Focal Plane Studies Chuck Joseph Rutgers University 21

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 TPF Final Architecture Review I - 1 12/11/01

Suggested TPF Logo F TPF Final Architecture Review In New Jersey Exits 8 & 9 I - 2 12/11/01

STIS Long-Slit Spectra of M 87 Cosmic Ray Contamination l. C ~ 8500 Angstroms -- 1700 sec. Exposure -- Observer: C. Joseph CR Noise was not included in S/N Calculations – Much Worse for HEO TPF Final Architecture Review I - 3 12/11/01

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 TPF Final Architecture Review I - 4 12/11/01

S/N Comparisons CCD vs. EBCCD Telescope Aperture: 2 x 4 m 2 Detector Parameter CCD with CRs present EBCCD with CRs present Ideal Detector Effective QE 0. 8 0. 4 0. 8 Read Noise 4 e- 0 0 Rad. Hard & Stable --- No Yes Operating Temperature -80 o. C High Voltage -80 o. C 20 o. C (0 for P. C. ) 20 o. C None 10 k. V --- 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 m 2 Telescope – CCD without CRs (Burrows 2001) TPF Final Architecture Review I - 5 12/11/01