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Detection of coloured tracks of heavy ion particles using photographic colour film
Radiation Measurements 34 (2001) 203–206
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Detection of coloured tracks of heavy ion particles using photographic colour $lm K. Kugea; ∗ , N. Yasudab; c , H. Kumagaid , K. Nakazawae , T. Kobayashia , N. Aokia , A. Hasegawaa a Faculty
of Engineering, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan Engineering and Systems Science, University of Tokyo, Hongo, Tokyo 113-8656, Japan c National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555, Japan d Radioisotope Research Center, Chiba University, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan e Physics Department, Gifu University, Yanagido, Gifu 501-1193, Japan
b Quantum
Received 28 August 2000; received in revised form 6 March 2001; accepted 7 March 2001
Abstract A photographic colour $lm, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour $lm consists of several layers and di3erent colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in di3erent colours represented di3erences of track depth and we also discussed the disadvantages of using commercial colour $lms. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the c 2001 Elsevier Science Ltd. All rights reserved. disadvantages. Keywords: Nuclear track; Colour photography; Nuclear emulsion
1. Introduction Nuclear emulsions are used for the detection of charged particles due to their ability to record the three-dimensional information of tracks with high spatial resolution. However, their measurement process, using the focal depth of optical microscope, is tedious and requires much e3ort. For example, it is necessary to measure the thickness twice before and after development, since the thickness of the emulsion layer changes during the development. We have reported a new method for displaying coloured tracks that correspond to depth information in the emulsion layer using commercial colour negative $lms (Kuge et al., 2000, 2001). This method is based on the principle of colour photography (Thirtle, 1975), and a schematic diagram of this principle is shown in Fig. 1. This method allows the ∗ Corresponding author. Fax: +81-43-290-3455. E-mail address: [email protected] (K. Kuge), [email protected] (N. Yasuda).
track range to be observed as changing of colours, and it is possible to obtain the information of track range and angle, at a glance. Moreover, since the information is recorded by the layers of the $lm as colour di3erence, changes of layer thickness during the development have no e3ect on the measurements of track range and angle. Therefore, once we measure its thickness before or after irradiation, it is not necessary to measure the thickness after the development. In addition, this $lm can be developed by a commercial laboratory. In this paper, we also pointed out disadvantages of this method. They were: (i) unclear yellow coloured tracks, resulting because the base colour of the negative $lm was yellow, and (ii) low resolution, resulting because of the wide size distribution for the silver halide grains. The $rst disadvantage can be overcome by using colour print $lm for movies with a transparent base. The second can be overcome by preparing a coating with a nuclear emulsion including colour couplers. It is necessary to prepare the coupler-dispersed emulsion and coat it on multi-layers. And
c 2001 Elsevier Science Ltd. All rights reserved. 1350-4487/01/$ - see front matter PII: S 1 3 5 0 - 4 4 8 7 ( 0 1 ) 0 0 1 5 2 - 4
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K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
(Fuji Photo Film) which is sensitive to the minimum ionization particle. The couplers were the cyan coupler N93 and the magenta coupler N104 (Konica Chemicals) which are solvent dispersion couplers (Tong, 1975). A hydrophobic coupler was dissolved in oil and the oil emulsion was dispersed in the photographic emulsion in order to prevent di3usion of coupler through the layers. We prepared solution A (10% gelatin solution (100 g) and 10% Alkanol XC (duPont) (5 ml)) and Solution B (coupler (10 g), diisobutyl phthalate (10 ml) and ethyl acetate (20 ml)). Solution B was added to solution A and they were dispersed with an ultrasonic homogenizer. The pressure was reduced in the mixing Hask to eliminate bubbles and ethyl acetate. Then, we added 40 g of the coupler-dispersed solution to 100 g of the nuclear emulsion. First we coated the emulsion with cyan coupler on the transparent PET base. After drying we coated the emulsion with magenta coupler on the $rst layer. Table 1 Procedure of modi$ed C41 process Colour developing Stop bath Washing Bleaching Washing Fixing Washing with running water
◦
28 C ◦ 28 C ◦ 28 C ◦ 28 C ◦ 28 C ◦ 28 C
10 min 0:5 min 3 times 8:5 min 3 times 10 min more than 5 min
Table 2 Formulae of modi$ed C41 process
Fig. 1. Schematic diagram displaying the tracks of di3erent depth with di3erent colours to obtain the three-dimensional information.
it is also necessary that we must develop the images ourselves. Here, we present a procedure for a self-made coating of nuclear emulsion, and the development formula for the self-made coating and the colour print $lm. 2. Experimental We used colour print $lm for movies and a self-made coating of nuclear emulsion including couplers. The colour print $lm was Vision colour print $lm 2383 (Kodak). It has a transparent base as it is used for projection, and it has three colouring layers of magenta, cyan and yellow starting from the bottom. The self-made coating of nuclear emulsion with couplers was prepared as follows: The used emulsion was Fuji-ET7C
Colour developer solution Sodium sul$te 4:25 g Potassium bromide 5g Sodium carbonate 37:5 g Hydroxylammonium chloride 2g Water to make 1 litre Add Kodak CD-3, 4:75 g before 6 h of development Stop bath solution Acetic acid Sodium sul$te Water to make
20 ml 10 g 1 litre
Bleach solution EDTA NaFe Potassium bromide Ammonia solution 20% Water to make
100 g 50 g 6 ml 1 litre
Fixer solution Ammonium thiosulfate Sodium sul$te Potassium disul$te Water to make
120 g 20 g 20 g 1 litre
K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
Fig. 2. Photomicrograph of tracks of the xenon ion beam which irradiated the colour print $lm for movies at a shallow angle.
Each of the two kinds of samples was exposed to 290 MeV=n xenon ions from Heavy Ion Medical Accelerator in Chiba (HIMAC) in the National Institute of Radiological Sciences at Huences of 104 –105 ions=cm2 . Then, the samples were developed with the modi$ed C41 process (Sasai, 1983) which is given in Tables 1 and 2. The development temperature was lowered from the normal ◦ condition of 38–28 C, and the development time was prolonged to 10 min, because the emulsion on the unhardened $lm coating dissolves on the normal development conditions. Then, the tracks on the $lms were observed using an optical microscope. 3. Results and discussion Fig. 2 shows a photomicrograph of xenon tracks recorded on the colour print $lm. It was developed with the modi$ed C41 process shown in Tables 1 and 2. Many tracks are represented with the three colours which are ordered yellow, cyan and magenta. Since the base of the $lm is transparent, the yellow part of the track is clearly shown. Some tracks have one or two colours. For example, track A has only a magenta part and track B has magenta and cyan parts. The lack of yellow colour suggests that the xenon ion enters
205
Fig. 3. Photomicrograph of tracks of the xenon ion beam which irradiated the self-made coating at a shallow angle.
from the bottom and stops in the magenta or cyan layer. The width of the yellow part of the track is thicker than those of the magenta and cyan parts, because large silver halide grains are used in the yellow layer in order to increase the sensitivity for colour photography. Fig. 3 shows a photomicrograph of xenon tracks recorded on the self-made coating. It was also developed with the modi$ed C41 process. This coating consisted of two layers including the magenta or cyan coupler. Coloured tracks of magenta and cyan are observed and this indicates information on tracks depth. There seems to be a high resolving power due to the smaller silver halide grains in the nuclear emulsion, since the tracks are thin compared to the commercial colour $lm. Fig. 4 shows a photomicrograph of tracks of the ions which irradiated the self-made coating at a right angle. Their blue colour is formed by mixing of magenta and cyan. This indicates that the ions passed through two layers and formed a dye in each layer. The dye cloud forming a track is not so compact and this would be due to oozing of dyes from dispersed oil drops. The resolution is not enough to detect -rays. There is some room for improvement in the preparation and development processes to observe the minimum ionization particles.
206
K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
due to the wide size distribution of silver halide grains. We presented a self-made coating and development formula in order to overcome the disadvantages. The $rst disadvantage was resolved by using a colour print $lm having a transparent base and a suitable development formula. Clear, yellow coloured tracks were observed on this $lm. For the second disadvantage, we prepared the self-made coating of nuclear emulsion (Fuji-ET7C) with couplers. It consisted of two layers and each layer included cyan or magenta coupler. We succeeded in observing two-coloured tracks which indicated the depth of the tracks. We expect that clearer tracks will be observed by optimization of the preparation and development processes. The results here ensure that the new method displays the coloured tracks corresponding to the depth information. This method will be useful for the study of particle physics, nuclear physics, cosmic ray physics and space radiation dosimetry, etc. Acknowledgements The experiments were performed as one link in the chain of the Research Project with Heavy Ions at NIRS-HIMAC (12P096). One of the authors (N.Y.) is grateful to the Research for the Future Program (JSPS-RFTF 98P00901) of JSPS (Japan Society for the Promotion of Science). Fig. 4. Photomicrograph of tracks of the xenon ion beam which irradiated the self-made coating at a right angle.
We have coated the emulsion on two layers and used only two kinds of couplers in this experiment. In commercial colour $lms, the emulsion layers are coated one over another to thinner than 1 m. Therefore, we can expect accuracy of the measurement of track depth to be at similar level to that when stacking many thin emulsion layers including di3erent couplers. 4. Conclusions There were two disadvantages to the new method to display coloured tracks using commercial colour negative $lms: (i) yellow colour of the $lm base and (ii) low resolution
References Kuge, K., Yasuda, N., Aoki, N., Hasegawa, A., 2000. Detection of heavy ion particles with coloured tracks using photographic colour $lm. In: Proceedings of the 37th Annual Meeting on Radioisotopes in the Physical Science and Industries, p. 7 (in Japanese). Kuge, K., Yasuda, N., Kumagai, H., Aoki, N., Hasegawa, A., Takahashi, H., Nakazawa, M., 2001. Coloured tracks of heavy ion particles recorded on the photographic colour $lm. Nucl. Instrum. Methods A, in press. Sasai, A., 1983. Shashin Shohou Binran, Shashin Kogyo Shuppan, Tokyo, pp. 230 –231 (in Japanese). Thirtle, J.R., 1975. Principles of colour photography. In: James, T.H. (Ed.), The Theory of the Photographic Process. Macmillan, New York, pp. 335 –339 (Chapter 12). Tong, L.K.J., 1975. Mechanism of dye formation and related reactions. In: James, T.H. (Ed.), The Theory of the Photographic Process. Macmillan, New York, pp. 348–349 (Chapter 12).
www.elsevier.com/locate/radmeas
Detection of coloured tracks of heavy ion particles using photographic colour $lm K. Kugea; ∗ , N. Yasudab; c , H. Kumagaid , K. Nakazawae , T. Kobayashia , N. Aokia , A. Hasegawaa a Faculty
of Engineering, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan Engineering and Systems Science, University of Tokyo, Hongo, Tokyo 113-8656, Japan c National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555, Japan d Radioisotope Research Center, Chiba University, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan e Physics Department, Gifu University, Yanagido, Gifu 501-1193, Japan
b Quantum
Received 28 August 2000; received in revised form 6 March 2001; accepted 7 March 2001
Abstract A photographic colour $lm, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour $lm consists of several layers and di3erent colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in di3erent colours represented di3erences of track depth and we also discussed the disadvantages of using commercial colour $lms. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the c 2001 Elsevier Science Ltd. All rights reserved. disadvantages. Keywords: Nuclear track; Colour photography; Nuclear emulsion
1. Introduction Nuclear emulsions are used for the detection of charged particles due to their ability to record the three-dimensional information of tracks with high spatial resolution. However, their measurement process, using the focal depth of optical microscope, is tedious and requires much e3ort. For example, it is necessary to measure the thickness twice before and after development, since the thickness of the emulsion layer changes during the development. We have reported a new method for displaying coloured tracks that correspond to depth information in the emulsion layer using commercial colour negative $lms (Kuge et al., 2000, 2001). This method is based on the principle of colour photography (Thirtle, 1975), and a schematic diagram of this principle is shown in Fig. 1. This method allows the ∗ Corresponding author. Fax: +81-43-290-3455. E-mail address: [email protected] (K. Kuge), [email protected] (N. Yasuda).
track range to be observed as changing of colours, and it is possible to obtain the information of track range and angle, at a glance. Moreover, since the information is recorded by the layers of the $lm as colour di3erence, changes of layer thickness during the development have no e3ect on the measurements of track range and angle. Therefore, once we measure its thickness before or after irradiation, it is not necessary to measure the thickness after the development. In addition, this $lm can be developed by a commercial laboratory. In this paper, we also pointed out disadvantages of this method. They were: (i) unclear yellow coloured tracks, resulting because the base colour of the negative $lm was yellow, and (ii) low resolution, resulting because of the wide size distribution for the silver halide grains. The $rst disadvantage can be overcome by using colour print $lm for movies with a transparent base. The second can be overcome by preparing a coating with a nuclear emulsion including colour couplers. It is necessary to prepare the coupler-dispersed emulsion and coat it on multi-layers. And
c 2001 Elsevier Science Ltd. All rights reserved. 1350-4487/01/$ - see front matter PII: S 1 3 5 0 - 4 4 8 7 ( 0 1 ) 0 0 1 5 2 - 4
204
K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
(Fuji Photo Film) which is sensitive to the minimum ionization particle. The couplers were the cyan coupler N93 and the magenta coupler N104 (Konica Chemicals) which are solvent dispersion couplers (Tong, 1975). A hydrophobic coupler was dissolved in oil and the oil emulsion was dispersed in the photographic emulsion in order to prevent di3usion of coupler through the layers. We prepared solution A (10% gelatin solution (100 g) and 10% Alkanol XC (duPont) (5 ml)) and Solution B (coupler (10 g), diisobutyl phthalate (10 ml) and ethyl acetate (20 ml)). Solution B was added to solution A and they were dispersed with an ultrasonic homogenizer. The pressure was reduced in the mixing Hask to eliminate bubbles and ethyl acetate. Then, we added 40 g of the coupler-dispersed solution to 100 g of the nuclear emulsion. First we coated the emulsion with cyan coupler on the transparent PET base. After drying we coated the emulsion with magenta coupler on the $rst layer. Table 1 Procedure of modi$ed C41 process Colour developing Stop bath Washing Bleaching Washing Fixing Washing with running water
◦
28 C ◦ 28 C ◦ 28 C ◦ 28 C ◦ 28 C ◦ 28 C
10 min 0:5 min 3 times 8:5 min 3 times 10 min more than 5 min
Table 2 Formulae of modi$ed C41 process
Fig. 1. Schematic diagram displaying the tracks of di3erent depth with di3erent colours to obtain the three-dimensional information.
it is also necessary that we must develop the images ourselves. Here, we present a procedure for a self-made coating of nuclear emulsion, and the development formula for the self-made coating and the colour print $lm. 2. Experimental We used colour print $lm for movies and a self-made coating of nuclear emulsion including couplers. The colour print $lm was Vision colour print $lm 2383 (Kodak). It has a transparent base as it is used for projection, and it has three colouring layers of magenta, cyan and yellow starting from the bottom. The self-made coating of nuclear emulsion with couplers was prepared as follows: The used emulsion was Fuji-ET7C
Colour developer solution Sodium sul$te 4:25 g Potassium bromide 5g Sodium carbonate 37:5 g Hydroxylammonium chloride 2g Water to make 1 litre Add Kodak CD-3, 4:75 g before 6 h of development Stop bath solution Acetic acid Sodium sul$te Water to make
20 ml 10 g 1 litre
Bleach solution EDTA NaFe Potassium bromide Ammonia solution 20% Water to make
100 g 50 g 6 ml 1 litre
Fixer solution Ammonium thiosulfate Sodium sul$te Potassium disul$te Water to make
120 g 20 g 20 g 1 litre
K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
Fig. 2. Photomicrograph of tracks of the xenon ion beam which irradiated the colour print $lm for movies at a shallow angle.
Each of the two kinds of samples was exposed to 290 MeV=n xenon ions from Heavy Ion Medical Accelerator in Chiba (HIMAC) in the National Institute of Radiological Sciences at Huences of 104 –105 ions=cm2 . Then, the samples were developed with the modi$ed C41 process (Sasai, 1983) which is given in Tables 1 and 2. The development temperature was lowered from the normal ◦ condition of 38–28 C, and the development time was prolonged to 10 min, because the emulsion on the unhardened $lm coating dissolves on the normal development conditions. Then, the tracks on the $lms were observed using an optical microscope. 3. Results and discussion Fig. 2 shows a photomicrograph of xenon tracks recorded on the colour print $lm. It was developed with the modi$ed C41 process shown in Tables 1 and 2. Many tracks are represented with the three colours which are ordered yellow, cyan and magenta. Since the base of the $lm is transparent, the yellow part of the track is clearly shown. Some tracks have one or two colours. For example, track A has only a magenta part and track B has magenta and cyan parts. The lack of yellow colour suggests that the xenon ion enters
205
Fig. 3. Photomicrograph of tracks of the xenon ion beam which irradiated the self-made coating at a shallow angle.
from the bottom and stops in the magenta or cyan layer. The width of the yellow part of the track is thicker than those of the magenta and cyan parts, because large silver halide grains are used in the yellow layer in order to increase the sensitivity for colour photography. Fig. 3 shows a photomicrograph of xenon tracks recorded on the self-made coating. It was also developed with the modi$ed C41 process. This coating consisted of two layers including the magenta or cyan coupler. Coloured tracks of magenta and cyan are observed and this indicates information on tracks depth. There seems to be a high resolving power due to the smaller silver halide grains in the nuclear emulsion, since the tracks are thin compared to the commercial colour $lm. Fig. 4 shows a photomicrograph of tracks of the ions which irradiated the self-made coating at a right angle. Their blue colour is formed by mixing of magenta and cyan. This indicates that the ions passed through two layers and formed a dye in each layer. The dye cloud forming a track is not so compact and this would be due to oozing of dyes from dispersed oil drops. The resolution is not enough to detect -rays. There is some room for improvement in the preparation and development processes to observe the minimum ionization particles.
206
K. Kuge et al. / Radiation Measurements 34 (2001) 203–206
due to the wide size distribution of silver halide grains. We presented a self-made coating and development formula in order to overcome the disadvantages. The $rst disadvantage was resolved by using a colour print $lm having a transparent base and a suitable development formula. Clear, yellow coloured tracks were observed on this $lm. For the second disadvantage, we prepared the self-made coating of nuclear emulsion (Fuji-ET7C) with couplers. It consisted of two layers and each layer included cyan or magenta coupler. We succeeded in observing two-coloured tracks which indicated the depth of the tracks. We expect that clearer tracks will be observed by optimization of the preparation and development processes. The results here ensure that the new method displays the coloured tracks corresponding to the depth information. This method will be useful for the study of particle physics, nuclear physics, cosmic ray physics and space radiation dosimetry, etc. Acknowledgements The experiments were performed as one link in the chain of the Research Project with Heavy Ions at NIRS-HIMAC (12P096). One of the authors (N.Y.) is grateful to the Research for the Future Program (JSPS-RFTF 98P00901) of JSPS (Japan Society for the Promotion of Science). Fig. 4. Photomicrograph of tracks of the xenon ion beam which irradiated the self-made coating at a right angle.
We have coated the emulsion on two layers and used only two kinds of couplers in this experiment. In commercial colour $lms, the emulsion layers are coated one over another to thinner than 1 m. Therefore, we can expect accuracy of the measurement of track depth to be at similar level to that when stacking many thin emulsion layers including di3erent couplers. 4. Conclusions There were two disadvantages to the new method to display coloured tracks using commercial colour negative $lms: (i) yellow colour of the $lm base and (ii) low resolution
References Kuge, K., Yasuda, N., Aoki, N., Hasegawa, A., 2000. Detection of heavy ion particles with coloured tracks using photographic colour $lm. In: Proceedings of the 37th Annual Meeting on Radioisotopes in the Physical Science and Industries, p. 7 (in Japanese). Kuge, K., Yasuda, N., Kumagai, H., Aoki, N., Hasegawa, A., Takahashi, H., Nakazawa, M., 2001. Coloured tracks of heavy ion particles recorded on the photographic colour $lm. Nucl. Instrum. Methods A, in press. Sasai, A., 1983. Shashin Shohou Binran, Shashin Kogyo Shuppan, Tokyo, pp. 230 –231 (in Japanese). Thirtle, J.R., 1975. Principles of colour photography. In: James, T.H. (Ed.), The Theory of the Photographic Process. Macmillan, New York, pp. 335 –339 (Chapter 12). Tong, L.K.J., 1975. Mechanism of dye formation and related reactions. In: James, T.H. (Ed.), The Theory of the Photographic Process. Macmillan, New York, pp. 348–349 (Chapter 12).