Dr. Michael W. J. Hubbard Profile

Dr. Michael W. J. Hubbard

Space Radiation Environment Scientist at The Open University

SPIE Involvement:

Author

Publications (4)

SPIE Journal Paper | 26 July 2023 Open Access

Impact of impurities in shielding material on simulations of instrument background in space

Michael W. J. Hubbard, David Hall, Oliver Hetherington, Timothy Arnold, Andrew Holland

JATIS, Vol. 9, Issue 03, 034004, (July 2023) https://doi.org/10.1117/12.10.1117/1.JATIS.9.3.034004

KEYWORDS: Beryllium, Simulations, Molybdenum, Equipment, Fluorescence, Particles, Aluminum, Iron, Space operations, Sensors

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 29 August 2022 Presentation + Paper

Calibrating and correcting charge transfer inefficiency in CCDs using Pyxel

Bradley Kelman, Thibaut Prod'homme, Jesper Skottfelt, Frédéric Lemmel, Matej Arko, Patricia Liebing, Peter Verhoeve, Ben Dryer, David Hall, Michael Hubbard

Proceedings Volume 12191, 121911F (2022) https://doi.org/10.1117/12.2629896

KEYWORDS: Calibration, Charge-coupled devices, Data modeling, Electrons, Sensors, Galactic astronomy, Computer simulations, Data corrections, Solid modeling, Image sensors

Read Abstract +

SPIE Journal Paper | 15 February 2022 Open Access

Mitigating the effects of particle background on the Athena Wide Field Imager

Eric Miller, Catherine Grant, Marshall Bautz, Silvano Molendi, Ralph Kraft, Paul Nulsen, Esra Bulbul, Steven Allen, David Burrows, Tanja Eraerds, Valentina Fioretti, Fabio Gastaldello, David Hall, Michael W. Hubbard, Jonathan Keelan, Norbert Meidinger, Emanuele Perinati, Arne Rau, Dan Wilkins

JATIS, Vol. 8, Issue 01, 018001, (February 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.1.018001

KEYWORDS: Particles, Signal to noise ratio, Sensors, Camera shutters, Signal attenuation, Imaging systems, Signal detection, X-rays, Photons, X-ray imaging

Read Abstract +

The Wide Field Imager (WFI) flying on Athena will usher in the next era of studying the hot and energetic Universe. Among Athena’s ambitious science programs are observations of faint, diffuse sources limited by statistical and systematic uncertainty in the background produced by high-energy cosmic ray particles. These particles produce easily identified “cosmic-ray tracks” along with less easily identified signals produced by secondary photons or x-rays generated by particle interactions with the instrument. Such secondaries produce identical signals to the x-rays focused by the optics and cannot be filtered without also eliminating these precious photons. As part of a larger effort to estimate the level of unrejected background and mitigate its effects, we here present results from a study of background-reduction techniques that exploit the spatial correlation between cosmic-ray particle tracks and secondary events. We use Geant4 simulations to generate a realistic particle background signal, sort this into simulated WFI frames, and process those frames in a similar way to the expected flight and ground software to produce a realistic WFI observation containing only particle background. The technique under study, self-anti-coincidence (SAC), then selectively filters regions of the detector around particle tracks, turning the WFI into its own anti-coincidence detector. We show that SAC is effective at improving the systematic uncertainty for observations of faint, diffuse sources, but at the cost of statistical uncertainty due to a reduction in signal. If sufficient pixel pulse-height information is telemetered to the ground for each frame, then this technique can be applied selectively based on the science goals, providing flexibility without affecting the data quality for other science. The results presented here are relevant for any future silicon-based pixelated x-ray imaging detector and could allow the WFI and similar instruments to probe to truly faint x-ray surface brightness.

DOWNLOAD PAPER

SPIE Journal Paper | 27 July 2021 Open Access

Enhanced simulations on the Athena/Wide Field Imager instrumental background

Tanja Eraerds, Valeria Antonelli, Chris Davis, David Hall, Oliver Hetherington, Andrew Holland, Michael Hubbard, Norbert Meidinger, Eric Miller, Silvano Molendi, Emanuele Perinati, Daniel Pietschner, Arne Rau

JATIS, Vol. 7, Issue 03, 034001, (July 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.3.034001

KEYWORDS: Particles, Molybdenum, Sensors, Aluminum, Device simulation, Imaging systems, Electrons, Physics, Luminescence, Monte Carlo methods

Read Abstract +

DOWNLOAD PAPER

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years