Search results for "Rutherford backscattering spectrometry"

showing 6 items of 26 documents

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…

Nuclear and High Energy PhysicsPhysics - Instrumentation and DetectorsMaterials sciencePhysics::Instrumentation and Detectors010308 nuclear & particles physicsRadioactive sourceFOS: Physical sciencesThoriumchemistry.chemical_elementInstrumentation and Detectors (physics.ins-det)RadiationRutherford backscattering spectrometry01 natural sciencesIon sourceRecoilchemistry0103 physical sciencesGamma spectroscopyNuclear Experiment (nucl-ex)Atomic physicsNuclear Experiment010306 general physicsSpectroscopyNuclear ExperimentInstrumentationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Time-of-flight telescope for heavy-ion RBS

2007

Abstract This paper describes a time-of-flight (TOF) spectrometer for Heavy-Ion Rutherford Backscattering Spectrometry (HI-RBS) recently installed at IMEC for thin film analysis. The TOF telescope allows the use of ion beams heavier than He, with advantages in terms of depth and mass resolution and sensitivity compared to conventional RBS based on planar Si detectors. The start timing-signal is produced by the secondary electrons emitted from a thin C foil when traversed by a backscattered ion; the electrons are deflected in an electrostatic mirror towards a Micro-channel plate (MCP) assembly which provides a fast timing response. The stop signal is obtained directly from a second MCP assem…

Nuclear and High Energy PhysicsSpectrometerPhysics::Instrumentation and Detectorsbusiness.industryChemistryRutherford backscattering spectrometrySecondary electronslaw.inventionIonElastic recoil detectionTelescopeTime of flightOpticslawTime-of-flight mass spectrometrybusinessInstrumentationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Structural characterization of a-plane Zn1−xCdxO (0 < x <0.085) thin films grown by metal-organic vapor phase epitaxy.

2006

Zn1−xCdxO(11math0) films have been grown on (01math2) sapphire (r–plane) substrates by metal-organic vapor phase epitaxy. A 800-nm-thick ZnO buffer, deposited prior to the alloy growth, helps to prevent the formation of pure CdO. A maximum uniform Cd incorporation of 8.5 at. % has been determined by Rutherford backscattering spectrometry. Higher Cd contents lead to the coexistence of Zn1−xCdxO alloys of different compositions within the same film. The near band-edge photoluminescence emission shifts gradually to lower energies as Cd is incorporated and reaches 2.93 eV for the highest Cd concentration (8.5 at. %). The lattice deformation, due to Cd incorporation, has been described using a n…

PhotoluminescenceMaterials scienceRutherford backscatteringCadmium compoundsUNESCO::FÍSICAAnalytical chemistrySemiconductor epitaxial layersGeneral Physics and AstronomyII-VI semiconductorsSurface structureChemical vapor depositionRutherford backscattering spectrometryEpitaxyVapour phase epitaxial growthCrystallographyLattice constantZinc compounds ; Cadmium compounds ; II-VI semiconductors ; MOCVD ; Vapour phase epitaxial growth ; Semiconductor epitaxial layers ; Rutherford backscattering ; Photoluminescence ; Surface structure ; Buffer layers:FÍSICA [UNESCO]MOCVDSapphireBuffer layersMetalorganic vapour phase epitaxyZinc compoundsThin filmPhotoluminescence
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Characterization of alpha sources by Rutherford backscattering spectrometry

1996

Radioactive sources for alpha spectrometry are usually prepared by electrodeposition onto stainless steel backings (and sometimes heated). In earlier work, using the conventional method with passivated implanted planar silicon detectors for the measurements, several sources had been characterized in terms of various parameters by fitting the data of each spectrum to a certain mathematical function. In the present work, the Rutherford Backscattering Spectrometry (RBS) technique with a 1.6 MeV He+ beam was used to study the influence of those factors on the surface distribution and depth profiles of the thin radionuclide layers. Simulations of the measurements using the RUMP computer code wer…

PhysicsNuclear and High Energy PhysicsPlanarSiliconchemistryAlpha spectrometryDetectorchemistry.chemical_elementAtomic physicsRutherford backscattering spectrometryInstrumentationBeam (structure)Characterization (materials science)Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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Semipermeable membrane to retain platinum atoms in the electrodeposition process of alpha spectrometry sources

1998

Abstract In earlier work alpha sources electrodeposited on stainless steel backings were analyzed by X-ray fluorescence (XRF) and Rutherford backscattering spectrometry (RBS) finding that during the electrodeposition process large quantities of platinum from the anode were deposited on the cathode surface jointly with the actinides. In the present work, a method to retain platinum atoms using an electrodeposition cell with a semipermeable membrane located between anode and cathode is proposed and tested. The XRF and RBS of alpha sources electrodeposited using this method show that there is less platinum on the stainless steel backing, thereby improving the quality of sources to be measured …

RadiationMaterials scienceAlpha spectrometryAnalytical chemistrychemistry.chemical_elementActinideRutherford backscattering spectrometryCathodelaw.inventionAnodechemistrylawScientific methodSemipermeable membranePlatinumApplied Radiation and Isotopes
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Light absorption in silicon quantum dots embedded in silica

2009

The photon absorption in Si quantum dots (QDs) embedded in SiO2 has been systematically investigated by varying several parameters of the QD synthesis. Plasma-enhanced chemical vapor deposition (PECVD) or magnetron cosputtering (MS) have been used to deposit, upon quartz substrates, single layer, or multilayer structures of Si-rich- SiO2 (SRO) with different Si content (43-46 at. %). SRO samples have been annealed for 1 h in the 450-1250 °C range and characterized by optical absorption measurements, photoluminescence analysis, Rutherford backscattering spectrometry and x-ray Photoelectron Spectroscopy. After annealing up to 900 °C SRO films grown by MS show a higher absorption coefficient a…

SOLAR-CELLSPhotoluminescenceMaterials scienceEFFICIENCYSiliconAnalytical chemistryGeneral Physics and Astronomychemistry.chemical_elementChemical vapor depositionOPTICAL-PROPERTIESRutherford backscattering spectrometryFILMSSettore ING-INF/01 - Elettronica3RD-GENERATION PHOTOVOLTAICSSettore FIS/03 - Fisica Della MateriaMULTIPLE EXCITON GENERATIONchemistryX-ray photoelectron spectroscopyPlasma-enhanced chemical vapor depositionQuantum dotRAY PHOTOELECTRON-SPECTROSCOPYLUMINESCENCESI NANOCRYSTALSCOEFFICIENTAbsorption (electromagnetic radiation)
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