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Winter, Wesley

Publications and source records attributed to Winter, Wesley.

Secondary Beamline Lattice Design at the MeV Test Area (MTA)

The MTA is currently configured to produce a secondary pion beam from a tungsten target, which subsequently generates muons from decay in flight. In its present lattice configuration, the currently installed air core quadrupoles are strength-limited in their ability to deliver a high muon flux to the end user. Recently, seven strong iron-core quadrupole spares from the 400-MeV Linac were acquired. Based on these quadrupoles, a new lattice has been designed that maximizes both pion transport and muon capture the line based on significantly shorter magnetic lengths, strong magnetic gradients, and consequently an enhanced angular acceptance. For this project, we demonstrated that the ratio of muons to pions increased by over an order of magnitude (approximately 75 for lattice configurations were studied), successfully capturing a phase space area as large as 13.2 [mm] x 24 [mRad] in simulation.

Winter, Wesley↗

Low Energy Muon Capture and Transport from a Heavy Target

The MeV Test Area (MTA) secondary beamline is currently designed to produce and capture a low energy pion beam that then produces a tertiary muon beam via decay along the secondary line. The challenge presented in capturing muons from low-energy decay-in-flight pions, is the large decay angle that results from the low momentum. The current air-core quadruples lack the strength to bend/capture muons at large angles. Recently much stronger 400- MeV Linac quadrupoles have become available which are capable of strong focusing and large-angle capture. Initial results from this upgrade and reconfiguration indicate a major improvements in angle acceptance and transport ability for low-energy muons.

Winter, Wesley↗

MTA Secondary Beamline Production and Optics Optimization

A new secondary beamline was recently installed in the MeV Test Area (MTA) with the objective of enhancing mu+/mu- production by factors of 3/8 by using a tungsten target versus the conventional graphite production target using the 400 MeV Fermilab proton Linac beam. Ultra-low energy muon beams can support world-class physics experiments for fundamental muon measurements, sensitive searches for symmetry violation, and precision tests of theory. Extensive production studies have confirmed higher muon yield from heavy targets (tungsten vs carbon), but also, surprisingly, showed significant differences in production fluence and energy spectrum between modern hadronic models (GENIEhad) and between GEANT and MCNP. Studies are also underway towards a high-efficiency source of muonium by stopping the mu+ beam in superfluid helium. Muon fluxes can be measured at MTA including using higher-Z and novel target geometries to test hadronic and production models which are critical to understanding ongoing experiments (Mu2e) and will significantly impact the planning of future HEP experiments and planning PIP II facilities. The MTA beamline will additionally support a broad user muon test beam for future experiments and R&D.

Ahmed, Shiza↗