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GRETINA at ATLAS: status and plan. I-Yang Lee Lawrence Berkeley National Laboratory ATLAS Users Workshop August 8 - 9, 2009. GRETINA. Collaboration Institutions : LBNL, ANL, MSU, ORNL, Wash. U. Cover ¼ of 4 p solid angle Seven 4-crystal detector modules All the required software.
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GRETINA at ATLAS:status and plan I-Yang Lee Lawrence Berkeley National Laboratory ATLAS Users Workshop August 8 - 9, 2009
GRETINA Collaboration Institutions : LBNL, ANL, MSU,ORNL, Wash. U. Cover ¼ of 4p solid angle Seven 4-crystal detector modules All the required software • Start Construction June 2005 • Start of Operation February 2011 • Engineering and commissioning runs at LBNL 2011 • Operation at: 2012 -2013 • NSCL MSU • HRIBF ORNL • ATLAS ANL
GRETINA Detector modules Three received A-type 36 segments/crystal 4 crystal/ module 148 signal channels /module B-type
Started at the 88” Cyclotron System Assembly Support structure in Cave 4C
Electronics All modules produced Digitizer module (LBNL) 14bit, 100 MHz Energy Leading edge time Constant fraction time Pulse shape Trigger Timing & Control module (ANL) Fast trigger (<300 nsec) Trigger conditions: Multiplicity Sum energy Hit pattern
Computing Data from GRETINA Detectors 37 segments per detector Segment events Crystal Event Builder Crystal events Signal Decomposition Interaction points 1-28 crystals Data from Auxiliary Detectors Global Event Builder Global Events 70 nodes 2 cpu / node 4 core / cpu Tracking Goal: Processing 20,000 Gamma rays /sec Analysis & Archiving
Pencil beam results Using the latest decomposition program and basis, we have achieved <2 mm (RMS) resolution in PIII: Pencil beam of 662 keV, 1 mm diameter Position resolution : x = 1.5 mm; y = 1.7 mm
Compactness- center of GRETINA is at the designed target position of FMA. Efficiency – comparable to current generation of 4p array Better position resolution – 1-2 mm (rms) Higher counting rate – 36 segments Important features
Installation at FMA • Center of GRETINA is at the designed target position of FMA
GRETINA efficiency • Simulated single-g efficiency 14% at 0.4 MeV 10% at 1.0 MeV
Efficiency of tracking Efficiency including tracking (4p)depends on position resolution and gamma-ray multiplicity Mg = 25, a =10 Eg = 1.33 MeV, Dr = 1 mm
GRETINA count rate • Segment rate is < 10% of that of crystal rate • Run segment at 10 kHz, 100 kHz crystal rate
GRETINA efficiency • Simulated single-g efficiency 10% at 1.0 MeV 5% at 4.0 MeV