Results and Data Products

The best-fit model for each flight detector was used to predict quantum efficiency as a function of energy. For historical reasons, our fits of the model to the data (both for the absolute response of the reference detectors, and the relative response of flight detectors) made use of standard (Henke, 1993) mass-absorbtion coefficients. It should be noted, however, that the predicted flight detector efficiency curves incorporate our measurements of the absorption edge structure near the nitrogen, oxygen and silicon edges (see section 4.6.4).

As an example, the best-fit quantum efficiency for ACIS detector S2 (the most efficient ACIS FI detector at all energies) is shown in Figure 4.91. The lower panel of the figure shows estimated 90% confidence envelope on the relative error in the model quantum efficiency; these error limits are discussed in detail in the next section.

The adopted quantum efficiency models for the two BI devices are shown in Figures 4.93 and 4.94.
 

Figure 4.91: Best-estimates for ACIS S2 (Front Illuminated) Detector Quantum Efficiency Model and 90% Confidence Envelope. See text for interpretation of the error envelope.

The best-fit quantum efficiency models for all FI detectors are shown in Figure 4.92. The quantum efficiency of the back-illuminated detector S3 is shown in Figure 4.94
 
 

Figure 4.92: Best-fit model quantum efficiency for all ACIS FI Detectors

 
 

Figure 4.93: Adopted ACIS S1 (Back-illuminated) Detector Quantum Efficiency Model

 
 

Figure 4.94: Adopted ACIS S3 (Back-illuminated) Detector Quantum Efficiency Model

The quantum efficiency of each ACIS flight detector will be made available as an ASCII table file. It is intended that these files be available from the MIT ACIS web page at

http://acis.mit.edu.

The files can also be found on the MIT CSR ACIS calibration database in the directory

 
/ohno/di/database/rsp/release.