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We designed and constructed a cryostat setup for MKID detectors. The goal for the cryostat is to have four stages: 40K, 4K, 1K and 250mK. Prior to the start of my thesis, the cryostat was reaching 70K and 9K on the first and second stages respectively. During the first semester

We designed and constructed a cryostat setup for MKID detectors. The goal for the cryostat is to have four stages: 40K, 4K, 1K and 250mK. Prior to the start of my thesis, the cryostat was reaching 70K and 9K on the first and second stages respectively. During the first semester of my thesis I worked on getting the second stage to reach below 4K such that it would be cold enough to add a sorption fridge to reach 250mK. Various parts were machined for the cryostat and some tweaks were made to existing pieces. The largest changes were we thinned our stainless steel supports from 2mm to 10mil and we added roughly 6-10 layers of multi-layer insulation to the first and second stages. Our result was that we now reach temperatures of 36K and 2.6K on the first and second stages respectively. Next we added the sorption fridge to the 4K stage by having the 4K stage remachined to allow the sorption fridge to be mounted to the stage. Then I designed a final, two stage, setup for the 1K and 250mK stages that has maximum capabilities of housing a six inch wafer for testing. The design was sent to a machinist, but the parts were unfinished by the end of my thesis, so the parts and stage were not tested. Once the cryostat was fully tested and proven to reach the necessary temperatures, preliminary testing was done on a Microwave Kinetic Inductance Detector (MKID) provided by Stanford. Data was collected on the resonance and quality factor as they shifted with final stage temperature (5K to 285mK) and with input power (60dB to 15dB). The data was analyzed and the results agreed within expectations, as the resonant frequency and quality factor shifted down with increased temperature on the MKID. Finally, a noise characterization setup was designed to test the noise of devices, but was not fully implemented.
ContributorsAbers, Paul (Author) / Mauskopf, Phil (Thesis director) / Groppi, Chris (Committee member) / Department of Physics (Contributor) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
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I present a trade-study of methods for a 1-port vacuum cryogenic in-situ calibration of a vector network analyzer. The three main methods I investigated in this work were: calibration using a commercial off the shelf latching electro-mechanical six way switch, a custom switch board, and a flexible multi channel stripline

I present a trade-study of methods for a 1-port vacuum cryogenic in-situ calibration of a vector network analyzer. The three main methods I investigated in this work were: calibration using a commercial off the shelf latching electro-mechanical six way switch, a custom switch board, and a flexible multi channel stripline based printed circuit board. The test procedure was developed for use in a ground based closed-cycle cryogenic test bench to measure the reflection coefficient of a single port connectorized device under test. The device was installed in the cryogenic system alongside calibration standards. The goal of the trade study was to find which method could be used to accomplish calibration and device measurement in a single thermal cycle. Four cycles were required for industry standard open-short-load device calibration. Room temperature measurements were done with all three calibration schemes but ultimately only the single pole six throw switch proved effective enough for further testing. The cryogenic testing was carried out on an arbitrary device at ∼ 3K temperature, over a 6 GHz bandwidth. The final objective was to develop a setup and procedure for measuring the frequency and temperature dependent complex impedance of superconducting devices such as hot electron bolometer mixers, which are used for down converting the signal in the IF chain of astronomy instruments. Characterization of superconducting devices while they are at their operating temperature is challenging using traditional calibration methods. This commercial alternative is less expensive and more efficient in terms of thermal cycles and set up because it can be installed in a wide variety of cyrogenic systems.
ContributorsNeric, Marko (Author) / Trichopoulos, Georgios (Thesis advisor) / Groppi, Chris (Committee member) / Aberle, James (Committee member) / Arizona State University (Publisher)
Created2023