HCAL Upgrade Workshop Summary Very successful workshop 30

HCAL Upgrade Workshop Summary • Very successful workshop • ~ 30 people attended the sessions • Covered – – – near term problems in detector Strawmen proposals for HB/HE/HF/HO SIPM status Back end readout (synergy with ECAL/RCT/GCT? ) Discussion with muon team on MTT joint proposal Brief discussions of Phase II upgrades • Developed plan of action of next months 11/19/2008 Jim Freeman

Talks Day 1 11/19/2008 Jim Freeman 2

Talks Day 2 11/19/2008 Jim Freeman 3

Phase I Upgrade (SIPMs) • Major concept is replacement of HPDs with SIPMs – Work well in B field – Much higher gain and QE less noise, can split signal for TDC – Operates at ~50 V (not 8 KV) – Geometry allows new segmentation possibilities 11/19/2008 Jim Freeman

Replace HPDs with SIPMs. Allows arbitrary segmentation Proposed by Arjan Heering and Sergey Los 1 Si. PM per fiber Light-tight 18 -connector Faceplate P. Rubinov B. Sands Basic Concept – Do Optical/Electrical Conversion at the Megatile Connector – 1 Si. PMs (1 mm 2) per fiber – Perform Analog Addition to form (segmented) towers 11/19/2008 Jim Freeman

HB Long. Segmentation 18 Channel RMs 11/19/2008 48 Channel HB RMs 32 Channel HE RMs Jim Freeman

Need for Improved Lepton Isolation at L 1 trigger @ 1035 Single electron trigger rate L = 2 x 1033 MHz Isolation criteria are insufficient to reduce rate at L = 1035 cm-2. s-1 5 k. Hz @ 1035 τ Removing Layer 0 from HCAL We need to get another x 200 (x 20) reduction for single (double) tau rate! Isolation cone improves rejection 11/19/2008 Jim Freeman 7

Allows other possible Longitudinal Segmentation 18 Channel RMs 11/19/2008 48 Channel HB RMs 32 Channel HE RMs Jim Freeman

Mohawk Events Muon goes straight down HB megatile 11/19/2008 Jim Freeman

HB Digital Readout Bandwidth Current Readout (1. 6 GHz) Format Possible HB Readout (3. 2 GHz) Format with GOL QIE 0 8 -bit QIE 1 8 -bit QIE 2 8 -bit TDC 0 Cap. ID(0 -3) Err. Bit 5 -bit 2 -bit 1 -bit Optical Cable 1 QIE 6 QIE 8 QIE 7 8 -bit TDC 6 5 -bit Optical Cable 2 11/19/2008 Cap. ID(6 -7) 2 -bit Err. Bit 1 -bit QIE 3 8 -bit TDC 3 5 -bit QIE 9 8 -bit TDC 9 5 -bit Jim Freeman QIE 4 8 -bit Cap. ID(4 -5) 2 -bit QIE 10 8 -bit QIE 5 8 -bit Err. Bit 1 -bit QIE 11 8 -bit Cap. ID(8 -11) Err. Bit 1 -bit 2 -bit

Phase I HCAL upgrade critical components • SIPM looks good • New QIE (QIE 10) • GOL studies on track to handle data flow • Cooling looks feasible • Discrete parts (regulators, FPGAs) look OK 11/19/2008 Jim Freeman

SIPM that satisfies HB dynamic range needs 11/19/2008 Jim Freeman 12

New SIPMs satisfy predicted SLHC Rad Needs HB HO 11/19/2008 Jim Freeman 13

Muon response for YB 1 HPD Si. PM Time slew Si. PM 11/19/2008 HPD Jim Freeman 14

HPD vs. Si. PM in 4 T B Field Si. PMs are very quiet and operate at higher gain. HPD 11/19/2008 Si. PM HPD Discharge Noise Jim Freeman LED calibration pulse

Quad QIE 10 Specs • QIE 10 – Clock > 40 MHz – Match to Si. PM response • HB - ZETEC 40, 000 pixel device • 4 X Dynamic range of QIE 8 – 1 Extra bit resolution (5 --> 6) – Keep non-linear response as in QIE 8 – Charge sensitivity of lowest range • QIE 8: Norm - 1 f. C/LSB, Calib - 1/3 f. C/LSB • QIE 10: 10 x less sensitive – Set by lowest Si. PM gain (Singapore Zecotek - HB? ) – Need to control rate effects (DC coupling) – 2 or 4 QIE 10 per package, either multi-channel QIE die or separate dice in single package – Form a “discriminated signal” to send to the FPGA for TDCing • 1 TDC signal per channel 11/19/2008 Jim Freeman

Back End Plan • FE changes require redesign of HCAL backend – Denser channel count, built-in resources for newer FPGAs, etc – Working with the evolution in RCT/GCT (u. TCA? ) • Ideas are in play to consider how to collaborate with evolution of ECAL – Selective Readout being considered • Increase in HCAL channel count by a factor of 4 • More DAQ links, harder zero suppression, more pileup – ECAL has faced this issue already • Incremental cost of current HCAL backend towards a more unified HCAL/ECAL approach – Work underway to understand physics gains especially at high luminosity • E. g. provides readout of necessary depths for isolation cuts on the E/Gamma path as well as fine-grain ECAL information for jets 11/19/2008 Jim Freeman

Advantages of this plan • Depth segmentation can be decided late in process allows experience with real CMS collision physics • Can accommodate new GBT if present on right timescale • Can have phased installation (ie HB one shutdown, HE next, or other combinations. ) Graceful installation in regular shutdowns 11/19/2008 Jim Freeman

HO SIPM RBXs • We will install 2 SIPM RBXs into HO in Feb. – Gain operational experience, lifetime – Develop control and monitoring system 11/19/2008 Jim Freeman

HF: proposed replacement PMT for HF 1 mm window New multi-anode pmt has 2 X better QE. Improves HF low end performance 11/19/2008 Jim Freeman 20

Muon-Induced Backgrounds Mini. PMT vs Standard HF PMT ~ like glass thickness… 11/19/2008 Jim Freeman 21

HF PMT Upgrade • Will further investigate metal wall pmts (with high QE) • Multi-pixel pmt will allow upgrade path to have 2 separate readouts eliminate pmt Cerenkov events. • Using Phase I electronics would also provide TDC information. 11/19/2008 Jim Freeman