0000000000041092

AUTHOR

James V. Porto

0000-0002-6290-7535

showing 5 related works from this author

Microcalorimeter/EBIT measurements of X-ray spectra of highly charged ions

2001

Spectra of highly charged Ar, Kr, Xe and Fe ions, produced in an Electron Beam Ion Trap (EBIT), have been recorded in a broad X-ray energy band (0.2 keV to 10 keV) with a microcalorimeter detector. The first analysis of the Kr spectra has been completed and most of the spectral lines have been identified as transitions of B- to Al-like Kr. Line intensity ratios of Fe XVII have been measured and compared with theoretical models.

PhysicsAtomic and Molecular Physics and OpticPhysics::Instrumentation and DetectorsDetectorTheoretical modelsCondensed Matter PhysicsAtomic and Molecular Physics and OpticsSpectral lineIonSettore FIS/05 - Astronomia E AstrofisicaMathematical PhysicAtomic physicsElectronic band structureX ray spectraMathematical PhysicsLine (formation)Electron beam ion trap
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Laboratory astrophysics survey of key x-ray diagnostic lines using a microcalorimeter on an electron beam ion trap

2000

Cosmic plasma conditions created in an electron beam ion trap (EBIT) make it possible to simulate the dependencies of key diagnostic X-ray lines on density, temperature, and excitation conditions that exist in astrophysical sources. We used a microcalorimeter for such laboratory astrophysics studies because it has a resolving power ≈1000, quantum efficiency approaching 100%, and a bandwidth that spans the X-ray energies from 0.2 keV to 10 keV. Our microcalorimeter, coupled with an X-ray optic to increase the effective solid angle, provides a significant new capability for laboratory astrophysics measurements. Broadband spectra obtained from the National Institute of Standards and Technology…

Physics::Instrumentation and DetectorsAstrophysics::High Energy Astrophysical Phenomenachemistry.chemical_elementFizikai tudományokAstrophysicsSpectral lineNeonTermészettudományokAtomic processeIonizationPhysics::Atomic PhysicsAtomic dataNuclear and High Energy PhysicPhysicsArgonKryptonAstronomy and AstrophysicsLine: IdentificationPlasmaX-rays: GeneralchemistrySpace and Planetary ScienceAstrophysical plasmaMethods: Laboratory plasmaAtomic physicsElectron beam ion trap
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Analysis of broadband x-ray spectra of highly charged krypton from a microcalorimeter detector of an electron-beam ion trap

2001

Spectra of highly charged Kr ions, produced in an electron-beam ion trap (EBIT), have been recorded in a broad x-ray energy band (0.3 keV to 4 keV) with a microcalorimeter detector. Most of the spectral lines have been identified as transitions of B- to Al-like Kr. The transition energies have been determined with 0.2% uncertainty. A semi-empirical EBIT plasma model has been created to calculate a synthetic spectrum of highly charged Kr and to determine a charge state distribution of Kr ions inside the EBIT.

PhysicsDetectorKryptonchemistry.chemical_elementFizikai tudományokPlasmaCondensed Matter PhysicSpectral lineIonPhysics and Astronomy (all)Settore FIS/05 - Astronomia E AstrofisicaTermészettudományokchemistryPhysics::Atomic PhysicsIon trapAtomic physicsElectronic band structureMathematical PhysicsElectron beam ion trapStatistical and Nonlinear Physic
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Emission-Line Intensity Ratios in F[CLC]e[/CLC] [CSC]xvii[/CSC] Observed with a Microcalorimeter on an Electron Beam Ion Trap

2000

We report new observations of emission line intensity ratios of Fe XVII under controlled experimental conditions, using the National Institute of Standards and Technology electron beam ion trap (EBIT) with a microcalorimeter detector. We compare our observations with collisional-radiative models using atomic data computed in distorted wave and R-matrix approximations, which follow the transfer of the polarization of level populations through radiative cascades. Our results for the intensity ratio of the 2p6 1S0-2p53d 1P1 15.014 A line to the 2p6 1S0-2p53d 3D1 15.265 A line are 2.94 ± 0.18 and 2.50 ± 0.13 at beam energies of 900 and 1250 eV, respectively. These results are not consistent wit…

PhysicsMethods: laboratorySun: coronaDetectorTechniques: spectroscopicAstronomy and Astrophysicslaboratory; Stars: individual (Capella); Sun: corona; Techniques: spectroscopic; X-rays: general [Atomic data; Methods]PlasmaX-rays: generalIntensity ratioPolarization (waves)IonSettore FIS/05 - Astronomia E AstrofisicaStars: individual (Capella)Space and Planetary ScienceRadiative transferEmission spectrumAtomic physicsAtomic dataElectron beam ion trapThe Astrophysical Journal
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Laboratory astrophysics and microanalysis with NTD-germanium-based X-ray microcalorimeters

2000

With the ability to create cosmic plasma conditions in the laboratory it is possible to investigate the dependencies of key diagnostic X-ray lines on density, temperature, and excitation conditions that exist in astrophysical sources with X-ray optics and a high-resolution X-ray microcalorimeter. The same instrumentation can be coupled to scanning electron microscopes or X-ray fluorescence probes to analyze the elemental and chemical composition of electronic, biological, geological and particulate materials. We describe how our microcalorimeter and X-ray optics provide significantly improved capabilities for laboratory astrophysics and microanalysis.

PhysicsNuclear and High Energy PhysicsX-ray spectroscopyAstrophysics::High Energy Astrophysical PhenomenaResolution (electron density)X-ray opticsX-ray fluorescencechemistry.chemical_elementFizikai tudományokGermaniumAstrophysicsMicroanalysisSettore FIS/05 - Astronomia E AstrofisicaTermészettudományokchemistryAstrophysical plasmaInstrumentationElectron beam ion trapNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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