The role of unresolved PWNe to the gamma-ray diffuse emission at GeV

Development of two dosimetry systems based on basic violet dye for possible use as radiation dosimeters

Pigment & Resin Technology ◽

10.1108/prt-11-2020-0118 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Nehad Magdy ◽

Sameh Gafar

Keyword(s):

Gamma Ray ◽

Raw Materials ◽

Absorbed Dose ◽

Chemical Yield ◽

Radiation Sensitivity ◽

Vital Role ◽

Radiation Chemical ◽

Content Type ◽

Before And After

Purpose The purpose of this research paper is to study a comparison between two dosimetry systems, both of them based on basic violet dye (BV). Design/methodology/approach The first system depends on (BV) (incorporating polyvinyl alcohol) as a thin-film dosimeter. The second system also relies on (BV) as a solution dosimeter, which is more sensitive to gamma rays. The two prepared film/solutions have a considerable signal that decreases upon irradiation and the strength of the signal decreases with increasing radiation dose. Findings The gamma ray absorbed dose for these dosimeters was found to be up to 35 kGy for films and 1 kGy for the liquid phase. All dosimetric characteristics as radiation chemical yield, additive substance, dose-response function, radiation sensitivity, also before and after-irradiation stability under various conditions were considered. Practical implications It is expected the vital role of gamma radiation on this dye in its two forms or two media. This reveals their wide applications in the field of gamma irradiation processing. Originality/value These two dosimetry systems which depend upon the same dye are safe to handle, inexpensive, available raw materials and can be applied in various dosimetry applications as mentioned above.

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Improving the performance of 241Am-Be for PGNAA applications using a proper shielding for neutron source and the NaI detector

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp1003205p ◽

2010 ◽

Vol 25 (3) ◽

pp. 205-211 ◽

Cited By ~ 1

Author(s):

Hamed Panjeh ◽

Hashem Hakimabad ◽

Lalle Motavalli

Keyword(s):

Gamma Rays ◽

Energy Region ◽

Gamma Ray ◽

Region Of Interest ◽

High Rate ◽

Prompt Gamma ◽

Peak Resolution ◽

Set Up ◽

Gamma Ray Detector

The gamma ray spectrum resolution from a 241Am-Be source-based prompt gamma ray activation analysis set-up has been observed to increase in the energy region of interest with enclosing the NaI detector in a proper neutron and gamma ray shield. We have investigated the tact that the peak resolution of prompt gamma rays in the region of interest from the set-up depends on the source activity to the great extent, size and kind of the detector and the geometry of the detector shield. In order to see the role of a detector shield, five kinds of the detector shield were used and finally the proper kind was introduced. Since the detector shield has an important contribution in the reduction of the undesirable and high rate gamma rays coming to the gamma ray detector, a good design of a proper shield enables the elimination of the unwanted events, such as a pulse pile-up. By improving the shielding design, discrete and distinguishable photoelectric peaks in the energy region of interest have been observed in the spectrum of prompt gamma rays.

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ROLE OF THE 3.6M DOT TO INVESTIGATE CONNECTIONS BETWEEN LONG-GRBS AND CORE-COLLAPSE SNE

Revista Mexicana de Astronomía y Astrofísica Serie de Conferencias ◽

10.22201/ia.14052059p.2021.53.25 ◽

2021 ◽

Vol 53 ◽

pp. 127-133

Author(s):

A. Kumar ◽

S. B. Pandey ◽

R. Gupta ◽

A. Aryan ◽

A. J. Castro-Tirado ◽

...

Keyword(s):

Time Domain ◽

Gamma Ray ◽

Gamma Ray Bursts ◽

Global Network ◽

Core Collapse ◽

Robotic Telescopes ◽

The Time Domain ◽

Time Critical ◽

Near Future

Newly installed 3.6m DOT at Nainital (Uttarakhand) is a novel facility for the time domain astronomy. Because of the longitudinal advantage of India, it could be used to study new transients reported by a global network of robotic telescopes. Observations with the 4K × 4K CCD Imager at the axial port of the 3.6m DOT will be very helpful in the near future towards understanding the different physical aspects of time-critical events, e.g., Gamma-ray bursts (GRBs), Supernovae, Gravitational wave candidates, etc. Using the Imager with broadband filters (Bessel UBVRI and SDSS ugriz), ~6.5' × 6.5' images could be obtained to attempt various science goals in synergy with other multi-band facilities. In this study, we present an analysis of unpublished R-band data of GRB 171205A/SN 2017iuk spanning between ~12 to 105 days since burst, that observed using the 3.6m DOT with 4K × 4K CCD Imager. In the R-band light curve, a bump appears to start from ~3 days, which shows the peak at ~15 days after the burst, clearly indicates photometric evidence of association of SN with GRB 171205A.

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The Role of Jet–Cocoon Mixing, Magnetization, and Shock Breakout in Neutrino and Cosmic-Ray Emission from Short Gamma-Ray Bursts

The Astrophysical Journal ◽

10.3847/2041-8213/ac05c5 ◽

2021 ◽

Vol 915 (1) ◽

pp. L4

Author(s):

Ore Gottlieb ◽

Noémie Globus

Keyword(s):

Gamma Ray ◽

Cosmic Ray ◽

Gamma Ray Bursts

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The GeV-TeV Galactic gamma-ray diffuse emission

Astronomy and Astrophysics ◽

10.1051/0004-6361/201116647 ◽

2011 ◽

Vol 531 ◽

pp. A37 ◽

Cited By ~ 24

Author(s):

T. Delahaye ◽

A. Fiasson ◽

M. Pohl ◽

P. Salati

Keyword(s):

Gamma Ray ◽

Diffuse Emission

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Gamma-Ray Solar Flares and In Situ Particle Acceleration

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317008067 ◽

2017 ◽

Vol 13 (S335) ◽

pp. 43-48 ◽

Cited By ~ 1

Author(s):

Alexei Struminsky

Keyword(s):

Gamma Ray ◽

Solar Energetic Particle ◽

High Energy ◽

Shock Acceleration ◽

Relative Role ◽

Energy Gamma ◽

Mass Ejection ◽

Flare Site

AbstractAt present two concurrent paradigms of solar energetic particle (SEP) origin exist: acceleration directly in the flare site or by the shock wave of coronal mass ejection (CME). Active discussions on a relative role of flares and coronal mass ejections for SEP acceleration and propagation are continuous until now. In my opinion only future observations of solar high energy γ–emission with better spectral, spatial and temporal resolution may clarify this issue. In my report I discuss possible signatures of the flare and shock acceleration processes. What is a picture provided by the current instruments? What can we expect to observe with a perfect instrument in high energy gamma rays in one or another case on a time scale of impulsive and long decay flare phases?

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RE-EVALUATION OF THE AIR KERMA PRIMARY STANDARD OF THE SMU IN 60Co AND 137Cs GAMMA RAY BEAMS

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz210 ◽

2019 ◽

Vol 186 (2-3) ◽

pp. 235-238

Author(s):

Norman Durný

Keyword(s):

Gamma Ray ◽

Primary Standard ◽

National Standard ◽

Key Comparisons ◽

Main Role ◽

Correction Factors ◽

Active Volume ◽

Air Kerma ◽

60Co Gamma

Abstract The primary standard for air kerma of the Slovak Institute of Metrology (SMU) as a part of national standard of dosimetric quantities of gamma radiation NE028/02, based on cylindrical graphite walled cavity ionization chamber was established in 2002 for the 60Co gamma ray beams. Since then the main role of SMU was to continuously maintain, develop and refurbish the standard with related accessory to ensure international equivalence. Since 2002, a re-evaluation of the active volume of the ionizing chamber, correction factors, the key data, due to adoption of ICRU Report 90(1), and changes of the calibrations methods and corrections of the equipment were made to obtain improved parameters. The range was extended for 137Cs gamma ray beams and key comparisons with the Bureau International des Poids et Mesures (BIPM) were performed. ICRU Report 90(1) implementation led to a decrease of the Gray of −0.84% for 60Co and −0.80% for 137Cs.

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The role of heat conduction to the formation of [WC]-type planetary nebulae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312012094 ◽

2011 ◽

Vol 7 (S283) ◽

pp. 494-495

Author(s):

Christer Sandin ◽

Matthias Steffen ◽

Ralf Jacob ◽

Detlef Schönberner ◽

Ute Rühling ◽

...

Keyword(s):

Heat Conduction ◽

Chemical Composition ◽

Physical Properties ◽

Planetary Nebulae ◽

Time Dependent ◽

Diffuse Emission ◽

Hydrodynamic Models ◽

X Ray ◽

Central Stars

AbstractX-ray observations of young Planetary Nebulæ (PNe) have revealed diffuse emission in extended regions around both H-rich and H-deficient central stars. In order to also reproduce physical properties of H-deficient objects, we have, at first, extended our time-dependent radiation-hydrodynamic models with heat conduction for such conditions. Here we present some of the important physical concepts, which determine how and when a hot wind-blown bubble forms. In this study we have had to consider the, largely unknown, evolution of the CSPN, the slow (AGB) wind, the fast hot-CSPN wind, and the chemical composition. The main conclusion of our work is that heat conduction is needed to explain X-ray properties of wind-blown bubbles also in H-deficient objects.

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