A.A. Voinov , V.G. Subbotin, V.K. Utyonkov, Yu.S. Tsyganov, A.M. Sukhov,

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


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


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).


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


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


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.


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.


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


Thank you for the attention

A.A. Voinov , V.G. Subbotin, V.K. Utyonkov, Yu.S. Tsyganov, A.M. Sukhov,

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