Nuclear Radiation Unit
Department of Physics and Materials Science
City University of Hong Kong
Tat Chee Ave, Kowloon Tong, Hong Kong
Email: apnru@cityu.edu.hk

Page last modified on 24-Sep-2008

  

on Track Physics Research

Fast moving charged particles are known to produce trails of atomic disorder (usually referred to as nuclear tracks or ion tracks) in an immense variety of dielectric solids (including crystals, glasses, and high polymers), intermetallics, certain metals and amorphous metals, oxide conductors and superconductors. The more common commercial nuclear track materials include polycarbonate (marketed as Makrofol), polyallyldiglycol carbonate (marketed as CR-39) and cellulose nitrate (marketed as LR 115). Nuclear tracks have found many applications in different branches of science (for a recent review, see the following review paper). Some examples of applications are design of track-etch templates for micro- and nano-fabrication, hole engineering and track membrane technology, radiobiological dosimetry, radon dosimetry and earth science applications.  

See the review paper: Nikezic, D., Yu, K.N., "Formation and Growth of Tracks in Nuclear Track Materials", 2004, Materials Science and Engineering R, 46 (3-5), 51-123. (download pdf version). 

"Different experimental methods have been established for the determination of the bulk etch rate. An excellent review of these methods and their advantages and disadvantages has been given by Nikezic and Yu (2004)." -- by D. Hermsdorf, M. Hunger, S. Starke and F. Weickert, Radiation Measurements 42 (2007) 1-7.

See the book chapter: Nikezic, D., Yu, K.N., "Computer Simulation of Radon Measurements with Nuclear Track Detectors", 2007, in Computer Physics Research Trends, Ed. S. J. Bianco, (Nova Science Publishers: New York), p. 119-150. (download pdf version) (purchase book)

Use the freeware program to calculate alpha track parameters in the CR-39 and LR 115 SSNTDs: We have prepared a program to calculate alpha track parameters in the CR-39 and LR 115 SSNTDs, namely the lengths of major and minor axes as well as the depths, in mm. Click here to go to the download page. 

Use the freeware program to determine the optical appearance of alpha-particle tracks in the CR-39 SSNTD: Click here to go to the download page. 

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Highlights of Recent Research:

V functions for SSNTDs

Optical properties of alpha-particle tracks in SSNTDs

Degradation of SSNTDs

 

V functions for SSNTDs

Use the freeware program to calculate alpha track parameters in the CR-39 and LR 115 SSNTDs: We have prepared a program to calculate alpha track parameters in the CR-39 and LR 115 SSNTDs, namely the lengths of major and minor axes as well as the depths, in mm. Click here to go to the download page. 

Much research has been devoted to understanding the mechanisms of track growth in SSNTDs. The most widely accepted track growth model involves two etch rates, namely, the track etch rate Vt (i.e., along a track in the SSNTD) and the bulk etch rate Vb (i.e., the in undamaged areas of the SSNTD). The most challenging tasks involve measurements of depth of the tracks as well as the removed layers during chemical etching. The available V functions for the CR-39 and LR 115 SSNTDs are collected in the following: 

For the CR-39 detector, the following functions are available:

(1) Durrani and Bull (1987):

 

(2) Brun et al. (1999):

with the constants a1 = 0.1, a2 = 1, a3 = 1.27 and a4 = 1.

(3) Yu et al. (2005a): This is similar to function  (2), i.e.,

but with constants a1 = 0.068, a2 = 0.6513, a3 = a4 = 1.1784.

(4) Yu et al. (2005b): the same as function (3) but with constants

a1 = 0.06082, a2 = 0.8055, a3 = a4 =1.119.

References:

Durrani, S.A., Bull, R.K., 1987. Solid State Nuclear Track Detection. Principles, Methods and Applications. Pergamon Press.

Brun, C., Fromm, M., Jouffroy, M., Meyer, P., Groetz, J.E., Abel, F., Chambaudet, A., Dorschel, B., Hermsdorf, D., Bretschneider, R., Kadner, K., Kuhne, H., 1999.  Intercomparative study of the detection characteristics of the CR-39 SSNTD for light ions: Present status of the Besancon-Dresden approaches. Radiation Measurements, 31, 89-98.

Yu, K.N., Ho, J.P.Y., Nikezic, D., Yip, C.W.Y., 2005a. Determination of the V function for CR-39 by atomic force microscope. In Recent advances in multidisciplinary applied physics. Ed. Antonio Mendez-Vilas. Elsevier, Amsterdam, p. 29-34.

Yu, K.N., Ng, F.M.F., Nikezic, D., 2005b. Measuring depths of sub-micron tracks in a CR-39 detector from replicas using atomic force microscopy. Radiation Measurements, 40, 380-383.

For the LR 115 detector, the following functions are available:

(1) Durrani and Green (1984):

with constants a1 = 100, a2 = 0.446, a3 = 5, a4 = 0.107.

(2) Yip et al. (2006): The same form as function (1), but with constants

a1 = 2.14, a2 = 0.12, a3 = 2.7, a4 = 0.135.

(3) Leung et al. (2007a): The same form as function (1), but with constants

a1 = 14.50, a2 = 0.5, a3 = 3.9, a4 = 0.066.

(4) Leung et al. (2007b): The same form as function (1), but with constants

a1 = 14.23; a2 = 0.48; a3 = 5.9 and a4 = 0.077

References:

Durrani, S.A., Green, P.F., 1984. The effect of etching conditions on the response of LR 115.  Nuclear Tracks 8, 21-24.

Yip, C.W.Y., Nikezic, D., Ho, J.P.Y., Yu, K.N., 2006, Chemical Etching Characteristics for Cellulose Nitrate. Materials Chemistry and Physics, 95, 307-312.

Leung, S.Y.Y., Nikezic, D., Leung, J.K.C., Yu, K.N., 2007a. Derivation of V function for LR 115 SSNTD from its sensitivity to 220Rn in a diffusion chamber. Applied Radiation and Isotopes, 65, 313-317.

Leung, S.Y.Y., Nikezic, D., Yu, K.N., 2007b. Derivation of V function for LR 115 SSNTD from its partial sensitivity to 222Rn and its short-lived progeny. Journal of Environmental Radioactivity, 92, 55-61.

 

Journal Publications (see here for impact factors):

  1. Nikezic, D., Yu, K.N., "Profiles and parameters of tracks in LR115 detector irradiated with alpha particles", 2002, Nuclear Instruments and Methods in Physics Research B, 196, 105-112.
  2. Ho, J.P.Y., Yip, C.W.Y., Koo, V.S.Y., Nikezic, D., Yu, K.N., "Measurement of bulk etch rate of LR115 detector with atomic force microscopy", 2002, Radiation Measurements, 35, 571-573.
  3. Nikezic, D., Ho, J.P.Y., Yip, C.W.Y., Koo, V.S.Y., Yu, K.N., “Feasibility and Limitation of Track Studies Using Atomic Force Microscopy”, 2002, Nuclear Instruments and Methods in Physics Research Journal (Section B), 197, 293-300.
  4. Nikezic, D., Yu, K.N., “Three-dimensional analytical determination of the track parameters. Over-etched tracks”, 2003, Radiation Measurements, 37, 39-45.
  5. Yip, C.W.Y., Ho, J.P.Y., Koo, V.S.Y., Nikezic, D., Yu, K.N., “Effects of stirring on the bulk etch rate of LR 115 detector”, 2003, Radiation Measurements, 37, 197-200.
  6. Ho, J.P.Y., Yip, C.W.Y., Nikezic, D., Yu, K.N., “Effects of stirring on the bulk etch rate of CR-39 detector”, 2003, Radiation Measurements, 36, 141-143.
  7. Ho, J.P.Y., Yip, C.W.Y., Nikezic, D., Yu, K.N., “Differentiation between tracks and damages in CR-39 detectors under the Atomic Force Microscope”, 2003, Radiation Measurements, 36, 155-159.
  8. Yip, C.W.Y., Ho, J.P.Y., Nikezic, D., Yu, K.N., “A fast method to measure the thickness of removed layer from etching of LR-115 detector based on EDXRF”, 2003, Radiation Measurements, 36, 161-164.
  9. Yip, C.W.Y., Ho, J.P.Y., Nikezic, D., Yu, K.N., “Study of inhomogeneity in thickness of LR 115 detector with SEM and Form Talysurf”, 2003, Radiation Measurements, 36, 245-248.
  10. Nikezic, D., Yu, K.N., “Calculations of track parameters and plots of track openings and wall profiles in CR39 detector”, 2003, Radiation Measurements, 37, 595-601.
  11. Ng, F.M.F., Yip, C.W.Y., Ho, J.P.Y., Nikezic, D., Yu, K.N., "Non-destructive Measurement of Active Layer Thickness of LR 115 SSNTD", 2004, Radiation Measurements, 38, 1-3.
  12. Nikezic, D., Yu, K.N., Kostic, D., "Three Dimensional Model of the Track Growth: Comparison with Other Models", 2003, Nuclear Technology & Radiation Protection, 18, 24-30.
  13. Yu, K.N., Ng, F.M.F., Ho, J.P.Y., Yip, C.W.Y., Nikezic, D., "Measurement of parameters of tracks in CR-39 detector from replicas", 2004, Radiation Protection Dosimetry, 111, 93-96.
  14. Yu, K.N., Ng, F.M.F., "Fast and non-destructive determination of active-layer thickness of LR 115 SSNTD using a color commercial document scanner", 2004, Nuclear Instruments and Methods in Physics Research Journal (Section B), 226, 365-368.
  15. Nikezic, D., Yu, K.N., "Formation and Growth of Tracks in Nuclear Track Materials", 2004, Materials Science and Engineering R, 46 (3-5), 51-123.
  16. Yu, K.N., Ng, F.M.F., Nikezic, D., "Measuring depths of sub-micron tracks in CR-39 detector from replicas using Atomic Force Microscopy", 2005, Radiation Measurements, 40, 380-383.
  17. Yip, C.W.Y., Nikezic, D., Ho, J.P.Y., Yu, K.N., “Chemical Etching Characteristics for Cellulose Nitrate”, 2006, Materials Chemistry and Physics, 95, 307-312.
  18. Nikezic, D., Kostic, D., Yip, C.W.Y., Yu, K.N., “Comparison among Different Models of Track Growth and Experimental Data“, 2006, Radiation Measurements, 41, 253-256.
  19. Nikezic, D., Yu, K.N., “Computer program TRACK_TEST for calculating parameters and plotting profiles for etch pits in nuclear track materials", 2006, Computer Physics Communications, 174, 160-165.
  20. Leung, S.Y.Y., Nikezic, D., Yu, K.N., "Derivation of V function for LR 115 SSNTD from its partial sensitivity to to 222Rn and its short-lived progeny", 2007, Journal of Environmental Radioactivity, 92, 55-61.
  21. Leung, S.Y.Y., Nikezic, D., Leung, J.K.C., Yu, K.N., "Derivation of V function for LR 115 SSNTD from its sensitivity to 220Rn in a diffusion chamber", 2007, Applied Radiation and Isotopes, 65, 313-317.
  22. Ng, F.M.F., Luk, K.Y., Nikezic, D., Yu, K.N., "Determination of alpha-particle track depths in CR-39 detector from their cross-sections and replica heights", 2007, Nuclear Instruments and Methods in Physics Research Journal (Section B), 263, 266-270.
  23. Chan, K.F., Ng, F.M.F., Nikezic, D., Yu, K.N., "Bulk and track etch properties of CR-39 SSNTD etched in NaOH/Ethanol", 2007, Nuclear Instruments and Methods in Physics Research Journal (Section B), 263, 284-289.
  24. Tse, K.C.C., Ng, F.M.F., Nikezic, D., Yu, K.N., "Bulk etch characteristics of colorless LR 115 SSNTD" , 2007, Nuclear Instruments and Methods in Physics Research Journal (Section B), 263, 294-299.
  25. Nikezic, D., Stevanovic, N., Kostic, D., Savovic, S., Tse, K.C.C., Yu, K.N., "Solving the track wall equation by the finite difference method", 2008, Radiation Measurements, 43 (Suppl. 1), S76-S78.

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Optical properties of alpha-particle tracks in SSNTDs

Use the freeware program to determine the optical appearance of alpha-particle tracks in the CR-39 SSNTD: Click here to go to the download page. 

Although the optical microscope was the main tool for track observation for many years, there has been relatively little investigation about the optical characteristics of the etched tracks. Knowledge of optical characteristics of tracks such as the average gray level can be important in automatic track measurements. We applied the ray tracing method to study etched tracks from alpha particles in CR-39 solid-state nuclear track detectors. The transmission mode of a microscope operation was simulated. A track was considered as a set of small triangular elements, and the brightness of all elements was calculated systematically through the entire track to create the final image. Total reflection, as well as the slope of a surface element in the track wall, were identified as the main factors that affect the brightness of that element. At this stage, comparisons with experimental results can be made in terms of the average gray levels for the entire tracks.

Journal Publications (see here for impact factors):

  1. Nikezic, D., Ng, F.M.F., Yip, C.W.Y., Yu, K.N., "Application of ray tracing method in studying alpha tracks in SSNTDs", 2005, Radiation Measurements, 40, 375-379.
  2. Yu, K.N., Lee, H.H.W., Wong, A.W.T., Law, Y.L., Cheung, S.F.L., Nikezic, D., Ng, F.M.F., "Optical appearance of alpha-particle tracks in CR-39 SSNTD", 2007, Nuclear Instruments and Methods in Physics Research Journal (Section B), 263, 271-278.
  3. Nikezic, D., Yu, K.N., "Computer program TRACK_VISION for simulating optical appearance of etched tracks in CR-39 nuclear track detectors", 2008, Computer Physics Communications, 178, 591–595.
  4. Law, Y.L., Nikezic, D., Yu, K.N., "Optical appearance of alpha-particle tracks in CR-39 SSNTDs", 2008, Radiation Measurements, 43 (Suppl. 1), S128-S131.
  5. Nikezic, D., Yu, K.N., "Analyses of Light Scattered from Etched Alpha-particle Tracks in PADC", 2008, Radiation Measurements, 43, 1417-1422.

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Degradation of SSNTDs

Journal Publications (see here for impact factors):

  1. Tse, K.C.C., Ng, F.M.F., Yu, K.N., "Photo-degradation of PADC by UV radiation at various wavelengths", 2006, Polymer Degradation and Stability, 91, 2380-2388.
  2. Ng, F.M.F., Yu, K.N., “X-Ray Irradiation Induced Degradation of Cellulose Nitrate”, 2006, Materials Chemistry and Physics, 100, 38-40.
  3. Tse, K.C.C., Nikezic, D., Yu, K.N., "Comparative studies of etching mechanisms of CR-39 in NaOH/H2O and NaOH/Ethanol", 2007, Nuclear Instruments and Methods in Physics Research Journal (Section B), 263, 300-305.
  4. Tse, K.C.C., Nikezic, D., Yu, K.N., "Effects of UVC irradiation on alpha-particle track parameters in CR-39", 2008, Radiation Measurements, 43 (Suppl. 1), S98-S101.
  5. Ng, F.M.F., Tse, K.C.C., Nikezic, D., Dai, J., Zhao, Z., Yu, K.N., "Surface effect of ultraviolet radiation on electrochemically etched alpha-particle tracks in PADC", 2008, Radiation Measurements, 43 (Suppl. 1), S102-S105.

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