A high-frequency, low-power resonant radio-frequency neutron spin flipper for high-resolution spectroscopy
Sam McKay (Indiana University)
Stephen J. Kuhn (Oak Ridge National Laboratory, Indiana University)
Jiazhou Shen (Indiana University)
F. Li (Oak Ridge National Laboratory)
Jak Doskow (Indiana University)
Gerard Visser (Indiana University)
S.R. Parnell (TU Delft - RID/TS/Instrumenten groep, Indiana University)
Kaleb Burrage (Oak Ridge National Laboratory)
Fumiaki Funama (Oak Ridge National Laboratory)
Roger Pynn (Indiana University, Oak Ridge National Laboratory)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
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.