1

JASMIN Activation Experiments (T-972/993/994)

Yoshimi Kasugai on behalf of JASMIN Activation team

JASMIN Activation teamY. Kasugai, K. Oishi, H. Matsumura, H. Yashima,

N. Matsuda, H. Iwase, A. Toyoda,

2

Introduction – What’s JASMIN• Shielding experiments under a collaborative project

of JASMIN started on 2007 using high-energy proton accelerator at Fermilab.– JASMIN: Japanese and American Study on Muon

Interaction and Neutron Detection

• The experiments are carrying out at – Pbar, NuMI and FTBF.

• JASIM has two experimental groups:– Counter Team Dec., 6’ s Talk by Sanami– Activation Team

• Results of the Activation team will be presented now.

3

Motivation and Experiment• Analysis of secondary particles (neutrons and muons) on in-shield

behavior for high-energy proton accelerators (Ep> 100 GeV)

=> Validation of high-energy particle transportation codes

=> Discovery of a macroscopic principle of particle behavior

=> Radiation safety• Chemical behavior of radioactive products

• Pbar– Neutron flux distribution and the attenuation in steel and concreted shield

– Analysis of air gas and cooling water in the radiation environment.

• NuMI– Muon-induced nuclide production

– Muon attenuation in rock

• Fermilab Test Beam Facility (FTBF):– Elemental study on the radioactivity production and the chemical behavior

4

Pbar

5

Shielding Experiment at PbarShielding Experiment at PbarMulti-foil Activation Method Position: In-steel & Shield surface Foils: In, Al, Nb, Bi => Coverage of Neutrons between1

MeV and 100 MeV

6

Comparison of neutron spectra between Comparison of neutron spectra between Expr. and Calc.Expr. and Calc.

10-12

10-11

10-10

10-9

10-8

10-7

10-6

1 10 100 1000

Neu

tron

Flu

x [/c

m2/le

thar

gy/p

roto

n]

Neutron Energy [MeV]

CC02

FP03

FP04

FP05

AG(=90o)

Expr.

Calc.

• The neutron attenuation length for iron shield was obtained: 150±5 g/cm2.• The shapes of neutron spectra by PHITS calculation was not so bad in comparison with

the experiments.• The experimental data of neutron attenuation in concrete shield are required for further

analysis. The experiments will be carried out in this series.

In Steel

On Steel

On Concrete

Target

OuterThe neutron spectra along the line from the inner to outer.

7

Measurement of Radioactive Aerosol in High-energy Proton Target Station at Fermilab.

Target room120 GeVproton

target

Existing gas-sampling system

Impactor

flow meter

Pump

Concrete shielding

Iron shielding

Sampling from target room using Impactor (2/15, 10:20- 3h sampling)

8

After sampling using Impactor ・・・ -ray spectrometry of

radioactive aerosols collected on aluminum foil which are equipped in each stage (10 stages in total) of the impactor

Be-7, Na-24, Sc-46, Sc-47, V-48, Cr-51, Mn-52, Mn-54, Co-56, Co-57, Co-58, Ni-57, Au-196, Au-198 from target room

10-7 10-6 10-50

1

2

3

4[103]

Particle diameter (dp, m)

(N0/

dlnd

p)

7Be aerosol fitted

　 　 GMD 1.6μ m　 　 GSD 2.3

Be-753.3 d

The experimental data indicate that:→ Particle size distribution of radionuclides show “aerosol growth” in the accelerator target room→We can estimate the velocity of particle growth using half-life of each nuclide.

9

NuMI

10

Nuclear reactions in NuMI beam line

0 10 20 30 40 50 60 70 8010-3

10-2

10-1

100

101

102

Ave

rage

of

(Yie

ld a

t Alc

ove-

X)/

(Yie

ld a

t Alc

ove-

2)

Depth (m)

Alcove-1

Alcove-2

Alcove-3

Alcove-420 30 40 50 60

10-37

10-36

10-35

10-34

10-33

10-32

Product mass number

Mas

s yi

elds

(1/

atom

/pro

ton)

Cu

Alcove-1Exp.MARS(Total)

Varia

tion

of a

ctivi

ty

High!

Theoretical

Experimental

20 30 40 50 6010-38

10-37

10-36

10-35

10-34

10-33

Product mass number

Mas

s yi

elds

(1/

atom

/pro

ton)

Cu

Alcove-2Exp.MARS(Total)

Muon Attenuation

Nuclide Production

Large gaps are seen in Alcove-1.

11

Measurement of the Original Beam

190 sets of samples were place on the front surface of the Hadron absorber.

12

We found two large peaks at the absorber

系列1

系列2

系列3

系列4

系列5

系列6

系列7

系列8

系列9

0.000

2.000

4.000

6.000

8.000

10.000

12.000

14.000

16.000

123456789

Flash report@AA-Au-196

14.000 -16.000

12.000 -14.000

10.000 -12.000

8.000 -10.000

6.000 -8.000

4.000 -6.000

2.000 -4.000

0.000 -2.000

40 cm

What are these large peaks???120 cm

Distribution of Au-196 activity

13

FTBF

14

120GeV p

monitor foil(Al)irradiation samples

SEM

Nuclide Production induced by 120 GeV-protons

Cross Section data of nuclide production for 120-GeV proton bombardment

15

Radiocolloid formation study by proton irradiation

020406080100

0 20 40 60 80 100Be-7

Na-24

Mg-28

S-38

Cl-39

K-42

K-43

Sc-44m

Sc-46

Sc-47

Cr-48

Mn-52

Mn-56

Fe-52

Co-55

Co-56

Co-58

Ni-57

Cu-61

Colloid rate [%]

Ion rate [%]

Ion rate from filtrate activity

Colloid rate from filter activity

No Data

No DataNo Data

No DataNo Data

Be-7

Na-24

Mg-28

S-38

Cl-39

K-42

K-43

Sc-44m

Sc-46

Sc-47

Cr-48

Mn-52

Mn-56

Fe-52

Co-55

Co-56

Co-58

Ni-57

Cu-61

No Data

No Data

No DataNo Data

Irradiation to Cu

Cu

Fe

Be-7 Ion-to-Colloid ratios for each radioactive products were measured.

Important data for handling the cooling water in the radiation environment from the radiation-safety point of view

16

SummarySummary• Experimental data on neutron behavior have been

obtained in the view points of attenuation of steel shield.– Experiments on concrete-attenuation will be done in this series.

• Experimental data of muon attenuation and muon-induced nuclide production data has been obtained.– Still remains the spitted beam issue at the Hadron-absorber

surface. => Now we are investigating.• Chemical behaviors of radionuclide produced in air gas

and cooling water has been investigated.

• Thanks to• Fermilab T972/T993/T994 members, N.Mokhov, A.Leveling,

D. Boehnlein, K.Vaziri• Pbar / NuMI / Rad. safety stuffs• FTBF members, A.Soha, E.Ramberg, R.Coleman, D.Jensen