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A new gas-discharge track detector streamer chamber
NUCLEAR
INSTRUMENTS
AND
METHODS
26 (I964) 3 4 5 - 3 4 7 ;
© NORTH-HOLLAND
PUBLISHING
CO.
A NEW GAS-DISCHARGE TRACK DETECTOR STREAMER CHAMBER B. A. DOLGOSHEIN and B. I. LUCHKOV P. N. Lebedev Physical Institute, ~loscow
Received 8 January 1964 Recently a new device for recording tracks o f charge particles-spark c h a m b e r was worked out a n d successfully applied in the experimental physics o f the elem e n t a r y particles 1 -4). The m a i n advantage o f the spark c h a m b e r as c o m p a r e d to the other track detectors is its high rate. However, a spark c h a m b e r has anisotropy in the degree of localisation o f the particles passing at different angles q~ to the direction of the electric field E. The spark follows along the trajectory of the particle only to q9 = 30-40 ~' 3,5). Across the path o f the particle passing t h r o u g h the greater angle ~0 a "series" of sparks following along the direction of the field E is produced. T h e trajectory o f such particle is well determined in the electrode plane 5) whereas the third coordinate parallel to E is k n o w n only with accuracy within the size o f the interelectrode distance. A n o t h e r disadvantage o f the spark c h a m b e r is difficulty of recording the particle interactions a n d the decays o f the particles. The purpose of this article is to describe a new type of a gas discharge chamber, " s t r e a m e r " c h a m b e r which records with the same efficiency tracks of the particles passing in any direction with reproduction of a space picture o f the phenomenon. A n essential p o i n t of the streamer c h a m b e r is the use o f unfinished spark discharge. As an indicator of the place o f the particle passage in the streamer chamber, there is not a spark, but initial regions of all streamers which are produced in the place of the particle m o t i o n from electron avalanches. A gas discharge in the c h a m b e r is artificially cut off at the stage when electron avalanches have overgrown into streamers, a n d the
latter starts to propagate towards electrodes with the velocity ~ 108 cm/sec.6). Luminescence o f gas in the streamer p l a s m a m a k e s the track visible. T h e particle track consists o f a n u m b e r o f light stripes which are the initial regions of positive a n d negative streamers. The length of the stripes depends on the duration o f electric impulse a n d can be m a d e sufficiently small. It is clear f r o m the m e c h a n i s m o f track production that any n u m b e r o f particles independently of the direction of their m o t i o n can be recorded in the streamer chamber. One of the used c h a m b e r s is s h o w n in fig. 1. T h e c h a m b e r is a box o f organic glass with the dimensions o f 60 x 50 x 25 cm 3. As electrodes d u r a l u m i n plates a n d also glass plates with a t r a n s p a r e n t conductive coating allowing to take p h o t o s t h r o u g h the electrode are used. T h e c h a m b e r is filled with neon up to the pressure of 0.3-1 atm. A block-diagram of pulse supply is s h o w n in fig. 2. Distinctive features of the d i a g r a m are a powerful pulse
3zS
T+¢6~VL
~
-
-
-
Fig. 2. A diagram of the high-voltage supply.
Fig. 1. A general view of the chamber with dimensions 60 x 50 x 25 cm 3.
]) S. Fukui and S. Miyamoto, Nuovo Cimento 11 (1959) 113. 2) Spark chamber symposium, Rev. Sci. Instr. 32, (1961) 481. 3) M. 1. Dayon and G. A. Leksin, Usp. Fly. Nauk. 80 (1963) 281. 4) Proc. 1962 Conference on Instrumentation for High-Energy Physics, CERN, Geneva, Nucl. Instr. and Meth. 20 (1963) 143-220. 5) B. A. Dolgoshein, B, I. Luchkov and G. I. Moiseev, Pribor i Teknhn. Experim., to be published. 6) I. M. Meek and I. D. Craggs, Electrical breakdown of gases (Oxford, 1953). 345
346
B. A. D O L G O S H E I N
voltage generator (PVG) a n d an air spark discharger which forms short high-voltage impulsed ( ~ 50 nsec). PVG is 20 stage Arcadjev-Marx generator 7) with a m a x i m u m voltage amplitude of 460 kV. The air spark
°-
AND
B. 1. L U C H K O V
electrodes in the projection perpendicular to E t a ) and parallel to E (b). In the projection (a) the track consists of a n u m b e r of light stripes with the m e a n length 1 -~ 7 mrn being initial areas o f streamers developing along the field E. Because o f the fluctuation of the development of avalanches a n d streamers, the stripes differ in length and in brightness. T h e narrowing o f the track in that projection is carried out by m e a n s o f shortening the time lag t o f the air discharger breakdown. Tracks with the stripe length 1 -~ 2 m m are observed visually. The track brightness diminishes with decrease o f their width 1 and narrow tracks are not recorded on the p h o t o g r a p h i c film. In the projection (b), the track is a chain o f points of a 1 m m in diameter in which streamers are projected. Tracks in the projection (b) are brighter, since light from every streamer is emitted from a less surface. The track width and spread o f the points relatively the trajectory o f the particle are smaller than in the convenient spark c h a m b e r in projection conditionsg), therefore the accuracy o f localisation o f the particle trajectory in the streamer c h a m b e r is better t h a n in the projection spark chamberS). In this projection one m a y observe with a good accuracy the events of interaction and decay of particles a n d m e a s u r e curvature of the tracks in a magnetic field. The projection (a) will then serve only to determine the place of the particle passage
Fig. 3. Photographs of tracks in a streamer chamber (neon, p = 1 arm, E ~ 8 kV/cm). discharger m o u n t e d directly on the c h a m b e r electrodes (fig. 1) suffers a b r e a k d o w n in the time t ( ~ 50 nsec) which it is possible to control after supplying a highvoltage pulse at the electrodesS). The c h a m b e r is set so that the angle between a vertical line and direction o f the electric field E is ~ 90 ° and cosmic particles cross the c h a m b e r almost in parallel to the electrodes. Tracks of cosmic particles are p h o t o g r a p h e d t h r o u g h a transparent electrode (~ E) and t h r o u g h a side wall of the c h a m b e r ( ± E) by the objectives "Upiter-3" (1:1.5) and R-Biotar (l :0.85) respectively on a high sensitive film (type 13, sensitivity 3000 units of the state standard). Fig. 3 shows p h o t o g r a p h s o f a single cosmic particle which crossed the c h a m b e r nearly in parallel with the 7) High voltage test equipment and measurenwnt, ed. A. A. Vorobjev tGostehizdat, Moscow, 1960). s) G. A. Mesja, Dissertation, Tomsk university, 1961. 9) A. I. Alikhanjan and M. 1. Dajon, Aspects ofthephysics o f the elemelltao, particles (Academi of Science of Armenia, Jerevan, 1963).
Fig. 4. Photograph of a single particle. by the c h a m b e r depth. Fig. 4 gives a p h o t o g r a p h of a single particle in the same projection (a) m a d e in the conditions when the resistance of ~ 1 kf2 is applied in series with the c h a m b e r that m a d e worse the front o f a high-voltage pulse. The track consists of c o l u m n s of positive and negative streamers separated by a dark b a n d which is, apparently, an initial region of streamers. Besides the a b o v e - m e n t i o n e d features of the streamer c h a m b e r it should be noted that dead time of the
A NEW
GAS-DISCHARGE
TRACK
streamer chamber would be much smaller than the dead time of the spark chamber, as the charge density in plasma of the initial streamer is essentially smaller than in the spark channel. That's why the spark chamber is, apparently, more fast track detector than the spark and discharge chambers. The measurement of particle ionisation in a streamer chamber seems to be more hopeful than in the spark chamber.
DETECTOR
STREAMER
CHAMBER
347
The streamer chamber is a very useful device for studying the initial stages of a spark discharge. The authors wish to thank professor A. I. Alikhanjan for the permanent interest in their work, scientific workers of the problem laboratory of Moscow institute of engineers-physisists V. V. Dmitrenko, V. V. Chizhov and collaborator of P. N. Lebedev Physica! Institute L. V. Suhov for their kind assistance.
INSTRUMENTS
AND
METHODS
26 (I964) 3 4 5 - 3 4 7 ;
© NORTH-HOLLAND
PUBLISHING
CO.
A NEW GAS-DISCHARGE TRACK DETECTOR STREAMER CHAMBER B. A. DOLGOSHEIN and B. I. LUCHKOV P. N. Lebedev Physical Institute, ~loscow
Received 8 January 1964 Recently a new device for recording tracks o f charge particles-spark c h a m b e r was worked out a n d successfully applied in the experimental physics o f the elem e n t a r y particles 1 -4). The m a i n advantage o f the spark c h a m b e r as c o m p a r e d to the other track detectors is its high rate. However, a spark c h a m b e r has anisotropy in the degree of localisation o f the particles passing at different angles q~ to the direction of the electric field E. The spark follows along the trajectory of the particle only to q9 = 30-40 ~' 3,5). Across the path o f the particle passing t h r o u g h the greater angle ~0 a "series" of sparks following along the direction of the field E is produced. T h e trajectory o f such particle is well determined in the electrode plane 5) whereas the third coordinate parallel to E is k n o w n only with accuracy within the size o f the interelectrode distance. A n o t h e r disadvantage o f the spark c h a m b e r is difficulty of recording the particle interactions a n d the decays o f the particles. The purpose of this article is to describe a new type of a gas discharge chamber, " s t r e a m e r " c h a m b e r which records with the same efficiency tracks of the particles passing in any direction with reproduction of a space picture o f the phenomenon. A n essential p o i n t of the streamer c h a m b e r is the use o f unfinished spark discharge. As an indicator of the place o f the particle passage in the streamer chamber, there is not a spark, but initial regions of all streamers which are produced in the place of the particle m o t i o n from electron avalanches. A gas discharge in the c h a m b e r is artificially cut off at the stage when electron avalanches have overgrown into streamers, a n d the
latter starts to propagate towards electrodes with the velocity ~ 108 cm/sec.6). Luminescence o f gas in the streamer p l a s m a m a k e s the track visible. T h e particle track consists o f a n u m b e r o f light stripes which are the initial regions of positive a n d negative streamers. The length of the stripes depends on the duration o f electric impulse a n d can be m a d e sufficiently small. It is clear f r o m the m e c h a n i s m o f track production that any n u m b e r o f particles independently of the direction of their m o t i o n can be recorded in the streamer chamber. One of the used c h a m b e r s is s h o w n in fig. 1. T h e c h a m b e r is a box o f organic glass with the dimensions o f 60 x 50 x 25 cm 3. As electrodes d u r a l u m i n plates a n d also glass plates with a t r a n s p a r e n t conductive coating allowing to take p h o t o s t h r o u g h the electrode are used. T h e c h a m b e r is filled with neon up to the pressure of 0.3-1 atm. A block-diagram of pulse supply is s h o w n in fig. 2. Distinctive features of the d i a g r a m are a powerful pulse
3zS
T+¢6~VL
~
-
-
-
Fig. 2. A diagram of the high-voltage supply.
Fig. 1. A general view of the chamber with dimensions 60 x 50 x 25 cm 3.
]) S. Fukui and S. Miyamoto, Nuovo Cimento 11 (1959) 113. 2) Spark chamber symposium, Rev. Sci. Instr. 32, (1961) 481. 3) M. 1. Dayon and G. A. Leksin, Usp. Fly. Nauk. 80 (1963) 281. 4) Proc. 1962 Conference on Instrumentation for High-Energy Physics, CERN, Geneva, Nucl. Instr. and Meth. 20 (1963) 143-220. 5) B. A. Dolgoshein, B, I. Luchkov and G. I. Moiseev, Pribor i Teknhn. Experim., to be published. 6) I. M. Meek and I. D. Craggs, Electrical breakdown of gases (Oxford, 1953). 345
346
B. A. D O L G O S H E I N
voltage generator (PVG) a n d an air spark discharger which forms short high-voltage impulsed ( ~ 50 nsec). PVG is 20 stage Arcadjev-Marx generator 7) with a m a x i m u m voltage amplitude of 460 kV. The air spark
°-
AND
B. 1. L U C H K O V
electrodes in the projection perpendicular to E t a ) and parallel to E (b). In the projection (a) the track consists of a n u m b e r of light stripes with the m e a n length 1 -~ 7 mrn being initial areas o f streamers developing along the field E. Because o f the fluctuation of the development of avalanches a n d streamers, the stripes differ in length and in brightness. T h e narrowing o f the track in that projection is carried out by m e a n s o f shortening the time lag t o f the air discharger breakdown. Tracks with the stripe length 1 -~ 2 m m are observed visually. The track brightness diminishes with decrease o f their width 1 and narrow tracks are not recorded on the p h o t o g r a p h i c film. In the projection (b), the track is a chain o f points of a 1 m m in diameter in which streamers are projected. Tracks in the projection (b) are brighter, since light from every streamer is emitted from a less surface. The track width and spread o f the points relatively the trajectory o f the particle are smaller than in the convenient spark c h a m b e r in projection conditionsg), therefore the accuracy o f localisation o f the particle trajectory in the streamer c h a m b e r is better t h a n in the projection spark chamberS). In this projection one m a y observe with a good accuracy the events of interaction and decay of particles a n d m e a s u r e curvature of the tracks in a magnetic field. The projection (a) will then serve only to determine the place of the particle passage
Fig. 3. Photographs of tracks in a streamer chamber (neon, p = 1 arm, E ~ 8 kV/cm). discharger m o u n t e d directly on the c h a m b e r electrodes (fig. 1) suffers a b r e a k d o w n in the time t ( ~ 50 nsec) which it is possible to control after supplying a highvoltage pulse at the electrodesS). The c h a m b e r is set so that the angle between a vertical line and direction o f the electric field E is ~ 90 ° and cosmic particles cross the c h a m b e r almost in parallel to the electrodes. Tracks of cosmic particles are p h o t o g r a p h e d t h r o u g h a transparent electrode (~ E) and t h r o u g h a side wall of the c h a m b e r ( ± E) by the objectives "Upiter-3" (1:1.5) and R-Biotar (l :0.85) respectively on a high sensitive film (type 13, sensitivity 3000 units of the state standard). Fig. 3 shows p h o t o g r a p h s o f a single cosmic particle which crossed the c h a m b e r nearly in parallel with the 7) High voltage test equipment and measurenwnt, ed. A. A. Vorobjev tGostehizdat, Moscow, 1960). s) G. A. Mesja, Dissertation, Tomsk university, 1961. 9) A. I. Alikhanjan and M. 1. Dajon, Aspects ofthephysics o f the elemelltao, particles (Academi of Science of Armenia, Jerevan, 1963).
Fig. 4. Photograph of a single particle. by the c h a m b e r depth. Fig. 4 gives a p h o t o g r a p h of a single particle in the same projection (a) m a d e in the conditions when the resistance of ~ 1 kf2 is applied in series with the c h a m b e r that m a d e worse the front o f a high-voltage pulse. The track consists of c o l u m n s of positive and negative streamers separated by a dark b a n d which is, apparently, an initial region of streamers. Besides the a b o v e - m e n t i o n e d features of the streamer c h a m b e r it should be noted that dead time of the
A NEW
GAS-DISCHARGE
TRACK
streamer chamber would be much smaller than the dead time of the spark chamber, as the charge density in plasma of the initial streamer is essentially smaller than in the spark channel. That's why the spark chamber is, apparently, more fast track detector than the spark and discharge chambers. The measurement of particle ionisation in a streamer chamber seems to be more hopeful than in the spark chamber.
DETECTOR
STREAMER
CHAMBER
347
The streamer chamber is a very useful device for studying the initial stages of a spark discharge. The authors wish to thank professor A. I. Alikhanjan for the permanent interest in their work, scientific workers of the problem laboratory of Moscow institute of engineers-physisists V. V. Dmitrenko, V. V. Chizhov and collaborator of P. N. Lebedev Physica! Institute L. V. Suhov for their kind assistance.