scholarly journals Reducing the Athena WFI charged particle background: results from Geant4 simulations

2020 ◽  
Author(s):  
Catherine E. Grant ◽  
Eric D. Miller ◽  
Marshall W. Bautz ◽  
Tanja Eraerds ◽  
Silvano Molendi ◽  
...  
Keyword(s):  
Charged Particle ◽  
Particle Background

scholarly journals OSO-8 X-Ray Polarimeter and Bragg Crystal Spectrometer Observations

1977 ◽  
Vol 4 (1) ◽  
pp. 95-97
Author(s):  
R. Novick ◽  
H.L. Kestenbaum ◽  
K.S. Long ◽  
E.H. Silver ◽  
M.C. Weisskopf ◽  
...  
Keyword(s):  
Charged Particle ◽  
Counting Rate ◽  
Crab Nebula ◽  
Position Angle ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Particle Background ◽  
The Crab Nebula ◽  
Satellite Spin

The OSO-8 satellite contains a focusing mosaic graphite crystal X-ray polarimeter that is oriented along the spin axis of the wheel section of the satellite. The polarimeter operates at 2.6 and 5.2 keV. Polarization in a source appears as a modulation of the counting rate at twice the satellite spin frequency. The amplitude and phase of the modulation are simply related to the polarization and position angle, respectively. Two independent polarimeters are employed, and their axes are offset by 128°. Focusing is achieved by mounting the crystals on a parabolic sector, which reduces the background without reducing the sensitivity. The low background that results from the focusing not only improves the statistical quality of the data but also substantially reduces the danger that an asymmetry in the charged particle background may produce a spurious polarization result. This is particularly important in the case of weak sources. The instrument has been described in detail elsewhere (Novick 1975); here we will briefly discuss the results obtained on the Crab Nebula, Cyg X-l, and Cyg X-2.

The X-ray Albedo from the Earth

1968 ◽  
Vol 1 (3) ◽  
pp. 111-112
Author(s):  
J.R. Harries ◽  
R.J. Francey
Keyword(s):  
Charged Particle ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Diffuse Flux ◽  
The Earth ◽  
Particle Background ◽  
The Difference

An albedo X-ray flux from the Earth was observed by experiments which were flown on Skylark rockets during April 1967. The details of the flights and the equipment have been covered in a previous paper. The celestial X-rays observed from discrete sources are superimposed on a diffuse X-ray flux. Most measurements of this diffuse flux have taken the difference between the number of X-rays observed from an area of sky, which is thought to be free of sources, and the flux from the direction of the Earth. By assuming that there are no X-rays from the direction of the Earth, this method removes the high-energy charged-particle background which should be the same in both cases.

scholarly journals A magnetic diverter for charged particle background rejection in the SIMBOL-X telescope

2008 ◽  
Author(s):  
D. Spiga ◽  
V. Fioretti ◽  
A. Bulgarelli ◽  
E. Dell'Orto ◽  
L. Foschini ◽  
...  
Keyword(s):  
Charged Particle ◽  
Background Rejection ◽  
Particle Background

Radiation of Charge Moving Between Two Planar Periodic Wire Structures

2020 ◽  
Vol 23 (1) ◽  
pp. 66-71
Author(s):  
E. A. Gurnevich ◽  
I. V. Moroz
Keyword(s):  
Angular Distribution ◽  
Charged Particle ◽  
Research And Development ◽  
High Power ◽  
Free Electron ◽  
Radiation Intensity ◽  
Free Electron Lasers ◽  
Radiation Sources ◽  
Power Radiation ◽  
High Power Radiation

The Smith-Purcell radiation of a charged particle moving in a periodic structure is analysed theoretically. The considered structure consists of two planar diffraction gratings with different periods which are formed by parallel conducting wires. The analytical expression for the spectral-angular distribution of radiation is obtained. It is shown that the angular distribution of radiation can be made narrower by using two gratings instead of one, and radiation intensity can be manipulated by parallel relative shift of gratings. The obtained results are of great importance for the research and development of high power radiation sources based on volume free-electron lasers.

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