The 10 Na2O-(30-x) MoO3- 60H3BO3-xSb2O3 glass system was prepared using the melt-quenching technique, where 30 ≥ x ≥ 10 mol%. X-ray diffraction and Fourier transform infrared spectroscopy were used ...to investigate the amorphous nature of the glass structure and the impacts of MoO3 and Sb2O3. As the antimony trioxide (Sb2O3) concentration increases at the expense of molybdenum trioxide (MoO3), the density and molar volume increase, and the optical bandgap energy and refractive index also increase. The radiation shielding characteristics were measured using a NaI(Tl) scintillation detector and calculated using the Phy-X/PSD platform. The increase in Sb2O3 concentration increases the values of μm and Zeff but decreases the HVL and MFP, indicating that the produced glass samples, which contain no lead or barium, have mass attenuation coefficients and effective atomic numbers comparable to those of samples with higher Pb or barium contents. Furthermore, all the prepared samples were found to have greater gamma attenuation than Portland and Barite concrete.
•10 Na2O-(30-x) MoO3- 60H3BO3-xSb2O3 glass system has been prepared, where 30 ≥ x ≥ 10 mol%.•Optical parameters are investigated.•Gamma ray attenuation properties are investigated.•Exposure build-up factor, the equivalent, and the effective atomic number are calculated.•XRD and FTIR for the prepared glasses are made.
The status of the GEM project for CMS high-η muon system Abbaneo, D.; Abbrescia, M.; Armagnaud, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
732
Journal Article
Recenzirano
Odprti dostop
The dedicated CMS R&D program was intended to study the feasibility of using micropattern detectors for the instrumentation of the vacant |η|>1.6 region in the present Resistive Plate Chambers (RPCs) ...endcap system. The proposed detector for CMS is a Triple-Gas Electron Multiplier (GEM) trapezoidal chamber, equipped with 1D readout. While during 2010–2011 the Collaboration worked on the prototyping of the detector, during the first part of 2012 a newly developed assembly technique to be used for the mass production was adopted. GEMs can provide precision tracking and fast trigger information, contributing on one hand to the improvement of the CMS muon Trigger and on the other hand to provide the missing redundancy in the high η region. In the view of the next LHC long shutdown (LS1) the CMS GEM Collaboration designed and built four full-size Triple GEM-based muon detectors.
The high pseudo-rapidity region of the CMS muon system is covered by Cathode Strip Chambers (CSC) only and lacks redundant coverage despite the fact that it is a challenging region for muons in terms ...of backgrounds and momentum resolution. In order to maintain good efficiency for the muon trigger in this region additional RPCs are planned to be installed in the two outermost stations at low angle named RE3/1 and RE4/1. These stations will use RPCs with finer granularity and good timing resolution to mitigate background effects and to increase the redundancy of the system.
The CMS GEM collaboration is performing a feasibility study to install triple-GEM detectors in the forward region of the muon system (1.6 < |eta| < 2.4) of the CMS detector at the LHC. Such ...micro-pattern gas detectors are able to cope with the extreme particle rates that are expected in that region during the High Luminosity phase of the LHC. With their spatial resolution of order 100 micron GEMs would not only provide additional benefits in the CMS muon High Level Trigger, but also in the muon identification and track reconstruction, effectively combining tracking and triggering capabilities in one single device. The present status of the full project will be reviewed, highlighting all importants steps and achievements since the start of the R&D in 2009. Several small and full-size prototypes were constructed with different geometries and techniques. The baseline design of the triple-GEM detector for CMS will be described, along with the results from extensive test measurements of all prototypes both in the lab and in test beams at the CERN SPS. The proposed on- and off-detector electronics for the final system will be presented.
The Resistive Plate Chambers (RPCs) are employed in the CMS experiment at the LHC as dedicated trigger system both in the barrel and in the endcap. This note presents results of the RPC detector ...uniformity and stability during the 2011 data taking period, and preliminary results obtained with 2012 data. The detector uniformity has been ensured with a dedicated High Voltage scan with LHC collisions, in order to determine the optimal operating working voltage of each individual RPC chamber installed in CMS. Emphasis is given on the procedures and results of the High Voltage calibration. Moreover, an increased detector stability has been obtained by automatically taking into account temperature and atmospheric pressure variations in the CMS cavern.
The CMS muon system includes in both the barrel and endcap region Resistive Plate Chambers (RPC). They mainly serve as trigger detectors and also improve the reconstruction of muon parameters. Over ...the years, the instantaneous luminosity of the Large Hadron Collider gradually increases. During the LHC Phase 1 ( similar to first 10 years of operation) an ultimate luminosity is expected above its design value of 10 super(34) cm super(-2)s super(-1) at 14 TeV. To prepare the machine and also the experiments for this, two long shutdown periods are scheduled for 2013-2014 and 2018-2019. The CMS Collaboration is planning several detector upgrades during these long shutdowns. In particular, the muon detection system should be able to maintain a low-pT threshold for an efficient Level-1 Muon Trigger at high particle rates. One of the measures to ensure this, is to extend the present RPC system with the addition of a 4th layer in both endcap regions. During the first long shutdown, these two new stations will be equipped in the region degree ' eta degree ' < 1.6 with 144 High Pressure Laminate (HPL) double-layer RPCs operating in avalanche mode, with a similar design as the existing CMS endcap chambers. Here, we present the upgrade plans for the CMS RPC system for the fist long shutdown, including trigger simulation studies for the extended system, and details on the new HPL production, the chamber assembly and the quality control procedures.
Resistive Plate Chambers have been chosen as dedicated trigger muon detector for the Compact Muon Solenoid experiment 1 at the Large Hadron Collider 2 at CERN. The system consists of about 3000m ...super(2) of double gap RPC chambers placed in both the barrel and endcap muon regions. About 5.6 fb super(-1) (2010-2011) of proton-proton collision data have been used to study the performance of the RPC detector and trigger. A full high voltage scan of all the RPC chambers has been done at beginning of 2011 data taking to evaluate the working point chamber by chamber and to eventually spot aging effects. The excellent behaviour of the RPC detector can be summarized with an average detector efficiency of about 97%, an average cluster size of 1.8 and an intrinsic noise rate of 0.1 Hz/cm super(2). This is a clear fulfilment of all the requirements decided 18 years ago in the CMS TDR document 3.
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