Abstract
We present a resonant-mode, transverse-field, radio-frequency (rf) neutron spin flipper design that uses high-temperature superconducting films to ensure sharp transitions between uniform magnetic field regions. Resonant mode allows for low-power, high-frequency operation but requires strict homogeneity of the magnetic fields inside the device. This design was found to efficiently flip neutrons at 96.6 ± 0.6% at an effective frequency of 4 MHz in bootstrap configuration with a beam size of 2.4 × 2.5 cm2 and a wavelength of 0.4 nm. The high frequency and efficiency enable this device to perform high-resolution neutron spectroscopy with comparable performance with currently implemented rf flipper designs. The limitation of the maximum frequency was found due to the field homogeneity of the device. We numerically analyze the maximum possible efficiency of this design using a Bloch solver simulation with magnetic fields generated from finite-element simulations. We also discuss future improvements of the efficiency and frequency to the design based on the experimental and simulation results.
| Original language | English |
|---|---|
| Article number | 113906 |
| Journal | Review of Scientific Instruments |
| Volume | 95 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 1 2024 |
Funding
The authors thank Lowell Crow and Rob Dalgliesh for useful discussions. Machining was primarily done by the Indiana University Physics machine shop: John Frye, Danny Clark, Darren Nevitt, and Todd Sampson. We thank Matthew Loyd for assistance with the Anger camera. This research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. F. Li also acknowledges the support from DOE Early Career Research Program Award No. KC0402010, under Contract No. DE-AC05- 00OR22725. The work reported here was funded by the Department of Energy STTR program under Grant Nos. DE-SC0021482, DE-SC0018453, and DE-SC0023624. S. McKay acknowledges the support from the US Department of Commerce through co-operative Agreement No. 70NANB15H259.