Decision on TPC vs DC for CEPC Detector Performance Comparison

A Request for Decision on TPC vs. DC WANG Meng CEPC detector TDR plenary, 2024.5.14

performance comparison unit T TPC, Higgs TPC, Z DC, Higgs DC, Z B-field Performance material budget barrel material budget endcap Npoint of measurement/full-trk point resolution in r , max point resolution in rz momentum resolution: (pT)/pT = a pT b a b K/ separation power @ 20GeV dE/dx or dN/dx resolution hit rate, max occupancy, max note 3 2 3 2 X0 X0 0.55% 15% 2300 1.14% plate 22.5% + cables 1.8% 66 100 2000 2300 66 100 2000 m m 100 (full) 100 - 500 400 (full) 200 - 800 1/GeV 1.2E-05 6.0E-04 2.7E-05 9.0E-04 2.1E-05 7.7E-04 3.2E-05 1.2E-03 3 3 3.2 3.2 2.5-2.6% 70 kHz/cell 2.9% 60031.5k 0.001% 2.9%2.5-2.6% /s/pad 1.6% 11% pad 0.5x0.5 mm2, ch 2x3e7 cell 18x18mm2, 27.6 kCells 2

comparison of cost estimation Time Projection Chamber (TPC) item Chamber Barrel inner cylinder Barrel outer cylinder Fieldcage (inner and outer) Cathode and HV crate Endplate Aluminum endcap MPGD detector module Readout PCB boards pre-assembly and testing Electronics FEE ASIC readout Cables, connectors BEE Readout PCB board Trigger/DAQ system Crate and controller Electronics cooling system Alignment and calibration Calibration system pre-assembly and testing HV and Gas system HV and low power Gas system Slow control system Online monitoring system Testing bef. Assembly 9250.00 [10k RMB] total 950.00 150.00 500.00 200.00 100.00 2300.00 1000.00 1000.00 200.00 100.00 4950.00 2000.00 600.00 700.00 550.00 600.00 500.00 500.00 450.00 50.00 550.00 200.00 200.00 50.00 50.00 50.00 Drift Chamber (DC) Item 8021.64 [10k RMB] total 650.00 40.00 110.00 500.00 Nr 1 1.1 1.2 1.3 1.4 2 2.1 2.2 2.3 2.4 3 3.1 3.2 3.3 3.4 3.5 3.6 4 4.1 4.2 5 5.1 5.2 5.3 5.4 5.5 unit price quantity note unit price quantity note Chamber Inner cylinder Outer cylinder Carbon-Fibre Frame 150.00 500.00 200.00 100.00 1 1 1 1 40.00 110.00 500.00 1 1 1 Endplate Aluminum endcap Feedthrough Sense Wire Field Wire Electronics FEE Preamp FEE Digital Board FEE Mix Cable BEE Board and DAQ 1861.36 810.00 471.40 47.67 532.29 4640.28 529.68 3707.76 264.84 138.00 500.00 1.82 0.37 100.00 2 405.00 0.002 0.0003 0.0011 2 550 550 235700 158900 483900 1 0.010 0.03 1.40 11.00 20.00 500.00 200000 20000 500 0.240 1.68 0.12 2.00 2207 2207 2207 69 50 30 1 Wiring Wiring tool Wire test system HV and Gas system HV Crate HV Module HV cable / fan-out Gas system Slow Control 430.00 350.00 80.00 440.00 60.00 150.00 110.00 100.00 20.00 450.00 1 1 350.00 80.00 1 1 50 0.40 200.00 50.00 50.00 50.00 500 10.00 3.00 110.00 100.00 20.00 6 1 1 1 1 50 1 1 1 3

mini-review on TPC and DC of CEPC on April 1stat IHEP, https://indico.ihep.ac.cn/event/22016/ committee: Ouyang Qun(chair), Li Yulan, Liu Jianbei, Zhao Lei, Wang Jianchun, Wei Wei participants: a few foreign experts in addition to Chinese members of two groups Charge of the review justify the feasibility of both TPC and DC identify critical R&Ds for TDR prioritise the choice of technology, if possible justify cost estimations Key recommendations Both scenarios are feasible, but are challenging in key techniques as well. Most of results are based on simulation and lack of experimental validation, which is NOT enough for TDR. According to their current R&D status, it is impossible to give a choice. It s recommended to take further reviews, for which a list of support materials are suggested. It s suggested that cost estimations shall be reviewed separately. 4

in my opinion I fully agree with the recommendations of the mini-review committee. We are forced to choose is mainly due to the PID requirement, which is dominantly relevant to the Z-pole run. However, we will start with the Higgs run for more than ten years. Should CEPC be approved by the 15th-Five, we need something deliverable immediately TPC, for instance, with non-pixelated readout, would be a choice of promising; We may continue our R&D for the PID-oriented TPC and DC with a serene certainty. Hence, I would recommend TPC for our reference-detector TDR. 5

Thanks! 6

Material budget of TPC Low material of the TPC endcap 15%X0in total, including Readout plane, front-end-electronics Cooling Power cables 4% 2% 9% Low material of the TPC barrel 0.55% X0in total, including Material budget of TPC barrel Layer of the barrels D[cm] X0[cm] d/X0[%] Copper shielding 0.001 1.45 0.07 CF outer barrel 0.010 25.28 0.04 Mirror strips 0.003 1.35 0.19 Polyimide substrate 0.005 32.65 0.02 Field strips 0.003 1.35 0.19 CF inner barrel 0.010 25.28 0.04 Sum of the material budget 0.55 7

Pixelated readout TPC beam test for PID Pixelated readout TPC is a good option at high luminosity Z on circular e+e- collider (2x36 cm-2s-1) High spatial resolution under 2T or 3T magnetic field Better momentum resolution High-rate operation (MHz/cm2) dE/dx and Cluster counting (in space) Very low voxel occupancy 8

Voxel Occupancy CEPC Soft Z-pole TPC 500 m 500 m 40MHz Voxel 4 107/s z Voxel Vd 25ns~2mm Voxel ~0.5 0.5 2=0.5 mm3 500ns z 20 voxel 200ns Voxel Occupancy=20 31.5k/4 107~1.58% 1mm 6mm Pad Voxel Occupancy~35% MDI TPC Occupancy 9

Drift Chamber 11

Overall Design (preliminary) CF Frame structure 8 longitudinal hollow beams + 8 annular hollow beams + inner CF cylinder and outer CF cylinder Length : 5800mm Outer diameter: 3600mm Inner Diameter: 1200mm Thickness of each end plate: 25mm/20mm weight :1100kg /880kg 12

Loads: Wire tension + Axial self weight End plate thickness: 20mm Stress 27.1MPa, Endplate deformation 3.4mm, CF frame deformation 1.6mm Results of FEA The structure is stable Vertical self weight Buckling coefficient : ~12 Horizontal self weight Buckling coefficient : ~14 13

Layout design of wiring

dN/dx Resolution and separation power dN/dx resolution: 2.5%-2.6% for pion 2.6%-2.7% for Kaon 1.2 m track length For 20 GeV/c K/ , Separation power: 3.2 15

CEPC tracking system, draft Three tracking regions (I) barrel: full Gas + Si trackers (II) endcap: partial Gas tracker (III)forward: Si tracker only 16

CDR layout for acronyms 17