Detector Characterisation Group A Boston and the Liverpool

Detector Characterisation Group A. Boston and the Liverpool group B. CCLRC Daresbury Laboratory C. Characterisation Group Preliminary report on AGATA detector #1 Detector Characterisation Group • Full characterisation of prototype crystal – Detailed source scans – Coincidence measurement

AGATA prototype triple cluster Detector Characterisation Group 90 × 80 mm 10º tapering angle • Prototype symmetric triple cluster • Ordered from CE • Segmentation scheme 8, 13, 15, 18, 18 mm

AGATA data analysis summary • A number of measurements have been made: • Analogue energy resolution results Detector Characterisation Group – A 370 k. Bq 60 Co source was placed near the detector. – An Ortec 671 Spectroscopy amplifier was used with 6 us of shaping to produce energy resolutions. – The count rate was <1000 cps. – The core energy resolution was measured to be 2. 6 ke. V. • Efficiency measurement • Digital electronics – Energy resolution – Scattering / Addback • Singles scan • Coincidence scan

AGATA detector scanning Detector Characterisation Group • Detector scans • MRD 26 connector blocks

Detector Characterisation Group AGATA detector measurements • Performance tests of the AGATA prototype detector. • Fitted with GANIL differential preamplifiers • CWC differential to single ended converters (manufactured at TU Munich) used to provide single ended signal to electronics. • GRT 4 digital electronics cards

AGATA cabling scheme • AGATA detector connected to CWC modules through 7 MRD cables. • 37 BNC > SMA cables connect to GRT 4 modules. • The cabling scheme groups segments in rings: – 1 -6 ring 1 – 7 -12 ring 2 etc. Detector Characterisation Group • The core is channel 37. Back Front 7 12 1 6 2 5 3 4 8 11 9 10 13 18 14 17 15 16 19 20 24 23 21 22 25 30 26 29 27 28 31 36 32 35 33 34

Digital Pulse Shape Processing Detector Characterisation Group • GRT 4 cards with 80 Mhz sampling 14 bit dynamic range • The cards now have MWD implemented, courtesy of Ian Lazarus and Martin Lauer. • Digital CFD is implemented. • Common card time stamping (48 bit) is implemented.

Detector Characterisation Group AGATA energy resolution results • Best energy resolution results from AGATA • Segment problems >2. 8 ke. V A 5 / C 4 / F 1

AGATA energy resolutions Detector Characterisation Group • Summary of best values for energy resolution from AGATA detector. Rings Sectors

Detector Characterisation Group AGATA energy analogue vs digital • Typical results -> specifically for sector F.

Automated Scanning Tables Liverpool System Detector Characterisation Group • • • Parker linear positioning table Pacific scientific stepper motors 0. 3 m. Ci 137 Cs/0. 2 m. Ci 57 Co 1 -2 mm collimator Singles/coincidence system Precise position calibration GSI / CSNSM Orsay

Example traces Detector Characterisation Group • Typical example of from detector for the singles scan measurement

20 Arbitrary Units Detector Characterisation Group AGATA Detector Pulse shapes 21 22 26 27 28 32 33 34

Detector Characterisation Group AGATA detector scan • • • AGATA singles scan Intensity map for 662 ke. V interaction on centre contact 2 mm collimator / 2 minutes per position 0. 3 m. Ci 137 Cs source 300 Gb of data on SDLT tape

AGATA singles scan 1 2 6 3 5 4 7 8 Detector Characterisation Group 24 12 9 18 11 13 17 10 14 16 30 15 36 19 23 25 29 31 35 20 22 26 28 32 34 21 27 • Detector response vs depth: 662 ke. V on core • Any energy on segments 33

AGATA singles scan 1 2 6 3 5 4 7 8 Detector Characterisation Group 24 12 9 18 11 13 17 10 14 16 30 15 36 19 23 25 29 31 35 20 22 26 28 32 34 21 27 • Detector response vs depth: 662 ke. V on core • 662 ke. V energy on segments 33

Scattering / Cross talk results 2 (B 1) – 27 (C 5) 34085 counts (695 bkgrd) Detector Characterisation Group 7 (A 2) – 25 (A 5) 132227 counts (1124 bkgrd) 3 (C 1) – 21 (C 4) 164556 counts (1235 bkgrd) • Multiplicity two scatter plot for AGATA segments (singles scan)

Detector Characterisation Group AGATA singles scan : Core risetime results T 30 T 90 T 60 Centre contact risetime results

Detector Characterisation Group AGATA singles scan – T 30 vs depth

Detector Characterisation Group AGATA singles scan – T 90 vs depth

Detector Characterisation Group Coincidence measurement • Sector E has been scanned – singles intensity profile.

What data was recorded? Detector Characterisation Group • Coincidence data was recorded on three lines and three radii. • 2 mm steps. • The data was recorded to SDLT tape. • • Position from scanning table and step number High resolution energy from core and Na. Is from Silena ADCs TAC of Ge core vs Na. I firing. GRT 4 data from 37 channels (512 samples 80 Mhz)

AGATA coincidence 80 mm 90 118. 55 mm 18 72 18 54 18 36 Detector Characterisation Group 15 21 13 8 8 36 100. 02 mm 83. 14 mm 66. 26 mm 53. 38 mm 44 mm 34 mm 0 3 mm Dead layer including Al can

AGATA coincidence • Coincidence 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 : 28 mm radius / 6 hours per position – Ring 2 : 23 mm radius / 8 hours per position – Ring 3 : 18 mm radius / 10 hour per position Detector Characterisation Group • In lines – Line 1 : 0 O 26 mm / 12 hours per position – Line 2 : 15 O 26 mm / 12 hours per position – Line 3 : 30 O 26 mm / 12 hours per position • The z depths are: Ø 1 st depth = 5 - 7. 88 mm Ø 2 nd depth = 14. 38 – 17. 26 mm Ø 3 rd depth = 27. 26 – 30. 14 mm Ø 4 th depth = 44. 14 – 47. 02 mm Ø 5 th depth = 61. 02 – 63. 9 mm Ø 6 th depth = 79. 55 – 82. 43 mm

Coincidence setup Detector Characterisation Group 374 ke. V 288 ke. V 662 ke. V • Utilises a multi-leaf collimator to measure six depths simultaneously. • 2 mm injection • 2 mm ring collimators • Typical count rates for outer radii – Singles Ge >60 ke. V : 500 c/s – Coincidence : 50 c/min – True Coincidence : 25 c/hour

Detector Characterisation Group Coincidence results • Coincident response in segment E 2 (11) and E 4 (23)

288 ke. V Detector Characterisation Group Na. I Energy Coincidence results Region of Interest 374 ke. V • Matrix of Ge energy vs Total Na. I derived from Silena ADCs • The region of interest for “true” coincidences is highlighted in red. • The data was presorted to keep only the data in this region. Ge Energy – This leaves ~ 400 Mb of data per line.

Detector Characterisation Group Coincidence measurements • 18 mm radius / 2 mm steps over 80 O (-10 O +70 O) • Total distance moved 26 mm / 10 hours per position

Detector Characterisation Group Coincidence measurement • Radial scan : line 1 : 12 hours per position

AGATA summary • The detector has been scanned. • Data is available: Detector Characterisation Group – Singles data 300 Gb – Coincidence data • The detector performance was reasonable. Improvements are possible. • Detail will be discussed in the detector characterisation group meeting this afternoon.