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1. Duality transformations and the entanglement entropy of gauge theories.

Author

Bulgarelli, Andrea and Panero, Marco

Abstract

The study of entanglement in gauge theories is expected to provide insights into many fundamental phenomena, including confinement. However, calculations of quantities related to entanglement in gauge theories are limited by ambiguities that stem from the non-factorizability of the Hilbert space. In this work we study lattice gauge theories that admit a dual description in terms of spin models, for which the replica trick and Rényi entropies are well defined. In the first part of this work, we explicitly perform the duality transformation in a replica geometry, deriving the structure of a replica space for a gauge theory. Then, in the second part, we calculate, by means of Monte Carlo simulations, the entropic c-function of the ℤ2 gauge theory in three spacetime dimensions, exploiting its dual description in terms of the three-dimensional Ising model. [ABSTRACT FROM AUTHOR]

Published
2024
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2. The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

Author

Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante. Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Barret, Didier, Albouys, Vincent, den Herder, Jan-Willem, Piro, Luigi, Cappi, Massimo, Huovelin, Juhani, Kelley, Richard, Mas-Hesse, J. Miguel, Paltani, Stéphane, Rauw, Gregor, Rozanska, Agata, Bernard, Vivian, Berrocal, Alicia, Audard, Marc, Blin, Sylvie, Bonino, Donata, Frericks, Martin, Bonnet, François, Bonny, Patrick, Boorman, Peter, Ptak, Andy, Chaoul, Laurence, Boreux, Charles, Bounab, Ayoub, Boutelier, Martin, Boyce, Kevin, Brienza, Daniele, Bandler, Simon, Bruijn, Marcel, Gabici, Stefano, Bulgarelli, Andrea, Calarco, Simona, Raulin, Desi, Gloaguen, Emilie, Callanan, Paul, Prada Campello, Alberto, Camus, Thierry, Canourgues, Florent, Capobianco, Vito, Cardiel, Nicolas, Castellani, Florent, Barbera, Marco, Gant, Florent, Simionescu, Aurora, Cheatom, Oscar, Doumayrou, Eric, Chervenak, James, Chiarello, Fabio, Clerc, Laurent, Clerc, Nicolas, Cobo, Beatriz, Coeur-Joly, Odile, Coleiro, Alexis, Colonges, Stéphane, Torrejon, Jose M., Corcione, Leonardo, Gao, Jian-Rong, Puccetti, Simonetta, Barcons, Xavier, Coriat, Mickael, Coynel, Alexandre, Cuttaia, Francesco, D’Ai, Antonino, D’anca, Fabio, Dadina, Mauro, Acero, Fabio, Daniel, Christophe, Dauner, Lea, DeNigris, Natalie, Puccio, Elena, Gastaldello, Fabio, Dercksen, Johannes, Bozzo, Enrico, DiPirro, Michael, Genolet, Ludovic, Durkin, Malcom, van Leeuwen, Bert-Joost, Charles, Ivan, Ghizzardi, Simona, Alcacera Gil, M. Angeles, Giovannini, Elisa, Ramon, Pascale, Godet, Olivier, Gomez-Elvira, Javier, Gonzalez, Raoul, Gonzalez, Manuel, Gottardi, Luciano, Branduardi-Raymont, Graziella, Granat, Dolorès, Fioretti, Valentina, Gros, Michel, Costantini, Elisa, Guignard, Nicolas, Reina, Manuel, Hieltjes, Paul, Hurtado, Adolfo Jesús, Irwin, Kent, Jacquey, Christian, Ettori, Stefano, Janiuk, Agnieszka, Jaubert, Jean, Jiménez, Maria, Geoffray, Hervé, Jolly, Antoine, Jourdan, Thierry, Rioland, Guillaume, Dauser, Thomas, Julien, Sabine, Kedziora, Bartosz, Finoguenov, Alexis, Korb, Andrew, Kreykenbohm, Ingo, König, Ole, Langer, Mathieu, Laudet, Philippe, Jacques, Lionel, Laurent, Philippe, Rodriguez, Louis, Laurenza, Monica, Lesrel, Jean, Etcheverry, Christophe, Decourchelle, Anne, Ligori, Sebastiano, Lorenz, Maximilian, Luminari, Alfredo, Maffei, Bruno, Maisonnave, Océane, Marelli, Lorenzo, Kirsch, Christian, Roig, Anton, Massonet, Didier, Petit, Pascal, Maussang, Irwin, Melchor, Alejandro Gonzalo, Le Mer, Isabelle, Duband, Lionel, San Millan, Francisco Javier, Millerioux, Jean-Pierre, Mineo, Teresa, Minervini, Gabriele, Molin, Alexeï, Gatti, Flavio, Grosso, Nicolas, Smith, Stephen, Monestes, David, Montinaro, Nicola, Mot, Baptiste, Murat, David, Nagayoshi, Kenichiro, Duval, Jean-Marc, Nazé, Yaël, Noguès, Loïc, Pailot, Damien, Kaastra, Jelle, Rollet, Bertrand, Panessa, Francesca, Adams, Joseph, Parodi, Luigi, Roncarelli, Mauro, Dubbeldam, Luc, Hoogeveen, Ruud, Roudil, Gilles, Rudnicki, Tomasz, Sanisidro, Julien, Mazzotta, Pasquale, Sciortino, Luisa, Silva, Vitor, Sordet, Michael, Soto-Aguilar, Javier, Spizzi, Pierre, Goldwurm, Andrea, Dupieux, Michel, Surace, Christian, Svoboda, Jiri, Fernández Sánchez, Miguel, Miller, Jon, Taralli, Emanuele, Terrasa, Guilhem, Terrier, Régis, Todaro, Michela, Ubertini, Pietro, Uslenghi, Michela, Vaate, Jan Geralt Bijd de, Dupourqué, Simon, Vaccaro, Davide, den Hartog, Roland, Miniutti, Giovanni, van der Hulst, Paul, Varisco, Salvatore, Varnière, Peggy, Vibert, Laurent, Vidriales, María, Villa, Fabrizio, Vodopivec, Boris Martin, Volpe, Angela, Durand, Jean Louis, Vries, Cor de, Nicastro, Fabrizio, Wakeham, Nicholas, Walmsley, Gavin, Kiviranta, Mikko, Jackson, Brian, Wise, Michael, Wit, Martin de, Woźniak, Grzegorz, Jonker, Peter, Kilbourne, Caroline, Eckert, Dominique, Sciortino, Salvatore, Korpela, Seppo, Macculi, Claudio, Mendez, Mariano, Mitsuda, Kazuhisa, van der Kuur, Jan, Molendi, Silvano, Pajot, François, Pointecouteau, Etienne, Porter, Frederick, Pratt, Gabriel W., van Loon, Dennis, Eiriz, Valvanera, Prêle, Damien, Ravera, Laurent, Sato, Kosuke, Schaye, Joop, Shinozaki, Keisuke, Ledot, Aurélien, Skup, Konrad, Soucek, Jan, Thibert, Tanguy, Yamaguchi, Hiroya, Vink, Jacco, Ercolani, Eric, Webb, Natalie, Beaumont, Sophie, Piconcelli, Enrico, Ceballos, Maria Teresa, Cucchetti, Edoardo, D’Andrea, Matteo, Eckart, Megan, Ferrando, Philippe, Kammoun, Elias, Lotti, Simone, Mesnager, Jean-Michel, Natalucci, Lorenzo, Lyautey, Bertrand, Pinto, Ciro, Peille, Philippe, Doriese, William, de Plaa, Jelle, Ardellier, Florence, Argan, Andrea, Bellouard, Elise, Carron, Jérôme, Cavazzuti, Elisabetta, Fiorini, Mauro, Khosropanah, Pourya, Encinas Plaza, Jose Miguel, Martin, Sylvain, Parot, Yann, Finkbeiner, Fred, Perry, James, Pinsard, Frederic, Pradines, Alice, Rigano, Manuela, Roelfsema, Peter, Schwander, Denis, Torrioli, Guido, Plaza, Borja, Ullom, Joel, Vera, Isabel, Medinaceli Villegas, Eduardo, Fiocchi, Mariateresa, Sakai, Kazuhiro, Zuchniak, Monika, Brachet, Frank, Lo Cicero, Ugo, van Weers, Henk, Wilms, Joern, Fiore, Fabrizio, Abdoelkariem, Shariefa, Adam, Thomas, Adami, Christophe, Aicardi, Corinne, Fossecave, Hervé, Akamatsu, Hiroki, Merino Alonso, Pablo Eleazar, Amato, Roberta, André, Jérôme, Angelinelli, Matteo, Poyatos, David, Anon-Cancela, Manuel, Yamasaki, Noriko, Anvar, Shebli, Atienza, Ricardo, Attard, Anthony, Franssen, Philippe, Auricchio, Natalia, Balado, Ana, Bancel, Florian, Barusso, Lorenzo Ferrari, Prouvé, Thomas, Bascuñan, Arturo, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante. Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Barret, Didier, Albouys, Vincent, den Herder, Jan-Willem, Piro, Luigi, Cappi, Massimo, Huovelin, Juhani, Kelley, Richard, Mas-Hesse, J. Miguel, Paltani, Stéphane, Rauw, Gregor, Rozanska, Agata, Bernard, Vivian, Berrocal, Alicia, Audard, Marc, Blin, Sylvie, Bonino, Donata, Frericks, Martin, Bonnet, François, Bonny, Patrick, Boorman, Peter, Ptak, Andy, Chaoul, Laurence, Boreux, Charles, Bounab, Ayoub, Boutelier, Martin, Boyce, Kevin, Brienza, Daniele, Bandler, Simon, Bruijn, Marcel, Gabici, Stefano, Bulgarelli, Andrea, Calarco, Simona, Raulin, Desi, Gloaguen, Emilie, Callanan, Paul, Prada Campello, Alberto, Camus, Thierry, Canourgues, Florent, Capobianco, Vito, Cardiel, Nicolas, Castellani, Florent, Barbera, Marco, Gant, Florent, Simionescu, Aurora, Cheatom, Oscar, Doumayrou, Eric, Chervenak, James, Chiarello, Fabio, Clerc, Laurent, Clerc, Nicolas, Cobo, Beatriz, Coeur-Joly, Odile, Coleiro, Alexis, Colonges, Stéphane, Torrejon, Jose M., Corcione, Leonardo, Gao, Jian-Rong, Puccetti, Simonetta, Barcons, Xavier, Coriat, Mickael, Coynel, Alexandre, Cuttaia, Francesco, D’Ai, Antonino, D’anca, Fabio, Dadina, Mauro, Acero, Fabio, Daniel, Christophe, Dauner, Lea, DeNigris, Natalie, Puccio, Elena, Gastaldello, Fabio, Dercksen, Johannes, Bozzo, Enrico, DiPirro, Michael, Genolet, Ludovic, Durkin, Malcom, van Leeuwen, Bert-Joost, Charles, Ivan, Ghizzardi, Simona, Alcacera Gil, M. Angeles, Giovannini, Elisa, Ramon, Pascale, Godet, Olivier, Gomez-Elvira, Javier, Gonzalez, Raoul, Gonzalez, Manuel, Gottardi, Luciano, Branduardi-Raymont, Graziella, Granat, Dolorès, Fioretti, Valentina, Gros, Michel, Costantini, Elisa, Guignard, Nicolas, Reina, Manuel, Hieltjes, Paul, Hurtado, Adolfo Jesús, Irwin, Kent, Jacquey, Christian, Ettori, Stefano, Janiuk, Agnieszka, Jaubert, Jean, Jiménez, Maria, Geoffray, Hervé, Jolly, Antoine, Jourdan, Thierry, Rioland, Guillaume, Dauser, Thomas, Julien, Sabine, Kedziora, Bartosz, Finoguenov, Alexis, Korb, Andrew, Kreykenbohm, Ingo, König, Ole, Langer, Mathieu, Laudet, Philippe, Jacques, Lionel, Laurent, Philippe, Rodriguez, Louis, Laurenza, Monica, Lesrel, Jean, Etcheverry, Christophe, Decourchelle, Anne, Ligori, Sebastiano, Lorenz, Maximilian, Luminari, Alfredo, Maffei, Bruno, Maisonnave, Océane, Marelli, Lorenzo, Kirsch, Christian, Roig, Anton, Massonet, Didier, Petit, Pascal, Maussang, Irwin, Melchor, Alejandro Gonzalo, Le Mer, Isabelle, Duband, Lionel, San Millan, Francisco Javier, Millerioux, Jean-Pierre, Mineo, Teresa, Minervini, Gabriele, Molin, Alexeï, Gatti, Flavio, Grosso, Nicolas, Smith, Stephen, Monestes, David, Montinaro, Nicola, Mot, Baptiste, Murat, David, Nagayoshi, Kenichiro, Duval, Jean-Marc, Nazé, Yaël, Noguès, Loïc, Pailot, Damien, Kaastra, Jelle, Rollet, Bertrand, Panessa, Francesca, Adams, Joseph, Parodi, Luigi, Roncarelli, Mauro, Dubbeldam, Luc, Hoogeveen, Ruud, Roudil, Gilles, Rudnicki, Tomasz, Sanisidro, Julien, Mazzotta, Pasquale, Sciortino, Luisa, Silva, Vitor, Sordet, Michael, Soto-Aguilar, Javier, Spizzi, Pierre, Goldwurm, Andrea, Dupieux, Michel, Surace, Christian, Svoboda, Jiri, Fernández Sánchez, Miguel, Miller, Jon, Taralli, Emanuele, Terrasa, Guilhem, Terrier, Régis, Todaro, Michela, Ubertini, Pietro, Uslenghi, Michela, Vaate, Jan Geralt Bijd de, Dupourqué, Simon, Vaccaro, Davide, den Hartog, Roland, Miniutti, Giovanni, van der Hulst, Paul, Varisco, Salvatore, Varnière, Peggy, Vibert, Laurent, Vidriales, María, Villa, Fabrizio, Vodopivec, Boris Martin, Volpe, Angela, Durand, Jean Louis, Vries, Cor de, Nicastro, Fabrizio, Wakeham, Nicholas, Walmsley, Gavin, Kiviranta, Mikko, Jackson, Brian, Wise, Michael, Wit, Martin de, Woźniak, Grzegorz, Jonker, Peter, Kilbourne, Caroline, Eckert, Dominique, Sciortino, Salvatore, Korpela, Seppo, Macculi, Claudio, Mendez, Mariano, Mitsuda, Kazuhisa, van der Kuur, Jan, Molendi, Silvano, Pajot, François, Pointecouteau, Etienne, Porter, Frederick, Pratt, Gabriel W., van Loon, Dennis, Eiriz, Valvanera, Prêle, Damien, Ravera, Laurent, Sato, Kosuke, Schaye, Joop, Shinozaki, Keisuke, Ledot, Aurélien, Skup, Konrad, Soucek, Jan, Thibert, Tanguy, Yamaguchi, Hiroya, Vink, Jacco, Ercolani, Eric, Webb, Natalie, Beaumont, Sophie, Piconcelli, Enrico, Ceballos, Maria Teresa, Cucchetti, Edoardo, D’Andrea, Matteo, Eckart, Megan, Ferrando, Philippe, Kammoun, Elias, Lotti, Simone, Mesnager, Jean-Michel, Natalucci, Lorenzo, Lyautey, Bertrand, Pinto, Ciro, Peille, Philippe, Doriese, William, de Plaa, Jelle, Ardellier, Florence, Argan, Andrea, Bellouard, Elise, Carron, Jérôme, Cavazzuti, Elisabetta, Fiorini, Mauro, Khosropanah, Pourya, Encinas Plaza, Jose Miguel, Martin, Sylvain, Parot, Yann, Finkbeiner, Fred, Perry, James, Pinsard, Frederic, Pradines, Alice, Rigano, Manuela, Roelfsema, Peter, Schwander, Denis, Torrioli, Guido, Plaza, Borja, Ullom, Joel, Vera, Isabel, Medinaceli Villegas, Eduardo, Fiocchi, Mariateresa, Sakai, Kazuhiro, Zuchniak, Monika, Brachet, Frank, Lo Cicero, Ugo, van Weers, Henk, Wilms, Joern, Fiore, Fabrizio, Abdoelkariem, Shariefa, Adam, Thomas, Adami, Christophe, Aicardi, Corinne, Fossecave, Hervé, Akamatsu, Hiroki, Merino Alonso, Pablo Eleazar, Amato, Roberta, André, Jérôme, Angelinelli, Matteo, Poyatos, David, Anon-Cancela, Manuel, Yamasaki, Noriko, Anvar, Shebli, Atienza, Ricardo, Attard, Anthony, Franssen, Philippe, Auricchio, Natalia, Balado, Ana, Bancel, Florian, Barusso, Lorenzo Ferrari, Prouvé, Thomas, and Bascuñan, Arturo

Abstract

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 th

Published
2023

3. Entanglement entropy from non-equilibrium Monte Carlo simulations.

Author

Bulgarelli, Andrea and Panero, Marco

Subjects
*MONTE Carlo method, *LATTICE field theory, *GRAPHICS processing units, *QUANTUM field theory, *ISING model, *CONFORMAL field theory
Abstract

We study the entanglement entropy in lattice field theory using a simulation algorithm based on Jarzynski's theorem. We focus on the entropic c-function for the Ising model in two and in three dimensions: after validating our algorithm against known analytical results from conformal field theory in two dimensions, we present novel results for the three-dimensional case. We show that our algorithm, which is highly parallelized on graphics processing units, allows one to precisely determine the subleading corrections to the area law, which have been investigated in many recent works. Possible generalizations of this study to other strongly coupled theories are discussed. [ABSTRACT FROM AUTHOR]

Published
2023
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4. Gamma-ray astrophysics in the MeV range: The ASTROGAM concept and beyond.

Author

De Angelis, Alessandro, Tatischeff, Vincent, Argan, Andrea, Brandt, Søren, Bulgarelli, Andrea, Bykov, Andrei, Costantini, Elisa, Silva, Rui Curado da, Grenier, Isabelle A., Hanlon, Lorraine, Hartmann, Dieter, Hernanz, Margarida, Kanbach, Gottfried, Kuvvetli, Irfan, Laurent, Philippe, Mazziotta, Mario N., McEnery, Julie, Morselli, Aldo, Nakazawa, Kazuhiro, and Oberlack, Uwe

Subjects
ASTROPHYSICS, BACKGROUND radiation, SILICON detectors, GALAXY formation, ASTRONOMY, PHOTON detectors, GAMMA ray astronomy, OBSERVATORIES
Abstract

The energy range between about 100 keV and 1 GeV is of interest for a vast class of astrophysical topics. In particular, (1) it is the missing ingredient for understanding extreme processes in the multi-messenger era; (2) it allows localizing cosmic-ray interactions with background material and radiation in the Universe, and spotting the reprocessing of these particles; (3) last but not least, gamma-ray emission lines trace the formation of elements in the Galaxy and beyond. In addition, studying the still largely unexplored MeV domain of astronomy would provide for a rich observatory science, including the study of compact objects, solar- and Earth-science, as well as fundamental physics. The technological development of silicon microstrip detectors makes it possible now to detect MeV photons in space with high efficiency and low background. During the last decade, a concept of detector ("ASTROGAM") has been proposed to fulfil these goals, based on a silicon hodoscope, a 3D position-sensitive calorimeter, and an anticoincidence detector. In this paper we stress the importance of a medium size (M-class) space mission, dubbed "ASTROMEV", to fulfil these objectives. [ABSTRACT FROM AUTHOR]

Published
2021
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5. The AGILE Gamma-Ray observatory: software and pipelines: Software management approach and lessons learned for the next generation of high-energy observatories.

Author

Bulgarelli, Andrea

Subjects
*COMPUTER software management, *WORKFLOW software, *OBSERVATORIES, *SOFTWARE architecture, *PIPELINES, *GATEWAYS (Computer networks), *NEXT generation networks
Abstract

In this paper is described the approach used to develop the software system of the AGILE γ-ray Observatory, from the definition phase to construction, verification and calibration activities of the satellite, until operations for scientific observations. Flexible software architectures, effective software management workflow, new algorithms (from payload simulators to reconstruction algorithms, from detection algorithms for Real-Time Analysis systems to the follow-up of science alerts in the multi-wavelenght and multi-messenger context) and team management approach are described. The approach followed by the AGILE Team in more than twenty years of work is a key element of the success of the AGILE Observatory, and the foundation for the involvement in new high-energy telescopes and observatories. Our legacy is not only in experience and tools but also in lesson learned, that are described in this work. [ABSTRACT FROM AUTHOR]

Published
2019
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6. The AGILE gamma-ray satellite software system: real-time analysis and Apps for multi-wavelength and multi-messenger astronomy.

Author

Bulgarelli, Andrea

Abstract

I describe in this paper the AGILE real-time analysis (RTA), that is, the software system developed for the AGILE γ -ray Mission operations and scientific observations. Important tasks of the software include scientific alerts and follow-up observations in the multi-wavelength and multi-messenger context. Key elements of the AGILE RTA are a flexible software architecture, an efficient software management workflow, and an optimised team management implemented by the AGILE Team in more than 20 years of work. All these elements contributed to the success of the AGILE Mission, and they also constitute the basis for future projects of high-energy observatories. We also describe the smartphone APP AGILEScience that displays the scientific results of the Mission for professional and outreach purposes: it is an essential element of the AGILE Ground System and a unique "gate" to the γ -ray sky for the public audience. [ABSTRACT FROM AUTHOR]

Published
2019
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7. AGILE search for gamma-ray counterparts of gravitational wave events.

Author

Verrecchia, Francesco, Tavani, Marco, Bulgarelli, Andrea, Cardillo, Martina, Casentini, Claudio, Donnarumma, Immacolata, Longo, Francesco, Lucarelli, Fabrizio, Parmiggiani, Nicoló, Piano, Giovanni, Pilia, Maura, Pittori, Carlotta, and Ursi, Alessandro

Abstract

AGILE is a space mission of the Italian Space Agency dedicated to X-ray and gamma-ray astrophysics operating since 2007. Since the discovery of gravitational wave (GW) events by the LIGO-Virgo Collaboration (LVC) announced in February 2016, AGILE is playing a very important role in the search for possible X-ray and gamma-ray counterparts. The large fields of view of the gamma-ray and hard X-ray imagers (2.5 sr and 1 sr, respectively) and the current spinning mode allow AGILE to cover at any moment a very large fraction of the sky. We present here an overview of AGILE observations of GW events during the LVC observing periods O1 and O2 which span the time interval September 2015–August 2017. In particular, we focus on the main characteristics of AGILE observations of the events GW150914, GW170104, and GW170817. The latter event is of great relevance being associated with a "kilonova" counterpart: we establish important physical constraints on the possible γ -ray emission from a magnetar-like remnant in the first ∼ 1000 s following the GW event time. We also present further developments and preliminary results obtained in preparation of the O3 observing run (start in April 2019). AGILE is fully operative in the search for GW event counterparts, and continues to observe the sky in a unique way because of its combination of large field-of-view hard X-ray and gamma-ray detectors. [ABSTRACT FROM AUTHOR]

Published
2019
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8. Geant4 simulations of soft proton scattering in X-ray optics.

Author

Fioretti, Valentina, Mineo, Teresa, Bulgarelli, Andrea, Dondero, Paolo, Ivanchenko, Vladimir, Lei, Fan, Lotti, Simone, Macculi, Claudio, and Mantero, Alfonso

Subjects
PROTON scattering, PARTICLE range (Nuclear physics), ANGULAR distribution (Nuclear physics), X-ray optics, X-ray detection, X-ray telescopes
Abstract

Low energy protons (< 300 keV) can enter the field of view of X-ray telescopes, scatter on their mirror surfaces at small incident angles, and deposit energy on the detector. This phenomenon can cause intense background flares at the focal plane decreasing the mission observing time (e.g. the XMM-Newton mission) or in the most extreme cases, damaging the X-ray detector. A correct modelization of the physics process responsible for the grazing angle scattering processes is mandatory to evaluate the impact of such events on the performance (e.g. observation time, sensitivity) of future X-ray telescopes as the ESA ATHENA mission. The Remizovich model describes particles reflected by solids at glancing angles in terms of the Boltzmann transport equation using the diffuse approximation and the model of continuous slowing down in energy. For the first time this solution, in the approximation of no energy losses, is implemented, verified, and qualitatively validated on top of the Geant4 release 10.2, with the possibility to add a constant energy loss to each interaction. This implementation is verified by comparing the simulated proton distribution to both the theoretical probability distribution and with independent ray-tracing simulations. Both the new scattering physics and the Coulomb scattering already built in the official Geant4 distribution are used to reproduce the latest experimental results on grazing angle proton scattering. At 250 keV multiple scattering delivers large proton angles and it is not consistent with the observation. Among the tested models, the single scattering seems to better reproduce the scattering efficiency at the three energies but energy loss obtained at small scattering angles is significantly lower than the experimental values. In general, the energy losses obtained in the experiment are higher than what obtained by the simulation. The experimental data are not completely representative of the soft proton scattering experienced by current X-ray telescopes because of the lack of measurements at low energies (< 200 keV) and small reflection angles, so we are not able to address any of the tested models as the one that can certainly reproduce the scattering behavior of low energy protons expected for the ATHENA mission. We can, however, discard multiple scattering as the model able to reproduce soft proton funnelling, and affirm that Coulomb single scattering can represent, until further measurements at lower energies are available, the best approximation of the proton scattered angular distribution at the exit of X-ray optics. [ABSTRACT FROM AUTHOR]

Published
2017
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