Cosmic X-Rays, γ-Rays, and Electrons

1968 ◽  
pp. 111-124
Author(s):  
R. R. Daniel
Keyword(s):  
X Rays ◽  
Γ Rays

Surface and Adhesive Properties of Low-Density Polyethylene after Radiation Cross-Linking

2014 ◽  
Vol 606 ◽  
pp. 265-268 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Performance ◽  
Chemical Properties ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Low Density ◽  
X Rays ◽  
Radiation Processing ◽  
Adhesive Properties ◽  
Γ Rays

Radiation cross-linking gives inexpensive commodity plastics and technical plastics the mechanical, thermal, and chemical properties of high-performance plastic. This upgrading of the plastics enables them to be used in conditions which they would not be able to with stand otherwise. The irradiation cross-linking of thermoplastic materials via electron beam or cobalt 60 (gammy rays) is performed separately, after processing. Generally, ionizing radiation includes accelerated electrons, gamma rays and X-rays. Radiation processing with an electron beam offers several distinct advantages when compared with other radiation sources, particularly γ-rays and x-rays. The process is very fast, clean and can be controlled with much precision. There is no permanent radioactivity since the machine can be switched off. In contrast to γ-rays and x-rays, the electron beam can steered relatively easily, thus allowing irradiation of a variety of physical shapes. The energy-rich beta rays trigger chemical reactions in the plastics which results in networking of molecules (comparable to the vulcanization of rubbers which has been in industrial use for so long). The energy from the rays is absorbed by the material and cleavage of chemical bonds takes place. This releases free radicals which in next phase from desired molecular bonds. This article describes the effect of radiation cross-linking on the surface and adhesive properties of low-density polyethylene.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

scholarly journals Pair Production in AGN

1989 ◽  
Vol 134 ◽  
pp. 194-196
Author(s):  
C. Done ◽  
A. C. Fabian
Keyword(s):  
Pair Production ◽  
Compton Scattering ◽  
Energy Flux ◽  
Large Fraction ◽  
Small Region ◽  
X Rays ◽  
X Ray ◽  
Electron Positron ◽  
Γ Rays ◽  
Radiant Power

The X-ray luminosity and variability of many AGN are sufficiently extreme that any hard γ-rays produced in the source will collide with the X-rays and create electron-positron pairs, rather than escape. A small region where vast amounts of energy are produced, such as an AGN, is an ideal place to accelerate particles to relativistic energies and so produce γ-rays by Compton scattering. The observed X-ray spectra of AGN are hard and indicate that most of the luminosity is at the highest energies so that absorption of the γ-rays represents a large fraction of the energy flux, which can then be re-radiated at lower energies. Pairs can thus effectively reprocess much of the radiant power in an AGN.

scholarly journals The `quasi-mosaic' effect in crystals and its applications in modern physics

2015 ◽  
Vol 48 (4) ◽  
pp. 977-989 ◽  
Author(s):  
Riccardo Camattari ◽  
Vincenzo Guidi ◽  
Valerio Bellucci ◽  
Andrea Mazzolari
Keyword(s):  
Hadron Collider ◽  
Proton Synchrotron ◽  
X Rays ◽  
Super Proton Synchrotron ◽  
Charged Particle Beams ◽  
Modern Physics ◽  
Volume Reflection ◽  
Comprehensive Survey ◽  
Γ Rays ◽  
Crystallographic Planes

`Quasi-mosaicity' is an effect of anisotropy in crystals that permits one to obtain a curvature of internal crystallographic planes that would be flat otherwise. The term `quasi-mosaicity' was introduced by O. Sumbaev in 1957. The concept of `quasi-mosaicity' was then retrieved about ten years ago and was applied to steering of charged-particle beams at the Super Proton Synchrotron at CERN. Beams were deviated by exploiting channeling and volume reflection phenomena in curved crystals that show the `quasi-mosaic' effect. More recently, a crystal of this kind was installed in the Large Hadron Collider at CERN for beam collimation by the UA9 collaboration. Since 2011, another important application involving the `quasi-mosaic' effect has been the focalization of hard X-rays and soft γ-rays. In particular, the possibility of obtaining both high diffraction efficiency and the focalization of a diffracted beam has been proved, which cannot be obtained using traditional diffracting crystals. A comprehensive survey of the physical properties of `quasi-mosaicity' is reported here. Finally, experimental demonstrations for adjustable values of the `quasi-mosaic' curvature are provided.

scholarly journals Dosimetry and Calorimetry Performance of a Scientific CMOS Camera for Environmental Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5746
Author(s):  
Alexis Aguilar-Arevalo ◽  
Xavier Bertou ◽  
Carles Canet ◽  
Miguel Angel Cruz-Pérez ◽  
Alexander Deisting ◽  
...  
Keyword(s):  
Drinking Water ◽  
World Health ◽  
X Rays ◽  
Cmos Camera ◽  
Silicon Sensors ◽  
Cmos Sensor ◽  
Detectable Rate ◽  
Measured Efficiency ◽  
Γ Rays ◽  
Health Organization

This paper explores the prospect of CMOS devices to assay lead in drinking water, using calorimetry. Lead occurs together with traces of radioisotopes, e.g., 210Pb, producing γ-emissions with energies ranging from 10 keV to several 100 keV when they decay; this range is detectable in silicon sensors. In this paper we test a CMOS camera (Oxford Instruments Neo 5.5) for its general performance as a detector of X-rays and low energy γ-rays and assess its sensitivity relative to the World Health Organization upper limit on lead in drinking water. Energies from 6 keV to 60 keV are examined. The CMOS camera has a linear energy response over this range and its energy resolution is for the most part slightly better than 2%. The Neo sCMOS is not sensitive to X-rays with energies below ∼10 keV. The smallest detectable rate is 40±3mHz, corresponding to an incident activity on the chip of 7±4Bq. The estimation of the incident activity sensitivity from the detected activity relies on geometric acceptance and the measured efficiency vs. energy. We report the efficiency measurement, which is 0.08(2)% (0.0011(2)%) at 26.3keV (59.5keV). Taking calorimetric information into account we measure a minimal detectable rate of 4±1mHz (1.5±1mHz) for 26.3keV (59.5keV) γ-rays, which corresponds to an incident activity of 1.0±6Bq (57±33Bq). Toy Monte Carlo and Geant4 simulations agree with these results. These results show this CMOS sensor is well-suited as a γ- and X-ray detector with sensitivity at the few to 100 ppb level for 210Pb in a sample.

scholarly journals Likely detection of pulsed high-energy γ-rays from millisecond pulsar PSR J0218+4232

2000 ◽  
Vol 177 ◽  
pp. 355-358
Author(s):  
L. Kuiper ◽  
W. Hermsen ◽  
F. Verbunt ◽  
A. Lyne ◽  
I. Stairs ◽  
...  
Keyword(s):  
Timing Analysis ◽  
High Energy ◽  
X Rays ◽  
Millisecond Pulsar ◽  
Imaging Analysis ◽  
Pulse Profile ◽  
Significance Level ◽  
Absolute Phase ◽  
Bl Lac ◽  
Γ Rays

AbstractWe report on the likely detection of pulsed high-energyγ-rays from the binary millisecond pulsar PSR J0218+4232 in 100–1000 MeV data from CGRO EGRET. Imaging analysis demonstrates that the highly significantγ-ray source 2EG J0220+4228 (∼ 10σ) is for energies > 100 MeV positionally consistent with both PSR J0218+4232 and the BL Lac 3C66A. However, above 1 GeV 3C66A is the evident counterpart, whereas between 100 and 300 MeV PSR J0218+4232 is the most likely one. Timing analysis using one ephemeris valid for all EGRET observations yields in the 100-1000 MeV range a double-pulse profile at a ∼ 3.5σsignificance level. The phase separation is similar to the component separation of ∼ 0.47 observed at X-rays. A comparison of theγ-ray profile with the 610 MHz radio profile in absolute phase shows that the twoγ- ray pulses coincide with two of the three emission features in the complex radio profile.

scholarly journals The effect of X-rays on the glucose and hexose-phosphate glycolysis of tumour tissue

1939 ◽  
Vol 127 (847) ◽  
pp. 223-237 ◽  
Keyword(s):  
Cell Metabolism ◽  
Lethal Effect ◽  
Clinical Approach ◽  
X Rays ◽  
Trial And Error ◽  
Hexose Phosphate ◽  
One Step ◽  
Γ Rays ◽  
Work Done ◽  
Different Tissues

The clinical approach to questions concerning the effect of X-rays γ-rays on cells has, of necessity, been highly empirical. By methods of trial and error, in fact by experience, it has been found that certain tissues are more easily injured by radiation than others, certain types of tumour more responsive than others to treatment by irradiation. The experiments described here and in previous papers (Holmes 1933, 1935) on the effects of irradiation upon cell metabolism have also been conducted on empirical lines. They represent simply an attempt to carry the work done by others on the lethal effect of the rays one step further and to describe this effect in terms of cell metabolism. The possibility that detectable differences in the metabolism of different tissues may account for their variability in response to radiation must also be considered, and such experiments may eventually provide the data necessary for investigating this possibility.

DISCOVERY OF STRONGLY ENHANCED LOW ENERGY ALPHA DECAY OF A LONG-LIVED ISOMERIC STATE OBTAINED IN 16O + 197Au REACTION AT 80 MeV, PROBABLY TO SUPERDEFORMED BAND

1996 ◽  
Vol 11 (11) ◽  
pp. 861-869 ◽  
Author(s):  
A. MARINOV ◽  
S. GELBERG ◽  
D. KOLB
Keyword(s):  
Isomeric State ◽  
Alpha Decay ◽  
Low Energy ◽  
X Rays ◽  
Superdeformed Band ◽  
Calculated Probability ◽  
Γ Rays ◽  
Bombarding Energy ◽  
Α Particles ◽  
Superdeformed Nucleus

The reaction 16 O + 197 Au has been studied at a bombarding energy of 80 MeV. A group of 5.20 MeV α particles with a half-life of about 90 m has been found in coincidence with characteristic X-rays of At and with γ-rays. The γ-ray energies fit predicted energies for superdeformed band. The data are interpreted as due to formation of a long-lived isomeric state which decays by low energy α-particles to SD band. The calculated probability for decay via a barrier of a superdeformed nucleus was found to be consistent with the experimental results.

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