The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental Astronomy with minor editin

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033

Modeling and simulation strategy of aeronautical assemblies in an uncertain context

Ce travail de recherche présente une stratégie de modélisation et de dimensionnement pour les assemblages boulonnés en milieu aéronautique. Dans le cas du dimensionnement de grandes structures, les bureaux d’étude se servent habituellement de techniques dites de « zoom structural ». Elles permettent de gérer les ressources numériques à disposition, avec des modèles simples et de grande taille à l’échelle globale, et des modèles plus complexes à l’échelle locale. Cette étude s‘insère dans le cadre d’un processus de zoom structural dans lequel les structures étudiées présentent un très grand nombre de fixations. Un premier travail consiste à proposer une modélisation pertinente des fixations à l’échelle globale. Dans une seconde partie, les dispersions de comportement observées dans les fixations boulonnées sont prises en compte par l’utilisation de la théorie des méconnaissances. Une technique de recalage de la modélisation complète est ensuite proposée afin de tirer partie d’éventuels essais réels ou numériques. Enfin, la stratégie proposée est appliquée sur des cas d’assemblages boulonnés de type aéronautique. Les avantages, mais aussi les limites de l’utilisation d’une telle stratégie y sont discutés.The objective of this work is to develop a modeling strategy for assemblies involving multiple joints in an aeronautical predesign context. In the process of designing large structures, industrial engineers usually get around computational limitations by using submodeling techniques. In order to take into account phenomena which vary during the global representation of the submodeling process, we propose a modeling approach for the scattering of these phenomena based on the Lack-Of-Knowledge (LOK) theory. The LOK model associated with a relevant deterministic joint model is updated based on experimental or simulated data. The proposed strategy is discussed and illustrated by the case of multiple-joint assemblies typical of those used in aeronautics

Stratégie de modélisation et de simulation des assemblages de structures aéronautiques en contexte incertain

The objective of this work is to develop a modeling strategy for assemblies involving multiple joints in an aeronautical predesign context. In the process of designing large structures, industrial engineers usually get around computational limitations by using submodeling techniques. In order to take into account phenomena which vary during the global representation of the submodeling process, we propose a modeling approach for the scattering of these phenomena based on the Lack-Of-Knowledge (LOK) theory. The LOK model associated with a relevant deterministic joint model is updated based on experimental or simulated data. The proposed strategy is discussed and illustrated by the case of multiple-joint assemblies typical of those used in aeronautics.Ce travail de recherche présente une stratégie de modélisation et de dimensionnement pour les assemblages boulonnés en milieu aéronautique. Dans le cas du dimensionnement de grandes structures, les bureaux d’étude se servent habituellement de techniques dites de « zoom structural ». Elles permettent de gérer les ressources numériques à disposition, avec des modèles simples et de grande taille à l’échelle globale, et des modèles plus complexes à l’échelle locale. Cette étude s‘insère dans le cadre d’un processus de zoom structural dans lequel les structures étudiées présentent un très grand nombre de fixations. Un premier travail consiste à proposer une modélisation pertinente des fixations à l’échelle globale. Dans une seconde partie, les dispersions de comportement observées dans les fixations boulonnées sont prises en compte par l’utilisation de la théorie des méconnaissances. Une technique de recalage de la modélisation complète est ensuite proposée afin de tirer partie d’éventuels essais réels ou numériques. Enfin, la stratégie proposée est appliquée sur des cas d’assemblages boulonnés de type aéronautique. Les avantages, mais aussi les limites de l’utilisation d’une telle stratégie y sont discutés

Stratégie de modélisation et de simulation des assemblages de structures aéronautiques en contexte incertain

Ce travail de recherche présente une stratégie de modélisation et de dimensionnement pour les assemblages boulonnés en milieu aéronautique. Dans le cas du dimensionnement de grandes structures, les bureaux d étude se servent habituellement de techniques dites de zoom structural . Elles permettent de gérer les ressources numériques à disposition, avec des modèles simples et de grande taille à l échelle globale, et des modèles plus complexes à l échelle locale. Cette étude s insère dans le cadre d un processus de zoom structural dans lequel les structures étudiées présentent un très grand nombre de fixations. Un premier travail consiste à proposer une modélisation pertinente des fixations à l échelle globale. Dans une seconde partie, les dispersions de comportement observées dans les fixations boulonnées sont prises en compte par l utilisation de la théorie des méconnaissances. Une technique de recalage de la modélisation complète est ensuite proposée afin de tirer partie d éventuels essais réels ou numériques. Enfin, la stratégie proposée est appliquée sur des cas d assemblages boulonnés de type aéronautique. Les avantages, mais aussi les limites de l utilisation d une telle stratégie y sont discutés.The objective of this work is to develop a modeling strategy for assemblies involving multiple joints in an aeronautical predesign context. In the process of designing large structures, industrial engineers usually get around computational limitations by using submodeling techniques. In order to take into account phenomena which vary during the global representation of the submodeling process, we propose a modeling approach for the scattering of these phenomena based on the Lack-Of-Knowledge (LOK) theory. The LOK model associated with a relevant deterministic joint model is updated based on experimental or simulated data. The proposed strategy is discussed and illustrated by the case of multiple-joint assemblies typical of those used in aeronautics.CACHAN-ENS (940162301) / SudocSudocFranceF

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

48 pages, 29 figures, submitted for publication in Experimental AstronomyThe Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. It is expected that thanks to the studies conducted so far on X-IFU, along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained (abridged)

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

48 pages, 29 figures, submitted for publication in Experimental AstronomyThe Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. It is expected that thanks to the studies conducted so far on X-IFU, along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained (abridged)