Studies of Deuteron and Neutron Cross-sections Important for ADS Research

Vladimír Wagner

Nuclear physics institute of CAS, 250 68 Řež, Czech Republic, E_mail: wagner@ujf.cas.cz

for collaboration “Energy plus transmutation”

(Russia, Belarus, Germany, Greece, Poland, Ukraine, Czech Republic …)

XXI INTERNATIONAL BALDIN SEMINAR ON HIGH ENERGY PHYSICS PROBLEMS

(XXI Baldin seminar)

Deuteron reaction cross-section measurements Neutron reaction cross-sections measurements

Production of 24Na on aluminum foil by deuteron beam

Only about this reaction are cross-section data, but only scarce. → uncertainty 10 %

2 GeV deuterons

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2

0 1 2 3 4 5 6

De

ute

ron

inte

gra

l [1

013

de

ute

ron

s]

4 GeV deuterons

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2

0 1 2 3 4 5 6

De

ute

ron

inte

gra

l [1

013

de

ute

ron

s]

1.5

1.6

1.7

1.8

1.9

2

2.1

2.2

2.3

2.4

2.5

0 1 2 3 4 5 6

De

ute

ron

inte

gra

l [1

013

de

ute

ron

s]

6 GeV deuterons

Beam integral determination by means of aluminum foils

2 GeV 1.54(7)·1013 deuterons4 GeV 1.39(4)·1013 deuterons6 GeV 1.97(10)·1013 deuterons

Cross-section uncertainty – 10 %

December 2011 set of QUINTA irradiations

Very good agreement – we have approved values

1.40E+131.42E+131.44E+131.46E+131.48E+131.50E+131.52E+131.54E+131.56E+131.58E+131.60E+13

0 1 2 3 4 5 6 7 8 9

Number of measurement [-]

Beam

inte

nsity

[-]

1.75E+13

1.80E+13

1.85E+13

1.90E+13

1.95E+13

2.00E+13

2.05E+13

2.10E+13

2.15E+13

0 2 4 6 8 10 12

Number of measurement [-]

Beam

inte

nsit

y [-

]December 2011 irradiations

1 GeV deuterons

4 GeV deuterons

1 GeV 1.533(9)·1013 deuterons4 GeV 1.932(10)·1013 deuterons

Only statistical uncertainties

Zhuk:

1 GeV 1.47 ·1013 4 GeV 1.96 ·1013

Necessary – all data with uncertaintiesDescription of all correction calculation (coincidences, self absorption, size of sample)

March 2012 irradiations

1.80E+131.82E+131.84E+131.86E+131.88E+131.90E+131.92E+131.94E+131.96E+131.98E+132.00E+13

0 1 2 3 4 5 6 7 8

Number of measurement [-]

Beam

inte

nsity

[-]

2.60E+13

2.65E+13

2.70E+13

2.75E+13

2.80E+13

2.85E+13

2.90E+13

2.95E+13

3.00E+13

0 1 2 3 4 5 6 7 8

Number of measurement [-]

Beam

inte

nsity

[-]

1 GeV deuterons

4 GeV deuterons

Energy Number of deuterons

1 GeV 1.886(8)·1013

4 GeV 2.796(26)·1013

8 GeV 0.565(6)·1013

Only statistical uncertainties

1 GeV 4 GeV 8 GeV

Zhuk 1.9 2.7 0.37KH1 1.8 3.5 0.49KH2 1.8 2.7 0.37JINR 1.87(10) 2.65(13) 0.55(4)

Preliminary

Studies of relativistic deuteron reactions on natural copper

Common irradiation of aluminum and copper foils

Production of different radionuclides

2.0E+08

2.1E+08

2.1E+08

2.2E+08

2.2E+08

2.3E+08

2.3E+08

2.4E+08

2.4E+08

0 2 4 6 8 10

yie

ld o

f ra

dio

nu

clid

e

52Mn 744 keV

March 2012 – 4 GeVMore measurements of copper sample in different times (possibility split influence of short lived and long lived isotopes with the same energy line – 43K and 43Sc, 56Co and 56Mn, 48Sc and 48V) and on different detectors with different geometry (suppression of systematic uncertainties influence)

Some deuteron energies were measured more times

Energy range of deuteron beam from 1 GeV up to 8 GeV

Comparison of different measurements with the same deuteron energy

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

0 2 4 6 8 10 12 14

Ra

tio

of

1 G

eV

me

as

ure

me

nts

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

0 2 4 6 8 10 12 14

Ra

tio

of

4 G

eV

me

as

ure

me

nts

Comparison of two measurements with 1 GeV neutron beam1. December 20112. March 2012

Mean value of ratio: 0.969

Comparison of three measurements with 4 GeV neutron beam1. March 20112. December 20113. March 2012

Mean value of ratio: 1./2. 0.8843./2. 0.926

57Ni, 58Co, 56Co, 55Co, 56Mn, 52Mn, 48Cr, 48V, 48Sc, 47Sc, 44mSc, 43Sc and 43K

Obtained deuteron reaction cross-sections on natural copper

58Co

15.0

20.0

25.0

30.0

35.0

40.0

45.0

0 1 2 3 4 5 6 7 8 9

Deuteron energy [GeV]

Cro

ss-s

ectio

n [m

barn

]

52Mn

4.0

6.0

8.0

10.0

12.0

14.0

16.0

0 1 2 3 4 5 6 7 8 9Deuteron energy [GeV]

Cro

ss-s

ecti

on

[m

bar

n]

43K

1.0

1.5

2.0

2.5

3.0

0 1 2 3 4 5 6 7 8 9Deuteron energy [GeV]

Cro

ss-s

ecti

on

[m

bar

n]

57Ni

0.5

0.7

0.9

1.1

1.3

1.5

0 1 2 3 4 5 6 7 8 9Deuteron energy [GeV]

Cro

ss-s

ecti

on

[m

bar

n]

BeamBeam-line-line

Li-targetLi-target

GraphiteGraphite stopper stopper

SamplesSamples

Measurement of neutron reaction cross/sections

Quasi-monoenergetic neutron source:protons from cyclotron + lithium target

NPI ASCR Řež: Energy range 18 -37 MeV, neutron intensity ~ 108 neutron cm-2 s-1

TSL Uppsala: Energy range 25 – 200 MeV neutron intensity ~ 105 neutron cm-2 s-1

Advantage of two neutron sources: very wide energy range, partial overlap – better estimation of systematical uncertainties

380.79 keV

9/2+

1/2-

87mY

ε+β+87Y

98.43(10) % 1.57(10) % <<

ε+β+

T1/2 = 13.38 hours

T1/2 = 79.8 hours

Yttrium cross-section measurement

Reaction (n,3n) - production of isomeric and ground state of 87Y

Yttrium – good material for activation detectorUsed by “Energy+Transmutation” collaboration

Very scare data about cross-sections

Methodical measurement – neutron energy 32.5 MeV (only reactions (n,2n) and (n,3n)), May 2011, to prepare systematic study of yttrium reactions using the NPI neutron source

No data about cross-sections of isomeric state production

Long irradiation, intensive beam, only limited number of samples → possibility to measure yttrium sample many times to study systematic uncertainties of gamma measurements

Concentration on isomeric state 87mY

tt eNeNNN

12

0121

101

21

1022

teNN 1011

87mY 87Y

0

2000000000

4000000000

6000000000

8000000000

10000000000

12000000000

14000000000

16000000000

0 50 100 150 200

Time after end of irradiation [hours]

Nu

mb

er

of

rad

ioa

cti

ve

nu

cle

i [1

09 ]

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

N02

N01

♦ - 87mY

■ - 87Y

N = N01exp(-λ1t)

N = N01exp(-λ2t)

teNNN

2

0121

102

Experimental points

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

0 200 400 600 800 1000

Time after end of irradiation [hours]

Nu

mb

er

of

rad

ioa

cti

ve

nu

cle

i teNNN

2

0121

102

Experimental points

■ - 87Y

♦ - 87mY

N = N01exp(-λ1t)

tt eNeNNN

12

0121

101

21

1022

teNN 1011

87mY 87Y

N01= 6.05(8)109

9

0121

102

10)11(38.14

NN

N02= 7.12(21)109

0

100

200

300

400

500

600

700

800

900

0 10 20 30 40

Neutron energy [MeV]

cros

s-se

ction

[mba

rn] 87mY

87Y

87gY

Higher threshold near to neutron energy → 93 % of radioactive nuclei is produced by peak, only 7 % by background

Cross-section of 87mY and 87gY

89Y(n,3n)87Y case

89Y(n,2n)88Y case

Uncertainties of proton beam integral and neutron spectra description are about 10 - 15 % > gamma spectroscopy uncertainties

Background production subtraction

σ(87mY) = 578(56) mbarn

σ(87gY) = 203(25) mbarn

87Y - EXFOR

squares - our datalines - TALYS

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 5 10 15 20 25 30 35 40Neutron energy [MeV]

Cro

ss-s

ecti

on [

barn

]

EXFOR

TALYS 1.2

our data

88Y

Reaction 89Y(n,2n)88Y

Neutron peak - only 34.8 % of production, 65.2 % of radioactive nuclei produced by background

New measurements next weeks

New measurements of neutron cross-section on yttriumtogether with Polish colleagues

Improvements:

1) Every irradiations two yttrium samples, one foil and one pressed tablet

2) Big number of measurements of every sample (very important for isomeric state measurement)

3) Measurement in different sample distance to detector

Measurement is in the framework ofERINDA

Four irradiations:

First two during weekend:

Energies 18 and 35 MeV

Next two during first half of October:

Energies 26 and 29 MeV

Conclusions

• Many cross-sections of deuteron and neutron reactions with different materials are needed (very scarce data at experimental data bases).

• We used Quinta measurements to obtain cross-sections of relativistic deuterons reactions on copper.

• The crucial is determination of beam integral (for all data). The common analysis of all monitor data and determination of common final of beam integral is necessary. We made this only fo first Quinta irradiation (March 2011)

• The set of thirteen reactions on copper was studied and cross-sections were determined within energy range from 1 GeV up to 8 GeV.

• The quasimonoenergy neutron sources are ideal possibility to obtain cross-sections of reactions which we use for activation measurement of neutron field.

• We started set of measurements of yttrium samples together with our Polish colleagues. The ERINDA project and NPI Rez neutron source are used.

BIG THANKSto students

Diploma and PhD students:

Ondřej Svoboda Jitka Vrzalová

Martin SuchopárPetr Chaloupka

Other students:

Ondřej SlámaAnne Laredo

Daniel Wagner

and also all colleagues

and JINR Dubna Nuclotronpeople