Calculation of X-ray bremsstrahlung and characteristic line emission produced by a Maxwellian electron distribution

McCall, Gene H.

doi:10.1088/0022-3727/15/5/012

Cited by 70 publications

(59 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This allowed us to determine the hot electron temperature. To determine the temperature of hot electrons generated we fit an electron energy distribution to the data using the methodology described by McCall et al 27 Because we examine hard x-rays being emitted from a thin target, we can assume there is an exponential distribution of the bremsstrahlung x-ray radiation and that the x-ray temperature and the hot-electron temperature are equivalent. 25 The x-ray spectrum is then convolved with the detector response and filter transmission functions.…”

Section: -mentioning

confidence: 99%

Hot electron and x-ray production from intense laser irradiation of wavelength-scale polystyrene spheres

et al. 2007

View full text Add to dashboard Cite

Hot electron and x-ray production from solid targets coated with polystyrene-spheres which are irradiated with high-contrast, 100fs, 400nm light pulses at intensity up to 2×1017W∕cm2 have been studied. The peak hard x-ray signal from uncoated fused silica targets is an order of magnitude smaller than the signal from targets coated with submicron sized spheres. The temperature of the x-rays in the case of sphere-coated targets is twice as hot as that of uncoated glass. A sphere-size scan of the x-ray yield and observation of a peak in both the x-ray production and temperature at a sphere diameter of 0.26μm, indicate that these results are consistent with Mie enhancements of the laser field at the sphere surface and multipass stochastic heating of the hot electrons in the oscillating laser field. These results also match well with particle-in-cell simulations of the interaction.

show abstract

Section: -mentioning

confidence: 99%

Hot electron and x-ray production from intense laser irradiation of wavelength-scale polystyrene spheres

et al. 2007

View full text Add to dashboard Cite

show abstract

“…On lui préfère un paramètre équivalent noté z qui est le ratio de l'énergie contenue dans les électrons supra-thermiques par rapport à J'énergie de l'impulsion laser. A partir des deux paramètres T,,, et 17, l'émission X se déduit directement à l'aide de lois semi-empiriques [25]. L'optimisation de la source X est donc essentiellement liée à notre habilité à maîtriser la génération des électrons supra-thermiques lors de l'interaction.…”

Section: La Distributionunclassified

“…L'optimisation de la source X est donc essentiellement liée à notre habilité à maîtriser la génération des électrons supra-thermiques lors de l'interaction. C'est pourquoi, dans un premier temps et en utilisant ces mêmes lois semi-empiriques [25], la mesure des X durs a été utilisée pour déduire les valeurs de la température Tho, et du taux de conversion z puis leur comportement en fonction des différents paramètres de l'expérience. Les paramètres dont l'influence a été étudiée sont essentiellement : la nature de la cible (i. e. son numéro atomique Z) et l'amplitude maximale du champ électrique laser.…”

Section: La Distributionunclassified

“…? de la distribution des électrons supra-thermiques responsables de l'émission X [25]. Pour chacun des spectres mesurés, nous avons vérifié que les valeurs déduites de ces paramètres étaient compatibles avec l'intensité observée du rayonnement K.. A partir du spectre représenté sur la figure 1, les valeurs déduites pour les électrons sont Tao, = 35 keV et z = 10 %.…”

Section: Dispositif Expérimentalunclassified

“…Ce taux 17, déprend du rapport de la température Tho, des électrons sur l'énergie E, des photons Ka. Cette dépendance peut se déduire des lois semi-empiriques de la référence [25]. Elle est représentée sur la figure 3 à partir des points expérimentaux.…”

Section: Lois D'échelle Obtenuesunclassified

See 2 more Smart Citations

Imagerie médicale avec des sources X créées par laser

et al. 2003

View full text Add to dashboard Cite

Practical Aspects

Reibenspies¹,

Bhuvanesh²

2009

Principles and Applications of Powder Diffraction

View full text Add to dashboard Cite

Generation of X-rays: general concepts and terminologyX-rays are produced by the collision of high-velocity electrons with a stationary or rotating metallic target. The most useful X-rays for the home laboratory have energies between 4 and 21 keV, which relates to wavelengths of 3.1-0.59 Å (1 Å = 10 −10 m). X-rays with energy below 4 keV are readily absorbed by air, while X-rays above 21 keV will return condensed powder patterns that can be difficult to interpret.In practice, the metallic target is made of chromium (Cr), cobalt (Co), copper (Cu) or molybdenum (Mo). These metals produce X-rays in the 4-21 keV range while providing stable heat conduction and corrosion resistance. The production of X-rays generates large quantities of heat, which must be dissipated rapidly in order to prevent the metallic targets from melting; therefore, the metals must be durable and conductive to both heat and electricity.The continuous and characteristic spectrum of X-ray radiation is produced when highvelocity electrons strike the metallic target. The continuous spectrum or Bremsstrahlung radiation is produced when the path of the electron that enters the target is altered by interactions with the metal atoms (McCall, 1982). The bending or braking action causes the electrons to lose momentum and release X-ray radiation. The Bremsstrahlung radiation displays a continuous spectrum due to the fact that not every electron will decelerate in a similar manner. The electrons that are completely stopped by the impact will release all of their energy at once, and thus produce the maximum energetic and lowest wavelength X-ray. The energy is thus described by the equation:where λ is in Å (10 −10 m) and V is the applied voltage. If one plots the intensity of the Bremsstrahlung radiation against increasing wavelength, one would etch a curve that begins at λ min and rapidly increases to a maximum of a few tenths of an Angstrom above λ min and then slowly decreases as one proceeds to longer wavelengths. The characteristic spectrum, on the other hand, is composed of sharp intensity maxima at critical wavelengths and is superimposed on the continuous spectrum. These narrow peaks are characteristic of the metal used in the target material and are associated with the Principles and Applications of Powder Diffraction. Edited

show abstract

Calculation of X-ray bremsstrahlung and characteristic line emission produced by a Maxwellian electron distribution

Cited by 70 publications

References 11 publications

Hot electron and x-ray production from intense laser irradiation of wavelength-scale polystyrene spheres

Hot electron and x-ray production from intense laser irradiation of wavelength-scale polystyrene spheres

Imagerie médicale avec des sources X créées par laser

Practical Aspects

Contact Info

Product

Resources

About