I currently work in the Eöt-Wash group at the University of Washington’s Center for Experimental Nuclear Physics and Astrophysics (CENPA). Our group performs world-class measurements of gravity and tests of modern theories using torsion balances.
As an undergraduate at Brigham Young University, I worked in the high-intensity laser group led by Justin Peatross.
(image of mechanism #77 from Henry T. Brown’s Five Hundred and Seven Mechanical Movements, via 507movements.com) The leading systematic uncertainty in our group’s test of the equivalence principle is variations in the local gravity gradient. The gravity gradient is the spatial derivative of the gravitational field—the amount of change in the strength and … Continue … Continue reading Wirelessly powered non-magnetic rotary actuator
I shared an office with a postdoc, Krishna, whose work centered around building an instrument to measure seismic tilt for LIGO, the gravity-wave observatory that made the first detection of gravitational waves. The instrument consisted of a long bar with weights on each end that hung from a pair of thin flexures EDM-cut from beryllium … Continue reading A motorized turntable in under 15 (times pi) minutes
As an undergraduate, I worked for two years in a high-intensity optics group. We were studying high-harmonic generation by femtosecond laser pulses passing through a dilute inert gas. These pulses have energies of millijoules and peak intensities of 1015 watts/cm2 (a comparable intensity could be achieved by focusing all of the sunlight hitting … Continue … Continue reading High-intensity laser pulse simulation
After becoming aware of unique fabrication needs within our group and other groups on campus, I initiated, wrote, and managed a successful grant proposal for a $200k high-power laser cutter system and have since been responsible for installing and managing the system. The system is a Kern HSE 100 with 400W laser and … Continue … Continue reading Laser cutters
The science data for our torsion-balance experiments is collected by measuring the rotation of the pendulum using laser autocollimators. In these autocollimators, light from a laser diode is collimated by a lens, reflected off a mirror on the pendulum, refocused by the original collimating lens, and directed onto a position-sensitive photodetector by a … Continue … Continue reading A device to measure picoradians
As an offshoot of our torsion-balance experiments, our group was involved in technology development for the Laser Interferometer Space Antenna, a proposed three-spacecraft space mission to detect gravity waves. These spacecraft were to stay in a perfect free-fall orbit by tracking a free-floating “test mass” contained within each spacecraft. We were investigating the … Continue … Continue reading Low-energy electron gun
One of the main areas of investigation in our research group at UW is the behavior of gravity at short distances. We have tested Newton’s inverse-square law down to distances less than 100 microns, about the average width of a human hair. These tests involve objects with dimensions of a few inches, with … Continue … Continue reading Custom cleanroom for short-range gravity experiment
