Determination of coincidence summing correction factors for 22na point source

The coincidence summing effect plays an important role in HPGe spectrometry, especially at low source-detector distances, due to a large solid angle; therefore, the calculation of correction factors is necessary. The aim of the research described in this paper was to compare values of correction factors for a 22Na point source obtained using the GESPECOR software package (Monte-Carlo method) and experimentally obtained values. Measurements were performed using a semiconductor HPGe spectrometer and the point source axially positioned at nine different distances from the detector end-cap. For the purpose of determining correction factors, a system of equations was formed, which, besides nuclear data as the input parameters, uses the experimentally obtained values of the total count in the entire spectrum, as well as the counts in the full energy peaks. The system of equations was solved for each particular case and correction factors were determined. By comparing the results obtained using the experimental and Monte-Carlo method, it was found that the correction factors for the 22Na point source have discrepancies less than 3%. The significance of these discrepancies was also verified from a statistical point of view using a Student's t-test. © 2019 RAD Association. All rights reserved.Conference of 6th International Conference on Radiation and Applications in Various Fields of Research, RAD 2018 ; Conference Date: 18 June 2018 Through 22 June 2018; Conference Code:14955

The New Setup in the Belgrade Low-Level and Cosmic-Ray Laboratory

The Belgrade underground laboratory consists of two interconnected spaces, a ground level laboratory and a shallow underground one, at 25 m.w.e.. The laboratory hosts a low-background gamma spectroscopy system and cosmic-ray muon detectors. With recently adopted digital data acquisition system it is possible to study simultaneously independent operation of two detector systems, as well as processes induced by cosmic-ray muons in germanium spectrometers. Characteristics and potentials of present experimental setup, together with some preliminary results for the flux of fast neutrons and stopped muons are reported.Comment: 12 pages, 16 figure

Measurement of the charge ratio of atmospheric muons with the CMS detector

We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 +/- 0.0032 (stat.) +/- 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments. (C) 2010 Published by Elsevier B.V

Transverse-Momentum and Pseudorapidity Distributions of Charged Hadrons in pp Collisions at root s=7 TeV

Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at root s = 7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dN(ch)/d eta vertical bar(vertical bar eta vertical bar LT 0.5) = 5.78 +/- 0.01(stat) +/- 0.23(stat) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from root s = 0.9 to 7 TeV is [66.1 +/- 1.0(stat) +/- 4.2(syst)]%. The mean transverse momentum is measured to be 0.545 +/- 0.005(stat) +/- 0.015(syst) GeV/c. The results are compared with similar measurements at lower energies

Određivanje korekcionih faktora za koincidentno sumiranje u slučaju tačkastog izvora Y88

У гама спектрометрији се често сусрећемо са ефектом коинцидентног сумирања, а самим тим постоји потреба за одређивањем корекционих фактора. Циљ истраживања описаног у овом раду је поређење вредности корекционих фактора за тачкасти извор 88Y добијених помоћу софтверског пакета GESPECOR (Монте Карло методом) и експериментално добијених вредности. Мерења су обављена помоћу полупроводничког HPGe спектрометра, при чему је тачкасти извор био позициониран на аксијалној оси детектора на девет различитих растојања од капе детектора. Формиран је систем једначина, који осим нуклеарних података, као улазне параметре користи и експериментално добијене вредности тоталног одброја у целом спектру, као и одброја испод фотопикова. На основу решавања система једначина одређени су корекциони фактори за коинцидентно сумирање. Упоређивањем резултата, утврђено је да се вредности корекционих фактора добијених помоћу ове две методе разликују до 3 %.In gamma ray spectrometry often deals with coincidence summing effect, and therefore calculation of correction factors is necessary. Coincidence summing effect play an important role in HPGe spectrometry at low source-detector distances, due to the large solid angle subtended by the detector at the source. The aim of research described in this paper was to compare values of correction factors for point source 88Y obtained using the software package GESPECOR (Monte-Carlo method) and experimentally obtained values. Measurements were performed using a semiconductor HPGe spectrometer, wherein point source was axially located on detector at nine different distances. The system of equations was formed whereas net areas in full energy peaks as well as in entire spectrum were used as input data. The system was solved and correction factors for point source 88Y were determined. By comparing the obtained values, it was found that correction factors obtained by these two methods have discrepancy less than 3 %.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Određivanje korekcionih faktora za koincidentno sumiranje u slučaju tačkastog izvora Y88

У гама спектрометрији се често сусрећемо са ефектом коинцидентног сумирања, а самим тим постоји потреба за одређивањем корекционих фактора. Циљ истраживања описаног у овом раду је поређење вредности корекционих фактора за тачкасти извор 88Y добијених помоћу софтверског пакета GESPECOR (Монте Карло методом) и експериментално добијених вредности. Мерења су обављена помоћу полупроводничког HPGe спектрометра, при чему је тачкасти извор био позициониран на аксијалној оси детектора на девет различитих растојања од капе детектора. Формиран је систем једначина, који осим нуклеарних података, као улазне параметре користи и експериментално добијене вредности тоталног одброја у целом спектру, као и одброја испод фотопикова. На основу решавања система једначина одређени су корекциони фактори за коинцидентно сумирање. Упоређивањем резултата, утврђено је да се вредности корекционих фактора добијених помоћу ове две методе разликују до 3 %.In gamma ray spectrometry often deals with coincidence summing effect, and therefore calculation of correction factors is necessary. Coincidence summing effect play an important role in HPGe spectrometry at low source-detector distances, due to the large solid angle subtended by the detector at the source. The aim of research described in this paper was to compare values of correction factors for point source 88Y obtained using the software package GESPECOR (Monte-Carlo method) and experimentally obtained values. Measurements were performed using a semiconductor HPGe spectrometer, wherein point source was axially located on detector at nine different distances. The system of equations was formed whereas net areas in full energy peaks as well as in entire spectrum were used as input data. The system was solved and correction factors for point source 88Y were determined. By comparing the obtained values, it was found that correction factors obtained by these two methods have discrepancy less than 3 %.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Performance study of the CMS barrel resistive plate chambers with cosmic rays

In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported

Aligning the CMS muon chambers with the muon alignment system during an extended cosmic ray run

The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 mu m and 30-200 mu rad, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 mu m based on comparisons with independent photogrammetry measurements

Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data

The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmic ray data were taken with and without magnetic field at the surface hall and after installation in the experimental hall, hundred meters underground. Various measurements were also performed during the few days of beam in the LHC in September 2008. Calibration parameters were extracted, and the energy response of the HCAL determined from test beam data has been checked