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1.
The track etch rates of
10
20
Ne-ion in cellulose nitrate (LR-115) have been measured for different temperatures and the activation energy is determined.
The experimental results show that both the track etch rate and the normalized track etch rate depend on the energy loss as
well as on etching temperature. The maximum etched track length of
10
20
Ne-ion agrees with the theoretically computed range. The experimental results show that there is no sharp threshold, at least
in CN(LR-115). 相似文献
2.
Makrofol polycarbonate plastic track detectors have been exposed to
54
132
Xe -ions of energy 1.1 MeV/N from the cyclotron beam. The bulk etch rate and track etch rate are measured for different temperatures
and the activation energies are calculated. The maximum etched track length is compared with the theoretically computed range.
The critical energy loss is (dE/dx)
c
=5 MeV cm2 mg−1 for this detector material. 相似文献
3.
Samples of Lexan and Makrofol-E polycarbonate plastic track detectors were exposed to 1·1 MeV/N
54
132
Xe-ions to investigate the thermal track fading properties of these plastics. The experimental results show that there is
no effect of annealing on the bulk etch rate while the track etch rate decreases with annealing. The track diameter decreases
with increase in annealing time and temperature. It is also observed that the track density is reduced as a result of annealing.
The experiments reveal that the track lengths are, in general, decreased by the application of heat and that the oblique tracks
are less stable than the vertical tracks. The decrease in diameter of
54
132
Xe-ion tracks in Makrofol-E due to heat treatment is faster than that of
54
132
Xe-ion tracks in Lexan. 相似文献
4.
Sample of cellulose nitrate (Russian) is exposed to
18
40
Ar ions. The bulk etch rate has been studied at different etching temperatures and the activation energy for bulk etch rate
has been calculated. The etched track lengths are measured for different etching times. The energy loss rate and range of
18
40
Ar ions in CN(R) is also calculated. The critical threshold value for etchable track in CN(R) is determined by comparing the
theoretical and experimental values of track length. The response curve of CN(R) is also presented. 相似文献
5.
A comparative study of track registration response of makrofol-(KG, KL & N) polycarbonate to Ar ions
In the present work a comparative study of track registration response of 40Ar ions in different types of Makrofol polycarbonates viz. Makrofol-KG, KL & N have been done. The etched track parameters viz. bulk etch rate, track etch rate, etch rate ratio, cone angle and etching efficiency were calculated. The variation of etching rates with temperature were found to be exponential and follow the Arrhenius equation. The values of activation energy for bulk and track etching were also calculated. Maximum etchable track length/range were also obtained and compared with the theoretical values obtained from computer program RANGE. From the results it is found that the polycarbonates having same chemical composition manufactured by different chemical processes have slightly different behavior. 相似文献
6.
The effect of heat treatment on the latent tracks in cellulose nitrate plastic track detectors has been studied. The bulk
etch rate increases with annealing temperature while the track diameters of different ions in cellulose nitrate decrease with
increase in annealing time and temperature. Experimental results show that for heavier ions higher temperatures are needed
for their complete erasure. The track length and track etch rate are decreased by the application of heat. Experiments reveal
that annealing reduces track density. The vertical tracks are more stable than the oblique tracks and require higher temperature
for their complete erasure. 相似文献
7.
Latent damage tracks of energetic40Ar ions (18·56 MeV/u) have been recorded in Lexan polycarbonate detector. Bulk and track-etch parameters are evaluated under successive chemical
etching. Our results show a linear correlation between the measured track-etch rate along the track and the corresponding
total energy-loss rate and predict a threshold value of 5·0 MeV mg−1 cm2 for track registration. Maximum etchable track lengths of40Ar ions as a function of energies have also been measured and compared with three different sets of theoretical ranges. 相似文献
8.
The etch pit diameters of soda glass detector samples exposed to
54
132
Xe-ions of different energies are measured for different etching times after etching the detector in a ‘new etchant’ free
of the adverse effect of the etch product layer. The dependence of track diameter on the energy and on the energy loss, dE/dx of
54
132
Xe-ion in soda glass has been presented. The energy resolution of soda glass and the critical angle for etching of fission
fragment tracks in glass detectors have also been determined. The maximum etched track length of
54
132
Xe-ion in soda glass has been compared with the theoretical range. The effects of different annealing conditions on bulk etch
rate of glass detector and on diameters of
54
132
Xe-ion tracks have been presented. Experimental results show that there is a decrease in track etch rate, etching efficiency
and etchable range of
54
132
Xe-ions with annealing. The annealing of oblique tracks shows that the vertical tracks are more stable than the oblique tracks. 相似文献
9.
Etching rates along tracks of protons and lithium ions with energies in the Bragg peak region were explored. The energy losses in this region, especially for protons of low energies, are of particular interest from the physical as well as biological points of view. The microscopic track etch rate, VT, is studied using the many-hit model in its first approximation assuming that VT is a function of the restricted energy loss (RELω). The ions multiple scattering and straggling effects on the average experimental VT values are corrected by shifting the calculated RELω values along the track, until its maximum coincides with that of the VT. The fitting of least square differences between calculated and experimental VT values is used in order to determine the many-hit model registration parameters for the detector under investigation. 相似文献
10.
Triafol-TN plastic detector foils have been irradiated with238U ions of energy 16.34 MeV/u and the tracks produced have been observed using the chemical etching technique. The bulk etch rate and track etch rate are determined under successive chemical etching. In our case, the validity of Arrhenius’s law is confirmed by the fact that the same value ofE a obtained for these different concentrations, within experimental errors. The results show a linear correlation between the measured track etch rate along the track and the corresponding total energy loss rate and a threshold value of ~ 5.0 MeV/(mg/cm2) for track registration was obtained. The maximum etched track length of238U-ion in triafol-TN has been compared with the theoretically computed range. 相似文献
11.
Micro-track structure analysis for 100 MeV Si ions in CR-39 by using atomic force microscopy
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To analyze the micro-track structure of heavy ions in a polymer material,parameters including bulk etch rate,track etch rate,etch rate ratio,and track core size were measured.The pieces of CR-39 were exposed to 100 MeV Si ions with normal incidence and were etched in 6.25N NaOH solution at 70 C.Bulk etch rate was read out by a profilemeter after several hours of etching.The other parameters were obtained by using an atomic force microscope(AFM)after a short time of etching.We have measured the second etch pits and minute etch pits to obtain the track growth curve and three dimension track structures to track the core size and etch rate measurements.The local dose of the track core was calculated by theδ-ray theory.In our study,we figure out that the bulk etch rate Vb=(1.58±0.022)μm/h,the track etch rate Vt=(2.90±0.529)μm/h,the etch rate ratio V=1.84±0.031,and the track core radii r≈4.65 nm.In the meantime,we find that the micro-track development violates the traditional track-growth model.For this reason,a scenario is carried out to provide an explanation. 相似文献
12.
A. El-Rahmany M. Mansy A. Hussein E. M. Ibrahim E. El-Araby 《Radiation measurements》1997,28(1-6):153-157
An extensive study of alpha particle track profile has been carried out in PADC plastic detectors. Track profile geometry and its parameters have been studied. Various values of alpha energies were used, and the etch rate ratio (V) was measured as a function of the residual range (RR) along the alpha particle track. A mathematical formula between V and RR was established. Also in this work, alpha particle ranges in plastic foils have been measured at various energies using two methods; namely the track profile technique (TPT) and the over etched track diameter method. A comparison between the measured ranges and calculated ones is presented, and a good agreement has been found. 相似文献
13.
B. Drschel R. Bretschneider D. Hermsdorf K. Kadner H. Kühne 《Radiation measurements》1999,31(1-6):103-108
Computation of the neutron response of CR-39 detectors needs to simulate the track formation by neutron induced charged particles taking into account the bulk etch rate and the track etch rate varying along the particle trajectories. The latter one was determined experimentally by track length measurement. The results allowed to derive the relationship between the track etch rate and the restricted energy loss of the charged particles. On this basis, the geometrical track parameters and track etch rates as well as the critical angle of particle incidence could be determined for protons and alpha particles in the energy range from 0.2 to 8.8 MeV. The energy dependence of the critical angle enabled to determine the detection efficiency for a charged particle of given energy and direction. 相似文献
14.
15.
Computation of etched track profiles needs the knowledge of the variable track etch rates along the ion trajectories. Using the depth-dependent track etch rates experimentally determined for perpendicularly incident protons, deuterons and alpha particles as well as 7Li, 11B, 12C, 14N and 16O ions of different energies simulations of the track development were performed. Two models of track etching were applied for that purpose recently published in literature. Although the models are based on the same physical fundamentals the results are slightly different. The reasons of the discrepancies were found by analysing the algorithms in detail. Comparison of the calculated track profiles with those determined experimentally from longitudinal sections of the etch pits showed good agreement for non-overetched as well as overetched tracks. The consistency of the whole experimental data set was checked by analysing the correlation of the track etch rates with geometric track parameters for all kinds of ions and etching times covered by the experiments. 相似文献
16.
J. P. Y. Ho C. W. Y. Yip V. S. Y. Koo D. Nikezic K. N. Yu 《Radiation measurements》2002,35(6):571-573
Equations for calculating track parameters have been proposed, which invariably involve the track etch rate Vt and the bulk etch rate Vb. The present study measured Vb for the LR115 solid-state nuclear track detector using atomic force microscopy (AFM). The detectors were partially masked using rubber cement and then etched in 2.5 N NaOH solution at 60°C for time periods ranging from 5 to 40 min. The rubber cement was then peeled off and cross-sectional images of the LR115 detectors were obtained by AFM. Vb has been found to have different values below and beyond the etching time of about 13.5 min, with the values of 0.0555 and 0.0875 μm min−1, respectively. The increase in Vb with the etching time can be explained by a diffusion-etch model, in which the additional damage of the detector material is due to those etchant ions diffused into the detector over time. Now that Vb has been determined, this can be combined with the track etch rate Vt to calculate track parameters. 相似文献
17.
At the beginning of the etching process a constant track etch rate can be assumed. In deeper detector layers, however, the etch rate varies drastically along the particle trajectories. Consequently, the indirect determination of the track etch rate by measuring the etch pit diameters on the detector surface does not yield correct results. Therefore, a method for the direct measurement of the track etch rate as a function of the depth within the detector was developed. Applying this method, the relationship between the track etch rate and the energy loss in CR-39/PATRAS could be derived. 相似文献
18.
The bulk etch rate for two types of CR-39 detector was measured as a function of temperature and the activation energies of bulk etching was determined. Experimental values of track etch rate were derived directly from the function of the succesive measured track length vrs. etching time for 209Bi, 129Xe and 20Ne ions.
The maximum etchable length of 13 MeV/u 209Bi and 13.04 MeV/u 129Xe ions have been measured at and below these energies. A comparison of the measured and calculated track length data is presented. 相似文献
19.
M. S. Abdel-Wahab H. M. Eissa N. El Enany S. El Fiki E. H. El-Adl M. A. El-Feky 《Isotopes in environmental and health studies》2013,49(4):208-210
Track etch rate characteristics of CR-39 plastic detector exposed to 28Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of 28Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector. 相似文献
20.
P. Yu. Apel A. Yu. Didyk B. I. Fursov L. I. Kravets V. G. Nesterov L. I. Samoilova G. S. Zhdanov 《Radiation measurements》1997,28(1-6):19-24
Registration temperature effect in two different polymers - poly(ethylene terephthalate) (PET) and polypropylene (PP) films - is investigated. Temperature effects on track formation are considered in terms of molecular mobility and relaxation transitions. The track eth rate is measured as a function of irradiation temperature in the range of 77 to 373 K. The obtained results are compared with the radical yields, radiothermoluminescence curves and thermally stimulated currents measured with the aim of detecting changes in the mobility of macromolecules and radiolysis intermediates. It is found that the change of the track etch rate with changing registration temperature correlates with γ- and glass transitions in PP and with β-and glass transitions in PET. 相似文献