CHIMERA Technical Specifications


  1. Documentation
  2. Telescope
  3. Detectors
  4. Scale
  5. Filters

1. Documentation

CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope (2016) L.K. Harding, G. Hallinan, J. Milburn, P. Gardner, N. Konidaris, N.Singh, M. Shao, J. Shandu, G. Kyne and H.E. Schlichting MNRAS 457, 3036-3049.

2. Telescope

  • 200-inch prime focus, f/3.3.
  • Field of view: 4.95 arc-minutes on a side.

3. Detectors

CHIMERA uses two Andor iXon Ultra DU-888, cameras for the red and blue channels. The iXon Ultra 888 cameras contain CCD201-20 EMCCD detectors from E2V.

Summary of Detector Characteristics
Sensor type EMCCD
Varian frame transfer, back illuminated, two-phase 
Active pixels (image) 1024×1024
Pixel pitch 13 μm
Digitization 16-bit
Amplifiers Conventional or EM
Calibrated gain range 1-1000
Multiplication stages 604
Read-out rate (conventional horizontal) 1, 0.1 MHz
Read-out rate (EM horizontal) 30, 20, 10, 1 MHz
Frame rates 26 fps (full) - 1000 fps (subarray)
Dark current (IMO, −85C) 5 x 10-4 e/pixel/s
Read noise (Conventional 1 MHz) ~6 e rms
Read noise (EM 1 MHz) ~20 e rms
Read noise (EM 10 MHz) ~53 e rms
Read noise (EM 20 MHz) ~120 e rms
Read noise (EM 30 MHz) ~160 e rms
Effective read noise (w/EM gain) < 1 e rms

4. Scale

Platescale: 0.29 arcseconds/pixel, 13μm pixels.

5. Filters

Each channel of the CHIMERA instrument contains a filter slide mechanism with 4 filter positions (not all are populated). The dichroic transmits light in the 570 to 850nm wavelength range into the RED camera and reflects light from 300 to 540nm into the BLUE camera. The primary broadband filters in the instrument are Sloan filters covering the wavelength range from 320nm to > 1000nm.

  • CHIMERA RED channel: Sloan r', i', z' and a custom 600nm filter (50nm width)
  • CHIMERA BLUE channel: Sloan g', u', clear and not populated

CHIMERA filters

The empirically measured optical throughput of the system for each of the Sloan filters is summarized below:

CHIMERA optical throughput.

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Chimera Specs / v 1.0.0
Last updated: 20 February 2020 JM