DEIMOS Detector Images


(Most images can be clicked on to view a larger version)

Two chips are mounted in the "test dewar" and cabled to the UCSD-II CCD controller for testing and characterization purposes.
DEIMOS test dewar assembly DEIMOS test dewar assembly DEIMOS test dewar assembly DEIMOS test dewar assembly
The fabrication of the CCD dewar assembly is nearing completion. We see that there are two ion pumps; one on the can which will hold the liquid Nitrogen, and the other on the chamber that will hold the CCD array. Between these two components is a connection that will hold a "dirty vacuum" and will allow for separation of the two without completly removing the whole assembly from the spectrograph or losing vacuum.
DEIMOS dewar assembly DEIMOS dewar assembly
CCD mounting plates These are three of the backing plates made of Aluminum Nitride that will hold the CCD chips in the mosaic at the focal plane. The Invar plate that they are mounted on is 5" diameter.
CCD mounting plates in LN2 The Aluminum Nitride and Invar assembly is put into liquid Nitrogen to check the thermal stability of the components at typical operating temperatures.
flexure component This is a key component of the CCD mounting fixture. The Aluminum pieces are held by rods made of G-10 (a form of glass epoxy). These rods will deflect sideways, but minimize movement in the compression/expansion direction.

Following are various views of the CCD mounting fixture that uses these Al/G-10 components. The central cylinder is isolated and suspended by these units which will constrain motion to the focus direction only.
flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount flexure compensating CCD mount

Since the flexure compensation will be done in the dewar at liquid Nitrogen temperatures, the feedthrough that will drive it is tested by submerging the "cold" end in LN2, and the "warm" (outside of dewar) end is checked to see how much cold is transferred.
feedthrough for flexure compensation feedthrough for flexure compensation

This page is maintained by Jim Burrous Jim@Lick.UCOLick.org