scholarly journals Cosmic Ray Events and Natural Radioactivity in CCD Cryostats

1995 ◽  
Vol 167 ◽  
pp. 207-211
Author(s):  
Ralph Florentin-Nielsen ◽  
Michael I. Andersen ◽  
Sven P. Nielsen
Keyword(s):  
Ionizing Radiation ◽  
Natural Radioactivity ◽  
Cosmic Ray ◽  
Steel Alloys ◽  
Optical Glasses ◽  
Potassium 40

We have found that many materials that are most commonly used in CCD cryostats are weakly radioactive and therefore contribute to what is rather liberally labelled as Cosmic Ray Events. Some standard optical glasses that are extensively used for lenses and optically flat windows such as UBK-7 contain large amounts of potassium 40, which renders them useless as windows in CCD dewars. Cobalt 60 is sometimes found in excessive amounts in some steel alloys, even in Covar used as a thermal match to silicon. The choice of materials that emit a minimum of ionizing radiation is discussed.

Cosmic Ray Events and Natural Radioactivity in CCD Cryostats

1995 ◽  
pp. 207-211 ◽  
Author(s):  
Ralph Florentin-Nielsen ◽  
Michael I. Andersen ◽  
Sven P. Nielsen
Keyword(s):  
Natural Radioactivity ◽  
Cosmic Ray

scholarly journals Mapping of Natural Radioactivity in Soil Samples of Kufa Districts, Iraq Using GIS Technique

2021 ◽  
Author(s):  
Lubna A. Alasadi ◽  
Ali Abid Abojassim
Keyword(s):  
Natural Radioactivity ◽  
Specific Activity ◽  
Detection System ◽  
Soil Samples ◽  
Average Value ◽  
Radiological Parameters ◽  
Three Samples ◽  
Safety Limit ◽  
Potassium 40 ◽  
Thorium 232

Abstract The aim from this work is to detect and draw the natural radioactivity of (uranium-238, thorium-232 and potassium-40) levels in soil samples that taken from Kufa districts, Najaf governorate, Iraq. The detection system used in study is NaI (Tl) with "3x3" dimension, while maps were drawn by geographic information system (GIS). Some radiological parameters were calculated depending on measuring of specific activity for 238U, 232Th, and 40K. The results of the average value with standard error in all samples of the present study for 238U, 232Th, 40K, and 235U were 6.2±0.74, 6.41±0.82, 278.10±19.43, and 0.28±0.03 Bq/kg, respectively. The specific activity of Uranium-238, Thourium-232, poasium-40 and Uranium-235 found in all soil samples were within the safety limit reported by UNSCEAR, except three samples have poasium-40 higher than safety limit. Also, the results of radiological parameters were all found to be below OECD, UNSCEAR safety limit. Generally, the average of specific activity in soil collected arranged of potassium-40 > thorium-232 > uranium-238. Mapping GIS for natural radioactivity and some radiological parameters were successfully draw for the study area. Finally, natural radioactivity and radiological parameters for soil samples at Kufa districts were safety.

scholarly journals NATURAL RADIOACTIVITY IN HUMAN ENVIRONMENT

2011 ◽  
Vol 1 (2) ◽  
pp. 5-8
Author(s):  
Ivana Vukanac ◽  
◽  
Aleksandar Kandić ◽  
Mirjana Đurašević ◽  
Bojan Šešlak ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Human Activity ◽  
Natural Radioactivity ◽  
Radiation Effects ◽  
Public Information ◽  
Human Environment ◽  
Common Concept ◽  
The Common ◽  
Usual Reaction ◽  
The Way

Since the radioactivity can not be detected by senses, the most usual reaction to it is fear of unknown. The majority of non-professionals share the common concept of radioactivity as something mysterious and dangerous. The main reason could be insufficient education as well as lack of public information on the properties of ionizing radiation and also on its influence on the environment. The fact is that radioactivity is inevitably present in human surroundings and that the humanity has been living for millennia without cognition and understanding of ionizing radiation effects. Nevertheless, proper usage of ionizing radiation in many fields of human activity could lead the way of prosperity.

Radiation-induced surface decomposition

1983 ◽  
Vol 41 ◽  
pp. 368-369
Author(s):  
M. L. Knotek
Keyword(s):  
Ionizing Radiation ◽  
Atomic Structure ◽  
Chemical Bonding ◽  
Neutral Species ◽  
Radiation Induced ◽  
Physical And Chemical ◽  
Surface Decomposition ◽  
The Relationship ◽  
Electron And Photon ◽  
Surface Bond

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.

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