Nuclear Physics Seminars

ics Nuclear
Tuesday, December 10, 2013
3:30 PM
Physics Building, Room 218
Note special room.
Chenyang Jiang [Host: Gordon Cates]
ORNL
"The Development of Polarized 3He Neutron Spin Filters at the Oak Ridge National Laboratory"
 
 Slideshow (PDF)
ABSTRACT:
The unique advantages of using polarized 3He as neutron spin filters, such as broadband and wide angular acceptance of neutron beams, have made it widely used among neutron scattering communities. Here we report the current status of the polarized 3He development at the Oak Ridge National Laboratory (ORNL). Over the last several years, we have developed a robust polarized 3He program to meet the increasing needs of 3He based neutron spin filters at ORNL’s High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). At ORNL, spin-exchange optical pumping is used to produce polarized 3He. Two optical pumping stations have been built in the lab to perform ex situ pumping of 3He. In order to solve the complications in data analysis brought by the 3He polarization relaxation in the ex situ pumping, we have constructed in situ pumping systems for several beamlines which has produced very high 3He polarization (76%) and the polarization has been maintained throughout the experiments. In addition, a novel polarized 3He filling station for the Hybrid Spectrometer (HYSPEC) at SNS is under development. We will present the preliminary test results of this system.
SLIDESHOW:

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