GRETINA - Argonne National Laboratory

GRETINA at ATLAS: status and plan I-Yang Lee Lawrence Berkeley National Laboratory ATLAS Users Workshop August 8 - 9, 2009 August 8, 2009 ATLAS Users 2009 1 GRETINA Collaboration Institutions : LBNL, ANL, MSU, ORNL, Wash. U. Cover of 4 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 August 8, 2009 ATLAS Users 2009 2 GRETINA Detector modules Three received

A-type 36 segments/crystal 4 crystal/ module 148 signal channels /module August 8, 2009 ATLAS Users 2009 Btype 3 System Assembly Started at the 88 Cyclotron Support structure in Cave 4C August 8, 2009 ATLAS Users 2009 4

Electronics All modules produced Digitizer module (LBNL) 14bit, 100 MHz Energy Leading edge time Constant fraction time Pulse shape August 8, 2009 Trigger Timing & Control module (ANL) Fast trigger (<300 nsec) Trigger conditions: Multiplicity Sum energy Hit pattern ATLAS Users 2009 5

Electronics installation August 8, 2009 ATLAS Users 2009 6 Computing Data from GRETINA Detectors Segment events 37 segments per detector Crystal Event Builder Crystal events Signal Decomposition Interaction points

Data from Auxiliary Detectors 1-28 crystals Global Event Builder Global Events 70 nodes 2 cpu / node 4 core / cpu August 8, 2009 Tracking Goal: Processing 20,000 Gamma rays /sec Analysis & Archiving

ATLAS Users 2009 7 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 August 8, 2009 ATLAS Users 2009 8 Important features Compactness- center of GRETINA is at the designed target position of FMA.

Efficiency comparable to current generation of 4 array Better position resolution 1-2 mm (rms) Higher counting rate 36 segments August 8, 2009 ATLAS Users 2009 9 Installation at FMA Center of GRETINA is at the designed target position of FMA August 8, 2009 ATLAS Users 2009 10 GRETINA efficiency Simulated single- efficiency 14%

at 0.4 MeV 10% at 1.0 MeV 0.20 Efficiency 0.15 0.10 Trigger 0.05 Peak 0.00 0.0 0.5 1.0

1.5 2.0 Energy (MeV) August 8, 2009 ATLAS Users 2009 11 Efficiency of tracking Efficiency including tracking (4)depends on position resolution and gamma-ray multiplicity M = 25, =10 August 8, 2009 E = 1.33 MeV, r = 1 mm

ATLAS Users 2009 12 GRETINA count rate segmet rate / crystal rate 0.10 0.2 MeV 0.4 0.662 1.332 0.08 0.06 0.04 0.02 0.00 0 1

2 3 4 5 6 7 layer Segment rate is < 10% of that of crystal rate Run segment at 10 kHz, 100 kHz crystal rate August 8, 2009

ATLAS Users 2009 13 GRETINA efficiency Simulated single- efficiency 10% at 1.0 MeV 5% at 4.0 MeVGRETINA Efficiency 0.20 0.15 0.10 Peak 0.05 Trigger

0.00 0 August 8, 2009 1 2 3 E (MeV) ATLAS Users 2009 4 5 14