characterisation Group123465789101112131415161718192021222324252627282930313233343536FrontBack
8 AGATA energy resolution results Detector Characterisation GroupAnalogue energy resolution results from AGATASegments problems A1 / A4 / A5 / B5 / C4 / D2 / D5 / F1
9 Digital Pulse Shape Processing GRT 4 cards with 80Mhz sampling 14bit dynamic rangeThe cards now have MWD implemented, courtesy of Ian Lazarus and Martin Lauer.Digital CFD is implemented.Common card time stamping (48bit) is implemented.Detector Characterisation Group
10 AGATA MWD energy resolution results Detector Characterisation GroupResults from GRT4 MWD.13.5s peak separation 8.0 s Shaping time5.5 s trapezoid width 7.8 s Peak sample time53 s decay time constant
11 AGATA – Example poor performance 225Detector Characterisation GroupPoor performance with MWD
12 AGATA energy resolution results Detector Characterisation GroupBest energy resolution results from AGATASegment problems >2.8 keV A5 / C4 / F1
13 AGATA energy resolutions Summary of best values for energy resolution from AGATA detector.Detector Characterisation GroupRingsSectors
14 AGATA energy analogue vs digital Detector Characterisation GroupTypical results -> specifically for sector F.
15 GRT4 time stamping problems Detector Characterisation GroupThere are problems with the time stamp on two GRT cards.Plot shows time different between core and segment time stamp.
16 GRT4 Energy correlation Detector Characterisation GroupThere were issues with the GRT 4 MWD code. A peak separation of >13us gives uncorrelated data.The plots above show MWD vs baseline difference energies.
17 GRT4 energy performance The energy resolution performance for the GRT4 MWD algorithm was assessed with the AGATA detector.Typical response for the centre contact is illustrated.What is the cause of this tailing?Detector Characterisation Group
18 GRT4 energy performance Detector Characterisation GroupMWD baselineProduce a plot of the energy derived from MWD vs the FADC baseline value.Is this tailing DNL? The effect is count rate dependent.
19 GRT4 energy performance It would be good to add martin lauers obesrvations hereBRING HOME MARTINS THESISADD HEREDetector Characterisation Group
20 GRT4 energy performance Options:Gate on the “true peak”Attempt to correct for effect linear? Energy dependent? Count rate dependent?Detector Characterisation Group
25 AGATA detector scan AGATA singles scan Detector Characterisation GroupAGATA singles scanIntensity map for 662keV interaction on centre contact2mm collimator / 2 minutes per position0.3mCi 137Cs source300Gb of data on SDLT tape
26 AGATA singles scan181261571113172481014169315243036192325293135Detector Characterisation Group202226283234212733Detector response vs depth: 662 keV on coreAny energy on segments
27 AGATA singles scan181261571113172481014169315243036192325293135Detector Characterisation Group202226283234212733Detector response vs depth: 662 keV on core662keV energy on segments
28 Segment Multiplicity The number of segments firing in coincidence: Detector Characterisation GroupThe number of segments firing in coincidence:Defined as MWD energy above trigger.
29 Segment Multiplicity The number of segments firing in coincidence: Detector Characterisation GroupThe number of segments firing in coincidence:Defined as energy > 3sd of baseline noise.
45 AGATA singles scan – T30 vs depth Detector Characterisation Group
46 AGATA singles scan – T90 vs depth Detector Characterisation Group
47 Risetime Results : Summary What do we need?Look at outer contact risetimesAre the segment risetimes well aligned?What is the profile?Can we use these values along with the coreOuter contact image charge responseImage charge asymmetry vs position of scanning tableDetector Characterisation Group
48 Coincidence scanInsert picture of sector to be scanned and the lines, along with the radii.Insert slide with “what is available” and how largeInsert slide with geometry of scanning assemblyExact dimsCollimator spread resultsInsert typical statistics example vs radius depthInsert typical quality exampleShow some pictures.Detector Characterisation Group
49 Coincidence measurement Detector Characterisation GroupSector E has been scanned – singles intensity profile.
50 What data was recorded?Coincidence data was recorded on three lines and three radii.2mm steps.The data was recorded to SDLT tape.Detector Characterisation GroupPosition from scanning table and step numberHigh resolution energy from core and NaIs from Silena ADCsTAC of Ge core vs NaI firing.GRT 4 data from 37 channels (512 samples 80Mhz)
52 AGATA coincidence 80mm 118.55mm 100.02mm 83.14mm 66.26mm 53.38mm 44mm 9018118.55mm7218100.02mm541883.14mm361566.26mm21Detector Characterisation Group1353.38mm8844mm34mm363mm Dead layer including Al can
53 AGATA coincidenceCoincidence data has been recorded along 3 lines and 3 radii inside sector E of the detector.The data is in rings w.r.t. centre (x,x):Ring 1 : 28mm radius / 6 hours per positionRing 2 : 23mm radius / 8 hours per positionRing 3 : 18mm radius / 10 hour per positionIn linesLine 1 : 0O 26mm / 12 hours per positionLine 2 : 15O 26mm / 12 hours per positionLine 3 : 30O 26mm / 12 hours per positionThe z depths are:Detector Characterisation Group1st depth = mm2nd depth = – 17.26mm3rd depth = – 30.14mm4th depth = – 47.02mm5th depth = – 63.9mm6th depth = – 82.43mm
54 Coincidence setupUtilises a multi-leaf collimator to measure six depths simultaneously.2mm injection2mm ring collimatorsTypical count rates for outer radiiSingles Ge >60keV : 500 c/sCoincidence : 50 c/minTrue Coincidence : 25 c/hour288keV374662Detector Characterisation Group
55 Coincidence results Coincident response in segment E2 (11) and E4 (23) Detector Characterisation GroupCoincident response in segment E2 (11) and E4 (23)
56 Coincidence results Region of Interest Ge Energy NaI Energy 374 keV Matrix of Ge energy vs Total NaI derived from Silena ADCsThe region of interest for “true” coincidences is highlighted in red.The data was presorted to keep only the data in this region.This leaves ~ 400Mb of data per line.Detector Characterisation Group
58 Coincidence measurements Detector Characterisation Group28mm radius / 2mm steps over 80O (-10O +70O)Total distance moved 40mm / 6 hours per position
59 Coincidence measurements Detector Characterisation Group18mm radius / 2mm steps over 80O (-10O +70O)Total distance moved 26mm / 10 hours per position
60 Coincidence measurement Detector Characterisation GroupRadial scan : line 1 : 12 hours per position
61 Coincidence measurement Detector Characterisation GroupRadial scan : line 2 : 12 hours per position
62 AGATA summary The detector has been scanned. Data is available: Singles data 300GbCoincidence dataThe detector performance was reasonable. Improvements are possible.Detail will be discussed in the detector characterisation group meeting this afternoon.Detector Characterisation Group