University of Chicago – Chicago Instrument for Laser Ionization (CHILI)

Univeristy of Chicago – Chicago Instrument for Laser Ionization (CHILI)

Specialized research facilities at the University of Chicago includes the Chicago Instrument for Laser Ionization where leading cosmochemistry is conducted, including:

• Analysis of interstellar dust particles (2006 Stardust Mission)
• Resonant Ionization Mass Spectrometry (RIMS)
• FIB/SEM Instrument
• Ion Guns
• Ion counters

This instrument is housed inside an older facility with that was designed in the 1960s with a 3 phase busway system without independent ground/neutral conductors.   This makes EMI control of the facility very challenging and subject to changes from other users of the facility.   To further complicate the situation, on busway was located within 10 feet of the instrument.

FMS was engaged to determine the source of a periodic recurring EMI disruption and to provide options for mitigation that avoided expensive shielding and did not disrupt the research of the Lab and assisted in the mitigation of other EMI artifacts that included Geomagnetic Field Drift

FMS worked with the UC facilities office to perform a building electrical system shutdown which allowed the periodic EMI source to be identified.   Additionally, FMS conducted geomagnetic field measurements around the campus and determined that the Geomagnetic field drift was caused by traction currents from multiple commuter rail options that pass to the east and west of the campus.