X-ray flux from discrete sources

Preliminary results of two rocket flights carrying X-ray payloads conducted from Thumba Equatorial Rocket Launching Station (TERLS), Trivandrum, India, on November 3, 1968, and November 7, 1968, respectively, are presented. The results indicate the first evidence for the existence of low energy X-ray flux in the energy range 2–20 keV from Cen-X2 source since the reported extinction in May, 1967. The energy spectrum and the absolute flux of X-rays from Cen-X2, Sco-X1 and Tau-X1 are presented and compared with other observations.

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Low-energy cosmic X-ray measurements

Canadian Journal of Physics ◽

10.1139/p69-324 ◽

1969 ◽

Vol 47 (23) ◽

pp. 2651-2666 ◽

Cited By ~ 14

Author(s):

A. J. Baxter ◽

B. G. Wilson ◽

D. W. Green

Keyword(s):

Spectral Analysis ◽

Energy Range ◽

Crab Nebula ◽

Spectral Characteristics ◽

Low Energy ◽

Data Recovery ◽

X Rays ◽

X Ray ◽

Recovery System ◽

The Crab Nebula

An experiment is described to investigate cosmic X rays in the energy range 0.25–12 keV. The data-recovery system and methods of spectral analysis are considered. Results are presented for the energy spectrum of the diffuse X-ray component and its distribution over the northern sky down to 1.6 keV with a limited extension at 0.27 keV.In the energy range 1.6 to 12 keV, the spectrum is represented by:[Formula: see text]although separate analyses indicate a flattening below 4.5 keV to give:[Formula: see text]and[Formula: see text]At the lowest energies, the flux appears to increase more rapidly and exhibits some anisotropy in arrival directions related to the gross galactic structure. Spectral characteristics of the Crab Nebula and Cygnus X-2 have also been determined.

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Simultaneous measurements of X-rays and electrons during a pulsating aurora

Annales Geophysicae ◽

10.1007/s00585-998-0148-0 ◽

1998 ◽

Vol 16 (2) ◽

pp. 148-160 ◽

Cited By ~ 6

Author(s):

N. Østgaard ◽

J. Stadsnes ◽

K. Aarsnes ◽

F. Søraas ◽

K. Måseide ◽

...

Keyword(s):

Energy Spectrum ◽

Energy Range ◽

Energetic Particle ◽

Good Method ◽

Electron Energy Spectrum ◽

Electron Precipitation ◽

X Rays ◽

X Ray ◽

Electron Spectra ◽

Simultaneous Measurements

Abstract. The PULSAUR II rocket was launched from Andøya Rocket Range at 23.43 UT on 9 February 1994 into a pulsating aurora. In this paper we focus on the observations of precipitating electrons and auroral X-rays. By using models it is possible to deduce the electron energy spectrum from X-ray measurements. Comparisons are made between the deduced electron fluxes and the directly measured electron fluxes on the rocket. We found the shape of the observed and the deduced electron spectra to fit very well, with almost identical e-folding energies in the energy range from 10 ke V to ~60–80 ke V. For the integrated fluxes from 10.8 to 250 ke V, we found a discrepancy of 30% . By combining two models, we have found a good method of deducing the electron precipitation from X-ray measurements. The discrepancies between calculations and measurements are in the range of the uncertainties in the measurements.Key words. Ionospheric particle precipitation · Magnetospheric physics · Annual phenomena · Energetic particle

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A Pinhole Camera for Photographing X-Rays from Laser-Produced Plasmas*

Advances in X-ray Analysis ◽

10.1154/s0376030800006650 ◽

1974 ◽

Vol 18 ◽

pp. 136-145

Author(s):

J. J. Hohlfelder ◽

M. A. Palmer

Keyword(s):

Energy Range ◽

Spatial Resolution ◽

Spatial Information ◽

Laser System ◽

Pulsed Laser ◽

Pinhole Camera ◽

Low Energy ◽

X Rays ◽

X Ray ◽

Laboratory Calibration

AbstractA pinhole camera has been used to record low-energy x rays produced from CD2 microsphere irradiation with Sandia Laboratories four-beam, pulsed laser system. Camera useful energy range, spatial resolution, and x-ray energy sensitivity are discussed. Camera x-ray energy sensitivity which was determined by laboratory calibration is compared with measurements obtained with a multi-channel x-ray spectrometer. X-ray photographs of laser-irradiated microspheres are presented. Spatial information about the x-ray source derived from these photographs is discussed.

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Low Energy Mass Absorption Coefficients from Proton Induced X-ray Spectroscopy

Advances in X-ray Analysis ◽

10.1154/s037603080001209x ◽

1976 ◽

Vol 20 ◽

pp. 481-486 ◽

Cited By ~ 1

Author(s):

A. Lurio ◽

W. Reuter ◽

J. Keller

Keyword(s):

Energy Range ◽

Experimental Technique ◽

Low Energy ◽

X Rays ◽

Proton Bombardment ◽

Absorption Coefficients ◽

X Ray ◽

Mass Absorption

We describe a new and reliable experimental technique for the measurement of mass absorption coefficients in the 0.1 to 1 keV energy range. In this technique, the absorbing film is supported directly on a substrate which under proton bombardment will generate the x-rays whose absorption will be measured. Results are given for thirteen different metals at the C Kα (277 eV) line.

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Development of low-energy X-ray detectors using LGAD sensors

Journal of Synchrotron Radiation ◽

10.1107/s1600577519005393 ◽

2019 ◽

Vol 26 (4) ◽

pp. 1226-1237 ◽

Cited By ~ 6

Author(s):

Marie Andrä ◽

Jiaguo Zhang ◽

Anna Bergamaschi ◽

Rebecca Barten ◽

Camelia Borca ◽

...

Keyword(s):

Energy Range ◽

Single Photon ◽

Signal To Noise Ratio ◽

Photon Counting ◽

Low Energy ◽

X Rays ◽

Single Photon Counting ◽

X Ray ◽

Internal Gain ◽

Silicon Sensors

Recent advances in segmented low-gain avalanche detectors (LGADs) make them promising for the position-sensitive detection of low-energy X-ray photons thanks to their internal gain. LGAD microstrip sensors fabricated by Fondazione Bruno Kessler have been investigated using X-rays with both charge-integrating and single-photon-counting readout chips developed at the Paul Scherrer Institut. In this work it is shown that the charge multiplication occurring in the sensor allows the detection of X-rays with improved signal-to-noise ratio in comparison with standard silicon sensors. The application in the tender X-ray energy range is demonstrated by the detection of the sulfur K α and K β lines (2.3 and 2.46 keV) in an energy-dispersive fluorescence spectrometer at the Swiss Light Source. Although further improvements in the segmentation and in the quantum efficiency at low energy are still necessary, this work paves the way for the development of single-photon-counting detectors in the soft X-ray energy range.

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Calibration and measurement of X-ray personal dose equivalent with a Hp(10) ionization chamber

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp210304019x ◽

2021 ◽

pp. 19-19

Author(s):

Yang Xu ◽

Rui Zhao

Keyword(s):

Energy Range ◽

Ionization Chamber ◽

Conversion Coefficient ◽

Low Energy ◽

X Rays ◽

Correction Factors ◽

Dose Equivalent ◽

X Ray ◽

Conversion Coefficients ◽

Small Change

The value of personal dose equivalent at10 mm depth is to characterize the energy deposition of strong penetrating radiation in human body and is derived by measurement of air kerma and application of conversion coefficients from ISO report. However, the conversion coefficients depend strongly on the photon energy and angles of incidence for low-energy photons. In order to overcome the problem that the conversion coefficient of low energy rays changes greatly due to the small change of energy, a secondary standard ionization chamber was used to measure personal dose equivalent directly. A matched reference field was established with (20-250) kV X-rays and correction factors with Hp(10) chamber were calculated under these radiation qualities with different angles of incidence. The results showed that the differences were almost 22.7 % of correction factors for the low energy photons at angles of incidence 0?. With conversion coefficient recommended in ISO 4037-3-2019, performance of the chamber response with respect to Hp(10) in the energy range from 33 keV to 208 keV was within about ?10%, and in the energy range from 12 keV to 208 keV and for angles of incidence between 0? and 75? was within about ?19%.

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Low-energy Bremsstrahlung X-ray spectra from a stable auroral arc

Canadian Journal of Physics ◽

10.1139/p69-298 ◽

1969 ◽

Vol 47 (21) ◽

pp. 2427-2430 ◽

Cited By ~ 6

Author(s):

B. G. Wilson ◽

A. J. Baxter ◽

D. W. Green

Keyword(s):

Energy Range ◽

Power Law ◽

Spectral Characteristics ◽

Low Energy ◽

X Rays ◽

X Ray ◽

Rocket Experiment

During a rocket experiment launched to investigate cosmic X rays, the directional features and spectral characteristics of X rays from an auroral arc have been determined in the 1.6 to 10 keV energy range. The spectrum was best represented by a power law of slope −3.365 ± 0.07.

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Observational results on diffuse cosmic X-rays: (Invited discourse)

Symposium - International Astronomical Union ◽

10.1017/s0074180900004393 ◽

1970 ◽

Vol 37 ◽

pp. 260-268

Author(s):

Minoru Oda

Keyword(s):

Energy Spectrum ◽

Energy Range ◽

Present Status ◽

X Rays ◽

X Ray ◽

Normal Galaxies ◽

The Universe

The present status of observations of the diffuse cosmic X-rays is discussed. The energy spectrum in the energy range 1–100 keV has been well established. The flux around 0.25 keV appears to be rather high. The basis of the classical argument that the integration of normal galaxies in the universe is not sufficient to explain the diffuse X-ray flux is re-examined. Recent observations around 0.25 keV are discussed and results are compiled.

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THE DOPPLER FACTORS AT X-RAY BAND OF THE BLAZARS

International Journal of Modern Physics D ◽

10.1142/s0218271805005888 ◽

2005 ◽

Vol 14 (06) ◽

pp. 947-956

Author(s):

D. C. MEI ◽

L. ZHANG

Keyword(s):

Synchrotron Radiation ◽

Energy Range ◽

High Energy ◽

Low Energy ◽

X Rays ◽

X Ray ◽

Inverse Compton Scattering ◽

Inverse Compton ◽

Doppler Factor ◽

Intrinsic Radiation

We study the Doppler factors for a group blazars at soft X-ray band. In our estimates, we have made the assumptions that (i) blazars can be divided into high-energy-peaked (HEP) objects whose synchrotron peak frequencies νp > 1014.7 Hz , and the low-energy-peaked (LEP) objects whose synchrotron peak frequencies νp≤1014.7 Hz , and (ii) the intrinsic radiation from a blazar in the energy range from radio to soft X-ray bands is the synchrotron radiation for HEP objects and the soft X-ray emission comes from inverse Compton scattering for LEP objects. Under the above assumptions, we estimate Doppler factors at optical (δO) and X-rays (δx) for 54 blazars by using the known radio Doppler factors and the observed flux densities in radio, optical and X-ray bands, and Doppler factors [Formula: see text] at X-ray band in which X-rays are assumed to be produced only by the synchrotron radiation. We get [Formula: see text] . The Doppler factors are different in various wavebands, and on average, the Doppler factor decreases with frequency from radio to X-ray bands.

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