Study of the radioactive decays of 140Ba and 140La

1991 ◽  
Vol 69 (2) ◽  
pp. 90-101 ◽  
Author(s):  
Bakhshish Chand ◽  
Jatinder Goswamy ◽  
Devinder Mehta ◽  
Nirmal Singh ◽  
P. N. Trehan
Keyword(s):  
Conversion Coefficient ◽  
Setup Time ◽  
X Rays ◽  
Conversion Electrons ◽  
X Ray ◽  
Mixing Ratios ◽  
Hpge Detectors ◽  
Conversion Coefficients ◽  
Γ Rays ◽  
First Time

The intensities of X rays and γ rays from the decays of 140Ba and 140La were measured precisely using Si(Li) and HPGe detectors. The L X-ray intensities in 140Ba decay are reported for the first time. The conversion electrons from these decays are investigated using a mini-orange electron spectrometer. The electron intensities for the (M + N.) conversion of 329, 487, 1596, and 1903 keV transitions in 140Ce were measured for the first time. From the present conversion-electron and γ-ray intensities, the conversion coefficients for various transitions in 140La and 140Ce were determined. Also, the γ–γ directional correlations for 15 cascades in,140Ce were studied using a HPGe–HPGe detector coincidence setup (time resolution = 7 ns). The 109–(329)– 487, 131–242, and 131–266 keV cascades in 140Ce were studied for the first time. The multipole mixing ratios for the 109, 131, 242, 266, 329, 432, 487, 751, 816, 868, 919, 925, and 951 keV transitions in 140Ce are deduced from the present directional correlation and conversion-coefficient measurements.

Preliminary Study Of the Behavior Of HPGe Detectors With Ion Implanted Contacts in the Ultralow-Energy X-Ray Region

1981 ◽  
Vol 25 ◽  
pp. 23-30 ◽  
Author(s):  
M. Slapa ◽  
J. Chwaszczewska ◽  
J. Jurkowski ◽  
A. Latussynski ◽  
G.C. Huth ◽  
...  
Keyword(s):  
Hpge Detector ◽  
Low Energy ◽  
Entrance Window ◽  
X Rays ◽  
X Ray ◽  
Ultralow Energy ◽  
Hpge Detectors ◽  
Preliminary Study ◽  
First Time ◽  
Ion Implanted

AbstractPreliminary study of performance of an HPGe detector with an ion implanted entrance window in the spectrometry of the ultralowenergy x-rays is presented.For the first time it has been shown that almost symmetric photopeaks and absence of low energy tailing can be obtained in this region from HPGe detectors.

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

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%.

scholarly journals Observations of X-rays from Laboratory Sparks in Air at Atmospheric Pressure under Negative Switching Impulse Voltages

Atmosphere ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 169 ◽  
Author(s):  
Mahbubur Rahman ◽  
Pasan Hettiarachchi ◽  
Vernon Cooray ◽  
Joseph Dwyer ◽  
Vladimir Rakov ◽  
...  
Keyword(s):  
Rise Time ◽  
Atmospheric Pressure ◽  
Opposite Polarity ◽  
X Rays ◽  
X Ray ◽  
Impulse Voltage ◽  
First Time ◽  
Switching Impulses ◽  
Low Rate

We present observations of X-rays from laboratory sparks created in the air at atmospheric pressure by applying an impulse voltage with long (250 µs) rise-time. X-ray production in 35 and 46 cm gaps for three different electrode configurations was studied. The results demonstrate, for the first time, the production of X-rays in gaps subjected to switching impulses. The low rate of rise of the voltage in switching impulses does not significantly reduce the production of X-rays. Additionally, the timing of the X-ray occurrence suggests the possibility that the mechanism of X-ray production by sparks is related to the collision of streamers of opposite polarity.

Mesoscopic structure of SiC fibers by neutron and x-ray scattering

1996 ◽  
Vol 11 (5) ◽  
pp. 1169-1178 ◽  
Author(s):  
Kentaro Suzuya ◽  
Michihiro Furusaka ◽  
Noboru Watanabe ◽  
Makoto Osawa ◽  
Kiyohito Okamura ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Volume Fraction ◽  
X Rays ◽  
X Ray ◽  
Sic Fibers ◽  
X Ray Scattering ◽  
Mesoscopic Structure ◽  
Angle Scattering ◽  
Momentum Transfer Range ◽  
First Time

Mesoscopic structures of SiC fibers produced from polycarbosilane by different methods were studied by diffraction and small-angle scattering of neutrons and x-rays. Microvoids of a size of 4–10 Å in diameter have been observed for the first time by neutron scattering in a medium momentum transfer range (Q = 0.1–1.0 Å−1). The size and the volume fraction of β–SiC particles were determined for fibers prepared at different heat-treatment temperatures. The results show that wide-angle neutron scattering measurements are especially useful for the study of the mesoscopic structure of multicomponent materials.

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

LOW-SPIN STATES OF 76Se EXCITED IN 76Br(β++EC)76Se DECAY

2004 ◽  
Vol 13 (05) ◽  
pp. 933-947
Author(s):  
YAN LI ◽  
SHUIFA SHEN ◽  
WENDA HUANG ◽  
SHUANGHUI SHI ◽  
JIAHUI GU ◽  
...  
Keyword(s):  
High Resolution ◽  
Energy Levels ◽  
Spin States ◽  
Hpge Detectors ◽  
New Energy ◽  
Coincidence Mode ◽  
Γ Rays ◽  
First Time

The decay of bromine-76 was studied using high resolution HpGe detectors in singles and coincidence mode. Bromine-76 was produced via two reactions: 75 As (α,3 n )76 Br and 76 Se ( p , n )76 Br . The results of these experiments verified the previously reported levels of 76 Se . In addition to the previously described transitions and levels, 37 new γ-rays and 15 new energy levels were found for the first time.

scholarly journals Optical Short-Time Variations in GK Persei during the 1983 Outburst

1987 ◽  
Vol 93 ◽  
pp. 485-485
Author(s):  
H. Steinle ◽  
W. Pietsck
Keyword(s):  
Accretion Disk ◽  
Time Resolution ◽  
X Rays ◽  
X Ray ◽  
Time Variations ◽  
Short Time ◽  
First Time ◽  
Calar Alto

AbstractDuring the August 1983 outburst of the old nova GK Persei observations with EXOSAT showed for the first time a 351 second periodicity in X-rays.Our fast photometry (U(B)V with 25 sec time resolution) was made at the end of the outburst in the nights of September 29 , and October 1–3 , using the 2.2 meter telescope at Calar Alto (Spain).Optical variations up to 10% in U and 4% in V with periodicities in the range 350 to 360 seconds were found, lasting only for few cycles.A comparison with the extrapolated prediction of the X-ray maxima did not show a coincidence, but rather an anticoincidence in several cases. This supports a model of reprocessed X-rays at the inner edge of an accretion disk.

scholarly journals The 3XMM/SDSS Stripe 82 Galaxy Cluster Survey – II. X-ray and optical properties of the cluster sample

2019 ◽  
Vol 486 (4) ◽  
pp. 4863-4879 ◽  
Author(s):  
Ali Takey ◽  
Florence Durret ◽  
Isabel Márquez ◽  
Amael Ellien ◽  
Mona Molham ◽  
...  
Keyword(s):  
Optical Properties ◽  
Galaxy Cluster ◽  
X Rays ◽  
Present Sample ◽  
X Ray ◽  
Cluster Galaxies ◽  
Cluster Survey ◽  
Cluster Sample ◽  
Cluster Mass ◽  
First Time

ABSTRACT We present X-ray and optical properties of the optically confirmed galaxy cluster sample from the 3XMM/SDSS Stripe 82 cluster survey. The sample includes 54 galaxy clusters in the redshift range of 0.05–1.2, with a median redshift of 0.36. We first present the X-ray temperature and luminosity measurements that are used to investigate the X-ray luminosity–temperature relation. The slope and intercept of the relation are consistent with those published in the literature. Then, we investigate the optical properties of the cluster galaxies including their morphological analysis and the galaxy luminosity functions (GLFs). The morphological content of cluster galaxies is investigated as a function of cluster mass and distance from the cluster centre. No strong variation of the fraction of early- and late-type galaxies with cluster mass is observed. The fraction of early-type galaxies as a function of cluster radius varies as expected. The individual GLFs of red sequence galaxies were studied in the five ugriz bands for 48 clusters. The GLFs were then stacked in three mass bins and two redshift bins. Twenty clusters of the present sample are studied for the first time in X-rays, and all are studied for the first time in the optical range. Altogether, our sample appears to have X-ray and optical properties typical of ‘average’ cluster properties.

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 A New Chapter in Hard X-rays of the M87 AGN

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 9
Author(s):  
Ka-Wah Wong ◽  
Rodrigo S. Nemmen ◽  
Jimmy A. Irwin ◽  
Dacheng Lin
Keyword(s):  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Accretion Flow ◽  
Relativistic Jet ◽  
Very High Energy ◽  
Γ Ray ◽  
High Energy Emission ◽  
First Time ◽  
Very High

The nearby M87 hosts an exceptional relativistic jet. It has been regularly monitored in radio to TeV bands, but little has been done in hard X-rays ≳10 keV. For the first time, we have successfully detected hard X-rays up to 40 keV from its X-ray core with joint Chandra and NuSTAR observations, providing important insights to the X-ray origins: from the unresolved jet or the accretion flow. We found that the hard X-ray emission is significantly lower than that predicted by synchrotron self-Compton models introduced to explain very-high-energy γ -ray emission above a GeV. We discuss recent models to understand these high energy emission processes.

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