1,198 research outputs found
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
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
Development of Hybrid Resistive Plate Chambers
Resistive Plate Chambers (RPCs) are essential active media of large-scale
experiments as part of the muon systems and (semi-)digital hadron calorimeters.
Among the several outstanding issues associated with the RPCs, the loss of
efficiency for the detection of particles when subjected to high particle
fluxes, and the limitations associated with the common RPC gases can be listed.
In order to address the latter issue, we developed novel RPC designs with
special anode plates coated with high secondary electron emission yield
materials such as AlO and TiO. The proof of principle was obtained
for various designs and is in progress for the rest. The idea was initiated
following the achievements on the development of the novel 1-glass RPCs.
Here we report on the construction of various different RPC designs, and
their performance measurements in laboratory tests and with particle beams; and
discuss the future test plans
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
Total Absorption Dual Readout Calorimetry R&D
Abstract This calorimetry R&D focuses on establishing a proof of concept for totally active hadron calorimetry. The research program involves evaluating the performance of the different crystal and glass samples in combination with different light collection and readout alternatives to optimize simultaneous collection of Cerenkov and scintillation light components for application of the Dual Readout technique to total absorption calorimetry. We performed initial studies in two short test beam phases in April and November 2010 at Fermilab. Here we present first measurements from these two beam tests
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