The Effects of Low‐ and High‐Energy Cutoffs on Solar Flare Microwave and Hard X‐Ray Spectra

Abstract“Solar X-ray Spectrometer (SOXS)” mission on-board GSAT-2 Indian spacecraft was launched on 08 May 2003 by GSLV-D2 and deployed in geostationery orbit to study the X-ray emission from solar flares with high spectral and temporal resolution. The SOXS consists of two independent payloads viz. SOXS Low Energy Detector (SLD) payload, and SOXS High Energy Detector (SHD) payload. The SLD consists of two solid state detectors Si PIN and CZT, which cover the energy range from 4-60 keV, while the SHD has NaI(Tl)/CsI(Na) sandwiched phoswich detector that covers energy range from 20 keV to 10 MeV. We present very briefly the science objectives and instrumentation of SLD payload. After the successful In-orbit Tests (IOT), the first light was fed into SLD payload on 08 June 2003 when the solar flare was already in progress. We briefly present the first results from the SLD payload.

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Probing solar flare accelerated electron distributions with prospective X-ray polarimetry missions

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038626 ◽

2020 ◽

Vol 642 ◽

pp. A79

Author(s):

Natasha L. S. Jeffrey ◽

Pascal Saint-Hilaire ◽

Eduard P. Kontar

Keyword(s):

Solar Flare ◽

Electron Distribution ◽

Electron Acceleration ◽

High Energy ◽

Transport Processes ◽

Spectral Measurements ◽

X Ray ◽

Electron Distributions ◽

Energy Cutoff ◽

Imaging Polarimetry

Solar flare electron acceleration is an extremely efficient process, but the method of acceleration is not well constrained. Two of the essential diagnostics, electron anisotropy (velocity angle to the guiding magnetic field) and the high energy cutoff (highest energy electrons produced by the acceleration conditions: mechanism, spatial extent, and time), are important quantities that can help to constrain electron acceleration at the Sun but both are poorly determined. Here, by using electron and X-ray transport simulations that account for both collisional and non-collisional transport processes, such as turbulent scattering and X-ray albedo, we show that X-ray polarization can be used to constrain the anisotropy of the accelerated electron distribution and the most energetic accelerated electrons together. Moreover, we show that prospective missions, for example CubeSat missions without imaging information, can be used alongside such simulations to determine these parameters. We conclude that a fuller understanding of flare acceleration processes will come from missions capable of both X-ray flux and polarization spectral measurements together. Although imaging polarimetry is highly desired, we demonstrate that spectro-polarimeters without imaging can also provide strong constraints on electron anisotropy and the high energy cutoff.

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The high-energy flare plasma

Symposium - International Astronomical Union ◽

10.1017/s0074180900021938 ◽

1968 ◽

Vol 35 ◽

pp. 480-482

Author(s):

C. De Jager

Keyword(s):

Solar Flare ◽

Energy Range ◽

High Energy ◽

Radio Observations ◽

X Ray ◽

Flare Plasma ◽

Optical Flare

A solar flare has various aspects: the optical flare is often associated with emissions in the microwave or X-ray regions: this indicates the occurrence of a highly excited plasma, which we call the high-energy flare plasma. The existence of the high-energy flare plasma was first shown by radio observations in the microwave regions (Hachenberg) and later confirmed by X-ray observations in the energy range 102–106 eV.

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Investigation of Relationship between High-energy X-Ray Sources and Photospheric and Helioseismic Impacts of X1.8 Solar Flare of 2012 October 23

The Astrophysical Journal ◽

10.3847/1538-4357/aa77f1 ◽

2017 ◽

Vol 843 (1) ◽

pp. 67 ◽

Cited By ~ 11

Author(s):

I. N. Sharykin ◽

A. G. Kosovichev ◽

V. M. Sadykov ◽

I. V. Zimovets ◽

I. I. Myshyakov

Keyword(s):

Solar Flare ◽

High Energy ◽

X Ray

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Analysis of Prognoz - 9 Solar Flare Hard X-ray Data-support for the Non-thermal thick target Model

Symposium - International Astronomical Union ◽

10.1017/s0074180900088410 ◽

1990 ◽

Vol 142 ◽

pp. 445-447

Author(s):

R. R. Rausaria ◽

Ranjana Bakaya ◽

P.N. Khosa

Keyword(s):

Solar Flare ◽

Energy Range ◽

Spectral Index ◽

High Energy ◽

Thick Target ◽

Low Energy ◽

X Ray ◽

Target Model ◽

Data Support ◽

Peak Emission

Solar flare hard X-ray data obtained by Prognoz-9 spacecraft (Abrosimov et al 1988) in the energy range 10-200 keV are analysed. In examples of events which we consider here, high energy X-ray pulses appear earlier than low energy ones, which is contrary to many other events where the low energy X-ray peak emission takes place earlier. The variation of the spectral index was dynamical.

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Radio and Hard X-Ray Images of High-Energy Electrons in an X-Class Solar Flare

The Astrophysical Journal ◽

10.1086/379274 ◽

2003 ◽

Vol 595 (2) ◽

pp. L111-L114 ◽

Cited By ~ 48

Author(s):

S. M. White ◽

S. Krucker ◽

K. Shibasaki ◽

T. Yokoyama ◽

M. Shimojo ◽

...

Keyword(s):

Solar Flare ◽

High Energy ◽

X Ray ◽

High Energy Electrons

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High-purity Ge x-ray detectors: Sensitivity factors and usefulness

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136350 ◽

1990 ◽

Vol 48 (2) ◽

pp. 548-548

Author(s):

E. B. Steel

Keyword(s):

High Purity ◽

High Energy ◽

Quantitative Chemical Analysis ◽

Detector Performance ◽

X Ray ◽

Detector Sensitivity ◽

Specimen Holder ◽

Many Instruments ◽

Charge Resolution ◽

Sensitivity Factors

High Purity Germanium (HPGe) x-ray detectors are now commercially available for the analytical electron microscope (AEM). The detectors have superior efficiency at high x-ray energies and superior resolution compared to traditional lithium-drifted silicon [Si(Li)] detectors. However, just as for the Si(Li), the use of the HPGe detectors requires the determination of sensitivity factors for the quantitative chemical analysis of specimens in the AEM. Detector performance, including incomplete charge, resolution, and durability has been compared to a first generation detector. Sensitivity factors for many elements with atomic numbers 10 through 92 have been determined at 100, 200, and 300 keV. This data is compared to Si(Li) detector sensitivity factors.The overall sensitivity and utility of high energy K-lines are reviewed and discussed. Many instruments have one or more high energy K-line backgrounds that will affect specific analytes. One detector-instrument-specimen holder combination had a consistent Pb K-line background while another had a W K-line background.

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Designing high-resolution slow scan CCD-based TEM camera systems

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012936x ◽

1992 ◽

Vol 50 (2) ◽

pp. 946-947

Author(s):

James F. Mancuso ◽

William B. Maxwell ◽

Russell E. Camp ◽

Mark H. Ellisman

Keyword(s):

Fiber Optics ◽

Ccd Camera ◽

High Energy ◽

Phosphor Layer ◽

X Ray ◽

Light Production ◽

Camera Systems ◽

X Ray Imaging ◽

Electron Image ◽

Scintillating Fiber

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.

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The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117777 ◽

1985 ◽

Vol 43 ◽

pp. 154-157

Author(s):

A.J. Tousimis

Keyword(s):

Ion Beam ◽

Depth Resolution ◽

Sample Surface ◽

High Energy ◽

X Rays ◽

X Ray ◽

Electrons And Ions ◽

Spatial Depth ◽

Minimum Surface Area ◽

Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

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