Applications of high-flux γ-ray beams to nuclear and...

PosiPol'08, Hiroshima, Jun.18, 2008. 1

Applications of high-flux γ-ray beams to nuclear and radioactive waste management

R. HajimaERL Development Group,

Japan Atomic Energy Agency


Acknowledgement

The author would like to thank

N. Kikuzawa, N. Nishimori, M. Sawamura,R. Nagai, H. Iijima (JAEA-ERL)T. Hayakawa, E. Minehara, T. Shizuma, T. Tajima (JAEA-APRC)H. Toyokawa (AIST)H. Ohgaki (Kyoto U.)J. Urakawa (KEK)C.P.J. Barty (LLNL)ERL collaboration team in Japan


Role of Nuclear Power in the World Energy Demand

a proven technology for baseload electricity generationsmaller dependence on imported gas & curbing CO2 emissionworld-wide efforts to promote peaceful use of nuclear power

IAEA, NPTGNEP (Global Nuclear Energy Partnership)

World Energy Outlook 2006, International Energy Agency

Electricity Demand

Wikipedia, the Free Encyclopedia

Nuclear Power


Physics Today, Sep. 2006.

X-ray science has contributedto the cost saving of $30 billion.

Photon Science resolves urgent issues of nuclear research and industry

nuclear weapons plant

Radioactive waste in JAEA

cleanup of all the waste in JAEAcosts $20 billion and 80 years.

the most urgent issue !


Outline

1. Nuclear Resonance Fluorescence2. Design of a High-flux γ-ray source3. Monte Carlo Simulations4. Summary

Proposal of a high-flux γ-ray sourcenondestructive assay of radioactive nuclidesmanagement of nuclear waste


Nondestructive Assay by Nuclear Resonant Fluorescence

Irradiation of γ-rays tuned at a NRF energy of nuclide to detectDetection of scattered γ-rays by energy-resolved detectorsNRF is a unique fingerprint of nuclides radioactive and stable nuclides can be detected

Using 1-4 MeV γ-rays applicable to thick objects

79Se

re-emission

1257keV

3948keV

14N

2312keV

4618keV

28Si

1779keV 1322keV

γ-ra

y E

nerg

y

flux

excitation

12C

4438keV

LCS

Brems.

detector79Se

γ

γ’

Nuclear Waste


For increasing the γ-ray flux

ANfNF CLe σ

=

A

NNf

C

L

e

σ

collision frequency

number of electrons

number of laser photons

scattering cross-section

effective sectional area

high-average current and small emittance are essentialto increase the γ-ray flux

short pulse is also important in oblique collision

electronlaser

ERL is suitable for a high-flux γ-ray source


Technology Innovations for a high-flux γ-ray sourceCompton scattering cross section is small.

Recycling the electrons and photons with keeping small beam sizes is the key.

ERL

Energy of spent e-beamis recycled to acceleratesucceeding e-beam.

High power laser

High average power fiber lasers

Supercavity

Supercavity to stack laser pulses

Technology Innovations

Interaction of stored photons with electrons makes efficient generation of γ-ray.

γ-ray

electronLaser


20m

Electron GUN

Optical Resonator

Undurator

PreAccelerator

Main Accelerator

ＪＡＥＡ－ERL (17MeV)

beam load

w ER

w/o ER

Accelerate

Decelerate

RF field

R. Hajima, et. al., Nucl. Instr. Meth. A507 (2003) 115-119.

JAEA ERL-FEL


Concept of a high-flux γ-ray source

Photocathode E-GUN

Laser ComptonScattering

High Power Laser

ERL

Pb SlitTarget

Ge Detector

γ-ray

Flux MonitorNaI Detector

NRF-based detection system

Laser

Supercavity

Electron bunch

γ-ray

Laser Compton Scattering (LCS)


R&D’s at the ERL collaboration in JapanA collaboration has launched towards a future ERL light source in Japan.

KEK, JAEA, ISSP and other laboratories.

Preliminary design

Test Facility ERL Light Source

60-200 MeV ERL 5-GeV X-ray light source

Components relevant to the ERL light sourceare under development.

electron gun, superconducting cavity ...

These components are common to the γ-ray source


Development of a Photocathode GUN

Ceramic

preparationchamber load-lock

chamber

Gun chamber

E-beam

cathode

anode

laser

E-beam

250 kV-50 mA / Photocathode DC gun

2006: design and construction started2007: construction completed & first photo emission2008: e-beam characterization (to be conducted)

N. Nishirmori et al., Proc. ERL-07


Development of a superconducting cavity

1) Cavity cell shapeIris diameter 80 mm, elliptical shape at equatorCavity diameter 206.6 mm

2) Large beampipe with microwave absorbersBeampipe diameter 120 mm & 100 mm

3) Eccentric fluted beampipeDamp quadrupole HOMs Oe/(MV/m)42.5Hp/Eacc

3.0Ep/Eacc

Ohms289Geometrical Factor

mm100, 120Diameter of beam pipes

mm80Iris diameter

%3.78Cell-to-cell Coupling

Ohms897R/Q

GHz1.3Frequency

Design optimizations for ERL operations

Bellows & HOM absorber Power coupler port

Monitoring port

Large diameterof 120 mm

Large diameter of 100 mm Large iris diameter of 80 mm

Bellows & HOM absorber

K. Umemori et al., Proc. APAC-07, p.570.


Design of an Injector (7 MeV, 13 mA)

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0

2

4

6

8

10

12

14

16

18

20

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5S (m) S (m)

εn

σx

norm

aliz

ed e

mitt

ance

(mm

-mra

d)

beam

siz

e (m

m) E

σt

ener

gy (M

eV)

bunc

h le

ngth

(ps)

DC gun

buncher 2-cell x 2-cavity SCA

solenoid

~3 m

to merger

100 pCbunch charge

13 mAaverage current130 MHzrepetition 0.1 %energy spread7 MeVenergy3 ps (rms)bunch length1.0 mm-mradnorm. emittance

15 MV/m2nd cavity field10 MV/m1st cavity field1.25 MV/mbuncher field500 kVgun voltage

PARMELA simulation

R. Hajima et al.,Proc. AccApp’07


Design of a 350 MeV ERL

4 m

7-Mev injector dump

9-cell x 6 9-cell x 6 9-cell x 6

collision pointrms size = 37μm x 24 μm

collision point

βx, β

y (m

)

s (m)acceleration deceleration

βxβy

13 mAaverage current

3 x 10-4energy spread3 ps (rms)bunch length2.5/1 mm-mradεn (x/y)

130 MHzrepetition100 pCbunch charge 7 MeVinjection energy350 MeVfull energy

42 m

R. Hajima et al.,Proc. AccApp’07


Design parameters of the γ-ray source

energy spread 3x10-4Supercavity Enhancement 3000

3 ps2 psPulse length (rms)

σ (x/y) = 37 / 24 μmεn (x/y) = 2.5 / 1 mm-mrad, β* = 0.4 m

σr = 30 μm (w = 2σr)ZR = 1.1 cm

Beam size (rms)

100 pC/bunch (13 mA)6.2x109 /bunch

1.8 μJ/bunch (230 W)9.6x1012 photons/bunch

Intensity

130 MHz350 MeV

130 MHzλ ＝ 1064 nm (1.17eV)

FrequencyEnergy

Electron BeamLaser

Yb-doped fiber laser ERL+ DC photocathode gun


γ-ray flux calculation by CAINCAIN is a Monte Carlo code: http://lcdev.kek.jp/~yokoya/CAIN/

ph/sec100.1 13×=totalF

ph/sec/keV107 9×=peakF

with a collimator of 0.1mrad

exceeds the existing facilitiesby several orders of magnitude

0.E+0

1.E+6

2.E+6

3.E+6

4.E+6

1.9 2.0 2.1 2.2 2.3

Photon Energy (MeV)

Spe

ctr

al D

ensi

ty(p

h/se

c/eV

)

doubled emittance

collision at 0 deg

collision at 3.5 deg.


36° Peak

σNRF = 28 mbarn･keV @ 2.176MeV

irradiation time ~ 0.1 sec.

radioactive waste drumconcrete + U238 (8 wt%)ρ= 2 g/cm3 , U238 : 1000 Bq/g

γ-ray

1keV

1200 counts

50cm

γ-ray

1keV

Ge Detectorφ8.4cm, L=8.6cm

Nγ=1x109/keV

tuning the γ-ray energy to the NRF

separation of the NRF signal fromthe background

Back ground = Compton scattering in the drum

Simulation by GEANT4 (with NRF routine)

Nondestructive Detection of Isotopes


Nondestructive Detection of Isotopes

Th-232

Th-232 : σNRF = 100 mbarn･keV @ 2.043 MeVU-238 : σNRF = 100 mbarn･keV @ 2.176 MeV

2.0~2.2 MeV

Nγ = 2x109

γ-rays

123counts

26countsU-238

radioactive waste drumconcrete + U238 + Th232, ρ = 2 g/cm3, U238 : 1000 Bq/g (8 wt%) Th232 : 1000 Bq/g (25 wt%)

irradiation time ~ 1 msec.

Back ground = Compton scattering in the drum

Simulation by GEANT4 (with NRF extension)

Detection of two kinds of isotopes at once.

Ge Detectorφ8.4cm, L=8.6cm

N. Kikuzawa et al.,Proc. AccApp’07


clearance

subsurface disposal

geological disposal

near surface disposal

8 M JPY / drum

3 M JPY / drum

0.27 M JPY / drum

68,900 drums stored in JAEA

Cl-36, 9.3E10 (Bq/ t), 1.6 secTc-99, 4.4E11 (Bq/ t), 0.48 secI-129, 2.2E10 (Bq/ t), 0.13 secPu-238, 1.6E14 (Bq/ t), 3.2 secAm-241, 1.8E14 (Bq/ t), 0.57 sec

C-14, 3.4E10 (Bq/ t), 230 secCo-60, 4.1E13 (Bq/ t), 210 secNi-63, 8.9E11 (Bq/ t), 500 secSr-90, 6.5E10 (Bq/ t), 24000 secNb-94, 1.1E10 (Bq/ t), 200 secI-129, 1.4E8 (Bq/ t), 20 secCs-137, 1.0E12 (Bq/ t), 1500 sec

Upper level for subsurface disposal

Upper level for concrete pit disposal

Segregation of Nuclear Wastes

radioactivity and measurement time

R. Hajima et al., J. Nucl. Sci. Tech. 45 (2008)

radi

oact

ivity


2-D Mapping of Shielded Isotopes

Fig.1 Schematic layout of the simulation.

5 cm

Scattering Detector

Transmission Detector

Concrete

γ-rays

Fig.3 2D imaging (a)transmission imaging, (b)scattering imaging.

6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6-3

-2

-1

0

1

2

3

X (mm)

Y (m

m)

6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6-3

-2

-1

0

1

2

3

X (mm)

Y (m

m)

U238 Pb

(a) Transmission radiography

(b) NRF scattering imaging

U-238 Pb-208

NRF Imaging

Absorption Imaging

Metal objectsin a concrete block

Simulation by GEANT4 (with NRF extension)

U-238 Pb-208Metal objects

in a concrete block


Inspection of cargo containers

γ-ray beam

Nuclear Non-ProliferationAdvanced Safeguard Technologies

Key Issues for peaceful use of nuclear energy

Significant quantities; 8 kg for Pu25 kg for U-235


SummaryWe have proposed nondestructive assay of radionuclides by laser Compton γ-ray and nuclear resonance fluorescence.LCS (quasi-monochromatic, tunable energy) is an ideal γ-ray source for the NRF measurements.Combination of an ERL, a fiber laser and a supercavityproduces a high-flux γ-ray ~ 109-1010 ph/sec/keV.The ERL can be constructed with components under development in the ERL light source projects.Nondestructive detection and assay of radionuclides

Segregation of nuclear wastes to save the disposal costInspection of cargo containers for the safeguard

Laser Compton γ-ray contributes tothe peaceful and economical use of nuclear power.

Applications of high-flux γ-ray beams to nuclear and...

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