• Analytical Science and Technology
• /
• v.17 no.5
• /
• pp.434-437
• /
• 2004

Alpha track technology can provide useful isotopic information of boron in the primary coolant water. In the quantitative analysis using the alpha track analysis, the shape or area of sample on the solid track detector becomes very important, especially for the analysis of liquid samples. In this research, a multi-dot plate has been developed for this purpose. The multi-dot plate provides fixed standard shape of the sample solution that stays inside of the printed circle, and consequently increases the reproducibility of the boron analysis.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.10
• /
• pp.1609-1612
• /
• 2006

The determination of the boron isotopic ratio in solutions was achieved by means of a solid state track detector by using an alpha track. The neutron flux was optimized by using a Cd-foil to find the optimum conditions for counting the number of alpha tracks on the selected solid detector caused by the (n, $\alpha$) nuclear reaction of boron. The home-made multi-dot detector plate was utilized in this study to increase the reproducibility of the measurement by uniformly drying the boron solution within the marked circle area on the detector plate. The experimental results of this study verified that the $^{11}B/^{10}B $ isotopic ratio can be measured by observing the number of alpha tracks for different concentrated standard solutions with various isotopic compositions. This technique was applied to the determination of $^{10}B$ enrichment factor in a biological sample for a boron neutron capture therapy.

• Nuclear Engineering and Technology
• /
• v.37 no.4
• /
• pp.395-400
• /
• 2005

An environmental radon monitoring system, comprising a radon-cup, an etching system, and a track counting system, was constructed. The radon cup is a cylindrical chamber with a radius of 2.2 cm and a height of 3.2 cm in combination with a CR-39 detector. Carbon is impregnated in the bodies of the detector chamber to avoid problem of an electrostatic charge. The optimized etching condition for the CR-39 exposed to a radon environment turned out to be a 6 N NaOH solution at 70^{\circ}$ over a 7hour period. The bulk etch rate under the optimized condition was $1.14{\pm}0.03\;{\mu}m\;h^{-1}$. The diameter of the tracks caused by radon and its progeny were found to be in the range of $10\~25\;{\mu}m$ under the optimized condition. The track images were observed with a track counting system, which consisted of an optical microscope, a color charged couple device (CCD) camera, and an image processor. The calibration factor of this system is obtained to be $0.105{\pm}0.006$ tracks $cm^2$ per Bq $m^{-3}$ d.

• Journal of Radiation Protection and Research
• /
• v.2 no.1
• /
• pp.1-8
• /
• 1977

A base of photographic posi-film which is commecially available has been found to be a possible alpha-particle track detector. Its neutron dosimetric characteristics, i. e., alpha-particle track registrating efficiency and optimum condition of track formation by chemical etching, have been determined experimentally. The range of neutron fluence and dose capable of being measured by a neutron dosimeter consisting of alpha-particle radiator foils $(^{10}B\;and\;^{27}Al)$ and posi-flim solid state track detector, has been estimated on the basis of experimental results and theoryetical background. This detector seems to be useful for neutron dosimetry because of many favorable properties, i. e., simplicity, cheapness and a wide range of sensitivitiy.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.10a
• /
• pp.386.1-386
• /
• 2002

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.11C
• /
• pp.896-900
• /
• 2010

We investigate the bit error rate against signal-to-noise ratio performance corresponding to track mis-registration for patterned media storage. The patterned media channels with and without soft underlayer are implemented, and we simulate using one-dimensional Viterbi detector and two-dimensional soft output Viterbi detector (SOVA) when the track mis-registration is 0% (on-track), 10%, 20%, 30%, and 40%. While the BER performance degrades approximate 0.3 ~ 0.5 dB at 10% track mis-registration, it degrades severe over 10% track mis-registration.

• Journal of Radiation Protection and Research
• /
• v.21 no.3
• /
• pp.167-173
• /
• 1996

The calibration method for the detection efficiency of solid state track detector to alpha is presented, and the detection efficiency of CN-85 and LEXAN to alpha is measured by this method. The results are 97% and 57% in CN-85 and LEXAN, respectively. The reason for a better result in CN-85 in not only the high sensitivity but also the low energy dependency with comparing for LEXAN. The peak detection efficiency is 3MeV and 1.8MeV in CN-85 and LEXAN, respectively.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1362-1369
• /
• 2007

Seoul Metro continuously converted the standard rail into continuous welded rail since the later part of 1990's, and currently, most of the sectors of the Seoul Metro are continuous welded rails. As the continuous welded rail is inhibited by the contraction and expansion force of the rail as well as rail-bed, this force is stored as the internal stress of the rail with the exception of portion of the both ends of the continuous welded rail. If the contraction and expansion of the rail is restricted, the internal stress, that is, the force in the direction of the axis, is proportional to the cross-sectional area of the rail. Therefore, with regards to the temperature changes, the internal stress changes in accordance with the type of rail, bolting apparatus, railroad tie and rail-bed. As such, the rail temperature becomes important data in securing the gap at the adjoining section of the rail in the standard rail section, and to determine the setting temperature for the continuous welded rail. In addition, it becomes basic data for maintenance of the track. Accordingly, this thesis introduces cases of installation of rail temperature detector in order to prevent and manage track defectiveness due to increase in rail temperature, and to utilize as basic data at the time of various construction and maintenance. Furthermore, this thesis aims to assist maintenance of track through systematic temperature management in the future by looking into means of its utilization.

• Journal of Multimedia Information System
• /
• v.5 no.3
• /
• pp.155-162
• /
• 2018

Nowadays, the tracking technology of Quadrant Detector will become actual by new micro devices. Based on the past filed data of the reception experiment with COMETS satellite, we have studied on new device (AD8302, phase difference detector) was acquired and suspect its abilities. In 1998, we have developed a Quadrant Detector for mobile to track a weak signal from satellite on Ka band of COMETS. The Quadrant Detector is comprised of four dedicated feed components for reception under an environment of Nakagami - Rician fading, and one transmission and reception feed component. We were successful in receiving a 23 GHz beacon signal from ICE transponder of the COMETS and succeeded in tracking the satellite from a moving vehicle at speeds of approximately 10 ~ 20 Km/h on paved roads. In 2018, with new device AD8302, we have verified new QD system and performed a simulation, based on the past filed experiment. This new device shall be improving the tracking abilities from mobile body on the earth to the multimedia satellite.

• Analytical Science and Technology
• /
• v.17 no.1
• /
• pp.8-15
• /
• 2004

The detection efficiencies of the several solid track detectors were investigated for the determination of boron content in aqueous solution by using the alpha muti-Radioisotope(RI) source. Polycarbonate (Lexan and CR-39) and cellulose nitrate (CN-85 and LR-115) were selected as materials for alpha track detection of boron. Alpha muti-RI source, uranium metal particles and boron standard solution were used for alpha emission. In this study, four solid track detectors(CN-85, LR-115, Lexan and CR-39) were characterized under various etching conditions as well as neutron irradiation conditions. As a result, the CN-85 was turned out to be best to provide good efficiency among the four detectors. The selected solid track detector was utilized for the determination of trace amount of boron in aqueous sample and its results were discussed in the text.