1. Focal Plane Studies Chuck Joseph – Rutgers University 21 March 2002
Overview
Detectors are always very problematic and they usually are the subcomponent limiting data quality.
Sub-electron-RN CCDs are likely to be inadequate for TPF and Hybrid Si FPA technology is immature. Cats => Suggests further studies are required.
Additional, detectors not surveyed by the TPF group should be explored (e.g. an EBCCD).
Performance Comparison between EBCCDs & CCDs.
Slide Format Courtesy of Ball Aerospace

2. Suggested TPF Logo F
In New Jersey
Exits 8 & 9

3. STIS Long-Slit Spectra of M87 Cosmic Ray Contamination
lC ~ 8500 Angstroms sec. Exposure -- Observer: C. Joseph
CR Noise was not included in S/N Calculations – Much Worse for HEO

4. What is an EBCCD? Princeton Scientific Instruments Very High QE ~ 50%
Photon-Counting, zero RN
Very High Dynamic Range
Radiation Hard – Long Life
Over light condition tolerant
CCD Operates at Room Temp.
Weight/Vol./Power on low end.
Magnet Design by John Lowrance, PSI

5. S/N Comparisons CCD vs. EBCCD
Telescope Aperture: 2x4 m2
Detector Parameter
CCD
CCD with CRs present
EBCCD with CRs present
Ideal Detector
Effective QE
0.8
0.4
Read Noise
4 e-
Rad. Hard & Stable
--- No
Yes
Operating Temperature
-80 oC
20 oC
(0 for P.C.)
High Voltage
None
10 kV
S/N per Frame (1800 sec. Exposure)
0.87
0.48
1.04
1.52
Total S/N (12,000 s)
2.25
1.23
2.68
3.93
c/f S/N = 6.4 for 40 m2 Telescope – CCD without CRs (Burrows 2001)