CCCP: a CCD controller for counting photons

WFIRST-AFTA is a 2.4m class NASA observatory designed to address a wide range of science objectives using two complementary scientific payloads. The Wide Field Instrument (WFI) offers Hubble quality imaging over a 0.28 square degree field of view, and will gather NIR statistical data on exoplanets through gravitational microlensing. The second instrument is a high contrast coronagraph that will carry out the direct imaging and spectroscopic analysis of exoplanets, providing a means to probe the structure and composition of planetary systems.The coronagraph instrument is expected to operate in low photon flux for long integration times, meaning all noise sources must be kept to a minimum. In order to satisfy the low noise requirements, the Electron Multiplication (EM)-CCD has been baselined for both the imaging and spectrograph cameras. The EMCCD was selected in comparison with other candidates because of its low effective electronic read noise at sub-electron values with appropriate multiplication gain setting. The presence of other noise sources, however, such as thermal dark signal and Clock Induced Charge (CIC), need to be characterised and mitigated. In addition, operation within a space environment will subject the device to radiation damage that will degrade the Charge Transfer Efficiency (CTE) of the device throughout the mission lifetime.Here we present our latest results from pre-and post-irradiation testing of the e2v CCD201-20 BI EMCCD sensor, baselined for the WFIRST-AFTA coronagraph instrument. A description of the detector technology is presented, alongside considerations for operation within a space environment. The results from a room temperature irradiation are discussed in context with the nominal operating requirements of AFTA-C and future work which entails a cryogenic irradiation of the CCD201-20 is presented.

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“…16 3. Clock Induced Charge (CIC) is signal generated by the process of clocking charge through the device.…”

mentioning

confidence: 99%

The impact of radiation damage on photon counting with an EMCCD for the WFIRST-AFTA coronagraph

et al. 2015

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“…This new mapping at Hα will allow us to calculate more precisely the kinematical parameters for those galaxies and to make a comparison of these results with those at Hi already well-known. In fact, the capacities of our instrument allow to get more details and resolution in galaxies observations (Daigle et al 2008(Daigle et al , 2009). …”

Section: Resultsmentioning

confidence: 99%

“…The OMM has a 1.6 m RitcheyChrétien telescope, located at the summit of mont Mégantic at an altitude of 1111m. We started observing M33 with an EMCCD, using the CCD Controller for Counting Photons (CCCP) (Daigle et al 2008(Daigle et al , 2009). With CCCP, it is possible to reduce the Clock Induced Charge (CIC -the major source of noise when the EMCCD is operated at high gain).…”

Section: Hα Mapping and Kinematics Of M31 And M33mentioning

confidence: 99%

HI and Hα Mapping of M31 & M33

Kam

Carignan²,

Chemin³

et al. 2010

Proc. IAU

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Résumé. We performed a deep Hi and Hα mapping of M31 and M33 in order to get accurate kinematical data of those two galaxies and also to make a comparison between the Hi and Hα kinematics. The Hi data were obtained with the DRAO interferometer and the Hα data with the Fabry-Perot system of the Observatoire du mont Mégantic using an EMCCD as a detector. These data will give us the best possible datasets to derive accurate rotation curves and mass models for those two Local Group spirals and provide some new data for the Hii regions studies of these galaxies. While the Hi observations are of low resolution (∼1 arcmin), the high resolution of the Hα data (∼1 arcsec) should allow us to get much more details in the central regions, allowing at the same time a much better determination of the kinematical parameters. Hence, the inner part of the rotation curve, so inportant to constraint properly the mass models, will be determined more accurately.

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“…For the purpose of this review, this threshold is fixed at five times the readout noise. 10 This value is used for subsequent post-processing methods requiring a threshold.…”

Section: Photon Counting (Pc)mentioning

confidence: 99%

Comparison of EMCCD post-processing methods for photon counting flux ranges

et al. 2014

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Several post-processing methods were proposed to overcome the excess noise factor induced by EMCCD multiplication register. Each method has a unique effect on SNR. However, since SNR does not account for photometric accuracy, it cannot be reliably used to directly compare the performance of these algorithms. A normalized quadratic error that accounts for both SNR and accuracy is proposed as an alternative figure of merit. This approach provides a quantitative and rigorous comparison. Using both experimental and simulated frames in the faint-flux range, it is used to compare the existing EMCCD post-processing methods.

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CCCP: a CCD controller for counting photons

Cited by 24 publications

References 13 publications

The impact of radiation damage on photon counting with an EMCCD for the WFIRST-AFTA coronagraph

The impact of radiation damage on photon counting with an EMCCD for the WFIRST-AFTA coronagraph

HI and Hα Mapping of M31 & M33

Comparison of EMCCD post-processing methods for photon counting flux ranges

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