In 2023, the NCNR will be closed for one year to install an upgraded cold neutron source doubling the flux at long wavelengths (\(\lambda\) > 8 Å). This new cold source, which will be liquid D2 rather than liquid H2, will improve the performance of most instruments in the neutron guide hall.
The NCNR will take advantage of this opportunity to upgrade neutron guides, NG5, NG6, and NG7. The current guides were installed 30 years ago and have 58Ni coatings which were state-of-the-art at the time. They will be replaced by modern supermirror guides. To minimize the length of the reactor outage, we will remove portions of NG-5, NG-6, and NG-7 in the guide hall prior to the beginning of the reactor outage. We expect these guides to be closed for the last time in October 2022 when SPINS and the horizontal sample reflectometer on NG-7 will be permanently retired.
The reactor will restart when the new NG5, NG6, and NG7, have been installed through the confinement wall (D100). However, the new guides will not have been installed in the guide hall. We expect that it will take up to a year to replace NG-7 (which serves one of our 30 m SANS instruments) back into operation. NG-5 and NG-6 will be completed sometime after that.
The new NG5, NG6, and NG7 will be designed to enhance the performance of instruments on these guides.
We will also use the outage to install a new neutron spin echo spectrometer on NG-A with hot commissioning expected to take 9 months after the reactor restarts. This instrument is funded by the National Science Foundation.