Neutron imaging of the deuterium-tritium tamping gas volume in an inertial confinement fusion hohlraum.

To benchmark the accuracy of the models and improve the predictive capability of future experiments, the National Ignition Facility requires measurements of the physical conditions inside inertial confinement fusion hohlraums. The ion temperature and bulk motion velocity of the gas-filled regions of the hohlraum can be obtained by replacing the helium tamping gas in the hohlraum with deuterium-tritium (DT) gas and measuring the Doppler broadening and Doppler shift of the neutron spectrum produced by nuclear reactions in the hohlraum. To understand the spatial distribution of the neutron production inside the hohlraum, we have developed a new penumbral neutron imager with a 12 mm diameter field of view using a simple tungsten alloy spindle.

An immersive virtual reality shopping task detects declines in instrumental activities of daily living in individuals with Parkinson's disease.

Introduction: Declines in instrumental activities of daily living (IADLs) have been proposed as a prodromal marker of Parkinson's disease (PD). The Cleveland Clinic Virtual Reality Shopping (CC-VRS) platform combines an omnidirectional treadmill with a virtual reality headset to create a virtual grocery store that a user physically walks through and completes a shopping task. The primary aim of this project was to determine the known-group validity of the CC-VRS platform in discriminating IADL performance and to characterize specific motor and cognitive declines responsible for PD-related IADL impairments.

Gait patterns during overground and virtual omnidirectional treadmill walking.

Background: Omnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults.