RADIATION DAMAGE TESTING

Low energy (100keV - 1 MeV) proton damage experiments are underway at various sites. The highlights of results are shown here. For  high energy proton damage experments go  here. ) The test device is w282c2, a front illuminated ccid-17 assembled in a 72-pin kovar package. This configuration will be familiar to HETE-1 users. Testing and analysis is conducted as for the ACIS devices during calibration stage. While this device performs well at lower temperature ( screening-report ) there is a problem at temperatures above -80c due to charge coming out of the serial register. This does not affect any measurement at higher temperatures provided care is used in selecting appropriate areas of the device for analysis. By modifying the readout technique through sequencer manipulations the impact of this radiation damage can be ameliorated. This page only shows results from the standard (calibration) timed exposure readout. An executive summary is contained in an ACIS memo.
Date of Irradiation Dose Date of Testing Image  Analysis
Oct 19 1999 1.8x108  /cm2   at  390 keV Oct 20 1999 -60c
Oct 22 1999 4.7x107  /cm2   at  150 keV Oct 25 1999
Oct 22 1999 3.3x107  /cm2   at  100 keV Oct 25 1999
Oct 22 1999

390 keV Results

This plot shows peak location fit to the Mn k-a line (ASCA grades 0234) as a function of row number. Events are restricted to columns passing through the damaged section and rows are binned by a factor of 16 to improve quality of fit. The damaged section starts at row 531, and the normalised slope of the curve(s) after this point can be treated as the CTI .
 
 

This plot shows the resolution (sigma) of the Mn k-a line plotted in the same fashion as above.

This plot shows the normalized cti per unit fluence as a function of temperature for the three energies tested to date.