Magnetic field devices for neutron spin transport and manipulation in precise neutron spin rotation measurements

Journal Article · Tue Feb 21 00:00:00 EST 2017 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI:https://doi.org/10.1016/j.nima.2017.02.066· OSTI ID:1534172

Maldonado-Velázquez, M. ^[1]; Barrón-Palos, L. ^[2]; Crawford, C. ^[3]; Snow, W. M. ^[4]

---

1. Univ. Nacional Autónoma de México, Mexico City (Mexico). Posgrado en Ciencias Físicas
2. Univ. Nacional Autónoma de México, Mexico City (Mexico). Inst. de Física
3. Univ. of Kentucky, Lexington, KY (United States)
4. Indiana Univ., Bloomington, IN (United States)

The neutron spin is a critical degree of freedom for many precision measurements using low-energy neutrons. Fundamental symmetries and interactions can be studied using polarized neutrons. Parity-violation (PV) in the hadronic weak interaction and the search for exotic forces that depend on the relative spin and velocity, are two questions of fundamental physics that can be studied via the neutron spin rotations that arise from the interaction of polarized cold neutrons and unpolarized matter. The Neutron Spin Rotation (NSR) collaboration developed a neutron polarimeter, capable of determining neutron spin rotations of the order of 10^-7 rad per meter of traversed material. This paper describes two key components of the NSR apparatus, responsible for the transport and manipulation of the spin of the neutrons before and after the target region, which is surrounded by magnetic shielding and where residual magnetic fields need to be below 100 μG. These magnetic field devices, called input and output coils, provide the magnetic field for adiabatic transport of the neutron spin in the regions outside the magnetic shielding while producing a sharp nonadiabatic transition of the neutron spin when entering/exiting the low-magnetic-field region. In addition, the coils are self contained, forcing the return magnetic flux into a compact region of space to minimize fringe fields outside. The design of the input and output coils is based on the magnetic scalar potential method.

• Research Organization: Univ. of Kentucky, Lexington, KY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: SC0008107
• OSTI ID: 1534172
• Alternate ID(s): OSTI ID: 1550549
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 854; ISSN 0168-9002
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
parity violation
nucleon spin-dependent interactions
neutron spin rotation
neutron spin transport
magnetic scalar potential