Pi‘ilani Lono currently lives in Hakalau on the Big Island. He is a 2004 graduate of Kamehameha Schools, and he is currently enrolled in the Electronics Technology program at Hawaii Community College, planning to graduate in Spring 2011. During his free time, Pi‘i enjoys surfing, digital art, reading, and fixing things. This is his first time working in the field of astronomy, and he is excited to obtain many new skills from this internship.
Home Island: Big Island
High School: Kamehameha Schools
Institution when accepted: Hawaii Community College
Akamai Project: Fabrication of a Portable Cold-Head Power Supply for Telescope Instruments
Project Site: National Astronomical Observatory of Japan — Subaru Telescope
Mentor: Lucio Ramos
Most instruments used on the Subaru Telescope require a helium-refrigeration system to produce cryogenic temperatures, in order to keep the components cold enough to operate properly. The helium-refrigeration system also prevents components from generating heat that interferes with the accuracy of collected data. Part of this refrigeration system consists of helium compressors and cold heads. Compressed (high-pressure) helium gas flows from the compressor to the cold heads where the gas expands and cools; the cold, low-pressure helium then flows back to the compressor where it is recompressed; and the cycle repeats itself. The Subaru Telescope does not currently have a portable cold-head power supply to use during maintenance and replacement of malfunctioning cold heads; the existing cold heads draw their electrical power from the helium compressor, which can be located inconveniently far away during maintenance procedures. In such a case, staff must communicate via handheld radios or telephones simply to request that the cold-head power be turned on or off—an inefficient arrangement. The goal of this project is to build a cold-head power supply that will make maintaining and replacing cold heads quicker and easier, and that is also safe to operate. This project requires mounting and wiring the components in a metal box, and testing to make sure everything works as it should. The input power signal of this power supply is a three-phase signal, so this project also required learning how three-phase power signals work, and understanding how to wire components correctly in such a system. This new power supply will bypass the power supply of the helium compressor and will be located near the cold heads, placing it within the technician’s view and reach, and increasing both convenience and efficiency.