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Nanosecond multiple coincidence and anticoincidence circuit on tunnel diodes and transistors
NUCLEAR INSTRUMENTS AND METHODS 28 ( 1 964) 341-345 ; C) NORTH-HOLLAND PUBLISHING CO .
NANOSECOND MUT TIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT ON TUNNEL DIODES AND TRANSISTORS A. F. DUNAITSEV
JoW.butitute for Mackar Research, Laboratory of Nuckar Problenu, Dubna, USSR Received 14 December 1963 A mul&-coincidence and anticoincidence circuit made on tunnel diodes, diodes and transistors is described. The resolving time of thecircuit measured with a nteson be= is about 2 ns . The anticoincidence efficiency is as large as 0.9997.
In designing fast coincidence and anticoincidence circuits for nuclear physics experiments the priaciple problem is to construct a pulse shaper which would allow to transform input signals into short pulses of standard ampliwde and duration. In the past time tunnel diodes with small switch time were widely used pulse in shapers'
termined by the resistances R, and R2 flows through the pulse germanium diode D. When a negative pulse of sufficient amplittude is fed to the cascade input, the diode is closed, and the voltage pulse with an amplitude U= IR appears on tae resistance R,2. But since the diode D has a comparatively longer time of reverse resistance recovery of some tens ns, the shaped pulse has firstly an overshoot, the amplitude of which depends upon the input pulse amplitude. Further pulse shaping in amplitude and duration is achieved with the tunnel diode TD with one stable state at the point A (fig. lb). In order that the tunnel diode had one stable state it is necessary that the value of R, should be smaller than the minimum negative resistance of the tunnel d-.ode . The sensitivity of the shaping cascade is determined by the position of the working poin't 4. thC -pere. pro% ide high sensitivity the initial working point A set with the help of R5 and R, near the maximurn of the characteristic . When the pulse with steep frorn edge conic ,, to the tonnel diode. the resistance of the lnductance L is large and the main fraction of current goes through the tunnel diode TD, causing quick switch to the point B'. The position of the point 13' tin b) the diffusion branch depends upon the value of the resistance of the inductance L and upon the input pulse front duration . The point B is the limit position of the point B' when the whole current of the input pulse goes through the tunnel diode. The duration of the input pulse t. is determined by the time of recharge of 'the inductance L through the resistance R, and that of the (b) tunnel diode . During the time interval the working Fig. 1. (a) The scheme of the shaping circuit . (b) Volt-arnp&c 1
V0",,ain
01-1
is
characteristic of the tunnel diodc and
Z:
the rcgime ofits operation .
A fast coincidence circuit, the %haping ca.scades of which are made on tunnel diodes "ah pichininary limitation of the pulse amplitude by means of a pulse diode is described in this paper. The scheme of the shaping cascade is sho\-\-n in fig . Ia. In the static state the direct current I which is de-
I
11
cn
point is shifted to the nosition C, and then tho imorst s",itch to the point D takes place . During ihe recovery A. 11mc oie ,,,voi kir,g point teturns to its -I'lle usco.'the prehininary diode hintier aiioNvs to a,, mul
the repeated action of the tunnel diode in uie ,~ase ol a long input pulse. After the dioue limiter the pulse has a flat top, the resistance of the inductance L being, small . and the main fraction ofcurrent goes through 1. and H,
A. F. DUNAITSEV
with time resolution ;:t~ 5 ns it is necessary to take L_- 0.5 pH. The above-described shaping Cascade has a distinguished threshold characteristic (fig. 2Q. The triggering Onvahold can be changed by varying the resistances R. and R6 (fig . la),,, The ' maximum, amplitude of input pulses is limited by the tolerable reverse voltage of the firniting diode D. Thus, for germanium diodes DIO, DI8 the maximum amplitudeofthe input pulses is not smaller than 20 V. The duration and the amplitude of the shaped pulses weaklY depend upon the amplitude 2Y and upon the duration of input pWm. The total electric circuit of triple coincidences one anticoincidenm channel is shown in fig. A. The negative pulses enter on the shaping, cascado,inj In the shaping c=ade input of the anticoiaWdence channel a pulse invertor-transformer Wth a ferrite core is used. Shaped pulses are summed up on the tunnel diode. Here also use is made of a one-stable circuit with inductance. The initial working point of the selft-ting tunnel diode is chosen so that the current SM Um of two simultaneously arrived input pulses would not shift the working , point through the maximum of the voltampere characteristic IQ and the sum a current of three pulses coincided in time would shift the working point to the position B'. If simultaneously with three coinciding pulses the anticoincidence pulse with opposite polarity enters the input of the selecting
n
Y (a) The dependenœ of ~ M ~~ " M ductance, load I- (b) The de~~m aU aWkude 2MM " " uM the arnplitudc of input pulses Ui,,. a shovs the measured dependence ofthe shaped ura -,ion upon the inductance L for tunnel gallium arsenide vvith the peak current 1, ~= 5-10 rnA and the capacity C < 20 pF. As I seen orn fig . , a . in c)rder to -_on~trijct coincidence circuits
n
tunnel diode, then the working point is not shifted through the maximum. In order to exclude the possiMy a triggering the shaping cascade by the pulses of the neighboLiring, channel, the diodes are placed be-
Md
- 'Pte el=rk circuit of triple c ,Ainded on a
annels 1, 2. 3) with one anticoincidence channel (channel A). The transformer is = 12~ = 600, the number of turns is 2 x 20. itt
NANOSECOND . MULTIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT
34 3
Fig. 4. Ptilse oscillograms : (a) the generator pulse front ; (b) the generator rectangular pulse . (c) the generator exponential pulse ; (d) the puhie after the limiting diode D ; (c) the pulse shaped with tunnel diode TD ; (f) the pulse on the output of the coincidence circuit. The time base is given under each 5gurc in ns on a large scate division .
A. F. DUNAITSEV
t1wv ;Aa mg cascades. Resis=eS 4 150 ohm di" ser~ for limiting the current, p~d*'through the selecting tunnel diode. In the anticoincidence channel this resistance is Men of such a value with which the triggering of the shaping current anticoincidcpcc~ casm-le from the coincidence ,
selection uixfficient is practically unlimited . The prenecessity sence of such a g*od selection elimh~ be of additional discrimination . These curves are analogous for the tripic coincidence circuit. Z" M. PC
the , circuit sensipihe-'i~ - exvAu"- Iti order to adjust tivity -t*t is. a potentiometer in the supply system, of
the sekc~'ng twnel diode. The coin6dence pulse from the selecting tunnel diode aWW by a ~=de aTftprifiu on W Output of which there is an emitter fbllower .'~'be .puslse on the about oxw of the ~er ~vqr has the duration WaYthe ,circuit adjusted with the help Wtbe genen ator of ub%es with the front duration of about 0.5 ns (see fig. dependence of the output pulse delay t between the input nsurements. fbr the double ence circuit with an circuit are ,&iven ia fig. 5a, - b. As is seen from - these. curves,, the ws, to obtain the nanosecond resolution, Its
.
W
Vb ~ Val
Mg. 6.
'be dependence of half-width r of the curves shown in mfig. Sa upon the amplitude of input pulses Ui,.
fi& 6 sho :~'~4ange of the hW7vidth -, of: the curves presen Ï9. 5à With inCtM';iog théaiMplit de of input pulses ~ the , double poinakince,titcuit. The threshold, is sho, by iwarro~w. The ~4rcuifdead time is a"'60 m W~~" 1 istics of the coinciden-ceq and anticoincidence - im were measured în the 70 MeV
"SEC
(b)
5, mc awit" depen&n. A Output Pulses U" ' Upon the dtllay t betwecrt the input pulses for (a) double coincidence circuits and an6cnincidicncc circuits .
t,nsec Fig. 7. The curves of the time resolution for the double coin cidence (0 ) and for the triple coincidence circuit measured with a .-T,~' meson hearn,
NANOSECOND NULTIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT
meson beam in the experiments performed on the synchroc.yclotron of the Laboratory of Nuclear Problems of' the Joint Institute for Nuclear Research . Scintillation counters with scintillators 10 x 10 x I cm' and 18 >~- 18 X I CM3 were put into the 1-. ' meson be,,;tm. Pulses from the.anodes of the photomultipliers 56-AVP were &d to the inputs ofthe coincidence circuit through cables FIK-~O 70 m long. When the resolution curves of the coinoidence circuit (fig. 7) was taken in order to delay one -pulse, a set of cable cuts PK-50 of various length was used. The circuit resolving time of double coincidences (white circles) ,r = 1 .6 ns, and of the triple coincidence circuit (black circles) T =2.7 ns. The halfwidth of the resolution curves on the 10' level for the double ,and triple coincidences is 5.4 and 6.4 ns, respectiveiy. The difference of the reso)ving times of the double and triple coincidences is explained by different positions of the initial working point A (see fig. I b). A V'See-, 7c +
34 5
Fig. 9 shows the dependence of the counting rate of 'the double coincidence circulit from the voltage on the photomulti pliers (the "plato" .). The range of the "plato" is > 300 V. N, WSW-
2m
M
2200
.1300
2t4X
2xv
V,*, ve
Fig. 9. The dependence of-meson counting rate of double -oincidencc N upon the voltage Vp h on photomultipliers 56AVP.
It should be noted that the circuit is simple in adjusting and is convenient in operarion. The mass difference of charged and neutral pions') has been measured with the h-Ap of this scheme at the Laboratory of Nuclear Problems. The possibility of rapid changing the multiplicity of the coincidence circuit enlarges application in physical research . its,
In conclusion 1. take an opportunity to express my gratitude to ~U- ("- Vr0-k0Sl1k1'1 I'Or diNCLINSIlIg UIC results of the present investigation. Fig. S. 11"Ie dependence of the -r' meson counting ratc of the double .ttincidence circuit N upon the delal i in the anticoincidence ch :tnnel .
The resolution curve for the double coincidence circuit ~vith variable pulse delay in the anticoincidence channel is shown in fig. 8. The anticoincidence circuit has the rcsolvir,~ time r = 3.6 ns and a high efficiency. The counting rate of the double coincidence circuit was reduce(I 3000 times when an anticoincidence counter was ad, Jed.
N.', Perez-Mendez, NUCI, Instr. ind kleth . 13 (1061) 1 0 7 . 2) S. Uorodetzky, A. Muser, 1. Zen and R. Armbruster, Nucl . Instr. and Meth. 13 (1961) 282. 3) S. Gorodetzky, A. Muscr, 1. Zen and R . Armbruster, Nucl . Instr. end Meth . 14 (1961) 205. 4) A. Whetstone and S. Kounosu, Rev. Sci. Instr. 3.3 (1962) 423 . 5) B. N. Kononov and A. S. Sidorov, Proceedings of the Fifth Technical-Scicntific Confercrice on Nuclear Electronics, Vol . 1, Gosatomisd . Moscow (1962) p. 169. 6) B. N. Kononov and Yu . A. Churin . PTE No . 4 ('1963) 67 . 7) V. 1. Petrukhin and Yu . D. Prokoshkin, JETP 45 (1963) 5. 1)
A . Adler . N1 . Palmai and
NANOSECOND MUT TIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT ON TUNNEL DIODES AND TRANSISTORS A. F. DUNAITSEV
JoW.butitute for Mackar Research, Laboratory of Nuckar Problenu, Dubna, USSR Received 14 December 1963 A mul&-coincidence and anticoincidence circuit made on tunnel diodes, diodes and transistors is described. The resolving time of thecircuit measured with a nteson be= is about 2 ns . The anticoincidence efficiency is as large as 0.9997.
In designing fast coincidence and anticoincidence circuits for nuclear physics experiments the priaciple problem is to construct a pulse shaper which would allow to transform input signals into short pulses of standard ampliwde and duration. In the past time tunnel diodes with small switch time were widely used pulse in shapers'
termined by the resistances R, and R2 flows through the pulse germanium diode D. When a negative pulse of sufficient amplittude is fed to the cascade input, the diode is closed, and the voltage pulse with an amplitude U= IR appears on tae resistance R,2. But since the diode D has a comparatively longer time of reverse resistance recovery of some tens ns, the shaped pulse has firstly an overshoot, the amplitude of which depends upon the input pulse amplitude. Further pulse shaping in amplitude and duration is achieved with the tunnel diode TD with one stable state at the point A (fig. lb). In order that the tunnel diode had one stable state it is necessary that the value of R, should be smaller than the minimum negative resistance of the tunnel d-.ode . The sensitivity of the shaping cascade is determined by the position of the working poin't 4. thC -pere. pro% ide high sensitivity the initial working point A set with the help of R5 and R, near the maximurn of the characteristic . When the pulse with steep frorn edge conic ,, to the tonnel diode. the resistance of the lnductance L is large and the main fraction of current goes through the tunnel diode TD, causing quick switch to the point B'. The position of the point 13' tin b) the diffusion branch depends upon the value of the resistance of the inductance L and upon the input pulse front duration . The point B is the limit position of the point B' when the whole current of the input pulse goes through the tunnel diode. The duration of the input pulse t. is determined by the time of recharge of 'the inductance L through the resistance R, and that of the (b) tunnel diode . During the time interval the working Fig. 1. (a) The scheme of the shaping circuit . (b) Volt-arnp&c 1
V0",,ain
01-1
is
characteristic of the tunnel diodc and
Z:
the rcgime ofits operation .
A fast coincidence circuit, the %haping ca.scades of which are made on tunnel diodes "ah pichininary limitation of the pulse amplitude by means of a pulse diode is described in this paper. The scheme of the shaping cascade is sho\-\-n in fig . Ia. In the static state the direct current I which is de-
I
11
cn
point is shifted to the nosition C, and then tho imorst s",itch to the point D takes place . During ihe recovery A. 11mc oie ,,,voi kir,g point teturns to its -I'lle usco.'the prehininary diode hintier aiioNvs to a,, mul
the repeated action of the tunnel diode in uie ,~ase ol a long input pulse. After the dioue limiter the pulse has a flat top, the resistance of the inductance L being, small . and the main fraction ofcurrent goes through 1. and H,
A. F. DUNAITSEV
with time resolution ;:t~ 5 ns it is necessary to take L_- 0.5 pH. The above-described shaping Cascade has a distinguished threshold characteristic (fig. 2Q. The triggering Onvahold can be changed by varying the resistances R. and R6 (fig . la),,, The ' maximum, amplitude of input pulses is limited by the tolerable reverse voltage of the firniting diode D. Thus, for germanium diodes DIO, DI8 the maximum amplitudeofthe input pulses is not smaller than 20 V. The duration and the amplitude of the shaped pulses weaklY depend upon the amplitude 2Y and upon the duration of input pWm. The total electric circuit of triple coincidences one anticoincidenm channel is shown in fig. A. The negative pulses enter on the shaping, cascado,inj In the shaping c=ade input of the anticoiaWdence channel a pulse invertor-transformer Wth a ferrite core is used. Shaped pulses are summed up on the tunnel diode. Here also use is made of a one-stable circuit with inductance. The initial working point of the selft-ting tunnel diode is chosen so that the current SM Um of two simultaneously arrived input pulses would not shift the working , point through the maximum of the voltampere characteristic IQ and the sum a current of three pulses coincided in time would shift the working point to the position B'. If simultaneously with three coinciding pulses the anticoincidence pulse with opposite polarity enters the input of the selecting
n
Y (a) The dependenœ of ~ M ~~ " M ductance, load I- (b) The de~~m aU aWkude 2MM " " uM the arnplitudc of input pulses Ui,,. a shovs the measured dependence ofthe shaped ura -,ion upon the inductance L for tunnel gallium arsenide vvith the peak current 1, ~= 5-10 rnA and the capacity C < 20 pF. As I seen orn fig . , a . in c)rder to -_on~trijct coincidence circuits
n
tunnel diode, then the working point is not shifted through the maximum. In order to exclude the possiMy a triggering the shaping cascade by the pulses of the neighboLiring, channel, the diodes are placed be-
Md
- 'Pte el=rk circuit of triple c ,Ainded on a
annels 1, 2. 3) with one anticoincidence channel (channel A). The transformer is = 12~ = 600, the number of turns is 2 x 20. itt
NANOSECOND . MULTIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT
34 3
Fig. 4. Ptilse oscillograms : (a) the generator pulse front ; (b) the generator rectangular pulse . (c) the generator exponential pulse ; (d) the puhie after the limiting diode D ; (c) the pulse shaped with tunnel diode TD ; (f) the pulse on the output of the coincidence circuit. The time base is given under each 5gurc in ns on a large scate division .
A. F. DUNAITSEV
t1wv ;Aa mg cascades. Resis=eS 4 150 ohm di" ser~ for limiting the current, p~d*'through the selecting tunnel diode. In the anticoincidence channel this resistance is Men of such a value with which the triggering of the shaping current anticoincidcpcc~ casm-le from the coincidence ,
selection uixfficient is practically unlimited . The prenecessity sence of such a g*od selection elimh~ be of additional discrimination . These curves are analogous for the tripic coincidence circuit. Z" M. PC
the , circuit sensipihe-'i~ - exvAu"- Iti order to adjust tivity -t*t is. a potentiometer in the supply system, of
the sekc~'ng twnel diode. The coin6dence pulse from the selecting tunnel diode aWW by a ~=de aTftprifiu on W Output of which there is an emitter fbllower .'~'be .puslse on the about oxw of the ~er ~vqr has the duration WaYthe ,circuit adjusted with the help Wtbe genen ator of ub%es with the front duration of about 0.5 ns (see fig. dependence of the output pulse delay t between the input nsurements. fbr the double ence circuit with an circuit are ,&iven ia fig. 5a, - b. As is seen from - these. curves,, the ws, to obtain the nanosecond resolution, Its
.
W
Vb ~ Val
Mg. 6.
'be dependence of half-width r of the curves shown in mfig. Sa upon the amplitude of input pulses Ui,.
fi& 6 sho :~'~4ange of the hW7vidth -, of: the curves presen Ï9. 5à With inCtM';iog théaiMplit de of input pulses ~ the , double poinakince,titcuit. The threshold, is sho, by iwarro~w. The ~4rcuifdead time is a"'60 m W~~" 1 istics of the coinciden-ceq and anticoincidence - im were measured în the 70 MeV
"SEC
(b)
5, mc awit" depen&n. A Output Pulses U" ' Upon the dtllay t betwecrt the input pulses for (a) double coincidence circuits and an6cnincidicncc circuits .
t,nsec Fig. 7. The curves of the time resolution for the double coin cidence (0 ) and for the triple coincidence circuit measured with a .-T,~' meson hearn,
NANOSECOND NULTIPLE COINCIDENCE AND ANTICOINCIDENCE CIRCUIT
meson beam in the experiments performed on the synchroc.yclotron of the Laboratory of Nuclear Problems of' the Joint Institute for Nuclear Research . Scintillation counters with scintillators 10 x 10 x I cm' and 18 >~- 18 X I CM3 were put into the 1-. ' meson be,,;tm. Pulses from the.anodes of the photomultipliers 56-AVP were &d to the inputs ofthe coincidence circuit through cables FIK-~O 70 m long. When the resolution curves of the coinoidence circuit (fig. 7) was taken in order to delay one -pulse, a set of cable cuts PK-50 of various length was used. The circuit resolving time of double coincidences (white circles) ,r = 1 .6 ns, and of the triple coincidence circuit (black circles) T =2.7 ns. The halfwidth of the resolution curves on the 10' level for the double ,and triple coincidences is 5.4 and 6.4 ns, respectiveiy. The difference of the reso)ving times of the double and triple coincidences is explained by different positions of the initial working point A (see fig. I b). A V'See-, 7c +
34 5
Fig. 9 shows the dependence of the counting rate of 'the double coincidence circulit from the voltage on the photomulti pliers (the "plato" .). The range of the "plato" is > 300 V. N, WSW-
2m
M
2200
.1300
2t4X
2xv
V,*, ve
Fig. 9. The dependence of-meson counting rate of double -oincidencc N upon the voltage Vp h on photomultipliers 56AVP.
It should be noted that the circuit is simple in adjusting and is convenient in operarion. The mass difference of charged and neutral pions') has been measured with the h-Ap of this scheme at the Laboratory of Nuclear Problems. The possibility of rapid changing the multiplicity of the coincidence circuit enlarges application in physical research . its,
In conclusion 1. take an opportunity to express my gratitude to ~U- ("- Vr0-k0Sl1k1'1 I'Or diNCLINSIlIg UIC results of the present investigation. Fig. S. 11"Ie dependence of the -r' meson counting ratc of the double .ttincidence circuit N upon the delal i in the anticoincidence ch :tnnel .
The resolution curve for the double coincidence circuit ~vith variable pulse delay in the anticoincidence channel is shown in fig. 8. The anticoincidence circuit has the rcsolvir,~ time r = 3.6 ns and a high efficiency. The counting rate of the double coincidence circuit was reduce(I 3000 times when an anticoincidence counter was ad, Jed.
N.', Perez-Mendez, NUCI, Instr. ind kleth . 13 (1061) 1 0 7 . 2) S. Uorodetzky, A. Muser, 1. Zen and R. Armbruster, Nucl . Instr. and Meth. 13 (1961) 282. 3) S. Gorodetzky, A. Muscr, 1. Zen and R . Armbruster, Nucl . Instr. end Meth . 14 (1961) 205. 4) A. Whetstone and S. Kounosu, Rev. Sci. Instr. 3.3 (1962) 423 . 5) B. N. Kononov and A. S. Sidorov, Proceedings of the Fifth Technical-Scicntific Confercrice on Nuclear Electronics, Vol . 1, Gosatomisd . Moscow (1962) p. 169. 6) B. N. Kononov and Yu . A. Churin . PTE No . 4 ('1963) 67 . 7) V. 1. Petrukhin and Yu . D. Prokoshkin, JETP 45 (1963) 5. 1)
A . Adler . N1 . Palmai and