Medium-Energy Neutron Attenuation in Iron and Concrete (8) H. - - PowerPoint PPT Presentation

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Medium-Energy Neutron Attenuation in Iron and Concrete (8) H. - - PowerPoint PPT Presentation

Oct 25, 2023 41 likes •438 views

Inter-comparison of Medium-Energy Neutron Attenuation in Iron and Concrete (8) H. Hirayama and Attenuation Length Sub-Working Group in Japan From Inter-comparison at SATIF-9 Study the reason for the large difference in the attenuation

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SLIDE 1

Inter-comparison of Medium-Energy Neutron Attenuation in Iron and Concrete (8)

  • H. Hirayama

and Attenuation Length Sub-Working Group in Japan

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SLIDE 2

From Inter-comparison at SATIF-9

Study the reason for the large difference in the attenuation length and dose between codes.

It is desired to receive improved results from

  • ther groups.

Study the reason of the different tendency of C/E values between codes.

It is desired that other groups attend this inter comparisons.

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SLIDE 3

Problems for an Inter-comparison (8)

 Problems are same with an inter-comparison (7)

 Neutron dose, spectrum inside 6m iron or 12m

concrete plane for parallel beam of mono-energy neutrons (0.04-100GeV) and

 Secondary neutrons produced by protons (0.2-

24GeV)

 Comparison with the experimental results of AGS

shielding experiments

 As the new item to be sent by participants, “particles

treated to obtain the results” is added.

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SLIDE 4

Summary of contributors for Neutron attenuation calculation

Name of participants and organization Name of computer code Particles treated

  • T. Koi and D. Wright

(SLAC National Accelerator Laboratory) Geant4 v9.3 (2009 Dec. released) All particles (Including recoil nucleus)

  • Y. Uwamino (Riken)

HETC-3STEP neutron, proton,

  • N. Matsuda (JAEA) and
  • K. Niita (RIST)

PHITS 2.24 all established hadoronic states

  • S. Roesler (CERN)

FLUKA 2008.3c. All hadrons which FLUKA can transport N.V. Mokhov and I.L. Rakhno (Fermilab) MARS15(2010) All elementary particles and heavy ions

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SLIDE 5

50 100 150 200 250 300 350 400 10 100 1000 10

4

10

5

  • Fig. 1 Com parison of the neutron attem uation length of iron.

ANISN(SATIF-6) M ARS(SATIF-8) FLU KA(SATIF-10) HE TC-3STEP(S ATIF-6) RO Z-6.6(SATIF-8) PH ITS(3m ,SATIF-10) PH ITS w ithout  0 (3m , SATIF-10) GE AN T-4(SATIF-10) Geant-321(SATIF-8) M CN PX (SATIF-8)

Attenuation Length (g cm

  • 2)

Source N eutron Energy (M eV)

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SLIDE 6

10

  • 20

10

  • 18

10

  • 16

10

  • 14

10

  • 12

10

  • 10

100 200 300 400 500 600

  • Fig. 2 Dose distribution inside iron for 10 G eV protons.

RO Z-6.6(SATIF-8) FLUKA(SATIF-10) G EANT-4(SATIF-10) G EANT-321(SATIF-8) MARS(SATIF-8) PH ITS(SATIF-10) PH ITS(without  0)(SA TIF-10)

D ose Eqivalent rate (Sv per n/cm 2) Depthin Iron (cm )

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SLIDE 7

1 10 100 1000 10 100 1000 10

4

10

5

  • Fig. 4 Neutron dose difference at 4m inside iron

betw een ROZ 6.6, FLUKA, M ARS, G EAN T4 and PHITS.

Include R OZ result MC results only MC results without PHIT S with Lab

M ax./Min. dose ratio at 4m Source neutron energy (MeV)

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SLIDE 8

Iron for mono energy neutrons

 General tendency of the attenuation length is

similar for all results except PHITS with 0 particle.

 Differences of dose itself are large.

 Difference between Monte Carlo results except PHITS with

transport 0 particle is about 10.

 The effects of 0 particle in PHITS

 The effects can be seen from 3 GeV and maximum at 10

GeV and decrees at 50 and 100 GeV.

 0 portion within produced particles except neutrons and

protons emitted from 1cm diameter and 1cm iron and concrete by high energy neutrons becomes maximum at 20 GeV and decrease with increase of neutron energy.

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SLIDE 9

10

  • 21

10

  • 19

10

  • 17

10

  • 15

10

  • 13

10

  • 11

10

  • 9

100 200 300 400 500 600

  • Fig. 5 Dose distribution inside iron by PHITS.

3G eV 3 G eV without  5 G eV 5 G eV without  10 G eV 10 G eV without  0 50 G eV 50 G eV without  0 100 G eV 100 G eV without 

Sv per n/cm 2 Depth in iron (cm )

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SLIDE 10

0.005 0.01 0.015 0.02 0.025 0.03 10

4

10

5

Fig.6 

0 portion w ithin produced particles

except neutrons and protons from 1cm diam eter and 1cm length of iron or concrete.

Iron Concrete

 0/total (except neutron and proton) Neutron Energy (MeV)

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SLIDE 11

0 contribution to neutron attenuation length

 Matsuda and Niita estimate the effect of 0 particle to the

neutron attenuation length as follows:

 The 0 particle is one of the stable baryon, which life time is 2.6x1010

sec and decayed to nucleon and pion. If the 0 particle is decayed very quickly after its production, as shown in Fig, 5, the additional contribution

  • f 0 is disappeared. Therefore the additional contribution of the 0

particle is realized by the collisions of Lambda on material nucleus.

 The mass of the 0 particles is heavier than that of nucleon. Thus much

larger energy can be transported by the Lambda particles.

 This is a reason, we suppose, that the attenuation through the Lambda

particle is much flatter than that of not through the Lambda particle.

General tendency of the attenuation length is similar for all results except PHITS with 0 particle.

 It is desired to check the contribution of 0 particle to the

neutron attenuation by other codes and also to compare various particles production rates from small target..

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SLIDE 12

50 100 150 200 10 100 1000 10

4

10

5

  • Fig. 7 Com parison of the neutron attenuation length of concrete.

AN IS N(S ATIF-6) FLU KA(SATIF-10) HE TC-3STEP(S ATIF-8) RO Z-6.6(SATIF-8) PH ITS(R=3m )(SATIF-8) GE AN T-4(S ATIF-10) GE AN T-321(SATIF-8) M CN PX (SATIF-8) M ARS(SATIF-8)

A ttenuation Length (g cm

  • 2)

Source Neutron Energy (M eV)

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SLIDE 13

1 10 100 1000 0.1 1 10 100

  • Fig. 10 Neutron dose difference at 8m inside concrete

betw een ROZ 6.6, FLUKA, M ARS, GEANT4 and PHITS.

Include ROZ result MC results only

M ax./M in. dose ratio at 8m Source neutron energy (GeV)

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SLIDE 14

Concrete for mono energy neutron

General Tendencies are same with at SATIF-9.

 The differences between the attenuation lengths

between each code are relatively small at low-energy region and increase with the increase of neutron energy.

 The attenuation length have the tendency to increase

slightly with increase of neutron energy for 12 m slab.

 The dose differences at 8m are about 10 or less

between Monte Carlo.

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SLIDE 15

Y=0 plane Y=15 plane Y=-15 plane Y=25 plane Z=0 plane X Z X Z X Z X Z X Y Inner Reflector Moderator Hg-Target Moderator Moderator Inner Reflector Inner Reflector Inner Reflector Inner Reflector Outer Reflector Outer Reflector Outer Reflector Outer Reflector Outer Reflector Hg-Target

(a) (b) (c) (d) (e)

H g Target M odel

Secondary neutrons produced by protons (0.2-24GeV)

10

  • 8

10

  • 7

10

  • 6

10

  • 5

10

  • 4

10

  • 3

10

  • 2

10

  • 1

10 100 1000 10

4

Secondary Neutron Spectrum from a H g Target Bom barded by 3 G eV Protons (by M CNPX) and 24 G eV P rotons (by N M TC /JAM ).

24GeV p: 90-105 deg. 3 G eV p: 0-15 deg. 3 G eV p: 45-60 deg. 3 G eV p: 90-105 deg. 3 G eV p: 135-150 deg.

Neutrons cm

  • 2 M eV
  • 1

Neutron Energy (MeV)

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SLIDE 16

40 80 120 160 100 1000 10

4

  • Fig. 13 Com parison of the neutron attenuation length of iron for secondary neutrons

em iited to 90 degrees from Fe and Hg (24GeV) targer w ith protons.

G EANT-4(SAT IF-10) AN ISN(S AT IF5) MARS(SATIF-8) PH ITS(R=3m )(SATIF-8) HE TC -3STEP (SATIF-6) RO Z-6.6(SATIF-8) FLU KA(SATIF-10) G EANT-321(SATIF-8) IS IS Exp. LANSCE Exp.

Attenuation Length (g cm -2) Proton Energy (MeV)

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SLIDE 17

Comparison with Fe Target

 General Tendencies are same with at

SATIF-9.

 All results show similar tendency to

reach an almost constant value above 1 GeV protons.

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SLIDE 18

Comparison with Experimental results at AGS

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SLIDE 19
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SLIDE 20

0.5 1 1.5 2 50 100 150 200 250 300

209Bi(n,4n)206Bi

2.83GeV, Steel

MC NPX(SATIF-9) PHITS(SATIF-9) Geant4(SATIF-10) FLUKA(SATIF-10) MARS(SAT IF-10)

Calc./ Expt. Steel Thickness (cm )

Range of Experim ental E rror

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SLIDE 21

0.5 1 1.5 2 50 100 150 200 250 300

209Bi(n,6n)204Bi

2.83GeV, Steel

MCN PX(SATIF -9) PHITS(SAT IF-9) Geant4(SATIF-10) FLUKA(SATIF-10) MAR S(SATIF-10)

Calc./ Expt. Steel Thickness (cm )

Range of Experim ental Error

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SLIDE 22

0.5 1 1.5 2 50 100 150 200 250 300

209Bi(n,4n) 206Bi

24GeV, Steel

M CNPX(SATIF-9) PHITS(SATIF-9) G eant4(SATIF-10) FLUKA(SATIF-10) M ARS(SATIF-10)

Calc./ Expt. Steel Thickness (cm )

Range of Experim ental Error

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SLIDE 23

0.5 1 1.5 2 50 100 150 200 250 300

209Bi(n,6n) 204Bi

24 GeV, Steel

MC NPX(SATIF-9) PHITS(SATIF-9) Geant4(SAT IF-10) FLUKA(SATIF-10) MARS(SATIF-10)

Calc./ Expt. Steel Thickness (cm )

Range of Experim ental Error

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SLIDE 24

Steel shield

 The calculated results are smaller than the

measured ones in general.

 The calculated results for 2.83 GeV protons

are agree each other.

 The C/E value differences for 24 GeV protons

are larger than those for 2.83 GeV.

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SLIDE 25

0.5 1 1.5 2 50 100 150 200 250 300 350 400

209Bi(n,4n) 206Bi

2.83 GeV, Concrete

M CNPX(SATIF-9) PHIT S(SATIF-9) G eant4(SATIF-10) FLUKA(SATIF -10) M ARS(SATIF-10)

Calc./ Expt. Concrete Thickness (cm )

Range of Experim ental E rror

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SLIDE 26

0.5 1 1.5 2 50 100 150 200 250 300 350 400

209Bi(n,6n)204Bi

2.83 G eV, Concrete

M CN PX(SATIF -9) PHITS(SAT IF-9) G eant4(SATIF-10) F LUKA(SATIF-10) M AR S(SATIF-10)

Calc./ Expt. Concrete Thickness (cm )

Range of Experim ental Error

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SLIDE 27

0.5 1 1.5 2 50 100 150 200 250 300 350 400

209Bi(n,4n)206Bi

24 G eV, Concrete

MC NPX(SATIF -9) PHITS(SATIF-9) Geant4(SATIF-10) FLUKA(SATIF-10) MAR S(SAT IF-10)

Calc./ Expt. Concrete Thickness (cm )

Range of Experim ental Error

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SLIDE 28

0.5 1 1.5 2 50 100 150 200 250 300 350 400

209Bi(n,6n)204Bi

24 G eV, Concrete

MC NPX(SATIF-9) PHITS(SATIF -9) Geant4(SAT IF-10) FLUKA(SATIF-10) MARS(SATIF-10)

Calc./ Expt. Concrete Thickness (cm )

Range of Experim ental E rror

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SLIDE 29

Concrete shield

 The results of PHITS, Geant4, FLUKA and

MARS relatively agree well each other and with the measured results than for the steel shield.

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SLIDE 30

Future Themes

0 effects for iron presented PHITS must be checked by other codes.

It is necessary to compare various produced secondary particles from small target to understand the reason of difference of dose at high energy region.

Study the reason for the large difference in the attenuation length and dose between codes.

Study the reason of difference between measured results and calculated ones by various codes and the reason of the different tendency of C/E values between codes.

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SLIDE 31

Appendix

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SLIDE 32

 [a] High energy model switched from QGS (Quark

Gluon String) to FTF (FriToF) model. Transition energy to the high energy model is lowered.

 [b] Calculation only inside concrete for secondary

neutrons by 24 GeV protons toward 90 degrees from a Hg target.

 [c] Calculation only inside iron for 3-100 GeV

neutrons.

 [d] PHITS code (JAM [12]: Jet AA Microscopic

Transport Model) explicitly treats all established hadoronic states including resonances with explicit spin and isospin as well as their anti-particles. All Hadron-Hadron interactions including lambda hayperon can be simulated up to 200GeV/u.

 [e] Calculation only comparison with for the AGS

experiments.

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SLIDE 33

10

  • 15

10

  • 13

10

  • 11

10

  • 9

10

  • 7

10 100 1000 10

4

  • Fig. 3 Neutron spectra at 4m inside iron for 10 G eV protons.

GE ANT-4(4m )(SA TIF-10) PH IT S(4m )(SATIF-10) PH IT S(4m , witout 

0)(SA TIF-10)

FLU KA (4m )(S AT IF-10) RO Z-6.6(4m )(SATIF-8) MARS(4m )(SATIF-8)

Neutrons/MeV/cm 2 per n/cm 2 N eutron Energy (MeV)

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SLIDE 34

10

  • 17

10

  • 16

10

  • 15

10

  • 14

10

  • 13

10

  • 12

10

  • 11

10

  • 10

10

  • 9

200 400 600 800 1000 1200

  • Fig. 8 Dose distribution inside concrete for 10 G eV neutrons.

RO Z-6.6(SATIF-8) FLU KA(SATIF-8) MARS-15(SATIF-8) G EANT-4 G EANT-321(SATIF-8) HETC -3ST EP PH ITS(SATIF-8)

D ose Eqivalent rate (Sv per n/cm 2) D epth in C oncrete (cm )

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SLIDE 35

10

  • 8

10

  • 7

10

  • 6

10

  • 5

10

  • 4

10

  • 3

10

  • 2

10

  • 1

10 100 1000 10

4

  • Fig. 9 Neutron spectra at 4m inside concrete for 10 G eV protons.

G E AN T-4(4m )(SATIF-10) PHITS(4m )(S AT IF-8) FLU KA (4m )(SATIF-10) HETC -3STEP(4m )(SA TIF-8) RO Z-6.6(4m )(S AT IF-8) MA RS (4m )(S AT IF-8)

N eutrons/M eV/cm 2 per n/cm 2 Neutron Energy (M eV)

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SLIDE 36

50 100 150 50 100 150

  • Fig. 12 Com parison of the neutron attenuation length of concrete

for secondary neutrons from a Hg target w ith 3 G eV protons.

HETC(3G eV)(SATIF-8) G EANT-4(3G eV)(SATIF-10) ANISN(3G eV,6m ,SATIF-6) RO Z-6.6(3G eV)(SATIF-8) PHITS(3G eV)(SATIF-8) MARS (3G eV)(SATIF-8) FLUKA(3G eV)(SATIF-10) G EANT-321(3G eV)(SATIF-8) ISIS Exp.(800MeV)

Attenuation Length of Concrete (g cm

  • 2 )

Em ission Angle (degree)

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SLIDE 37

50 100 150 200 50 100 150

HE TC -3STEP(3G eV,SA TIF-6) G E AN T-4(3G eV )(S AT IF-10) AN IS N(3G eV ,SAT IF-6) RO Z-6.6(3G eV)(SATIF-8) PH ITS(3G eV)(SATIF-8) MA RS (3G eV)(SA TIF-8) FLU KA (3GeV)(SA TIF-10) G E AN T-321(3GeV)(SA TIF-8) ISIS E xp.(800MeV ) LAN SCE E xp.(800M eV )

Attenuation Length of Iron (g cm

  • 2)
  • Fig. 11 C om parison of the neutron attenuation of iron

for secondary neutrons from a Hg target w ith 3 G eV protons. Em ission angle (degrees)

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SLIDE 38

Attenuation Length for Secondary Neutrons from Hg Target

 General Tendencies are same with at

SATIF-9.

 In the case of iron, all results show similar weak

dependence on the emission angle but their values are largely scattered between each other.

 In the case of concrete, all results show stronger

dependence on the emission angle than in the case of iron and a different dependence between the code used.

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SLIDE 39

20 40 60 80 100 120 140 100 1000 10

4

  • Fig. 14 Com parison of the neutron attenuation length of concrete for secondary neutrons

em iited to 90 degrees from Fe and Hg (24 G eV) target w ith protons.

G EAN T-4(SA TIF-10) ANISN(6m ,SATIF-6) HETC-3STEP(SATIF-8,10) PHITS(R=3m )(S ATIF-8) FLUKA(S ATIF-10) MARS (SATIF-8) G EAN T-321(S ATIF-8) RO Z-6.6(SATIF-8) ISIS Exp.

Attenuation Length (g cm -2) Proton Energy (MeV)