Geant4 simulation of the residual background in the ATHENA Wide Field Imager from protons deflected by the Charged Particle Diverter

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F22%3APU147315" target="_blank" >RIV/00216305:26620/22:PU147315 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1117/12.2629994" target="_blank" >http://dx.doi.org/10.1117/12.2629994</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1117/12.2629994" target="_blank" >10.1117/12.2629994</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Geant4 simulation of the residual background in the ATHENA Wide Field Imager from protons deflected by the Charged Particle Diverter

Popis výsledku v původním jazyce

X-ray telescopes opened up a new window into the high-energy universe. However, the last generation of these telescopes encountered an unexpected problem: their optics focused not only X-rays but low-energy (so called soft) protons as well. These protons are very hard to model and can not be distinguished from X-rays. For example, 40% of XMM-Newton observations is significantly contaminated by soft proton induced background flares. In order to minimize the background from such low-energy protons the Advanced Telescope for High ENergy Astrophysics (ATHENA) satellite introduced a novel concept, the so called Charged Particle Diverter (CPD). It is an array of magnets in a Hallbach design, which deflects protons below 76 keV before they would hit the Wide Field Imager (WFI) detector. In this work, we investigate the effect of scattering of the deflected protons with the CPD walls and the inner surfaces of the WFI detector assembly. Such scattered protons can loose energy, change direction and still hit the WFI. In order to adopt the most realistic instrument model, we imported the CAD model of both the CPD and the WFI focal plane assembly. Soft protons corresponding to similar to 2.5 hours of exposure to the L1 solar wind are simulated in this work. The inhomogeneous magnetic field of the CPD is included in the simulation. We present a preliminary estimate of the WFI residual background induced by soft proton secondary scattering, in the case of the optical blocking filter present in the field of view. A first investigation of the volumes responsible for scattering the protons back into the field of view is reported.

Název v anglickém jazyce

Geant4 simulation of the residual background in the ATHENA Wide Field Imager from protons deflected by the Charged Particle Diverter

Popis výsledku anglicky

X-ray telescopes opened up a new window into the high-energy universe. However, the last generation of these telescopes encountered an unexpected problem: their optics focused not only X-rays but low-energy (so called soft) protons as well. These protons are very hard to model and can not be distinguished from X-rays. For example, 40% of XMM-Newton observations is significantly contaminated by soft proton induced background flares. In order to minimize the background from such low-energy protons the Advanced Telescope for High ENergy Astrophysics (ATHENA) satellite introduced a novel concept, the so called Charged Particle Diverter (CPD). It is an array of magnets in a Hallbach design, which deflects protons below 76 keV before they would hit the Wide Field Imager (WFI) detector. In this work, we investigate the effect of scattering of the deflected protons with the CPD walls and the inner surfaces of the WFI detector assembly. Such scattered protons can loose energy, change direction and still hit the WFI. In order to adopt the most realistic instrument model, we imported the CAD model of both the CPD and the WFI focal plane assembly. Soft protons corresponding to similar to 2.5 hours of exposure to the L1 solar wind are simulated in this work. The inhomogeneous magnetic field of the CPD is included in the simulation. We present a preliminary estimate of the WFI residual background induced by soft proton secondary scattering, in the case of the optical blocking filter present in the field of view. A first investigation of the volumes responsible for scattering the protons back into the field of view is reported.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20304 - Aerospace engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings of SPIE

ISBN

978-1-5106-5344-3

ISSN

—

e-ISSN

—

Počet stran výsledku

9

Strana od-do

„“-„“

Název nakladatele

SPIE-INT SOC OPTICAL ENGINEERING

Místo vydání

BELLINGHAM

Místo konání akce

Montreal

Datum konání akce

17. 7. 2022

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000865607100098