Conceptual design and RD Progress of STCF ECAL

Conceptual design and R&D Progress of STCF ECAL Yunlong Zhang State Key Laboratory of Particle Detection and Electronics, China University of Science and Technology of China On behalf of calorimeter working group

Outline Ø Motivation Ø STCF ECAL Ø Sensitive material Options Ø ECAL Optimization Ø Some Results Ø Photon-sensors and crystals Ø Electronics Ø Summary Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 2

Outline Ø Motivation Ø STCF ECAL Ø Sensitive material Options Ø ECAL Optimization Ø Some Results Ø Photon-sensors and crystals Ø Electronics Ø Summary Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 3

Motivation 1. 1 关键分系统研制 Ø Super T-C Facility (STCF) Ø Ecm 2 - 7 Ge. V, luminosity ~1 1035 cm-2 s-1 at 4 Ge. V Ø ~600 m double ring Detector Snakes Crab Sextupole Wigglers Injector e. V 5 G e+0. Linac 0. 5 -3. 5 Ge. V e- 0. 5 Ge Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 V 2020/9/10 4

STCF Detector • BESIII-like detector with additional considerations. • Challengers: – Higher luminosity – Same or better performance than BESIII Detector Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 5

Outline Ø Motivation Ø STCF ECAL Ø Sensitive material Options Ø ECAL Optimization Ø Some Results Ø Photon-sensors and crystals Ø Electronics Ø Summary Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 6

ECAL: From BESIII to STCF l Requirements Ø High Luminosity Ø Pile up: FAST Scintillator Ø Radiation hardness Ø Gamma/neutron separation Ø good time resolution Ø Precise angular resolution Ø High granularity Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 7

ECAL: From BESIII to STCF l Barrel includes 5376 crystals arranged in 128 sectors with 42 logs. l Endcap is composed of 12 sectors, with 74 crystals each. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 8

High luminosity Ø Occupancy (from BESIII ECAL) 30 hits/ cluster 24 hits/ cluster Occupancy of each crystal Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 9

High luminosity Ø Radiation dose (from BESIII ECAL, 7 years) 100 rad/y 200 rad/y Only Cs. I and LYSO could be considered with such high radiation dose Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 10

High luminosity Ø Radiation dose (from BELLE ECAL, 10 years) Seems that BGO could be considered in barrel. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 11

Crystal Options for STCF Fast Scintillator 2020/9/10 Ba. F 2 4. 89 1280 2. 03 3. 1 1. 5 Ba. F 2: Y 4. 89 1280 2. 03 3. 1 1. 5 No 300 220 600 1. 2 42 4. 8 No 1. 7 4. 8 No TBA 12

Crystal Options for STCF Ba. F 2: Y 4. 89 1280 2. 03 3. 1 1. 5 No 300 220 600 1. 2 1. 7 4. 8 No TBA Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 13

ECAL Optimization I • Total thickness: 15 X 0 3 Ge. V gamma Resolution Energy linearity Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 14

ECAL Optimization II 1. 1 关键分系统研制 • Dynamic range of ECAL SD – Max edep in one crystal: 2500 Me. V – Min edep in one crystal: depends on the threshold, here we set 1 Me. V 2500 Me. V • Photoelectric devices – PD, APD, Si. PM… • Electronics Suppose: Light Yield is 100 p. e/Me. V l Min: 100 p. e l Max: 250000 p. e； Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 Max edep in ECAL crystal 2020/9/10 15

ECAL Optimization III • Time response – Based on Bes. Sim package, Statistic gamma and neutron arrival time distribution in the calorimeter The time resolution should be better than 160 ps (500 ps / 3. ) @ ~1 Ge. V Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 16

ECAL Optimization IV • Granularity • The position resolution determines the reconstruction precision of π0 mass Compare different size of crystals for 1 Ge. V γ. 4*4 cm 2, position resolution is 3. 9 mm， 2*2 cm 2, position resolution is 2. 7 mm Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 4 cm*4 cm Sigma=3. 9 mm 2 cm*2 cm Sigma=2. 7 mm 2020/9/10 17

ECAL Optimization • Radiation length: 15 X 0 – Dynamic range： 1 Me. V ~2500 Me. V • Time resolution： 160 ps @ 1 Ge. V • ECAL crystal – Barrel：Pure Cs. I or BGO crystal – FWD：LYSO Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 18

Outline Ø Motivation Ø STCF ECAL Ø Sensitive material Options Ø ECAL Optimization Ø Some Results Ø Photon-sensors and crystals Ø Electronics Ø Summary Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 19

crystals 50% @310 nm Pure Cs. I Transmission Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 20

Light yield xp 2262 B for BGO and LYSO xp 2020 Q for pure Cs. I Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 21

Light yield Single p. e signal L. Y with PMT(pe/Me. V) L. Y with APD(pe/Me. V) BGO-1 24. 2 513. 4 358. 4 159. 3 BGO-2 23. 5 633. 2 456. 5 202. 9 LYSO-1 2. 4(*) 2018. 7 1343. 3 597. 0 LYSO-2 2. 4 2586. 4 1721. 0 764. 9 CSI-1 39 1647. 5 63. 8 28. 4 CSI-2 39 1475. 8 57. 2 25. 4 Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 22

Radiation Test l 60 Co source 20, 000 Ci l. The radiation intensity was calibrated in different position Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 60 Co 2020/9/10 23

APD Capacity（p. F） gain@Vop Size comments S 8664 -55 80 50 5 mm*5 mm Small size induced the low light collection efficiency. But the capacity is small too, so the response time could be faster. S 8664 -1010 270 50 10 mm*10 mm Light collection efficiency is high, but the higher capacity induced lower time response Multiple small-area APDs are tested together to improve signal-to-noise ratio. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 24

APD & Cosmic Test muon Cosmic Signal of BGO Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 Cosmic Signal of LYSO 2020/9/10 25

WLS plate for pure Cs. I EJ-286 Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 26

CSA-based technique route According to simulation, time measure is better than 100 ps for signals larger than 188 f. C (250 Me. V). High gain and low gain is used to cover the high dynamic range. The structure of CR-RC 4 can achieve a good SNR. ADC with a sample rate higher than 25 MSPS samples the peak of the shaped signal. CFDD and FPGA-based TDC fulfill the time measure. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 27

TIA-based technique route Without integral circuits, TIA based method can solve the problem of pileup due to high hit rate, especially at endcap. TIA transform the current signal to the voltage signal, and FADC (Sample rate > 200 MSPS) digitizes the signal directly. High gain and low gain is adopted to cover the high dynamic range. By fitting the digitized data, precise time measure results (better than 50 ps) can be reached. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 28

Outline Ø Motivation Ø HIEPA ECAL Ø Sensitive material Options Ø ECAL Optimization Ø Some Results Ø Photon-sensors and crystals Ø Electronics Ø Summary Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 29

Summary and outlook Ø The main challenges of STCF detector Ø The high luminosity Ø For ECAL Ø Some studies from BESIII (occupancy, radiation dose et al. ) tell us the option of crystals for STCF ECAL Ø Barrel: pure Cs. I; Endcap: LYSO Ø The APD could be used as the choices for ECAL Ø Two different electronics designs in parallel Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 30

Outlook Ø Optimize the ECAL overall design Ø The APD devices neutron radiation test Ø The wavelength shift materials test Ø Test crystal+APD+electronics unit Ø Response to cosmic rays Ø Use laser to test the unit Ø Dynamic range Ø Time resolution of different amplitude Ø Pile up Ø GSO and Ba. F 2: Y crystals could be considered in future? Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 31

Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 32

Results Improved light response uniformity (LRU), L. O. & RMS, especially for A end coupling Large sampl e Ref. : Presentation N 37 -04 by Junfeng Chen in IEEE NSS/MIC 2018 at Sydney, Australia Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 3

Specification 2500 Me. V • • • Two APDs on each scintillator for backup and large active area. Based on MC simulation, energy deposition is about 2. 5 Me. V~2500 Me. V on each scintillator. LY of Cs. I is 100 pe/Me. V, and the gain of APD is about 50. Dynamic range of electronics is about 2 f. C~2000 f. C. The capacity of APD is 270 p. F, which may cause a noise of 2 f. C. Time measure is needed, and precision is demanded to be better than 100 ps @1 Ge. V according to MC. Very high hit rate because of the high intensity, 100 k. Hz at barrel and even higher at endcap. Two technique route: TIA-based and CSA-based. Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 34

Hamamatsu S 13371 -6050 CQ-02 Si. PM with VUV response is available: QE = 22% at 220 nm VUV-4 has a much better performance than VUV 3 Joint Workshop of future tau-charm factory, Orsay Dec. 6 th 2018 2020/9/10 3