The University of Chicago's role in the SZA
The SZA is in an advanced stage of implementation and is projected to be operational around the end of 2003. The University of Chicago is extensively involved in numerous aspects of the development of the array. This page contains brief descriptions of the ongoing work. Details of some of this work are provided through the links on the left, which are duplicated in the text below. We plan to add more over the course of the project, so we invite you to re-visit this page periodically.
The first four SZA telescopes were delivered to the University of Chicago in June 2003. The telescope mounts have been designed and constructed by Vertex/RSI, a company which specializes in large steerable radio antenna. At the University of Chicago, they are being assembled and will be re-shipped to the experimental site in California. The panels that make up the dish have been fabricated by a separate vendor. The remaining four telescopes will be assembled on site in California. Some of the people involved in this effort are Clem Pryke, Ryan Hennessy, etc. More details of the telescope assembly are available through this link.
The University of Chicago has been instrumental in preparing the electronics and support systems for the telescopes when they arrive. Clem Pryke has been supervising graduate student Michael Loh and staff engineer Frank DiDonna in the design and fabrication of a range of custom electronic modules including several varieties of phase lock boxesfor the local oscillators and a receiver support module which provides bias voltages for the HEMT amplifiers and reads out the cryogenic temperature monitors. The complete local oscillator (LO) system is in an advanced stage of implementation and testing. Graduate student Bryan Epley has assisted in the assembly of one of the boards for the LO system. Graduate student Chris Greer has designed a card which will be installed inside the receivers to protect the sensitive RF components from accidental damage.
With supervision and direction from John Carlstrom, graduate students Dan Siegal and Ryan Hennessy have designed and implemented a scalar network analyzer system to allow characterization of the 90-100 GHz HEMT amplifiers for the SZA receivers. These amplifiers are being fabricated at Chicago using MMICs provided through NRAO. Cold testing is well underway and the performance is good. Cristina Tcheyan, an undergraduate student, spent the summer of 2003 testing the amplifiers for the 90GHz receivers. Ryan Hennessy has also been working on the design of the microwave horns which feed the receivers.
Clem Pryke is developing the telescope drive system. Motors, encoders and a UMAC servo controller have been obtained. All these as well as the various custom parts of the system are being installed and tested on the four telescopes that are at Chicago currently.
Pryke has also been developing increasingly sophisticated simulations of the SZA instrument using as input simulated maps of the SZ sky provided by a number of people working in the large scale structure field. Further details of the simulations are available here.
CfCP fellow Marcus Runyan is working on the motorized tertiary mirror which allows switching between the receiver bands. He is also working on the calibration load mechanism, and the housing which will protect and thermally regulate both of these, as well as the receiver and its associated electronics.