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February 6, 2014 CLIC Workshop 2014 @CERN , Switzerland. “Review of electron linac based neutron sources for nuclear data study". Mitsuru Uesaka (Nuclear Professional School, University of Tokyo), ○ Walter Wuensch (CERN ). CONTENTS. - PowerPoint PPT Presentation
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“Review of electron linac based neutron sources for nuclear data study"
Mitsuru Uesaka (Nuclear Professional School, University of Tokyo), ○ Walter Wuensch (CERN)
February 6, 2014CLIC Workshop 2014@CERN, Switzerland
CONTENTS
1. Necessity of more precise nuclear data for melt fuel analysis in Fukushima and design of ADS
2. S-band electron linac neutron system in Belgium, USA and Japan
3. L-band electron linac neutron system in Japan
4. Proposal of new X-band linac system
Debris in TMI-2 have been analyzed by INEL (USA).EC and Canada also analyzed debris supplied by USA.JAERI (JAEA) also analyzed debris obtained at 1991.
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Research Background and Purpose
Quantity of nuclear materials in melted cores which are generated in nuclear accident like Fukushima is measured by non-destructive and high accuracy methods
Non-destructive measurement method of nuclear fuels in melted core hasn’t been developed yet.
J. M. Broughton, et al., “A Scenario of the Three Mile Island Unit 2 accident”, Nucl. Technol. 87, 35 (1989). H. Uetsuka, et al., “Gamma Spectrometry of TMI-2 Debris” (written in Japanese), JAERI-Research 95-084.
Hideo Harada (JAEA)
Conceptual Diagram of NRD Facility
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• By NRTA, 3-7 kg of small sized MF will be measured within 20 min. (The 3-7 kg: a MF area of 300-700 cm2 and a thickness of 10 g/cm2). • By NRCA, 30 g of MF including 109 Bq (mainly 137Cs) will be
measured within 1 hour for each beam line.
Neutron detector
Sample for NRTA
Gamma detector
Beam dump
n ～ 1012 n/sec
Sample for NRCA
Accelerator for pulsed neutron
generation
Hideo Harada (JAEA)
TOF Measurement by Small Pulse Neutron Source
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A Rough Sketch of Prototype Neutron Resonance Densitometer
Flight path = 5 m for NRTA
Hideo Harada (JAEA)
Typical NRTA Data of Nuclear Materials
Neutron Energy / eV
Tran
smis
sion
1 2 4 6 8 10 20 40
240 P
u24
1 Am
243 A
m
242 P
u
239 P
u23
8 U238 U
131 X
e
152 S
m23
5 U
145 N
d24
1 Pu
236 U
133 C
s23
8 U
235 U
239 P
u
235 U
Behrens et al., Nucl. Techn. 67 (1984) 162
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Hideo Harada (JAEA)
Precision of nuclear data
FacilityReference
Beamenergy
Beam powern Intensity
Beam pulse widthPulse per sec
Flux
IRMM, GELINAND2007, p.563
Electron100 MeV
6 kW 1 ns800 Hz @ 12 m
ORNL, ORELAND2007, p.441
Electron180 MeV
5 kW1013 n/s
8 ns525 Hz @ 40 m
Kyoto, e LinacND2007, p.591
Electron30 MeV
1 kW 100 ns100 Hz @ 10 m
CERN, n-TOFND2007, p.537
Proton20 GeV
9 kW1015 n/s
6 ns0.4 Hz
4×105 n/cm2/s@ 185 m
LANL, LujanND2007, p.415
Proton0.8 GeV
80 kW 135 ns20 Hz @ 20 m
J-PARC, MLF(Expected)
Proton3 GeV
1 MW ～ 1017 n/s～ 100 ns
25 Hz～ 109 n/cm2/s
@ 22 m
Neutron TOF facility for nuclear data measurements
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CONTENTS
1. Necessity of more precise nuclear data for melt fuel analysis in Fukushima and design of ADS
2. S-band electron linac neutron system in Belgium, USA and Japan
3. L-band electron linac neutron system in Japan
4. Proposal of new X-band linac system
EC – JRC – IRMMInstitute for Reference Materials & Measurements
Pulsed white neutron source (10 meV < En < 20 MeV)
Neutron energy : time – of – flight (TOF)
Multi-user facility: 10 flight paths (10 m - 400 m)
Measurement stations with special equipment to perform:
• Total cross section measurements• Partial cross section measurements
TOF - Facility GELINA
FLIGHT PATHS SOUTH
FLIGHT PATHS NORD
ELECTRON LINAC
TARGET HALL
Mondelaers and Schillebeeckx, Notizario 11 (2006) 19
Hokkaido University 45 MeV electron linac
1717
6.12m3.5m
3.5m
Neutron room
1m
6.4m 1.96m
21.1m
Target roomTarget room + LINAC =42.5 m
Electron energy ~45MeV (gun current ~50mA ）~30 MeV （ gun current~210 ｍ A ）
Electron current Average （ example, 60μA pulse width 3μs)
Pulse rate 10 ～ 100p.p.s(variable 、 single pulse ）
45 MeV LINAC
Performance of Hokkaido University 45 MeV electron linac
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•S-band electron linear accelerator•Maximum energy:45 MeV•Maximum current: 140μA•Repetition: single 10pps~200pps•Pulse width: 10ns ~3μs
•The electron beam is transported to the target room.•RIGHT: Pulsed cold neutron source•CENTER: Pulsed thermal neutron source, electron beam irradiation•LEFT: Fast neutron experiments
Typical Neutron and Photon Source
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Cold neutron
Intensity of neutronsBelow 25.3meV 1.0×103 (1/cm2/s)@L=6m 4.8×10^9(1/s)@Neutron Source
• 2mm thick lead radiator• Electron Beam Energy = 25 MeV• Pulse Width = 0.2 μs• Rep.rate = 50 pps• Electron beam current = 2 μAIntensity 20~30MeV ~1012 (1/s)
Bremsstrahlung photon
PHITSSimulation
By Prof. Kiyanagi, and Prof. Kino’s presentation
exp
CONTENTS
1. Necessity of more precise nuclear data for melt fuel analysis in Fukushima and design of ADS
2. S-band electron linac neutron system in Belgium, USA and Japan
3. L-band electron linac neutron system in Japan
4. Proposal of new X-band linac system
・ Specification of injectorelectric gun : YU-156(EIMAC)incident voltage : 100kV DC, incident current : Max 10A・ Specification of RF driveroutput : 3kW, frequency : 1300.8 MHz・ Energy of electron for neutron generation ： ～ 30 MeV・ Peak current : ～ 5A (short pulse) 2 ～ 100ns width ～ 0.5A(long pulse) 0.1 ～ 4 ms width・ Frequency ： 1 ～ 300 Hz (short pulse)
1 ～ 100Hz (long pulse)・ Neutron target : Ta with H2O moderator・ Power on target : Maximum 6 kW (200mA, 30MeV)・ Electron beam diameter on target : 1 cm・ Neutron production : ～ 8×1012 n/s @6kW
Present status of KURRI-L-band LinacResearch Reactor Institute, Kyoto UniversityJun-ichi Hori
Injector and accelerator tubes
Ta target and water moderator (Type-1)
Target roomWater moderator in Al case
Ta target
Ta target and water moderator (Type-2)
2. Flight path
Target room
Ta target
Flight tube : 2 linesFlight path : 10.0, 12.7, 24.2 m
Measurement room at 10m
Measurement room at 24m
Measurement room at 12.7m
Control room
Cooling tower
Lead spectrometer
Experimental room
CONTENTS
1. Necessity of more precise nuclear data for melt fuel analysis in Fukushima and design of ADS
2. S-band electron linac neutron system in Belgium, USA and Japan
3. L-band electron linac neutron system in Japan
4. Proposal of new X-band linac system
TOF (Time-Of-Flight) system for nuclear data measurement
電子ビーム
レーザー
X 線
電子ビーム
レーザー
X 線
Ce:LiCAF
Laser
X-ray
電子ビーム
レーザー
X線
電子ビーム
レーザー
X線
Existing X-band 30 MeV electron linac will be moved for neutron source
70 cm accelerator tube
5 m TOF planning area
More than 10 m TOFplanning area
More than 40 m TOFplanning area
Klystron and power source are set around the reactor
20 keV electorn gun + 5 MeV buncher+30 MeV structure+ Neutron target
Peak Beam current: 250mA (Beam energy: 30MeV ・ Pulse width: 1μsec)Beam Power: 0.375kW (50pps)（ S-band 30MeV 1kW(Hokkaido ⇒
Univ.) ）
30 MeV X-band Linac
S-band vs X-band- Electron Energy: Both are available- Charge per microbunch: X is ~1/10- Bunches for RF pulse: X is 3~4 times- Charge and Peak Current per RF pulse and
Average Current/Power: S is higher by ~2. However, X-band 6 MW 400Hz Klystron is under development so that the current/power becomes closer.- Size: X is smaller.- Price is linear to Beam Power, maybe.
Summary
• Several L/S-band electron linac neutron sources are operating for nuclear data study in the world.
• Precision of nuclear data must be improved for Fukushima accident analysis and design of new nuclear system such as ADS.
• New X-band electron linac neutron source is proposed and under construction at University of Tokyo.
• Almost all L/S-band systems are older than 40 years and it is the time of renewing.
• Due to compactness of X-band system, it can be installed in existing shielding facilities. Even its intensity is expected to be upgraded by new X-band high rep rate klystron.
Thank you for your attention.
