Development and application of compact neutron source
We are developing a new compact neutron source in Nagoya University
for researching neutron imaging, device development and fundamental physics experiments.
Large facilities such as J-PARC are powerful neutron sources and suitable
for experiments and measurement which require a high neutron flux,
whereas such large facilities are not flexible to use.
More handy neutron sources are suitable for researches
in a early stage requiring "trial and error".
We are developing a new compact neutron source (NUANS) in Higashiyama campus of Nagoya University.
In NUANS, neutrons are generated by bombarding 2.8 MeV protons
accelerated on a Beryllium or Lithium target.
Two proton beamlines are being constructed.
The first one is for Boron Neutron Capture Therapy (BNCT)
and being developed by Uritani laboratory of Graduate School of Engineering.
The second one is being developed by our laboratory
and its first purpose is for neutron imaging cooperating with Toyota Corp.
Neutron imaging has high sensitivity against Hydrogen atoms
unlike in the case of X-ray whose interaction is stronger for atoms with large atomic numbers.
The neutron induced interaction cross section of Hydrogen atoms becomes larger
for slow neutrons, therefore neutrons should be moderated.
Neutrons generated by Be(p,n) reactions have initially MeV order energy.
Their energy can be decreased to about 25 meV
by collistions with moderators made by polyethylene.
Reflectors made by carbon maintain the number density of such thermalized neutrons.
We are developing a neutron moderator and shield optimized for neutron imaging
using a Monte-Carlo simulation.
