THOMSON SCATTERING WITH A HIGH BACKGROUND LEVEL OF PLASMA RADIATION

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-851-C7-852
Author(s):  
B. Van der Sijde ◽  
T. Poorter ◽  
S. Adema ◽  
B. F.M. Pots ◽  
D. C. Schram
Keyword(s):  
Background Level ◽  
Thomson Scattering ◽  
Plasma Radiation ◽  
High Background

scholarly journals Techniques for X-Ray Diffraction Studies of Radioactive Materials

1958 ◽  
Vol 2 ◽  
pp. 261-274
Author(s):  
W. V. Cummings ◽  
W. J. Gruber
Keyword(s):  
Energy Spectrum ◽  
Radiation Damage ◽  
Background Level ◽  
Operating Conditions ◽  
Limiting Factor ◽  
X Ray Diffraction ◽  
Radioactive Materials ◽  
High Background ◽  
X Ray

AbstractMany materials, both fissionable and non-fissionable, become very radioactive when subjected to nuclear radiations. This radioactivity results in a high background level in X-ray diffraction studies and becomes a limiting factor in an analysis of radiation damage. A description is given of special techniques that are used to minimize this background and produce optimum diffraction conditions. The radioactive intensity of irradiated X-ray specimens varies from levels that are only mildly troublesome to levels that are extremely hazardous to personnel. The diffraction methods employed at the various levels are explained. An example of the radioactive energy spectrum of a specimen is given to show the method of selecting the best operating conditions and techniques.

scholarly journals A multistep image analysis method to increase automated identification efficiency in immunohistochemical nuclear markers with a high background level

2013 ◽  
Vol 8 (Suppl 1) ◽  
pp. S13 ◽  
Author(s):  
Marylène Lejeune ◽  
Vanessa Gestí ◽  
Barbara Tomás ◽  
Anna Korzyńska ◽  
Albert Roso ◽  
...  
Keyword(s):  
Image Analysis ◽  
Background Level ◽  
Analysis Method ◽  
Image Analysis Method ◽  
Automated Identification ◽  
Nuclear Markers ◽  
High Background

scholarly journals Sensory adaptation of Dictyostelium discoideum cells to chemotactic signals.

1983 ◽  
Vol 96 (6) ◽  
pp. 1559-1565 ◽  
Author(s):  
P J Van Haastert
Keyword(s):  
Folic Acid ◽  
Dictyostelium Discoideum ◽  
Background Level ◽  
Cell Aggregation ◽  
Constant Concentration ◽  
Camp Concentration ◽  
High Background ◽  
The Mean ◽  
Mean Concentration ◽  
Concentration Cells

Postvegetative Dictyostelium discoideum cells react chemotactically to gradients of cAMP, folic acid, and pterin. In the presence of a constant concentration of 10(-5) M cAMP cells move at random. They still are able to respond to superimposed gradients of cAMP, although the response is less efficient than without the high background level of cAMP. Cells which are accommodated to 10(-5) M cAMP do not react to a gradient of cAMP if the mean cAMP concentration is decreasing with time. This indicates the involvement of adaptation in the detection of chemotactic gradients: cells adapt to the mean concentration of chemoattractant and respond to positive deviations from the mean concentration. Cells adapted to high cAMP concentrations react normally to gradients of folic acid or pterin. Adaptation to one of these compounds does not affect the response to the other attractants. This suggests that cAMP, folic acid, and pterin are detected by different receptors, and that adaptation is localized at a step in the transduction process before the signals from these receptors coincide into one pathway. I discuss the implications of adaptation for chemotaxis and cell aggregation.

scholarly journals Feasibility Study of a New Cherenkov Detector for Improving Volcano Muography

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1183 ◽  
Author(s):  
Domenico Lo Presti ◽  
Giuseppe Gallo ◽  
Danilo Bonanno ◽  
Daniele Bongiovanni ◽  
Fabio Longhitano ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Background Noise ◽  
Cherenkov Radiation ◽  
Background Level ◽  
Cosmic Ray ◽  
Muon Flux ◽  
Arrival Direction ◽  
High Background ◽  
X Ray ◽  
Preliminary Study

Muography is an expanding technique for internal structure investigation of large volume object, such as pyramids, volcanoes and also underground cavities. It is based on the attenuation of muon flux through the target in a way similar to the attenuation of X-ray flux through the human body for standard radiography. Muon imaging have to face with high background level, especially compared with the tiny near horizontal muon flux. In this paper the authors propose an innovative technique based on the measurement of Cherenkov radiation by Silicon photo-multipliers arrays to be integrated in a standard telescope for muography applications. Its feasibility study was accomplished by means of Geant4 simulations for the measurement of the directionality of cosmic-ray muons. This technique could be particularly useful for the suppression of background noise due to back-scattered particles whose incoming direction is likely to be wrongly reconstructed. The results obtained during the validation study of the technique principle confirm the ability to distinguish the arrival direction of muons with an efficiency higher than 98% above 1 GeV. In addition, a preliminary study on the tracking performance of the presented technique was introduced.

Optimizing a Thomson scattering diagnostic for fast dynamics and high background

2008 ◽  
Vol 79 (10) ◽  
pp. 10E735 ◽  
Author(s):  
R. O’Connell ◽  
D. J. Den Hartog ◽  
M. T. Borchardt ◽  
D. J. Holly ◽  
J. A. Reusch ◽  
...  
Keyword(s):  
Thomson Scattering ◽  
High Background ◽  
Thomson Scattering Diagnostic

Continuous Background Originated From Neutrons By 65Cu(p,n)65Zn Under 4 MeV Protons — A problem on detecting trace elements in old copper alloys by PIXE

1998 ◽  
Vol 08 (02n03) ◽  
pp. 175-183
Author(s):  
Masuchika KOHNO ◽  
Koji YOSHIDA ◽  
Kimikazu MORITANI ◽  
Osamu TAKAHASHI ◽  
Kazuyuki ENAMI ◽  
...  
Keyword(s):  
Trace Elements ◽  
Copper Alloys ◽  
Background Level ◽  
Neutron Counter ◽  
Metallic Elements ◽  
Easy Method ◽  
High Background ◽  
Continuous Background ◽  
Ge Detector ◽  
Mev Protons

EDS-PIXE is a very useful and easy method for detecting trace elements in ancient materials. However, relatively high continuous background is observed, when old copper alloys are measured under 4 MeV protons. The background makes the detection limits of trace metallic elements such as Au , Ag , As , Sn , Sb and Pb in these alloys worse. The cause of the high background was investigated using a Si ( Li ) detector, a pure- Ge detector and a 3 He neutron counter, and it was found that the continuous background level is correlated with the amount of neutron released from 65 Cu ( p , n )65 Zn reaction.

scholarly journals Assessment of radiation exposure in the settlements located in Stepnogorsk area

2021 ◽  
Vol 5 (1) ◽  
pp. 52-63
Author(s):  
D.S. Ibrayeva ◽  
M.N. Aumalikova ◽  
K.B. Ilbekova ◽  
M.M. Bakhtin ◽  
P.K. Kazymbet ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Group Living ◽  
Background Level ◽  
Health Impacts ◽  
Mining Activities ◽  
Combined Effects ◽  
Radiological Assessment ◽  
Annual Dose ◽  
High Background ◽  
Mining Site

The Stepnogorsk area Northern Kazakhstan has a long history mining activities. Mining activities have lots of environmental and health impacts. The aims of this study were to characterizing the general radiological situation of the area and evaluate radiation exposure by scenarios in settlements. In this study radiological assessment was performed for critical group living in the territory contaminated with radionuclides; working and studying at school located on territory former mining site. The annual dose burden is 2.5 mSv y−1 in Zavodskoy, 1.9 mSv y−1 in Kvartsitka and 3.6 mSv y−1 in Aqsu; and exposure from radon is around 11 mSv y−1 at the ground floor, and for teachers - up to 12 mSv*y−1. At settlements, however, under the hypothesis that all food contaminated with radionuclides and vegetables is cultivated locally in the territories with high background level, exposure from ingestion is 9.1 mSv y−1 in Zavodskoy, 8.3 mSv y−1 in Kvartsitka and 11.5 mSv y−1 in Aqsu. The combined effects of environmental problems have culminated into health problems. There are such possibility of the higher prevalence of cardiovascular, digestive and respiratory systems so it is necessary to evaluate or protect people living in Stepnogorsk area.

scholarly journals Effects of Plasma Radiation on the Thomson Scattering Diagnostic Installed on the Large Helical Device

2007 ◽  
Vol 2 ◽  
pp. S1107-S1107 ◽  
Author(s):  
Kazumichi NARIHARA ◽  
Ichihiro YAMADA ◽  
Hiroshi HAYASHI ◽  
Hisamichi FUNABA
Keyword(s):  
Thomson Scattering ◽  
Plasma Radiation ◽  
Thomson Scattering Diagnostic

scholarly journals Feasibility Study of a New Cherenkov Detector for Improving Volcano Muography

2019 ◽  
Author(s):  
Domenico Lo Presti ◽  
Giuseppe Gallo ◽  
Danilo L. Bonanno ◽  
Daniele G. Bongiovanni ◽  
Fabio Longhitano ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Internal Structure ◽  
Particle Tracking ◽  
Cherenkov Radiation ◽  
Background Level ◽  
Muon Flux ◽  
Cherenkov Detector ◽  
High Background ◽  
X Ray ◽  
Charged Particle Tracking

Muography is an expanding technique for the investigation of the internal structure of targets of interest in geophysics. The flux of high penetrating muons produced by primary cosmic rays is attenuated by traversing kilometer size objects like X-ray flux is attenuated through the human body. This gives the possibility to study the internal structure of volcanoes or underground cavities, e.g., starting from the measure of the muon flux transmission through the target. Many groups of researchers working with this technique have to face with high background level that afflicts the reconstruction of muon tracks near the horizontal direction. An important source of background is the scattering of particles near the detector that produces a wrong reconstruction of the incoming direction. An innovative technique based on Cherenkov radiation was investigated by means of Monte Carlo simulations developed in Geant4 toolkit and MATLAB. The results reported in this paper show that the presented technique is able to correctly distinguish the incoming direction of particles with an efficiency higher than 98%. This new kind of detector could represent an alternative for high resolution charged particle tracking also for other applications.

Time-sensitive neophobic responses to risk

Behaviour ◽  
2015 ◽  
Vol 152 (12-13) ◽  
pp. 1623-1635 ◽  
Author(s):  
Maud C.O. Ferrari ◽  
Grant E. Brown ◽  
Douglas P. Chivers
Keyword(s):  
Temporal Variation ◽  
Background Level ◽  
Time Of Day ◽  
Test Time ◽  
Alarm Cues ◽  
Water Control ◽  
Lithobates Sylvaticus ◽  
High Background ◽  
High Level ◽  
And Control

Prey animals that experience a high background level of risk are known to exhibit considerable phenotypic plasticity in their responses to unknown predators. When background risk is high, prey exhibit neophobic responses to unknown odours, i.e. they show a fear response to any new stimulus. Here, we examine whether temporal variation in the pattern of risk to which prey are exposed influences neophobic responses. To establish prey groups with different temporal patterns of risk, embryonic woodfrogs (Lithobates sylvaticus) were exposed to conspecific alarm cues each morning and control cues in the evening, or conspecific alarm cues each evening and control cues in the morning, for their entire embryonic period. After the tadpoles hatched they were tested at both times of day for known risk cues (alarm cues), unknown predator odours or water control. Tadpoles responded to alarm cues at any time of day, but showed neophobic responses to predator odours only if their test time matched their embryonic risk exposure time. These results demonstrate a high level of sophistication of neophobic responses and points to temporal variation in risk as a key driver of antipredator decision making.

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