WIYN 3.5m Observatory

ONE DEGREE IMAGER (ODI) Status Updates

ODI News Roundup: January 2010

ODI Dewar

The major effort of the last month was the assembly of the dewar for ODI. This is the vacuum vessel in which the 64 detectors will be mounted and operated at a temperature of -100^oC. Instead of the actual detectors we will first mount 64 mockups that will allow us to simulate the heat load and to optimize the temperature uniformity across the focal plane.

Assembling the dewar vessel

64 detector simulators with resistor and temperature sensors mounted on the focal plate

Fit-checking the ODI detecor package on the focal plate

Fit-checking the ODI detector package on the focal plate

ODI Data Storage

ODI will generate about 1/2 to 4 Terabyte of data per night, depending on the science programs of the observer. A full image with the size of 2 GB will be read out in approximately 6 seconds and wants to be written to disk in that time. The challenges for an ODI data storage are both the amount of data (we need to buffer one week worth of observations) and the demand on the write speed (i.e., hand bursts when storing 2GB of data in 6 seconds).

A possible solution is a central storage server. For evaluation we were able to loan a storage server (a SUN 7210), that holds 22 TB on an array of 48 disk drives.