T02 Overview of Endcap Calorimetry 402.04 Jeremiah Mans, L2 - PowerPoint PPT Presentation

T02 – Overview of Endcap Calorimetry 402.04 Jeremiah Mans, L2 Manager, 402.04 November 29, 2017 J. Mans, 2017 November 29 Technical Review -- Endcap Calorimetry Overview 1

Outline  Conceptual Design  Scope  Project organization  Summary Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 2 2

Conceptual Design Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 3 3

Overview of the Upgrade Endcap Calorimetry Endcap Calorimetry Current : PbW0 4 crystal ECAL+ Current : PbW0 4 crystal ECAL+ plastjc-scintjllator/WLS HCAL plastjc-scintjllator/WLS HCAL Upgrade : Silicon-based ECAL, Upgrade : Silicon-based ECAL, silicon and plastjc- silicon and plastjc- scintjllator/SiPM HCAL scintjllator/SiPM HCAL Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 4 4

Drivers for Endcap Upgrade  Selected physics drivers  Jet reconstruction at 200 pileup (particularly for vector-boson- fusion and vector-boson-scattering studies)  Electron and photon reconstruction and id for Higgs (H→ ɣɣ , H→ZZ→eell) at 200 pileup  Muon identification in region 2.4 < |η| < 3.0  Missing transverse energy resolution at high pileup, for dark- matter searches/studies  Technical drivers  Very high radiation dose: current CMS endcap calorimeters lose > 90% of signal amplitude over large portions of detector if kept for HL-LHC era  Increased L1 readout rate (100 kHz increases up to 750 kHz) and longer L1 trigger latency (3 μs increases to 12.5 μs) Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 5 5

Motivation for the Upgrade  Radiation damage will greatly reduce the energy resolution of the endcap calorimeters after 500 fb -1  Segmentation and performance is marginal for management of HL-LHC pileup conditions Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 6 6

Requirements Flowdown  Calibration: Detector response will change due to ongoing radiation damage  Require 3% cell-to-cell intercalibration to retain performance for EM Use MIP calibration to track changes to ● cells → sets requirements for end-of-life MIP S/N Operate detector at low temperature to ● minimize noise  Resolution and Robustness Longitudinal segmentation arranged to limit  number of layers required while maintaining ability to make good measurements near the front of the shower where f(π 0 ) is large and for tracking showers in the dense region, even if a layer is lost Maintain high density to limit shower spreading,  total thickness (>10λ) for both measurement resolution and shielding of the muon system Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 7 7

Conceptual design  Silicon/(tungsten+lead) electromagnetic calorimeter (CE-E)  28 layers with total 26X 0 thickness  Stainless-steel absorber for hadron calorimeter (CE-H)  8 layers with silicon-only readout and Δλ=0.25 longitudinal segmentation  4 layers with mixed silicon and scintillator readout and Δλ=0.25  12 layers with mixed silicon/scintillator and Δλ=0.45  Full detector operated at -30°C using CO 2 cooling Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 8 8

Building blocks of the detector  Detector system constructed out of cassettes consisting of a copper cooling plate (CO 2 ) with a mixture of silicon modules and scintillator tileboards mounted on it Each cassette covers 30° of a single layer  Modules/tileboards connect to motherboards which host a  concentrator ASIC  Modules and tileboards are constructed and tested as units and shipped to the cassette assembly site Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 9 9

Calorimeter Silicon Sensors  Calorimeter sensor design is driven by balance of cost, radiation-damage and keeping pad capacitance low-enough to control noise  Primary calibration/monitoring technique is based on MIP tracks in the detector  Three regions in detector with different active thickness (300, 200, 120 um) with 120 um sensors having smaller pad sizes Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 10 10

Calorimeter Silicon Sensors  Cell layout optimized for efficient channel-use while constructing 2x2 trigger cells (3x3 in 120um modules)  Special calibration cells also included, with small area  Excellent results achieved with 6” HPK sensors and “stepper” 8” sensors  Hamamatsu procuring necessary equipment for alignment of 8” sensors Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 11 11

Silicon Calorimeter Modules  Stack of baseplate/kapton/sensor/PCB  PCB hosts HGROC ASIC, has holes to allow downbonds from PCB to the sensor  Automated assembly process developed using gantries for high precision and large-volume  Work has been done with 6” sensors/PCBs so far, will shift to 8” in 2018 Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 12 12

Tileboards, Scintillator, and SiPMs  SiPM directly observes the scintillation light from the tile, allowing for tile-by-tile corrections for radiation damage  Scintillator construction concepts include both individually-wrapped tiles and “macrotiles” combining an array of tiles into a single mechanical unit  Tileboard hosts SiPMs and HGROC ASICs Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 13 13

Electronics Architecture  Design makes heavy use of standard HL-LHC ASICs and components LpGBT data link – VTRX+ optical interface – GBTSCA slow-control ASIC –  Two custom ASICs required ADC: HGCROC – Concentrator: combines the output – from multiple HGCROC chips into individual trigger or DAQ fibers Allows for significant savings on ● optical fibers and off-detector electronics at the cost of additional on-detector engineering Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 14 14

Integrated Cassettes  Cassette integration requires mounting modules and tileboard onto the cooling plate, adding motherboards, and dressing the overall cassette with cables and fibers Geometric variation from layer-to-layer – due to inner and outer boundary variations, but many common components in use on all layers Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 15 15

US Scope Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 16 16

Organizing Principle: Hadron Calorimetry and Electronics  Since the original construction of CMS, the US has had a leading role in hadron calorimetry and in automated assembly of silicon detectors  Construction of the barrel hadron calorimeter, electronics for all hadron calorimeter sections (including Phase 1 Upgrade)  Construction of a large fraction of the tracker outer barrel, construction of the full forward pixel Phase 1 Upgrade)  For the HL-LHC upgrades, the US contributions to the endcap calorimeter center on the production of the hadronic calorimeter silicon and scintillator modules and cassettes and aspects of the electronics and services where the US can provide particular leadership Technical Review -- Endcap Calorimetry Overview Technical Review -- Endcap Calorimetry Overview J. Mans, 2017 November 29 J. Mans, 2017 November 29 17 17