The SLHC Program and CMS Hadron Calorimeter Upgrades

The Large Hadron Collider (LHC) is designed to provide 14 TeV center of mass energy with proton-proton collisions every 25 ns. After several years of running, the LHC will be upgraded to the super-LHC (SLHC), which will operate with 10 times higher luminosity (L = 10^35 cm^-2s^-1), thereby allowing new physics discoveries. The impact of the LHC luminosity upgrade on the CMS detector is discussed

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

Radiation-Hard Quartz Cerenkov Calorimeters

New generation hadron colliders are going to reach unprecedented energies and radiation levels. Quartz has been identified as a radiation-hard material that can be used for Cerenkov calorimeters of the future experiments. We report from the radiation hardness tests performed on quartz fibers, as well as the characteristics of the quartz fiber and plate Cerenkov calorimeters that have been built, designed, and proposed for the CMS experiment

CMS (LHC) Measurements and Unusual Cosmic Ray Events

At the LHC, for the first time, laboratory energies are sufficiently large to reproduce the kind of reactions that occur when energetic cosmic rays strike the top of the atmosphere. The reaction products of interest for cosmic ray studies are produced at small angles, even with colliding beams. Most of the emphasis at the LHC is on rare processes that are studied with detectors at large angles. It is precision measurements at large angles that are expected to lead to discoveries of Higgs bosons and super symmetric particles. CMS currently has two small angle detectors, CASTOR and a Zero Degree Calorimeter (ZDC). CASTOR, at $0.7^{\circ}$ down to $0.08^{\circ}$, is designed to study "Centauro" and "long penetrating" events, observed in VHE cosmic-ray data. As a general purpose detector it also makes measurements of reaction products at forward angles from p-p collisions, which provide input for cosmic ray shower codes. The ZDC is small, 9 cm. wide, between the incoming and outgoing beam pipes out at a distance of 140 m. The ZDC measures neutral objects that follow the direction of the beam at the interaction point. If the long penetrating objects are spectators they could be seen in the ZDC if their charge to mass ratio, Z/A, is less than 0.2.Comment: Invited talk presented at the XVI International Symposium on Very High Energy Cosmic Ray Interactions, ISVHECRI 2010, Batavia, IL, USA (28 June - 2 July 2010). 4 pages, 5 figure

Status of Zero Degree Calorimeter for CMS Experiment

The Zero Degree Calorimeter (ZDC) is integral part of the CMS experiment, especially, for heavy ion studies. The design of the ZDC includes two independent calorimeter sections: an electromagnetic section and a hadronic section. Sampling calorimeters using tungsten and quartz fibers have been chosen for the energy measurements. An overview of the ZDC is presented along with a current status of calorimeter's preparation for Day 1 of LHC.Comment: 8 pages, 5 figures, 1 table, to appear in the proceedings of CALOR06, June 5-9, 2006 Chicago, US

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

Physics at Very Small Angles with CASTOR at CMS

CASTOR is a small (56 cm diameter) quartz-tungsten Cerenkov calorimeter covering the small angles 0.2-0.6 deg (5.2<="eta"<=6.4) in CMS, a major experiment at the LHC. Particularly with heavy-ion reactions a substantial fraction of the total reaction energy goes into this large "eta" region. CASTOR will function as a part of CMS and also as an independent detector to search for special types of events in the far-forward region. It is divided into 16 azimuthal sectors, each with 18 longitudinal segments to allow identification of particles by their energy-loss profiles. The most forward segments are smaller to better characterize electromagnetic events

Measurements of the Rate Capability of Various Resistive Plate Chambers

Resistive Plate Chambers (RPCs) exhibit a significant loss of efficiency for the detection of particles, when subjected to high particle fluxes. This rate limitation is related to the usually high resistivity of the resistive plates used in their construction. This paper reports on measurements of the performance of three different glass RPC designs featuring a different total resistance of the resistive plates. The measurements were performed with 120 GeV protons at varying beam intensitie