The CMS Silicon Strip Tracker

The CMS strip tracker is the first large scale tracker entirely based on silicon detectors technology. It consists of 198 m^2 of detector sensitive area instrumenting the inner region of the experiment with a pseudo-rapidity coverage of eta <2.5. This instrument, together with a silicon pixel system, is expected to perform robust tracking and detailed vertex reconstruction while embedded in the LHC high radiation and high luminosity environment. The project is in a well advanced construction phase: the detector module production is completed, the integration of the single components into large sub-detector units is underway and the full tracker commissioning is about to start. In this paper, after a description of the tracker layout, a detector modules production overview and a summary of the integration procedures for the inner barrel part of the tracker will be reported

tracking for proton computed tomography

In hadron therapy a highly conformed irradiation field is delivered to the target by precisely moving the particle beam and, at the same time, modulating its energy with the aim to cover the tumor volume with the requested dose sparing the surrounding healthy tissues as much as possible. To setup a robust treatment plan the Stopping Power (SP) map for each patient should be measured and the volume to be irradiated precisely located. To improve the precision of the SP map determination the use of a proton beam to perform a 'proton Computed Tomography' (pCT) could be the ideal solution. To be effective in reducing the uncertainties in dose spatial distribution, this novel method should keep the SP map spatial resolution below one millimeter. Tracking in presence of large multiple scattering will be discussed in these proceedings together with the concept of 'most likely path' (MLP). A generalization of the studies on this issue will be introduced with the aim to describe instrumental effects on the MLP spatial resolution. The pCT apparatus, based on a Silicon microstrip tracker followed by a calorimeter to measure single protons trajectory and their residual energy, will be reviewed with particular emphasis on the R&D ongoing on this subject and the results already obtained. New prototypes presently under construction, which will be suitable for pre-clinical studies, will be described too

Hip Fracture Surgery in Severe Aortic Stenosis: A Study of Factors Affecting Mortality

BACKGROUND: In elderly patients with hip fracture, the prevalence of severe aortic stenosis (valve area <1 cm(2)) is close to 5%. Few studies have evaluated the prognostic role of aortic stenosis in hip fracture surgery and none has considered the effects of the postoperative setting (intensive care unit vs general ward) on clinical outcome. PURPOSE: The aim of the present study was to evaluate the factors affecting mortality in patients with severe aortic stenosis undergoing surgery for hip fracture. We also evaluated whether postoperative monitoring in the intensive care unit may affect the prognosis in comparison to return to the general ward after surgery. PATIENTS AND METHODS: All 2274 patients referred for hip fracture to our tertiary teaching hospital between January 1 2015 and December 31 2019 were screened for the presence of severe aortic stenosis, defined by an aortic valve area <1.0 cm(2). RESULTS: The study included 66 patients (27 males, 39 females) with a mean±SD age of 85±7 years. The average time between trauma and surgery was 2.6±3 days. The mean aortic valve area was 0.74±0.15 cm(2). Seven patients died during hospitalization (10.4%). Diabetes, having two or more comorbidities, a low degree of autonomy, heart failure, history of coronary artery disease, atrial fibrillation, postoperative delirium and pulmonary hypertension were associated with poorer outcome. In logistic multivariate analysis, the number of diseases and values of pulmonary artery pressure were the only independent factors related to mortality. In hospital mortality (12 and 9%, respectively) and complication rates were not statistically different between patients referred to the intensive care unit for postoperative monitoring and patients returned to the general ward after surgery. CONCLUSION: In patients undergoing hip fracture surgery, severe aortic stenosis is associated with high hospital mortality, and two or more comorbidities and pulmonary hypertension are associated with a worse prognosis. The postoperative setting (intensive care unit or general ward) does not affect outcome

PRIMA+: A proton Computed Tomography apparatus

The proton Computed Tomography (pCT) is a medical imaging method, based on the use of proton beams with kinetic energy of the order of 250 MeV, aimed to directly measure the stopping power distribution of tissues thus improving the present accuracy of treatment planning in hadron therapy. A pCT system should be capable to measure tissue electron density with an accuracy better than 1% and a spatial resolution better than 1 mm. The blurring effect due to multiple Coulomb scattering can be mitigated by single proton tracking technique. As a first step towards pCT the PRIMA+ Collaboration built a prototype capable to carry out a single radiography and a tomographic image of a rotating object. This apparatus includes a silicon microstrip tracker to identify the proton trajectory and a YAG:Ce calorimeter to measure the particle residual energy

La Fanciulla del West

Direcció: Mario ParentiEmpresa: Juan A. PamiasDe cada obra s'ha digitalitzat un programa sencer. De la resta s'han digitalitzat les parts que són diferents

The 2003 Tracker Inner Barrel Beam Test

Before starting the CMS Silicon Strip Tracker (SST) mass production, where the quality control tests can only be done on single components, an extensive collection of activities aiming at validating the tracker system functionality has been performed. In this framework, a final component prototype of the Inner Barrel part (TIB) of the SST has been assembled and tested in the INFN laboratories and then moved to CERN to check its behaviour in a 25~ns LHC-like particle beam. A set of preproduction single-sided silicon microstrip modules was mounted on a mechanical structure very similar to a sector of the third layer of the TIB and read out using a system functionally identical to the final one. In this note the system setup configuration is fully described and the results of the test, concerning both detector performance and system characteristics, are presented and discussed

Study of radiation damage and substrate resistivity effects from beam test of silicon microstrip detectors using LHC readout electronics

We present the beam test results of single-sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied for a detector irradiated to a fluence of 2.4 multiplied by 10**1**4 n/cm**2. The detectors are read out with the APV6 chip, which is compatible with the 40 MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-to-noise ratio and efficiency

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio