Future usage of quasi-infinite depleted uranium target

(BURAN) for benchmark studies

Pavel Tichý

XII International Baldin Seminar on High Energy Physics ProblemsRelativistic Nuclear Physics & Quantum ChromodynamicsSeptember 15-20, 2014, Dubna, Russia

Nuclear Physics Institute of the ASCR, v. v. i., Rez, Czech Republic Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Czech Republic

Outline• BURAN setup description

• Neutron flux spectra

• Longitudinal maximums of neutron fluxes

• Energy neutron spectra

• Hardening of energy neutron spectra

Preliminary simulations and

calculations• For designing of ADS (Accelerator Driven Systems) or fast

reactors, it is necessary to use simulation programs which are able to simulate the production and transport of neutrons - MCNPX

• For benchmark studies of such simulation programs (which use various models and cross sections libraries), experiments with simple or more complicated setups are being realized (E+T, KVINTA, BURAN)

• These experiments practically test the function of transmutation systems

• Simulation code: MCNPX 2.7a• Experimental setup: BURAN• Incident beam on the setup: 1 GeV protons 1 GeV deuterons

• The results are normalized to one incident particle

BURAN setup• Setup for study of transport and multiplication of high energy

neutrons• Cylindrical shape : depleted uranium (0.3% 235U) longitudinal distance = 1000 mm diameter = 1200 mm surrounded with 100 mm steel covering• The beam enters the setup in the Ø 200 mm hole in the steel

cover and Ø 100 mm channel (length of the channel: 0 mm, 100 mm, 200 mm)

BURAN setup• 72 channels in the blanket - parallel with the central longitudinal axis - Ø 30 mm - various distances from the center (140, 180, 220, 260, 300, 340, 380, 440, 520 mm)• 20 measuring points in every channel - for placing of detectors - first point in 25 mm from the edge - each next point in 50 mm from the previous one - 72 channels × 20 points = 1440

BURAN setup

• Geometry modeled by Martin Suchopár

Neutron flux• Average neutron fluxes in the

setup for 1 GeV proton (left) and 1 GeV deuteron (right) beam

0 10 20 30 40 50 60 70 80 90 1000.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Longitudinal distance [cm]

Neutr

om

flux [

cm

-2*p

-1]

0 10 20 30 40 50 60 70 80 90 1000.00

0.02

0.04

0.06

0.08

0.10

0.12

14 cm18 cm22 cm26 cm30 cm34 cm38 cm44 cm52 cm

Longitudinal distance [cm]

Neutr

on fl

ux [

cm

-2*d

-1]

10 15 20 25 30 35 40 45 50 550.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Radial distance [cm]

Neutr

on fl

ux [

cm

-2*p

-1]

10 15 20 25 30 35 40 45 50 550.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

2,5 cm 7,5 cm12,5 cm 17,5 cm22,5 cm 27,5 cm32,5 cm 37,5 cm42,5 cm 47,5 cm52,5 cm 57,5 cm62,5 cm 67,5 cm72,5 cm 77,5 cm82,5 cm 87,5 cm92,5 cm 97,5 cm

Radial distance [cm]

Neutr

on fl

ux [

cm

-2*d

-1]

Neutron flux - longitudinal

maximums• Positions of the neutron flux maximums were determined

by fitting the central part of neutron flux spectra by polynomial functions of degree 6

• The particular values of longitudinal maximums were calculated by using Wolfram Mathematica and Polynomial & Scientific Calculator from http://xrjunque.nom.es

10 15 20 25 30 35 40 45 50 550.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Longitudinal distance [cm]

Neutr

on fl

ux [

cm

-2*p

-1]

10 15 20 25 30 35 40 45 50 550

0.02

0.04

0.06

0.08

0.1

0.1214 cmPolynomial (14 cm)18 cmPolynomial (18 cm)22 cmPolynomial (22 cm)26 cmPolynomial (26 cm)30 cmPolynomial (30 cm)34 cmPolynomial (34 cm)38 cmPolynomial (38 cm)44 cmPolynomial (44 cm)52 cmPolynomial (52 cm)Longitudinal distance [cm[

Neutr

on fl

ux [

cm

-2*d

-1]

Neutron flux – longitudinal

maximums• Longitudinal

positions of the neutron flux maximums

Radial distance [cm]

Maximums for 1GeV proton beam [cm]

Maximums for 1GeV deuteron beam [cm]

14 cm 29,734 29,281

18 cm 30,134 29,691

22 cm 30,525 30,131

26 cm 30,786 30,527

30 cm 31,252 30,922

34 cm 31,603 31,369

38 cm 32,012 31,758

44 cm 32,609 32,553

52 cm 33,366 33,435

10 15 20 25 30 35 40 45 50 5527.0

28.0

29.0

30.0

31.0

32.0

33.0

34.0

f(x) = 0.108944520547945 x + 27.7089136986301f(x) = 0.0954827685652488 x + 28.386187815429

protonLinear (proton)deuteronLinear (deuteron)

Radial distance [cm]

Posi

tion o

f lo

ngit

udin

al

maxim

um

[cm

]0 20 40 60 80 10

00.00

0.02

0.04

0.06

0.08

0.10

Longitudinal distance [cm]

Neutr

om

flux [

cm

-2*p

-1]

0 10 20 30 40 50 60 70 80 901000.00

0.02

0.04

0.06

0.08

0.10

0.12

14 cm18 cm22 cm26 cm30 cm34 cm38 cm44 cm52 cm

Longitudinal distance [cm]

Neutr

on fl

ux [

cm

-2*d

-1]

Neutron flux – longitudinal maximums

• Positions of longitudinal maximums increase towards higher radial distances

• Linear dependence of the maximum shifts• Positions of maximums are of lower values for

deuteron beam – shorter range of deuterons in material

Radial distance [cm]

Maximums for 1GeV proton beam [cm]

Maximums for 1GeV deuteron beam [cm]

14 cm 29,734 29,28118 cm 30,134 29,69122 cm 30,525 30,13126 cm 30,786 30,52730 cm 31,252 30,92234 cm 31,603 31,36938 cm 32,012 31,75844 cm 32,609 32,55352 cm 33,366 33,435 10 15 20 25 30 35 40 45 50 55

27.0

28.0

29.0

30.0

31.0

32.0

33.0

34.0

f(x) = 0.108944520547945 x + 27.7089136986301f(x) = 0.0954827685652488 x + 28.386187815429

protonLinear (proton)deuteronLinear (deuteron)

Radial distance [cm]

Posi

tion o

f lo

ngit

udin

al

maxim

um

[c

m]

Energy neutron spectra

System of marking of measuring points in BURAN setup

Energy neutron spectra1 GeV proton beam

1 GeV deuteron beam1E-03 1E-02 1E-01 1E+00 1E+01 1E+02 1E+03

0.0E+00

5.0E-02

1.0E-01

1.5E-01

2.0E-01

2.5E-01

3.0E-01

3.5E-01

Energy [MeV]

Neutr

on fl

ux [

cm

-2*p

-1]

1E-0

3

1E-0

2

1E-0

1

1E+00

1E+01

1E+02

1E+03

1.0E+00

1.0E+01

110111061515

Energy [MeV]

Neutr

on fl

ux {

cm

-2*p

-1]

1E-03 1E-02 1E-01 1E+00 1E+01 1E+02 1E+030.0E+00

5.0E-02

1.0E-01

1.5E-01

2.0E-01

2.5E-01

3.0E-01

3.5E-01

4.0E-01

Energy [MeV]

Neutr

on fl

ux [

cm

-2*d

-1]

1.00

E-04

1.00

E-02

1.00

E+00

1.00

E+02

1.00

E+041.00E+00

1.00E+01

110111061515

Energy [MeV]

Neutr

on fl

ux [

cm

-2*d

-1]

Neutron spectra hardening

• Hardening in each measuring point is defined as the ratio of the total flux of neutrons with energies > 10MeV and the total flux of neutrons with energies <= 10MeV

• Hardening in 3 longitudinal lines of measuring points was investigated:

1) Line 11: points 1101 – 1120 2) Line 13: points 1301 – 1320

3) Line 16: points 1601 – 1620

Neutron spectra hardening

• Dependence of neutron spectrum hardening for 1 GeV proton (left) and 1 GeV deuteron (right) beam

0 20 40 60 80 100 1200.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

Longitudinal distance [cm]

Hard

enin

g [

-]

0 20 40 60 80 100 1200.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

110013001600

Longitudinal distance [cm]

Hard

enin

g [

-]

Neutron spectra hardening

• Similar hardness of neutron spectra for lower longitudinal distances both for proton and deuteron beam

• For higher distances – higher values of hardness for spectrums where deuteron beam was used

• The curves cross each other around longitudinal distance of 60 cm – around this value, the hardness is approximately the same for all radial distances

• The shape of dependences becomes more linear with rising radial distance – the most remote distances are reached by the most energetic neutrons

0 20 40 60 80 100 1200.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

Longitudinal distance [cm]

Hard

enin

g [

-]

0 20 40 60 80 100 1200.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

110013001600

Longitudinal distance [cm]

Hard

enin

g [

-]

Thank you for attention