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Heavy ion range measurements in some glasses using back track etching technique
Radiation Measurements 32 (2000) 283±287
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Heavy ion range measurements in some glasses using back track etching technique G.S. Randhawa a, H.S. Virk b,* a
Department of Physics, Khalsa College, Amritsar, India Department of Physics, Guru Nanak Dev University, Amritsar 143 005, India
b
Received in revised form 27 October 1999
Abstract The samples of soda, quartz and barium phosphate (BP-1) glasses were irradiated by dierent heavy ions from UNILAC, GSI, Darmstadt. The range of these heavy ions in these glasses were measured by using back track etch technique. The experimental values of heavy ion ranges were compared with the theoretical values computed from Mukherjee and Nayak (1979), TRIM-95 and SRIM-97 computer codes based on the formulations of Ziegler et al. (1985). 7 2000 Elsevier Science Ltd. All rights reserved.
1. Introduction The theoretical and experimental investigations about the penetration of charged particles in matter played a very important role in the development of modern physics. Solid state nuclear track detectors (SSNTDs) have become one of the most important tool for many branches of science and technology (Fleischer et al., 1975; Durrani and Bull, 1987; Spohr, 1990). For many fundamental discoveries, such as the ®rst evidence of cluster radioactivity (Rose and Jones, 1984), the search of super heavy elements (Bhandari et al., 1971), the detection of very low cross-sections (Brandt, 1980) etc., the credit goes to these passive detectors. For identi®cation of charge, mass and energy of particle in dierent applications, there is need to establish a relationship between the track parameters and ionization losses and range of ions in
SSNTDs. These particle track parameters can be described by measuring the rate of etching of material along the track VT (a quantitiy proportional to energy loss) and particle range. Dwivedi and Mukherjee (1979) proposed a technique for measuring ranges of heavy ions in dierent track recording dielectrics which was used successfully by Randhawa et al. (1996) for CR-39 and lexan polycarbonate. Recently, various glasses viz., sodalime, quartz, phosphate etc., were used as SSNTDs due to their better charge resolution and possibility of using them under vacuum without loss of sensitivity (Price, 1993). Due to high value of bulk etch rate of dierent glasses in various etching solutions, it is dicult to ®nd the end point of tracks in glasses. In the present study, a new technique is proposed for the measurement of heavy ion ranges in track recording glasses. 2. Materials and methods
* Corresponding author. Tel.: +91-183-258237; fax: +91183-258237. E-mail address: [email protected] (H.S. Virk).
The samples of sodalime glass were irradiated by U (11.4 and 5.9 MeV/u) and 132Xe (14.5 MeV/u)
238
1350-4487/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S 1 3 5 0 - 4 4 8 7 ( 0 0 ) 0 0 0 3 6 - 6
284
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Fig. 1. Basic layout of back track etch technique.
heavy ions from UNILAC at GSI, Darmstadt, Germany. Similarly, the samples of barium phosphate (BP-1) and quartz glasses were irradiated by 238U (11.4 MeV/u) heavy ions from the same source. All these irradiations were made at an angle of 908 w.r.t. the sur-
face of the target material. The irradiated samples were cut into 1 cm 1 cm pieces. The range of heavy ions in dierent glasses were measured by using back track etching method. In this technique, the samples were deposited on a substrate glass slide from the irradiated side by an adhesive paste. In the present investigation, the material of substrate is similar to the sample under investigation. Fig. 1 displays the basic layout of this technique. The combination of substrate and irradiated samples were etched in dierent volumes of hydro¯uoric acid (HF). Before etching, the thickness of dierent combinations were measured by a sensitive micrometer (least count = 1 mm). The combination of sodalime glasses were etched in 12 vol% HF at room temperature for intervals of 10 min. The bulk etch rate on both sides was the same due to similarity of substrate and sample ma-
Table 1 Experimental details on range measurements Material
Heavy ion
Thickness of combination before etching (t1) (mm)
Thickness of sample slide (x ) (mm)
Thickness of combination after etching (t2) (mm)
Thickness removed from each side (y) [(t1 ÿ t2 )/2] (mm)
Range of heavy ion (x ÿ y ) (mm)
Sodalime Sodalime Sodalime BP-1 Quartz
238
290223 291022 289224 251023 169325
140524 140722 140523 120224 80422
30825 22823 34623 30425 28923
129728 134125 127327 110328 70228
108212 6627 132210 99212 102210
U (11.4 MeV/u) U (5.9 MeV/u) 132 Xe (14.5 MeV/u) 238 U (11.4 MeV/u) 238 U (11.4 MeV/u) 238
Fig. 2. Microphotograph of
238
U (11.4 MeV/u) ion tracks in BP-1 phosphate glass.
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Fig. 3. Microphotograph of
238
U (11.4 MeV/u) ion tracks in soda glass.
terial. The etching intervals were reduced to 30 s in the expected range of heavy ions. After each etching interval, the combination was washed in running water and scanned under the optical microscope from the sample side. The etching process continued till the etched track was just visible under the optical microscope.
Fig. 4. Microphotograph of
285
238
The remaining thickness was again measured by using the micrometer. Similarly, the samples of BP-1 phosphate and quartz glasses were deposited on a substrate of BP-1 and quartz, respectively. Both these combinations were etched in 40 vol.% HF. The details of experimental measurements are given Table 1. Finally, a
U (11.4 MeV/u) ion tracks in quartz glass.
286
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Table 2 Intercomparison of experimental and theoretical range values of heavy ions in dierent glassesa Glass
Sodalime Sodalime Sodalime BP-1 Quartz a
Ion
238
U U 132 Xe 238 U 238 U 238
Energy (MeV/u)
11.4 5.9 14.5 11.4 11.4
RExperimental (mm)
108212 6627 132210 99212 102210
RTheoretical (mm) Mukherjee and Nayak
TRIM-95
SRIM-97
98.32 (ÿ9) 60.90 (ÿ8) 129.32 (ÿ2) 93.87 (ÿ5) 101.10 (ÿ1)
103.22 (ÿ4) 63.45 (ÿ3) 125.12 (ÿ5) 100.03 (1) 94.56 (ÿ7)
103.43 (ÿ4) 62.67 (ÿ5) 130.05 (ÿ2) 98.78 (0) 99.63 (ÿ2)
Parentheses give % deviation of theoretical range values from the experimental ones.
comparison has been made between the measured range values and theoretically computed values from dierent formulations.
3. Results and discussion The experimental range data of dierent heavy ions in soda-glass, BP-1 phosphate and quartz glasses is given in Table 2. The theoretically computed values of heavy ion ranges from Mukherjee and Nayak (1979), TRIM-95 (Ziegler, 1995) and SRIM-97 (Biersack and Ziegler, 1997) based on the formulations of Ziegler et al. (1985) are also summarized in this table. The percentage deviation of the computed values from the experimental ones is given in parentheses. From this table it is evident that in case of soda-glass, all the theoretical formulations underestimate the range data from the experimental data. The Mukherjee and Nayak formulation underestimates the range data about 10% in case of 238U (11.4 and 5.9 MeV/u) in soda glass. For 132Xe (14.5 MeV/u) ion in soda glass, this formulation gives range values within the errors (25%). For 238U (11.4 MeV/u) ion in BP-1 phosphate glass, all the three formulations give theoretical range values compatible to the experimental value. A similar evidence can be made for 238U (11.4 MeV/u) ion in quartz glass. Figs. 2±4 show microphotographs of etched tracks of 238U (11.4 MeV/u) ions in BP-1, soda glass and quartz glasses, respectively. All these tracks are for an oblique incidence of heavy ions w.r.t. the surface of the detector. From these microphotographs it is clear that the tracks are very dark in case of BP-1 phosphate glass. The end points of tracks are also very sharp. The sensitivity (S = VT/VB) of BP-1 phosphate glass is many times more than that of soda and quartz glasses (Randhawa and Virk, 1995). The variation of projected track length versus etching time for BP-phosphate, soda and quartz glasses was also studied in that investigation. The projected track length in case of BP-
1 phosphate glass becomes constant after a certain time of etching. Once the end point is achieved, tracks start etching at the rate of bulk etching which is very low in this case. The total range of 238U (11.4 MeV/u) ion in BP-1 phosphate glass for oblique incidence has already been measured (Randhawa and Virk, 1997) by applying corrections due to bulk etching and over etching as required in the method of Dwivedi and Mukherjee (1979). The measured value of range was 101.09 mm which is compatible to the present value (99 mm). In case of soda glass the achievement of end point is very dicult. Even after a certain limit of overetching, the starting point of track disappears as shown in Fig. 3. Similar problem is faced in range measurment of heavy ions in quartz glass by using the technique of Dwivedi and Mukherjee (1979). 4. Conclusions 1. Back track etching technique can be used successfully for determination of heavy ion ranges in glass track detectors. 2. TRIM-95 and SRIM-97 based on the formulation of Ziegler et al. (1985) give theoretical range values in agreement to the experimental values.
References Bhandari, N., Bhat, S., Lal, D., Rajagopalan, G., Tamhane, A.S., Venktavardan, V.S., 1971. Super heavy elements in extraterrestrial samples. Nature 230, 219±224. Biersack, J.P., Ziegler, J.F., 1997. SRIM-97: stopping power and range of ions in matter, private communication. Brandt, R., 1980. Overall review of the applications of SSNTDs in ®ssion physics. Nucl. Instr. Meth 173, 147± 153. Dwivedi, K.K., Mukherjee, S., 1979. Heavy ion track lengths in solid dielectric track detectors. Nucl. Instr. Meth 161, 317±326.
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287 Durrani, S.A., Bull, R.K., 1987. Solid State Nuclear Track Detection: Principles, Methods and Applications. Pergamon Press, Oxford, UK. Fleischer, R.L., Price, P.B., Walker, R.M., 1975. Nuclear Tracks in Solids: Principles and Applications. University of California Press, Berkeley. Mukherjee, S., Nayak, A.K., 1979. Calculation of heavy ion ranges in complex media. Nucl. Instr. Meth 159, 421±431. Price, P.B., 1993. Advances in solid state nuclear track detectors. Nucl. Tracks and Radiat. Meas 22, 9±21. Randhawa, G.S., Virk, H.S., 1996. Track etching characteristics of dierent glass track detectors. Appl. Radiat. Isot. (UK) 47, 351±354. Randhawa, G.S., Sharma, S.K., Virk, H.S., 1996. Intercomparison of experimental and theoretical values of
287
heavy ion ranges in plastic track detectors. Nucl. Instr. Meth B108, 7±10. Randhawa, G.S., Virk, H.S., 1997. Study of charged particle tracks in barium phosphate (BP-1) glass. Nucl. Instr. Meth B132, 653±659. Rose, H.J., Jones, G.A., 1984. A new kind of natural radioactivity. Nature 307, 185. Spohr, R., 1990. Ion Tracks and Microtechnology: Principles and Applications. Vieweg-Verlag. Ziegler, J.F. Biersack, J.P., Littmark, U., 1985. The Stopping Power and Range of Ions in Solids (Vol. 1, J.F. Ziegler, ed.). Pergamon Press, New York. Ziegler, J.F., 1995. TRIM-95: the transport of ions in matter. IBM, Research, 28-0, Yorktown, NY 10598, USA.
www.elsevier.com/locate/radmeas
Heavy ion range measurements in some glasses using back track etching technique G.S. Randhawa a, H.S. Virk b,* a
Department of Physics, Khalsa College, Amritsar, India Department of Physics, Guru Nanak Dev University, Amritsar 143 005, India
b
Received in revised form 27 October 1999
Abstract The samples of soda, quartz and barium phosphate (BP-1) glasses were irradiated by dierent heavy ions from UNILAC, GSI, Darmstadt. The range of these heavy ions in these glasses were measured by using back track etch technique. The experimental values of heavy ion ranges were compared with the theoretical values computed from Mukherjee and Nayak (1979), TRIM-95 and SRIM-97 computer codes based on the formulations of Ziegler et al. (1985). 7 2000 Elsevier Science Ltd. All rights reserved.
1. Introduction The theoretical and experimental investigations about the penetration of charged particles in matter played a very important role in the development of modern physics. Solid state nuclear track detectors (SSNTDs) have become one of the most important tool for many branches of science and technology (Fleischer et al., 1975; Durrani and Bull, 1987; Spohr, 1990). For many fundamental discoveries, such as the ®rst evidence of cluster radioactivity (Rose and Jones, 1984), the search of super heavy elements (Bhandari et al., 1971), the detection of very low cross-sections (Brandt, 1980) etc., the credit goes to these passive detectors. For identi®cation of charge, mass and energy of particle in dierent applications, there is need to establish a relationship between the track parameters and ionization losses and range of ions in
SSNTDs. These particle track parameters can be described by measuring the rate of etching of material along the track VT (a quantitiy proportional to energy loss) and particle range. Dwivedi and Mukherjee (1979) proposed a technique for measuring ranges of heavy ions in dierent track recording dielectrics which was used successfully by Randhawa et al. (1996) for CR-39 and lexan polycarbonate. Recently, various glasses viz., sodalime, quartz, phosphate etc., were used as SSNTDs due to their better charge resolution and possibility of using them under vacuum without loss of sensitivity (Price, 1993). Due to high value of bulk etch rate of dierent glasses in various etching solutions, it is dicult to ®nd the end point of tracks in glasses. In the present study, a new technique is proposed for the measurement of heavy ion ranges in track recording glasses. 2. Materials and methods
* Corresponding author. Tel.: +91-183-258237; fax: +91183-258237. E-mail address: [email protected] (H.S. Virk).
The samples of sodalime glass were irradiated by U (11.4 and 5.9 MeV/u) and 132Xe (14.5 MeV/u)
238
1350-4487/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S 1 3 5 0 - 4 4 8 7 ( 0 0 ) 0 0 0 3 6 - 6
284
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Fig. 1. Basic layout of back track etch technique.
heavy ions from UNILAC at GSI, Darmstadt, Germany. Similarly, the samples of barium phosphate (BP-1) and quartz glasses were irradiated by 238U (11.4 MeV/u) heavy ions from the same source. All these irradiations were made at an angle of 908 w.r.t. the sur-
face of the target material. The irradiated samples were cut into 1 cm 1 cm pieces. The range of heavy ions in dierent glasses were measured by using back track etching method. In this technique, the samples were deposited on a substrate glass slide from the irradiated side by an adhesive paste. In the present investigation, the material of substrate is similar to the sample under investigation. Fig. 1 displays the basic layout of this technique. The combination of substrate and irradiated samples were etched in dierent volumes of hydro¯uoric acid (HF). Before etching, the thickness of dierent combinations were measured by a sensitive micrometer (least count = 1 mm). The combination of sodalime glasses were etched in 12 vol% HF at room temperature for intervals of 10 min. The bulk etch rate on both sides was the same due to similarity of substrate and sample ma-
Table 1 Experimental details on range measurements Material
Heavy ion
Thickness of combination before etching (t1) (mm)
Thickness of sample slide (x ) (mm)
Thickness of combination after etching (t2) (mm)
Thickness removed from each side (y) [(t1 ÿ t2 )/2] (mm)
Range of heavy ion (x ÿ y ) (mm)
Sodalime Sodalime Sodalime BP-1 Quartz
238
290223 291022 289224 251023 169325
140524 140722 140523 120224 80422
30825 22823 34623 30425 28923
129728 134125 127327 110328 70228
108212 6627 132210 99212 102210
U (11.4 MeV/u) U (5.9 MeV/u) 132 Xe (14.5 MeV/u) 238 U (11.4 MeV/u) 238 U (11.4 MeV/u) 238
Fig. 2. Microphotograph of
238
U (11.4 MeV/u) ion tracks in BP-1 phosphate glass.
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Fig. 3. Microphotograph of
238
U (11.4 MeV/u) ion tracks in soda glass.
terial. The etching intervals were reduced to 30 s in the expected range of heavy ions. After each etching interval, the combination was washed in running water and scanned under the optical microscope from the sample side. The etching process continued till the etched track was just visible under the optical microscope.
Fig. 4. Microphotograph of
285
238
The remaining thickness was again measured by using the micrometer. Similarly, the samples of BP-1 phosphate and quartz glasses were deposited on a substrate of BP-1 and quartz, respectively. Both these combinations were etched in 40 vol.% HF. The details of experimental measurements are given Table 1. Finally, a
U (11.4 MeV/u) ion tracks in quartz glass.
286
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287
Table 2 Intercomparison of experimental and theoretical range values of heavy ions in dierent glassesa Glass
Sodalime Sodalime Sodalime BP-1 Quartz a
Ion
238
U U 132 Xe 238 U 238 U 238
Energy (MeV/u)
11.4 5.9 14.5 11.4 11.4
RExperimental (mm)
108212 6627 132210 99212 102210
RTheoretical (mm) Mukherjee and Nayak
TRIM-95
SRIM-97
98.32 (ÿ9) 60.90 (ÿ8) 129.32 (ÿ2) 93.87 (ÿ5) 101.10 (ÿ1)
103.22 (ÿ4) 63.45 (ÿ3) 125.12 (ÿ5) 100.03 (1) 94.56 (ÿ7)
103.43 (ÿ4) 62.67 (ÿ5) 130.05 (ÿ2) 98.78 (0) 99.63 (ÿ2)
Parentheses give % deviation of theoretical range values from the experimental ones.
comparison has been made between the measured range values and theoretically computed values from dierent formulations.
3. Results and discussion The experimental range data of dierent heavy ions in soda-glass, BP-1 phosphate and quartz glasses is given in Table 2. The theoretically computed values of heavy ion ranges from Mukherjee and Nayak (1979), TRIM-95 (Ziegler, 1995) and SRIM-97 (Biersack and Ziegler, 1997) based on the formulations of Ziegler et al. (1985) are also summarized in this table. The percentage deviation of the computed values from the experimental ones is given in parentheses. From this table it is evident that in case of soda-glass, all the theoretical formulations underestimate the range data from the experimental data. The Mukherjee and Nayak formulation underestimates the range data about 10% in case of 238U (11.4 and 5.9 MeV/u) in soda glass. For 132Xe (14.5 MeV/u) ion in soda glass, this formulation gives range values within the errors (25%). For 238U (11.4 MeV/u) ion in BP-1 phosphate glass, all the three formulations give theoretical range values compatible to the experimental value. A similar evidence can be made for 238U (11.4 MeV/u) ion in quartz glass. Figs. 2±4 show microphotographs of etched tracks of 238U (11.4 MeV/u) ions in BP-1, soda glass and quartz glasses, respectively. All these tracks are for an oblique incidence of heavy ions w.r.t. the surface of the detector. From these microphotographs it is clear that the tracks are very dark in case of BP-1 phosphate glass. The end points of tracks are also very sharp. The sensitivity (S = VT/VB) of BP-1 phosphate glass is many times more than that of soda and quartz glasses (Randhawa and Virk, 1995). The variation of projected track length versus etching time for BP-phosphate, soda and quartz glasses was also studied in that investigation. The projected track length in case of BP-
1 phosphate glass becomes constant after a certain time of etching. Once the end point is achieved, tracks start etching at the rate of bulk etching which is very low in this case. The total range of 238U (11.4 MeV/u) ion in BP-1 phosphate glass for oblique incidence has already been measured (Randhawa and Virk, 1997) by applying corrections due to bulk etching and over etching as required in the method of Dwivedi and Mukherjee (1979). The measured value of range was 101.09 mm which is compatible to the present value (99 mm). In case of soda glass the achievement of end point is very dicult. Even after a certain limit of overetching, the starting point of track disappears as shown in Fig. 3. Similar problem is faced in range measurment of heavy ions in quartz glass by using the technique of Dwivedi and Mukherjee (1979). 4. Conclusions 1. Back track etching technique can be used successfully for determination of heavy ion ranges in glass track detectors. 2. TRIM-95 and SRIM-97 based on the formulation of Ziegler et al. (1985) give theoretical range values in agreement to the experimental values.
References Bhandari, N., Bhat, S., Lal, D., Rajagopalan, G., Tamhane, A.S., Venktavardan, V.S., 1971. Super heavy elements in extraterrestrial samples. Nature 230, 219±224. Biersack, J.P., Ziegler, J.F., 1997. SRIM-97: stopping power and range of ions in matter, private communication. Brandt, R., 1980. Overall review of the applications of SSNTDs in ®ssion physics. Nucl. Instr. Meth 173, 147± 153. Dwivedi, K.K., Mukherjee, S., 1979. Heavy ion track lengths in solid dielectric track detectors. Nucl. Instr. Meth 161, 317±326.
G.S. Randhawa, H.S. Virk / Radiation Measurements 32 (2000) 283±287 Durrani, S.A., Bull, R.K., 1987. Solid State Nuclear Track Detection: Principles, Methods and Applications. Pergamon Press, Oxford, UK. Fleischer, R.L., Price, P.B., Walker, R.M., 1975. Nuclear Tracks in Solids: Principles and Applications. University of California Press, Berkeley. Mukherjee, S., Nayak, A.K., 1979. Calculation of heavy ion ranges in complex media. Nucl. Instr. Meth 159, 421±431. Price, P.B., 1993. Advances in solid state nuclear track detectors. Nucl. Tracks and Radiat. Meas 22, 9±21. Randhawa, G.S., Virk, H.S., 1996. Track etching characteristics of dierent glass track detectors. Appl. Radiat. Isot. (UK) 47, 351±354. Randhawa, G.S., Sharma, S.K., Virk, H.S., 1996. Intercomparison of experimental and theoretical values of
287
heavy ion ranges in plastic track detectors. Nucl. Instr. Meth B108, 7±10. Randhawa, G.S., Virk, H.S., 1997. Study of charged particle tracks in barium phosphate (BP-1) glass. Nucl. Instr. Meth B132, 653±659. Rose, H.J., Jones, G.A., 1984. A new kind of natural radioactivity. Nature 307, 185. Spohr, R., 1990. Ion Tracks and Microtechnology: Principles and Applications. Vieweg-Verlag. Ziegler, J.F. Biersack, J.P., Littmark, U., 1985. The Stopping Power and Range of Ions in Solids (Vol. 1, J.F. Ziegler, ed.). Pergamon Press, New York. Ziegler, J.F., 1995. TRIM-95: the transport of ions in matter. IBM, Research, 28-0, Yorktown, NY 10598, USA.