PowerPoint Presentation - Dish Surface Optimization System

Melanie Leong

Dish Surface Optimization Sys Primary Specifications

•Desired Performance Specifications

–+/- 25 Micron Length Change for Most of Dish

–Reduce RMS Surface Error from 25 Micron RMS to 15 Micron RMS

–Improve Aperture Efficiency by a Factor of 2, Integration Time by a Factor of 4

–+/- 50 Micron Length Change for Perimeter of Dish

•3 Toothpick Controller/Driver Prototype Demonstrated that desired length changes can be achieved

•99 Channel Dish Surface Optimization System Requested to Build ASAP


	Back in February 1999, the only specification given to me was to build a system to expand or contract 99 steel rod standoffs +/- 25µm.
	The steel rod standoffs are called toothpicks.

	After calculating what kind of force would be needed to attain such a goal, I built and tested several versions of a single channel prototype to see if the desired expansion and contraction could be reached. These tests agreed with our calculated predictions of temperature to length change, along with determining the parts and material that would accomplish this.

	A single channel setup was tested on the summit during the day and also at night. Night performance is more relevant. I conducted other tests to check the degree of temperature effects in areas around an acted upon standoff. These effects were determined tolerable.

	A 3 Channel Controller/Driver prototype was built and tested on the dish. I demonstrated its capabilities with dial indicators to Tom Phillips. In response, he wanted all 99 done ASAP.

	~Melanie Leong~