PbWO 4 crystals Calorimeter Liping Gan University of North Carolina Wilmington

Updated PWO Specification The following is specification for CMS crystals: 1. Longitudinal transmission (absolute values): >23 % at 360nm and >55 % at 420nm and >65 % at 620nm 2. Light yield: LY >8 pe / MeV at 18° 3. Decay time: LY(100ns)/LY(1000s) > 90%. 4. Radiation hardness: u<1.5 m-1 at 420 nm after lateral 60Co irradiation with a dose rate of 150 Gy/h 3/18/2016

Comparison of heavy crystals from A.E. Borisevish, Nucl. Exp. Tech., 49, 199 (2006)  For N a I, light yield is about 46 photons /KeV

3/18/2016 Light Yield Temperature Dependence Nucl. Inst. Meth., A365, 291 (1995) d(LY)/dT is about -1.9 %/C o

3/18/2016 Radiation Hardness Protvino beam test result, Nucl.Instrum.Meth.A512: ,2003

Electron Beam Irradiation  Dose rate: rad/hour 27-GeV electron beam  Average saturated light loss of ~8% after 1-2 Krad  Recovery study shows that 85% damage can be recovered in 2 months after irradiation 3/18/2016

 rad/hour 40-GeV pion irradiation, average ~12% light loss after ~1-2 krad total dose  rad/hour 40-GeV pion irradiation, average ~20% light loss after ~2 krad total dose  500 rad/hour by charge hadrons, γ-quanta and neutrons, ~20% light loss after ~2 krad total dose  Energy resolution is not noticeably degraded by the radiation damage Pion Beam Irradiation 3/18/2016

 100 krad/hour 40-GeV pion irradiation, about a factor of 3 light loss after ~2.5 Mrad total dose  Degradation of energy resolution is 20-50% after ~2.5 Mrad dose Radiation Hardness continue ----Super-intensive beam

3/18/2016 PrimEx PbWO 4 from SIC Specified Size: 20.5x20.5x180 mm 3 Tolerances: in trans in long. Collaboration managed to triple the number of crystals from 450 to 1250 through collaboration with Chinese Institutions

3/18/2016 PbWO 4 Development: Optical Properties Optical transparency

3/18/2016 Rate dependence

Result from PrimEx-I 3/18/2016

The energy resolution as function of X coordinate PWO 3/18/2016

PWO Energy Resolution

Energy Resolution in Transition Region 3/18/2016

Coordinate resolution VS. X on Crystal. PWO 3/18/2016

Reconstructed Event Occupancy 3/18/2016 Before correction After correction

PWO Position Resolution 3/18/2016

Position Resolution in Transition Region 3/18/2016

I sland algorithm for the PWO calorimeter by I. Larin Island algorithm: 1. Find maximum energy deposition cell 2.Declare all simply connected area around as initial “raw” cluster 3.Try to split “raw” cluster into many hits based on the shower profile function 3/18/2016

PWO Transverse Shower Profile  Experimental electron scan data (E e ~4 GeV)  extracted shower profile function 3/18/2016

Probability of two-cluster separation vs. distance between hits  Study done by using PrimEx-II snake scan data  First cluster: “permanent” with energy 5 GeV  Second cluster: “moving” with energy 1-5 GeV PWOPb glass Reconstruction efficiency (100%) Separation distance (cm) 3/18/2016

Current Production and price in SIC Production line in SIC is still alive. They can provide 4000 modules in one year Price will be ~$5.0 per cm 3.

3/18/2016 Summary FCAL-II will be a state-of-art calorimeter for Hall D Physics projects. Excellent energy and position resolution Compact shower size Fast signal Excellent radiation hardness 4000 modules can be delivered by SIC within 1 year Price is ~$5.0 per cc