Pulsed Neutron Powder Diffraction for Materials Science


The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded
by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization
(Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK).
Since then, the next generation source has been pursued for 20 years, and IMW-class spallation neutron sources will be
appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (JPARC),
a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about JPARC
and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials
and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz
from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal
groups have started to get fund. Those proposals include five poly crystalline diffractometers: a super high resolution
powder diffractometer (SHRPD), a 0.2 %-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering
diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer.
SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University,
whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD
is a super high intensity diffractometer with the highest resolution of Mid = 0.3%. VSD can measure rapid timedependent
phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution
function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as
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