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1.
Amol Mhatre P. C. Kalsi Onkar Singh Choudhary G. P. Sachdev 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(3):795-798
The gamma irradiation effects in the dose range of 2.5?C43.0 Mrad on the etching and optical characteristics of CR-39 solid state nuclear track detector (SSNTD) have been studied by using etching and UV?CVisible spectroscopic techniques. From the measured bulk etch rates at different temperatures, the activation energies for bulk etching at different doses have also been determined. It is seen that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. The optical band gaps of the unirradiated and the gamma -irradiated detectors determined from the UV?CVisible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. The present studies can be used for the estimation of gamma dose in the range of 2.5?C43.0 Mrad and can also be used for estimating track registration efficiency in the presence of gamma dose. The CR-39 detector has also been applied for the assay of uranium in some soil samples of Jammu city. 相似文献
2.
Vivek Chavan P. C. Kalsi Amol Mhatre 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(1):273-276
The bulk-etch rates of a newly developed track detector which is a copolymer of N-allyloxycarbonyl diethanolamine-bis allylcarbonate
(NADAC) and allyl diglycol carbonate (ADC) [NADAC-ADC (1:1, w/w)] have been determined at different temperatures to deduce
its activation energy. The energy of activation is found to be (0.93 ± 0.07) eV. This compares very well with the values of
activation energy reported in the literature for the most commonly used nuclear track detectors. The effects of gamma irradiation
on this new detector in the dose range of 47.0–145.0 kGy have also been studied using bulk etch, UV–visible spectroscopic,
and thermogravimetric analysis (TGA) techniques. The activation energy for bulk etching calculated from bulk etch rates measurements
at different temperatures, optical band gaps determined from the UV–visible spectra, and the values of onset temperature of
decomposition (T0) calculated from TGA curves were found to decrease with the increase in gamma dose. These results have been explained on
the basis of scission of the detector due to gamma irradiation. 相似文献
3.
Amol Mhatre Vivek Chavan P. C. Kalsi V. S. Nadkarni 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):99-101
The gamma irradiation effects on the bulk etch rate, V
b of an indigenously prepared new nuclear track detector which is a copolymer of allyl bis-(2-nitroxy-ethyl) carbomate (ABNEC)
and allyl diglycol carbonate (ADC) [ABNEC:ADC (1:9)] were studied in the dose range of 25.0–250.0 kGy and etching temperature
range of 60–80 °C. The bulk etch rates increase and the activation energy values for bulk etching of gamma-irradiated detectors
decrease with the increase in gamma dose indicating the scission of the detector. UV–visible spectra of the unirradiated and
the irradiated films were also taken to explore the possibility of using this new detector for gamma dose measurements. 相似文献
4.
The etching and optical response of Tuffak polycarbonate nuclear track detector to gamma irradiation
《Radiation Physics and Chemistry》2009,78(2):81-84
The effects of gamma irradiation in the dose range of 1.0–20.0 Mrad on the etching and optical characteristics of Tuffak polycarbonate (C16H14O3)n nuclear track detector have been studied by using etching and UV–visible spectroscopic techniques. The bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. The optical band gaps determined from the UV–visible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. 相似文献
5.
Vivek Chavan P. C. Kalsi V. S. Nadkarni A. K. Pandey 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):181-183
The fission track registration efficiency of an indigenously prepared Cellulose Acetate Butyrate (CAB) solid state nuclear
track detector (SSNTD) has been determined and is found to be (0.89 ± 0.04). Radiation chemical yield, G-value for loss of ester bonds in this detector exposed to gamma rays from a Co-60 source has also been determined by FT-IR
spectrometry. The amount of ester bonds lost due to the exposure was estimated from the change in absorbance of C=O and C–O–C
bonds with the gamma dose. The G-value for breaking of ester bonds in CAB detector is found to be about 37/100 eV. 相似文献
6.
《Radiation Physics and Chemistry》2008,77(9):1002-1004
In the present work, we have determined the bulk-etch rates of a newly developed track detector called poly-[N-allyloxycarbonyl diethanolamine-bis allylcarbonate] (PNADAC) homopolymer at different temperatures to deduce its activation energy. The energy of activation is found to be (1.02±0.04) eV. This compares very well with the values of activation energy reported in the literature for the most commonly used nuclear track detectors. The effects of gamma irradiation on this new detector in the dose range of 4.7–14.5 Mrad have also been studied using UV–visible spectroscopic technique. The optical band gaps of the unirradiated and the gamma-irradiated detectors determined from the UV–visible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. 相似文献
7.
Ashok Kumar R. K. Jain Praveen Yadav R. N. Chakraborty B. K. Singh B. K. Nayak 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):95-98
It is observed that for Lexan and Makrofol-DE polycarbonate plastic detectors the mean diameters of fission fragments from a 252Cf source increases as a result of gamma-ray exposure. We have studied the bulk etching rate and track etching rate before and after gamma-ray irradiation on Lexan and Makrofol-DE polycarbonate plastics. The mechanism of Lexan and Makrofol-DE polycarbonate plastic detectors can be understood with the help of this exposures. It is also noted that degree of ordering of Lexan and Makrofol-DE polycarbonate is dependent on the gamma ray dose due to degradation and cross-linking processes. The results show that bulk and track etch rate increases with gamma dose while activation energy associated with bulk and track etch rates at a particular temperature and sensitivity decreases with gamma dose. 相似文献
8.
P. C. Kalsi Pramilla D. Sawant A. Ramaswami V. K. Manchanda 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):473-477
Garware Polyester Film, an indigenously available material has been evaluated systematically as a nuclear track detector for
the detection of fission fragments. The relative fission track detection efficiency of this film was found to be (86.0±4.0)%.
The bulk etch rate, determined by the gravimetric method, was found to be 0.75±0.05 μm/h. The track etch rate was determined
as 15.0±1.5 μm/h. This detector was employed for the estimation of uranium in seawater samples and the results obtained were
compared with the results obtained by using the commonly used Lexan detector. Uranium fractions after chemical separation
from seawater samples were also analyzed by alpha-spectrometry and neutron activation analysis techniques and the results
were compared with that obtained by the fission track method. Fission track method has the advantage, as it does not require
any chemical separation. The indigenously available polyester film (polyethylene terphthalate) appears to be a good substitute
of Lexan as nuclear track detector. 相似文献
9.
10.
M. J. A. Armelin R. L. Ávila R. M. Piasentin M. Saiki 《Journal of Radioanalytical and Nuclear Chemistry》2003,258(2):449-451
The effects of gamma-irradiation at a dose range of 5-56 Mrad on the fission track registration efficiency of the Tuffak polycarbonate track detector from dry (K
dry) as well as the solution media (K
wet) are investigated. Fission tracks were recorded in the gamma-irradiated detectors along with the unirradiated ones by an electrodeposited source of 252Cf and also separately from a 252Cf solution. The fission track registration efficiencies for the irradiated detectors were determined in comparison with those of the unirradiated detectors. The results show that while the K
dry values for the irradiated detectors decrease by about 2-10%, the corresponding K
wet values decrease by about 3-20% as compared to unirradiated detectors . Further, the bulk etch rates were found to increase with the increase in gamma dose. The changes induced in the gamma-irradiated detectors as a function of dose have been studied also by thermogravimetry (TG). 相似文献
11.
Disintegration, ventilation and deposition were considered as removal processes of the radon and its short-lived daughters in air and the respective concentration equations were applied. Calibration coefficient (KF) of the solid state nuclear track detector (SSNTD) LR-115 for radon and the equilibrium factor (F) were related to track densities of the bare detector (D) and the filtered one (Do). A useful relationship between KF, F and detector sensitivity coefficient (k) was derived. Using the calibrated value k=3.29×10–3 m, the exposed detectors gave the average values of the equilibrium factor, calibration coefficient and indoor radon concentration of a single house living room in Osijek 0.46, 142.3 m–1 and 37.8 Bq m–3, respectively. 相似文献
12.
The effects of UV irradiation (λ=254 nm) on polyester nuclear track detector have been investigated employing bulk-etch technique, UV–visible spectrophotometry and infra-red spectrometry (FTIR). The activation energy values for bulk-etching were found to decrease with the UV-irradiation time indicating the scission of the polymer. Not much shift in the absorption edge due to UV irradiation was seen in the UV–visible spectra. FTIR studies also indicate the scission of the chemical bonds, thereby further validating the bulk-etch rate results. 相似文献
13.
A. M. Golubenkov A. F. Malenchenko 《Journal of Radioanalytical and Nuclear Chemistry》1977,36(2):547-556
For the solution of most of the problems which are connected to the biological and physiological role of natural uranium in
plants and animal organisms about 10−14 g uranium should be determined. However most of the physico-chemical methods for the determination of natural uranium in
biomaterials are time-consuming and possess considerable error. On the basis of addition and inner standard methods a version
of Solid State Nuclear Track Detectors (SSNTD) method has been developed in order to determine the natural uranium in biospecimens.
According to the experimental data simple relations have been obtained for the calculation of uranium concentration in biomaterial
and minium uranium concentration in biosolution which can be measured by the detector used. Under irradiation of SSNTD at
a thermal neutron flux of (3–5)·1015n·cm−2 the detector sensitivity is 2.30·10−9 g U/ml for glass detectors; 9.60·10−10g U/ml for the detectors made from artificial mica. 相似文献
14.
P. D. Sawant S. Prabhu P. C. Kalsi K. A. Pendharkar 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):179-183
Individual monitoring of radiation workers handling Pu in various nuclear installations requires the detection of trace levels
of plutonium in bioassay samples. It is necessary to develop methods that can detect urinary excretion of Pu in fraction of
mBq range. Therefore, a sensitive method such as fission track analysis has been developed for the measurement of trace levels
of Pu in bioassay samples. In this technique, chemically separated plutonium from the sample and a Pu standard were electrodeposited
on planchettes and covered with Lexan solid state nuclear track detector (SSNTD) and irradiated with thermal neutrons in APSARA
reactor of Bhabha Atomic Research Centre, India. The fission track densities in the Lexan films of the sample and the standard
were used to calculate the amount of Pu in the sample. The minimum amount of Pu that can be analyzed by this method using
doubly distilled electronic grade (E. G.) reagents is about 12 μBq/L. 相似文献
15.
O. A. Bondarenko Yu. N. Onishchuk A. V. Berezhnoy P. B. Aryasov D. Antonyuk 《Journal of Radioanalytical and Nuclear Chemistry》2000,243(2):555-558
Solid state nuclear track detectors (SSNTD) find wide application in registration of different types of ionization irradiation due to excellent features: low cost, compactness, passivity and possibility of long term exposure for low activity measurements. One of the most shortcomings is in complex processing of the detector surface and following image analysis. However, present methods which allow reconstruction of track ranges and particle energies are intensively being developed. A developing trend in SSNTD alpha-spectrometry uses automated scanning microscope systems and specially designed mathematical software. Several parameters obtained from the analysis of etched tracks indi information about alpha-particle ranges in detector. The possibility to use some parameters (minor axis m and track end diameter d) for the spectrometry has been reported earlier. Intercomparison of SSNTD with semiconductor detectors (SCD) for 238,239Pu content in bioassay within the interval 10-3 to 1 Bq has been carried out. This comparison has demonstrated a good coincidence between these independent radiometric methods. A perspective of SSNTD use for spectrometric determination of low level activity is discussed. The background level playing a main role in low level detection has been also estimated. Influence of radon and thoron has been found as insignificant. 相似文献
16.
H. El-Samman A. Hussein S. Hassan 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(2):259-262
A well performance Electrolytic Controlled Etching (ECE) unit has been designed and constructed in our laboratory. Low electric
field strength of few volts and a 2 kHz wave signals has been applied across the electrodes that confined the 9 and 12 μm
thick PET foils in the ECE unit. PET foils were exposed to fission fragments (FFS) using 252Cf source. The dependence of different measurable parameters such as FFS fluence (Φ), applied voltage (V), etching temperature (T) and etching concentration (C) on both track etch rate (V
T) and breakthrough time (T
B) have extensively been studied using the FFS-irradiated PET foils. Various empirical relationships connecting the results of the present work have been extracted. Moreover,
the constructed ECE technique has proven to be an encouraged time saving method in the development of trusting measurements
comparing with others that might involve expensive sophisticated tools. 相似文献
17.
Radon α-activity concentrations have been measured inside and outside various building materials by combining a calculational method with the solid state nuclear track detector (SSNTD) technique. Radon emanation coefficients of the studied materials have been evaluated. A new calibration method for determining the radium (226Ra) and thorium (232Th) specific activities of the considered building materials has been developed. The radon production rates per unit volume of the studied materials have been evaluated. The influence of the material porosity on the radon emanation coefficient and radon production rate have been investigated. 相似文献
18.
M. A. Misdaq A. Bakhchi A. Ktata J. Lamine 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(1):41-48
Samples have been collected from different layers in a sedimentary phosphatic deposit and sieved. Different granulometric
fractions have been selected. The uranium and thorium contents have been determined in each phosphate sample and its corresponding
selected fractions. Radon (222Rn) α-activities per unit volume have been evaluated inside and outside each phosphate sample and its corresponding selected
fractions by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD). The radon emanation coefficient in
each phosphate layer has been determined and the global radon alpha activity outside a parallelepipedic block of the layers
studied was evaluated. The influence of the lithology and granulation on the radon emanation has been studied. 相似文献
19.
J. Planinić 《Journal of Radioanalytical and Nuclear Chemistry》1993,175(2):95-101
Statistical errors of the track etching method were investigated by using the LR-115 nuclear track detector and visual microscopic counting. In the experiment, four persons counted tracks of the same detector and the analysis of variance was applied to the respective means and standard deviations. Another experiment was performed with ten detectors exposed to air in the same room; after standard etching and counting, the relative error of the detector track density was obtained as 11.2%. Taking into account the errors of the detector sensitivity coefficient and background, the total relative error of the track etching method was 19.5% in case of measurements of the indoor radon concentration of 8.2 Bq m–3. 相似文献
20.
《Radiation Physics and Chemistry》1999,53(4):377-384
Uranium and thorium contents in different layers of an archaeological site have been determined by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) and calculating the probabilities for α-particles emitted by the uranium and thorium series to reach and be registered on the SSNTD films. A new method has been developed based on calculating the self-absorption coefficient of the gamma-photons emitted by the uranium (238U), thorium (232Th) and their corresponding decay products as well as the potassium-40 (40K) isotope for evaluating the annual absorbed gamma dose rates in the considered material samples. Results obtained have been compared with data obtained by using the TL dosimetry and Bell's (Bell, 1979) methods. Ceramic samples belonging to the studied archaeological site have been dated. 相似文献