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XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
A.A. VoinovA.A. Voinov,, V.G. Subbotin,V.G. Subbotin, V.K. Utyonkov, Yu.S. Tsyganov, A.M. Sukhov, Yu.S. Tsyganov, A.M. Sukhov, A.N. Polyakov, A.M. ZubarevaA.N. Polyakov, A.M. Zubareva
Joint Institute for Nuclear Research, 141980 Dubna, RussiaJoint Institute for Nuclear Research, 141980 Dubna, Russia
CALIBRATION OF THE SILICON POSITION-SENSITIVE DETECTORS USING THE IMPLANTED REACTION PRODUCTS
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
Dubna Gas Filled Recoil Separator
12 strips 300μm 40mm*10mmeach in focal plane
Particals’ signals: EVRs, alpha, FFParticals’ signals: EVRs, alpha, FFMeasurement: energy, (x,y), timeMeasurement: energy, (x,y), time
EfficiencyEfficiency 87% of 487% of 4pp for a-particles for a-particles 100% of 4100% of 4pp for FF for FF
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
5 6 7
98
1
1B1
1T14
6 7
6 7
4 76
3
3
2
2
Eff position
Ea и Eff energy
Eff energy
Ea и Erecoil position
Logic of registration1 E
1 - position-sensitive strips of Si detector.2 - charge-sensitive preamplifier micro Catsa.3 - sum-invert-amplifier SU-206K.4 - amplifier SU-4K.5 - amplifier ORTEC575.6 - analog multiplexer AM-206K.7 - ADC PA-24K.
Measuring CAMAC Crate
8 - analog discriminator of energies DF-202.9 - logical block KL-203 (to control all ADCs).10 - charge-sensitive preamplifier PA-201.11 - timing filter amplifier Polon 1501.12 - nanosecond delay Polon 1506.13 - constant fraction discriminator.14 - T/A converter Polon 1701A.
71413
131211
1110
10
TOF
"stop""start"
Block diagram of the measuring electronics (only one detector circuit is shown completely).Block diagram of the measuring electronics (only one detector circuit is shown completely).
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
TOF-chamber
"stop"
"start"
blocking ofTOFselect
DF-201
Еrecoil >Еthreshold
TOF
1 chip
2 chip
3 chip
side
coincidencen > 2
1
&
ALL SIGNALS
TOFselect
anticoin-cidence
1
&
(TOFselect)Х(DECAY)Х(DEAD-TIMEmain)Х(DEAD-TIMEadd)
TOFDECAY
MAJORITYCOINCIDENCES
to КР-005
deblocking of ADCmain
beginning of measurementin КС-011add
KL-203block
KL-033КК-202
Selected TOF
debloking of ADCadd
"+1" in КС-002main
Еrecoil >8 MeV
Diagram of the logic of the registration of nuclear reactions products at DGFRS
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
6 7 8 9a- ( )particle energy MeV
0
1000
2000
3000
4000
217Th
216Th
215Ra
214Ra
211,212Ra
211Po
215Th
213Ra
Cou
nts
/ 20
keV
Energy spectrum of a-particles detected in the natYb + 48Ca reaction.
150 200100Fission-fragment energy (MeV)
100
200
0
300
252No
Cou
nts
/ 5 M
eV
Spectrum of total energies deposited by the fission fragments of 252No implants as measured by the both focal-plane and side detectors (blue line) and by the focal-plane detector only (red line).
48Ca
+nat.Yb
2
1
R a
T h
2 1 2
2 1 6
6 . 9 M e V
2 8 m s
1 3 . 0 s
7 . 9 2 M e V
2
1
R a
T h
2 1 3
2 1 7
2 . 7 4 m
6 . 6 2 M e V
2 5 2 u s
9 . 2 5 M e V
T K E = 1 0 0 - 2 2 0 M e V
F 1
F 2
N o
2 5 2+206Pb48Ca
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
ER-a and ER-SF time intervals measured for 217Th and 252No produced in 48Ca-induced reactions with natYb and 206Pb, respectively.
100
Decay time (s)101 10210-110-210-310-410-510-6
217Th
252No
dN /
d ln
t
800
600
400
200
0
a- ( )particle energy MeV0 2 4 6 8 10
0
2
4
6
8
Posi
tion
reso
lutio
n (m
m)
Dependence of ER-a position resolution (FWHM) on the amplitude of a-particle signal. The position resolution was derived by examining the atYb+48Ca data for escaping a particles depositing varying mounts of energy in the focal-plane detector.
-5 0 5 10 15 20 25
0
2
4
6
8
10
12
YA
xis
Title
X Axis Title10 15 10 15105 15
10
12
0
2
4
6
8
Coun
ts
Evaporation-residue energy MeV ( )
252No217Th Z=112-118
1/30 1/15
294117293117
a ) b) c)
Spectra of measured energies of implants 217Th (left), 252No (right) and superheavy nuclei with Z=112-118 (middle). Solid histogram shows energies of Z=117 recoils observed in the reaction 249Bk+48Ca.
y0=6.0±2.1
xc=0.0±0.0
w=0.249±0.003A=497.3±4.9
y =y0+A*exp(-0.5*((x-x
c)/w)2)
y0=7.2±2.0
xc=0.0±0.03
w =0.479±0.003A =655.3±3.5
0 1 2-2 -1Position deviation (mm)
0
200
400
600
800
ER
ER SF
Cou
nts
Distributions of position deviations of ER-a and ER-SF signals measured for 217Th and 252No produced in 48Ca-induced reactions with natYb and 206Pb,respectively.
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
7,0 7,5 8,0 8,5 9,0 9,5 10,0 10,5 11,0 11,5 12,0
1
10
100
1000
10000
100000
Cou
nts
/20
keV
Energy (MeV)7 8 9 1 0 1 1 1 2
Co
un
ts
/
2
0
ke
V
1 00
1 01
1 02
1 03
1 04
1 05
( + e-)( + e
-)
1 1 3
2 1 2
P o
2 1 2
P o
2 1 1
P o
2 1 4
P o
2 1 3
P o
a )
1 1 5
1 1 7
50 100 150 200
1
10
100
1000
Cou
nts
/1M
eV
Energy (MeV)2 0 0
E n e r g y ( M e V )
1 5 01 0 05 0
Co
un
ts
/
1
M
eV
1 00
1 01
1 02
1 03
1 1 1
b )
b e a m - o n
b e a m - o f f
b e a m - o n
b e a m - o f f
a) Total energy spectra of beam-on a-like signals and beam-off particles.
Energy spectra recorded during the 252 MeV 48Ca+ 249Bk run (E=39MeV).
b) Total fission-fragment energy spectra, both beam-on and beam-off. The arrows show the energies of events observed in the correlated decay chains.
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
Results High efficiency of rare decays detecting Good energy and position resolution (35 keV and 0.9 mm for the
unirradiated detectors) Low system “dead-time” T = 8 us Operating in low background conditions for the descendant decays
Future
New double side silicon strip detector array (x: 128 channels, y: 48 channels – 6144 cells)
Apropriate modern digital electronics (based on PIXIE-16) “dead-time” less 1 us Operating in better background conditions
XXIII International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 12-19 September, 2011.
Thank you for the attention