DUAL-PARTICLE DOSEMETER BASED ON ORGANIC SCINTILLATOR

2020 ◽  
Vol 191 (3) ◽  
pp. 319-327
Author(s):  
C A Miller ◽  
A Di Fulvio ◽  
S D Clarke ◽  
S A Pozzi
Keyword(s):  
Scintillation Detector ◽  
New Method ◽  
Proof Of Concept ◽  
Dose Equivalent ◽  
Spectral Deconvolution ◽  
Dose Rates ◽  
Fission Spectrum ◽  
Photon Dose ◽  
Single Instrument ◽  
Better Than

Abstract Traditionally available handheld dosemeters are generally sensitive to only one type of radiation: neutrons or photons. Some dosemeters also rely on very specific attenuation correlations between response and dose, are not scalable in size and multiple dosemeters are required to characterise mixed-particle fields. The research presented here serves as a proof-of-concept for a method to simultaneously measure dose rates from neutrons and photons using a particle discriminating organic scintillation detector without the need for spectral deconvolution. The method was compared with traditional instruments and to simulation. Isotopic photon dose rates measured with this method were within 4% of simulated truth, whereas fission spectrum neutron dose rates were measured within 21%. Measurements of dose rates from both particles agree with simulated truth better than traditional instruments. This new method allows for measurement of dose equivalent from both neutrons and photons with a single instrument and no reliance on spectral deconvolution.

Atomic resolution AEM (ARAEM) of oxide superconductors

1992 ◽  
Vol 50 (1) ◽  
pp. 74-75
Author(s):  
Vinayak P. Dravid ◽  
H. Zhang ◽  
L.D. Marks ◽  
J.P. Zhang
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Atomic Resolution ◽  
Oxide Superconductors ◽  
Electron Holography ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Point To Point ◽  
Single Instrument ◽  
Better Than

A 200 kV cold field emission gun atomic resolution analytical electron microscope (ARAEM, Hitachi HF-2000) has been recently installed at Northwestern. The ARAEM offers an unprecedented combination of atomic structure imaging of better than 0.20 nm nominal point-to-point resolution and about 0.10 nm line resolution, alongwith nanoscale analytical capabilities and electron holography in one single instrument. The ARAEM has been fully functional/operational and this paper presents some illustrative examples of application of ARAEM techniques to oxide superconductors. Additional results will be presented at the meeting.

Radiation exposure in the environment of patients after application of radiopharmaceuticals

2008 ◽  
Vol 47 (06) ◽  
pp. 267-274 ◽  
Author(s):  
F. Boldt ◽  
C. Kobe ◽  
W. Eschner ◽  
H. Schicha ◽  
F. Sudbrock
Keyword(s):  
Nuclear Medicine ◽  
Radiation Exposure ◽  
Radioactive Source ◽  
Time Intervals ◽  
The Public ◽  
Dose Rates ◽  
Diagnostic Nuclear Medicine ◽  
Photon Dose ◽  
Order Of Magnitude ◽  
Study Dose

Summary Aim: After application of radiopharmaceuticals the patient becomes a radioactive source which leads to radiation exposure in the proximity. The photon dose rates after administration of different radiopharmaceuticals used in diagnostic nuclear medicine were measured at several distances and different time intervals. These data are of importance for estimating the exposure of technologists and members of the public. Patients, method: In this study dose rates were measured for 67 patients after application of the following radiopharmaceuticals: 99mTc-HDP as well as 99mTcpertechnetate, 18F-fluorodeoxyglucose, 111In-Octreotid and Zevalin® and 123I-mIBG in addition to 123I-NaI. The dose rates were measured immediately following application at six different distances to the patient. After two hours the measurements were repeated and – whenever possible – after 24 hours and seven days. Results: Immediately following application the highest dose rates were below 1 mSv / h: with a maximum at 780 μSv/h for 18F (370 MBq), 250 μSv/h for 99mTc (700 MBq), 150 μSv/h for 111In (185 MBq) and 132 μSv/ h for 123I (370 MBq). At a distance of 0.5 m the values decrease significantly by an order of magnitude. Two hours after application the values are diminished to 1/3 (99mTc, 18F), to nearly ½ (123I) but remain in the same order of magnitude for the longer-lived 111In radiopharmaceuticals. Conclusion: For greater distances the doses remain below the limits outlined in the national legislation.

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

Bounded Elastic Moduli Multiplier Technique for Limit Loads: Part 2 - Case Studies

2021 ◽  
Author(s):  
Sathya Prasad Mangalaramanan
Keyword(s):  
Lower Bound ◽  
Case Studies ◽  
Power Law ◽  
Elastic Moduli ◽  
New Method ◽  
Stress Distributions ◽  
Limit Loads ◽  
Elastic Plastic ◽  
Thick Cylinder ◽  
Better Than

Abstract An accompanying paper provides the theoretical underpinnings of a new method to determine statically admissible stress distributions in a structure, called Bounded elastic moduli multiplier technique (BEMMT). It has been shown that, for textbook cases such as thick cylinder, beam, etc., the proposed method offers statically admissible stress distributions better than the power law and closer to elastic-plastic solutions. This paper offers several examples to demonstrate the robustness of this method. Upper and lower bound limit loads are calculated using iterative elastic analyses using both power law and BEMMT. These results are compared with the ones obtained from elastic-plastic FEA. Consistently BEMMT has outperformed power law when it comes to estimating lower bound limit loads.

Study on Radiation Dose Calculation of PWR Spent Fuel Storage and Transportation

2021 ◽  
Author(s):  
Wen Yang ◽  
Xing Li ◽  
Jinrong Qiu ◽  
Lun Zhou
Keyword(s):  
Radiation Dose ◽  
Normal Condition ◽  
Radiation Safety ◽  
Spent Fuel ◽  
Dose Rates ◽  
Storage Pool ◽  
Transport Container ◽  
Photon Dose ◽  
Spent Fuel Storage ◽  
Fuel Storage

Abstract With the rapid development of nuclear energy, spent fuel will accumulate in large quantities. Spent fuel is generally cooled and placed in a storage pool, and then transported to a reprocessing plant at an appropriate time. Because spent fuel is content with a high level of radiation, spent fuel storage and transportation safety play important roles in the nuclear safety. Radiation dose safety are checked and validated using source analysis and Monte Carlo method to establish a radiation dose rate calculation model for PWR spent fuel storage pool and transport container. The calculation results show that the neutron and photon dose rates decrease exponentially with increase of water level under normal condition of storage pool. The attenuation multiples of neutron and photon dose rates are 4.64 and 1.59, respectively. According to radiation dose levels in different water height situations, spent fuel pool under loss of coolant accident can be divides into five workplaces. They are supervision zone, regular zone, intermittent zone, restricted zone and radiation zone. Under normal condition of transport container, the dose rates at the surface of the container and at a distance of 1 m from the surface are 0.1759 mSv/h and 0.0732 mSv/h, respectively. The dose rates decrease with the increasing radius of break accident, and dose rate at the surface of the transport container is 0.278 mSv/h when the break radius is 20 cm. Transport container conforms to the radiation safety standards of International Atomic Energy Agency (IAEA). This study can provide some reference for radiation safety analysis of spent fuel storage and transportation.

Dosage du Sr-90 dans l'eau des lacs et des rivières du Québec par précipitation avec l'oxine et comptage β

1988 ◽  
Vol 66 (1) ◽  
pp. 174-177 ◽  
Author(s):  
E. Haddad ◽  
L. Zikovsky
Keyword(s):  
Detection Limit ◽  
Surface Waters ◽  
New Method ◽  
The Mean ◽  
Better Than

A new method for the determination of Sr-90 dissolved in surface waters has been developed. It is based on the precipitation of Sr with 8-hydroxyquinoline at pH 11.3 and counting of β particles with energy above 150 keV. The detection limit obtained is 0.5 mBq/L and the mean yield is 28%. The decontamination factors from other β emitters achieved are better than 10 000. This method has been used to measure the Sr-90 in 5 lakes and 5 rivers in Québec and activities ranging from 3 to 15 mBq/L were obtained. This new method is as efficient and reliable as conventional techniques while being less tedious.

scholarly journals Assessment of radiological risk in the area around surface disposal at Al -Tuwaitha site

2019 ◽  
Vol 14 (30) ◽  
pp. 90-97
Author(s):  
Asia H. Al-Mashhadani
Keyword(s):  
Health Risk ◽  
Hpge Detector ◽  
Specific Activity ◽  
Gamma Dose ◽  
Dose Equivalent ◽  
Radiological Risk ◽  
Dose Rates ◽  
Gamma Dose Rates ◽  
Specific Activities

The gamma dose rates and specific activity of 137Cs, 60Co and 40K insamples of soil taken from places near the landfill radiation at Al-Tuwaitha site were measured using a portable NaI(Tl) detector. Theresults of gamma dose rates in samples were ranged from 52.6nGy.h-1 to 131nGy.h-1. Then the specific activity of 137Cs, 60Co and40K in soil were determined using high pure germanium (HPGe)detector. The specific activities were varied from 1.9 to 115500 Bq.kg-1 for 137Cs, from 6.37 to 616.5 Bq. kg-1 for 60Co, and from 3 to839.5 Bq. kg-1 for 40K. The corresponding health risk for the annualeffective dose equivalent varied from 1.85×10-14 to 15.7mSv/y. Theresults were compared with various international recommendations.

The Performance of Low Pressure Tissue-Equivalent Chambers and a New Method for Parameterising the Dose Equivalent

1986 ◽  
Vol 15 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Y. Eisen ◽  
R.J. Brake ◽  
D.G. Vasilik ◽  
B.H. Erkkila ◽  
G.J. Littlejohn
Keyword(s):  
Low Pressure ◽  
New Method ◽  
Dose Equivalent ◽  
Tissue Equivalent
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