Search results for "Thermal Neutrons"

showing 3 items of 3 documents

THE EFFECT OF GADOLINIUM ON THE ESR RESPONSE OF ALANINE AND AMMONIUM TARTRATE EXPOSED TO THERMAL NEUTRONS

2008

Many efforts have been made to develop neutron capture therapy (NCT) for cancer treatment. Among the challenges in using NCT is the characterization of the features of the mixed radiation field and of its components. In this study, we examined the enhancement of the ESR response of pellets of alanine and ammonium tartrate with gadolinium oxide exposed to a thermal neutron beam. In particular, the ESR response of these dosimeters as a function of the gadolinium content inside the dosimeter was analyzed. We found that the addition of gadolinium improves the sensitivity of both alanine and ammonium tartrate. However, the use of gadolinium involves a reduces in or abolishes tissue equivalence b…

High atomic numberHot TemperatureGadoliniumBiophysicschemistry.chemical_elementGadoliniumRadiation DosageSensitivity and SpecificityRadiology Nuclear Medicine and imagingAmmonium tartrateRadiometryTartratesAlanineNeutronsRadiationDosimeterAlanineRadiation fieldRadiochemistryElectron Spin Resonance SpectroscopyReproducibility of ResultsDose-Response Relationship RadiationNeutron temperatureSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Neutron capturechemistryESR dosimetry thermal neutronsNuclear chemistry
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Positron lifetime measurements on neutron‐irradiated InP crystals

1996

Neutron‐irradiated InP single crystals have been investigated by positron‐lifetime measurements. The samples were irradiated with thermal neutrons at different fluences yielding concentrations for Sn‐transmuted atoms between 2×1015 and 2×1018 cm−3. The lifetime spectra have been analyzed into one exponential decay component. The mean lifetimes show a monotonous increase with the irradiation dose from 246 to 282 ps. The increase in the lifetime has been associated to a defect containing an Indium vacancy. Thermal annealing at 550 °C reduces the lifetime until values closed to those obtained for the as‐grown and conventionally doped InP crystals. navarrof@evalvx.ific.uv.es ; Jose.Ferrero@uv.es

Materials sciencePhysics::Instrumentation and DetectorsPhysics::Medical PhysicsAnalytical chemistryGeneral Physics and Astronomychemistry.chemical_elementDefect StructureMonocrystalsSpectral lineCondensed Matter::Materials Science:FÍSICA [UNESCO]Vacancy defectNeutronIrradiationIndium Phosphides ; Radiation Effects ; Thermal Neutrons ; Monocrystals ; Positron Probes ; Lifetime ; Defect StructureExponential decayPositron ProbesDopingRadiochemistryUNESCO::FÍSICANeutron temperatureRadiation EffectschemistryIndium PhosphidesThermal NeutronsLifetimeIndiumJournal of Applied Physics
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Neutron–gamma mixed field measurements by means of MCP–TLD600 dosimeter pair

2007

Abstract In this paper, we compared the TL response of three types of thermoluminescence dosimeters, TLD600 (6LiF:Mg,Ti), TLD700 (7LiF:Mg,Ti) and MCP (LiF:Mg,Cu,P) after exposure to a n–γ mixed field in the fluence range of radiotherapeutic applications. Since a dosimeter pair is required to discriminate the two components of the mixed field, we analyzed the ability of each dosimeter pair to provide the fluence value in the mixed field. At this aim we performed a 60Co–γ calibration and a neutron calibration for all three dosimeter types. Finally, a blind test was performed in order to analyze the accuracy of each dosimeter pair and we found that in this mixed field the fluence value obtaine…

Nuclear and High Energy PhysicsDosimeterField (physics)ChemistryThermoluminescenceTLD600TLD700MCPThermal neutronsNeutron dosimetryRadiochemistryAnalytical chemistryFluenceThermoluminescenceNeutron temperatureCalibrationDosimetryNeutronInstrumentationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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