On January 5, 2020, Hadar, Nick, and I began our three-and-a-half day drive from Berkeley, CA to the Columbia Scientific Balloon Facility (CSBF) in Palestine, TX. While most of the COSI equipment traveled by truck and the rest of the team by plane, we drove a minivan to Palestine in order to transport the COSI cryostat separately.
You may be asking why we journeyed across the American Southwest with the cryostat instead of shipping it with everything else.
The cryostat houses COSI’s twelve high-purity germanium semiconductor detectors. These detectors must be kept very cold, at about 77 K, in order to function properly. A mechanical cryocooler runs continuously to maintain this temperature. When the cryocooler is off, the temperature of the detectors slowly increases. “Warming the cryostat,” as we call it, is a delicate operation that typically requires close monitoring over the course of several days. We ensure that the COSI team is always close by to watch the cryostat’s pressure change, for example, as we take it through the warming process.
Cooling the cryostat after it as been warmed also takes several days. We could have warmed, shipped, and then cooled the cryostat upon arrival in Palestine. However, much more important than the time cost of warming and cooling, temperature cycling increases the risk of damage to the detectors’ crucial electrical contacts that form COSI’s cross-strip electrodes.
Damage to the electrodes would compromise the quality of our data, so instead we opted to keep our cryostat cold during transport. We loaded the cryostat into a minivan with batteries that powered the cryocooler while driving throughout the day. We charged the batteries during each overnight stop and completed the journey with a cold cryostat!
Road trip highlights
Although our focus was on keeping the cryostat safe, we were sure to take in the beauty of the landscape as we drove through California, Arizona, New Mexico, and Texas.
We spent the first night in Needles, CA, where I enthusiastically provided an unsolicited explanation of the town’s role in John Steinbeck’s “The Grapes of Wrath.” Hadar and Nick were kind enough to listen. Thanks for humoring me. We also enjoyed meals at the delightful “Wagon Wheel Restaurant.”
The next day, we drove from Needles to Albuquerque, NM. The views along I-40 E were beautiful. Many of the mountains in the high-elevation region of Flagstaff, AZ were snow-covered (though thankfully there was no hazardous active snowfall). Per the recommendation of a friend, we stopped at “Frontier Restaurant” in Albuquerque for breakfast the next morning and devoured delicious green chile breakfast burritos with a “Frontier Sweet Roll” as dessert. I highly recommend this order to anyone traveling near Albuquerque.
For our final full day of driving, we headed to Wichita Falls, TX. After spending the night there we drove the remaining four hours to Palestine, moved the cryostat into our designated facility at CSBF, and prepared for our thermal vacuum test.
Special thanks to ’70s rock, ’90 hits, early 2000s pop, the “Frankenstein” audio book, and chocolate-covered peanut butter pretzels for powering us through the ride.