Search results for "Radioactive source"
showing 10 items of 10 documents
A portable readout system for silicon microstrip sensors
2010
Abstract This system can measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256. The system is able to operate with different types (p- and n-type) and different sizes (up to 3 cm 2 ) of microstrip silicon sensors, both irradiated and non-irradiated. Heavily irradiated sensors will be used at the Super Large Hadron Collider, so this system can be used to research the performance of microstrip silicon sensors in conditions as similar as possible to the Super Large Hadron Collider operating conditions. The system has two main parts: a hardware part and a software part. The hardware part acquires the sensor signals eith…
The ATLAS Tile Calorimeter performance at LHC
2013
The Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. Due to the very good muon signal to noise ratio it assists the spectrometer in the identification and reconstruction of muons. TileCal is built of steel and scintillating tiles coupled to optical fibers and read out by photomultipliers. The calorimeter is equipped with systems that allow to monitor and to calibrate each stage of the read-out system exploiting different signal sources: laser light, charge injection and a radiactive source. The performance of the calorimeter has been …
Characterization of 233U alpha recoil sources for 229()Th beam production
2019
Radioactive $^{233}$U alpha recoil sources are being considered for the production of a thorium ion source to study the low-energy isomer in $^{229}$Th with high-resolution collinear laser spectroscopy at the IGISOL facility of the University of Jyv\"askyl\"a. In this work two different $^{233}$U sources have been characterized via alpha and gamma spectroscopy of the decay radiation obtained directly from the sources and from alpha-recoils embedded in implantation foils. These measurements revealed rather low $^{229}$Th recoil efficiencies of only a few percent. Although the low efficiency of one of the two sources can be attributed to its inherent thickness, the low recoil efficiency of th…
SU-FF-T-14: Monte Carlo Derivation of TG-43 Dosimetric Parameters for Radiation Therapy Resources and 3M Cs-137 Sources
2005
Purpose: In clinical brachytherapydosimetry a detailed dose rate distribution of the radioactive source in water is needed to make a quality treatment planning. Two Cs‐137 sources are considered in this study the Radiation Therapy Resources 67–800 source(Radiation Therapy Resources Inc., Valencia, CA) and the 3M model 6500/6D6C source.Material and methods: A complete dosimetric dataset for both sources has been obtained by means of the Monte Carlo GEANT4 code. Results:Dose rate distributions are presented in two different ways, following the TG43 formalism and in a 2D rectangular dose rate table. Conclusion: This 2D dose rate table is helpful for the TPS quality control and it is fully cons…
The “accumulation effect” of positrons in the stack of foils, detected by measurements of the positron implantation profile
2013
The profiles of positrons implanted from the radioactive source 22Na into a stack of foils and plates are the subject of our experimental and theoretical studies. The measurements were performed using the depth scanning of positron implantation profile method, and the theoretical calculations using the phenomenological multi-scattering model (MSM). Several stacks consisting of silver, gold and aluminum foils, and titanium and germanium plates were investigated. We notice that the MSM describes well the experimental profiles; however when the stack consisting of silver and gold foils, the backscattering and linear absorption coefficients differ significantly from those reported in the litera…
Trial for the long neutron counter TETRA using $^{96,97}$Rb radioactive sources
2019
International audience; The TETRA long neutron counter is operated at ALTO ISOL facility behind the PARRNe mass separator. TETRA has been proven to be a unique instrument for measurements of β-decay properties of short-lived neutron-rich nuclei having applications for the nuclear structure and/or astrophysical r-process calculations. A proper calibration of TETRA can allow validation of the experimental procedure used for determination of β-delayed one-neutron emission probabilities (P1n). It requires the use of a well-known β-neutron decaying radioactive source which can be only produced and measured on-line due to its short half-life. Thus, the present paper reports on measurements of P1n…
Progettazione e realizzazione di un irradiatore neutronico modulare basato su sorgenti Am-Be
2012
Irradiatori neutronici basati su sorgenti radionuclidiche sono impiegati in diversi paesi per studiare le caratteristiche dei materiali sottoposti a irradiazione e/o la risposta di rivelatori e/o dosimetri personali sensibili alla componente neutronica. Per quest’ultima applicazione, l’uso di un irradiatore con sorgenti radionuclidiche risulta molto vantaggioso per la stabilità nel tempo del flusso neutronico, mentre è relativamente poco importante il valore assoluto del flusso neutronico, che può anche essere di qualche ordine di grandezza inferiore a quello di reattori o di acceleratori di particelle. Per l’effettuazione di test su rivelatori e/o dosimetri personali neutronici risulta mol…
A monte carlo study of dose rate distribution around the specially asymmetric CSM3-a 137Cs source.
2001
The CSM3 137Cs type stainless-steel encapsulated source is widely used in manually afterloaded low dose rate brachytherapy. A specially asymmetric source, CSM3-a, has been designed by CIS Bio International (France) substituting the eyelet side seed with an inactive material in the CSM3 source. This modification has been done in order to allow a uniform dose level over the upper vaginal surface when this `linear' source is inserted at the top of the dome vaginal applicators. In this study the Monte Carlo GEANT3 simulation code, incorporating the source geometry in detail, was used to investigate the dosimetric characteristics of this special CSM3-a 137Cs brachytherapy source. The absolute do…
Technical note: Monte Carlo derivation of TG-43 dosimetric parameters for radiation therapy resources and 3M Cs-137 sources
2005
In clinical brachytherapy dosimetry, a detailed dose rate distribution of the radioactive source in water is needed in order to plan for quality treatment. Two Cs-137 sources are considered in this study; the Radiation Therapy Resources 67-800 source (Radiation Therapy Resources Inc., Valencia, CA) and the 3M model 6500/6D6C source. A complete dosimetric dataset for both sources has been obtained by means of the Monte Carlo GEANT4 code. Dose rate distributions are presented in two different ways; following the TG43 formalism and in a 2D rectangular dose rate table. This 2D dose rate table is helpful for the TPS quality control and is fully consistent with the TG43 dose calculation formalism…
Background radiation effects and hazards in planetary instrumentation
2006
Recent and proposed future planetary missions are becoming increasingly concerned with detailed geochemical assessment, often in a bid to ascertain the presence of water and life supporting geochemical systems. The instruments involved may use some kind of radioactive source, e.g. X-ray fluorescence spectrometry, Mossbauer spectrometry, neutron scattering. Having radioactive sources on a lander/rover poses various potential problems, in regard to both safety to personnel involved in the building of the instrument and to radiation effects on spacecraft structure and on other instruments. Indeed background radiation effects from one instrument may dominate measurements in another resulting in…