Commissioning of CMS Forward Hadron Calorimeters with Upgraded Multi-anode PMTs and {\mu}TCA Readout

The high flux of charged particles interacting with the CMS Forward Hadron Calorimeter PMT windows introduced a significant background for the trigger and offline data analysis. During Long Shutdown 1, all of the original PMTs were replaced with multi-anode, thin window photomultiplier tubes. At the same time, the back-end electronic readout system was upgraded to {\mu}TCA readout. The experience with commissioning and calibration of the Forward Hadron Calorimeter is described as well as the {\mu}TCA system. The upgrade was successful and provided quality data for Run 2 data-analysis at 13 TeV

SNOWMASS WHITE PAPER - SLHC Endcap 1.4<y<4 Hadron Optical Calorimetry Upgrades in CMS with Applications to NLC/T-LEP, Intensity Frontier, and Beyond

Radiation damage in the plastic scintillator and/or readout WLS fibers in the HE endcap calorimeter 1.4<y<4 in the CMS experiment at LHC and SLHC will require remediation after 2018. We describe one alternative using the existing brass absorber in the Endcap calorimeter, to replace the plastic scintillator tiles with BaF2 tiles, or quartz tiles coated with thin(1-5 micron) films of radiation-hard pTerphenyl(pTP) or the fast phosphor ZnO:Ga. These tiles would be read-out by easily replaceable arrays of straight, parallel WLS fibers coupled to clear plastic-cladded quartz fibers of proven radiation resistance. We describe a second alternative with a new absorber matrix extending to 1.4<y<4 in a novel Analog Particle Flow Cerenkov Compensated Calorimeter, using a dual readout of quartz tiles and scintillating (plastic, BaF2, or pTP/ ZnO:Ga thin film coated quartz, or liquid scintillator) tiles, also using easily replaceable arrays of parallel WLS fibers coupled to clear quartz transmitting fibers for readout. An Analog Particle Flow Scintillator-Cerenkov Compensated Calorimeter has application in NLC/T-LEP detectors and Intensity Frontier detectors

Radiation Damage and Recovery Properties of Common Plastics PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate) Using a 137Cs Gamma Ray Source Up To 1 MRad and 10 MRad

Polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET) are cheap and common polyester plastics used throughout the world in the manufacturing of bottled drinks, containers for foodstuffs, and fibers used in clothing. These plastics are also known organic scintillators with very good scintillation properties. As particle physics experiments increase in energy and particle flux density, so does radiation exposure to detector materials. It is therefore important that scintillators be tested for radiation tolerance at these generally unheard of doses. We tested samples of PEN and PET using laser stimulated emission on separate tiles exposed to 1 MRad and 10 MRad gamma rays with a 137Cs source. PEN exposed to 1 MRad and 10 MRad emit 71.4% and 46.7% of the light of an undamaged tile, respectively, and maximally recover to 85.9% and 79.5% after 5 and 9 days, respectively. PET exposed to 1 MRad and 10 MRad emit 35.0% and 12.2% light, respectively, and maximally recover to 93.5% and 80.0% after 22 and 60 days, respectively

Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System

This White Paper outlines a proposal for an upgraded forward region to extend CMS lepton (e, mu) and photon physics reach out to 2.2<eta<5 for LHC and SLHC, which also provides better performance for the existing or new forward hadron calorimetry for jet energy and (eta, phi) measurements, especially under pileup/overlaps at high lumi, as LHC luminosity, energy and radiation damage increases

Tests of a Digital Hadron Calorimeter

In the context of developing a hadron calorimeter with extremely fine granularity for the application of Particle Flow Algorithms to the measurement of jet energies at a future lepton collider, we report on extensive tests of a small scale prototype calorimeter. The calorimeter contained up to 10 layers of Resistive Plate Chambers (RPCs) with 2560 1 \times 1 cm2 readout pads, interleaved with steel absorber plates. The tests included both long-term Cosmic Ray data taking and measurements in particle beams, where the response to broadband muons and to pions and positrons with energies in the range of 1 - 16 GeV was established. Detailed measurements of the chambers efficiency as function of beam intensity have also been performed using 120 GeV protons at varying intensity. The data are compared to simulations based on GEANT4 and to analytical calculations of the rate limitations

Tests of a Novel Design of Resistive Plate Chambers

A novel design of Resistive Plate Chambers (RPCs), using only a single resistive plate, is being proposed. Based on this design, two large size prototype chambers were constructed and were tested with cosmic rays and in particle beams. The tests confirmed the viability of this new approach. In addition to showing an improved single-particle response compared to the traditional 2-plate design, the novel chambers also prove to be suitable for calorimetric applications

Characterization of photomultiplier tubes in a novel operation mode for Secondary Emission Ionization Calorimetry

Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes have been characterized for use in a Secondary Emission (SE) Ionization Calorimetry study. SE Ionization Calorimetry is a novel technique to measure electromagnetic shower particles in extreme radiation environments. The different operation modes used in these tests were developed by modifying the conventional PMT bias circuit. These modifications were simple changes to the arrangement of the voltage dividers of the baseboard circuits. The PMTs with modified bases, referred to as operating in SE mode, are used as an SE detector module in an SE calorimeter prototype, and placed between absorber materials (Fe, Cu, Pb, W, etc.). Here, the technical design of different operation modes, as well as the characterization measurements of both SE modes and the conventional PMT mode are reported