1. Recent Activities in Neutron Standardization at NMIJ/AIST
Tetsuro Matsumoto, Hideki Harano,
Akihiko Masuda
National Metrology Institute of Japan (NMIJ),
National Institute of Advanced Industrial Science and Technology (AIST)
2011 APMP TCRI meeting, Kobe , December 2011

2. Neutron Standard Group at NMIJ/AIST
Quantum Radiation Division
(Head: Dr. Norio Saito)
X/g-ray Standard
Section
Radioactivity and Neutron
Standard Section
(Head: Dr. Akira Yunoki)
Radioactivity
Standard Group
Neutron Standard Group
Dr. Hideki Harano (Head)
Dr. Tetsuro Matsumoto
Mr. Akihiko Masuda
In NMIJ, Quantum Radiation Division covers ionizing radiation field.
In this division, X/g-ray Standard Section covers photon radiation standards, and our Neutron Standard Group is combined with Radioactivity Standard Group.
We are four members, Dr. Hideki HARANO, the head of Neutron Standard Group, Dr. Tetsuro MATSUMOTO, Dr. Jun NISHIYAMA and Akihiko MASUDA.
I have joined this group in 2009 from Waseda University. When I was a student, I studied an accelerator based new X-ray source using laser and electron beam interaction.
We are working with Dr. Yoshio HINO, the Head of Quantum Radiation Division, as well as Deputy Director of NMIJ, and Dr. Akira YUNOKI, the Head of Radioactivity and Neutron Standard Section.

3. Calibration Service on Neutron Standard at NMIJ

4. Recent Activities
Development of high energy neutron standard fields from 45 MeV to 75 MeV
Development of a pulsing system on the 4 MV Pelletron accelerator
Development of a thermal neutron calibration method using a research reactor

5. High-energy Neutron Field (TIARA: 20-100 MeV)
Developing high energy neutron reference fields from 45 MeV to 75 MeV at TIARA
７Li(p,n) reaction
Collimator of 10 cm diameter made of concrete and iron
Fluence determination using a proton recoil telescope
~ 105 n/cm2s
19 m(W) x 11 m(D) x 6 m(H)

6. Installing a pulsing system on the 4 MV Pelletron accelerator
Neutron energy determination using a time-of-flight method
Pulsing system: Klystron bunching method
Repetition rate : 0.5 – 4 MHz
Pulse width : 1.5 ns
Ion source and
pulsing unit
Pelletron
Electronics

7. Thermal neutrons from JRR-3
Chopper
Small neutron probe
(6Li-glass : 1mmf ×1.5mmt)
0.5 mm Slit
HPGe
Detector
PGA Room
Reactor
JRR-3M
Pulse neutrons
Shutter
2cmx2cm
Collimator
(Teflon+6LiF)
Flight Path : 2.05 m
Neutron
Spectrum
Beam Hall
Fluence rate:
104 ~ 107 cm-2s-1

8. Future Work
The development of heavy water moderated Cf neutron fluence is in progress and the calibration service will commence in FY2012.
The development of 19 MeV monoenergetic neutron fluence standard is in progress and the calibration service will commence in FY2013.
We proceed with the development of the standard fields at TIARA (45-75MeV neutrons).