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1. The PLATO Mission

Author

Rauer, Heike, Aerts, Conny, Cabrera, Juan, Deleuil, Magali, Erikson, Anders, Gizon, Laurent, Goupil, Mariejo, Heras, Ana, Lorenzo-Alvarez, Jose, Marliani, Filippo, Martin-Garcia, Cesar, Mas-Hesse, J. Miguel, O'Rourke, Laurence, Osborn, Hugh, Pagano, Isabella, Piotto, Giampaolo, Pollacco, Don, Ragazzoni, Roberto, Ramsay, Gavin, Udry, Stéphane, Appourchaux, Thierry, Benz, Willy, Brandeker, Alexis, Güdel, Manuel, Janot-Pacheco, Eduardo, Kabath, Petr, Kjeldsen, Hans, Min, Michiel, Santos, Nuno, Smith, Alan, Suarez, Juan-Carlos, Werner, Stephanie C., Aboudan, Alessio, Abreu, Manuel, Acuña, Lorena, Adams, Moritz, Adibekyan, Vardan, Affer, Laura, Agneray, François, Agnor, Craig, Børsen-Koch, Victor Aguirre, Ahmed, Saad, Aigrain, Suzanne, Al-Bahlawan, Ashraf, Gil, M de los Angeles Alcacera, Alei, Eleonora, Alencar, Silvia, Alexander, Richard, Alfonso-Garzón, Julia, Alibert, Yann, Prieto, Carlos Allende, Almeida, Leonardo, Sobrino, Roi Alonso, Altavilla, Giuseppe, Althaus, Christian, Trujillo, Luis Alonso Alvarez, Amarsi, Anish, Eiff, Matthias Ammler-von, Amôres, Eduardo, Andrade, Laerte, Antoniadis-Karnavas, Alexandros, António, Carlos, del Moral, Beatriz Aparicio, Appolloni, Matteo, Arena, Claudio, Armstrong, David, Aliaga, Jose Aroca, Asplund, Martin, Audenaert, Jeroen, Auricchio, Natalia, Avelino, Pedro, Baeke, Ann, Baillié, Kevin, Balado, Ana, Balestra, Andrea, Ball, Warrick, Ballans, Herve, Ballot, Jerome, Barban, Caroline, Barbary, Gaële, Barbieri, Mauro, Forteza, Sebastià Barceló, Barker, Adrian, Barklem, Paul, Barnes, Sydney, Navascues, David Barrado, Barragan, Oscar, Baruteau, Clément, Basu, Sarbani, Baudin, Frederic, Baumeister, Philipp, Bayliss, Daniel, Bazot, Michael, Beck, Paul G., Bedding, Tim, Belkacem, Kevin, Bellinger, Earl, Benatti, Serena, Benomar, Othman, Bérard, Diane, Bergemann, Maria, Bergomi, Maria, Bernardo, Pierre, Biazzo, Katia, Bignamini, Andrea, Bigot, Lionel, Billot, Nicolas, Binet, Martin, Biondi, David, Biondi, Federico, Birch, Aaron C., Bitsch, Bertram, Ceballos, Paz Victoria Bluhm, Bódi, Attila, Bognár, Zsófia, Boisse, Isabelle, Bolmont, Emeline, Bonanno, Alfio, Bonavita, Mariangela, Bonfanti, Andrea, Bonfils, Xavier, Bonito, Rosaria, Bonomo, Aldo Stefano, Börner, Anko, Saikia, Sudeshna Boro, Martín, Elisa Borreguero, Borsa, Francesco, Borsato, Luca, Bossini, Diego, Bouchy, Francois, Boué, Gwenaël, Boufleur, Rodrigo, Boumier, Patrick, Bourrier, Vincent, Bowman, Dominic M., Bozzo, Enrico, Bradley, Louisa, Bray, John, Bressan, Alessandro, Breton, Sylvain, Brienza, Daniele, Brito, Ana, Brogi, Matteo, Brown, Beverly, Brown, David, Brun, Allan Sacha, Bruno, Giovanni, Bruns, Michael, Buchhave, Lars A., Bugnet, Lisa, Buldgen, Gaël, Burgess, Patrick, Busatta, Andrea, Busso, Giorgia, Buzasi, Derek, Caballero, José A., Cabral, Alexandre, Calderone, Flavia, Cameron, Robert, Cameron, Andrew, Campante, Tiago, Martins, Bruno Leonardo Canto, Cara, Christophe, Carone, Ludmila, Carrasco, Josep Manel, Casagrande, Luca, Casewell, Sarah L., Cassisi, Santi, Castellani, Marco, Castro, Matthieu, Catala, Claude, Fernández, Irene Catalán, Catelan, Márcio, Cegla, Heather, Cerruti, Chiara, Cessa, Virginie, Chadid, Merieme, Chaplin, William, Charpinet, Stephane, Chiappini, Cristina, Chiarucci, Simone, Chiavassa, Andrea, Chinellato, Simonetta, Chirulli, Giovanni, Christensen-Dalsgaard, Jorgen, Church, Ross, Claret, Antonio, Clarke, Cathie, Claudi, Riccardo, Clermont, Lionel, Coelho, Hugo, Coelho, Joao, Cogato, Fabrizio, Colomé, Josep, Condamin, Mathieu, Conseil, Simon, Corbard, Thierry, Correia, Alexandre C. M., Corsaro, Enrico, Cosentino, Rosario, Costes, Jean, Cottinelli, Andrea, Covone, Giovanni, Creevey, Orlagh L., Crida, Aurelien, Csizmadia, Szilard, Cunha, Margarida, Curry, Patrick, da Costa, Jefferson, da Silva, Francys, Dalal, Shweta, Damasso, Mario, Damiani, Cilia, Damiani, Francesco, Chagas, Maria Liduina das, Davies, Melvyn, Davies, Guy, Davies, Ben, Davison, Gary, de Almeida, Leandro, de Angeli, Francesca, de Barros, Susana Cristina Cabral, Leão, Izan de Castro, de Freitas, Daniel Brito, de Freitas, Marcia Cristina, De Martino, Domitilla, de Medeiros, José Renan, de Paula, Luiz Alberto, de Plaa, Jelle, De Ridder, Joris, Deal, Morgan, Decin, Leen, Deeg, Hans, Degl'Innocenti, Scilla, Deheuvels, Sebastien, del Burgo, Carlos, Del Sordo, Fabio, Delgado-Mena, Elisa, Demangeon, Olivier, Denk, Tilmann, Derekas, Aliz, Desidera, Silvano, Dexet, Marc, Di Criscienzo, Marcella, Di Giorgio, Anna Maria, Di Mauro, Maria Pia, Rial, Federico Jose Diaz, Díaz-García, José-Javier, Dima, Marco, Dinuzzi, Giacomo, Dionatos, Odysseas, Distefano, Elisa, Nascimento Jr., Jose-Dias do, Domingo, Albert, D'Orazi, Valentina, Dorn, Caroline, Doyle, Lauren, Duarte, Elena, Ducellier, Florent, Dumaye, Luc, Dumusque, Xavier, Dupret, Marc-Antoine, Eggenberger, Patrick, Ehrenreich, David, Eigmüller, Philipp, Eising, Johannes, Emilio, Marcelo, Eriksson, Kjell, Ermocida, Marco, Giribaldi, Riano Isidoro Escate, Eschen, Yoshi, Estrela, Inês, Evans, Dafydd Wyn, Fabbian, Damian, Fabrizio, Michele, Faria, João Pedro, Farina, Maria, Farinato, Jacopo, Feliz, Dax, Feltzing, Sofia, Fenouillet, Thomas, Ferrari, Lorenza, Ferraz-Mello, Sylvio, Fialho, Fabio, Fienga, Agnes, Figueira, Pedro, Fiori, Laura, Flaccomio, Ettore, Focardi, Mauro, Foley, Steve, Fontignie, Jean, Ford, Dominic, Fornazier, Karin, Forveille, Thierry, Fossati, Luca, Franca, Rodrigo de Marca, da Silva, Lucas Franco, Frasca, Antonio, Fridlund, Malcolm, Furlan, Marco, Gabler, Sarah-Maria, Gaido, Marco, Gallagher, Andrew, Galli, Emanuele, Garcia, Rafael A., Hernández, Antonio García, Munoz, Antonio Garcia, García-Vázquez, Hugo, Haba, Rafael Garrido, Gaulme, Patrick, Gauthier, Nicolas, Gehan, Charlotte, Gent, Matthew, Georgieva, Iskra, Ghigo, Mauro, Giana, Edoardo, Gill, Samuel, Girardi, Leo, Winter, Silvia Giuliatti, Giusi, Giovanni, da Silva, João Gomes, Zazo, Luis Jorge Gómez, Gomez-Lopez, Juan Manuel, Hernández, Jonay Isai González, Murillo, Kevin Gonzalez, Gorius, Nicolas, Gouel, Pierre-Vincent, Goulty, Duncan, Granata, Valentina, Grenfell, John Lee, Grießbach, Denis, Grolleau, Emmanuel, Grouffal, Salomé, Grziwa, Sascha, Guarcello, Mario Giuseppe, Gueguen, Loïc, Guenther, Eike Wolf, Guilhem, Terrasa, Guillerot, Lucas, Guiot, Pierre, Guterman, Pascal, Gutiérrez, Antonio, Gutiérrez-Canales, Fernando, Hagelberg, Janis, Haldemann, Jonas, Hall, Cassandra, Handberg, Rasmus, Harrison, Ian, Harrison, Diana L., Hasiba, Johann, Haswell, Carole A., Hatalova, Petra, Hatzes, Artie, Haywood, Raphaelle, Hébrard, Guillaume, Heckes, Frank, Heiter, Ulrike, Hekker, Saskia, Heller, René, Helling, Christiane, Helminiak, Krzysztof, Hemsley, Simon, Heng, Kevin, Hermans, Aline, Hermes, JJ, Torres, Nadia Hidalgo, Hinkel, Natalie, Hobbs, David, Hodgkin, Simon, Hofmann, Karl, Hojjatpanah, Saeed, Houdek, Günter, Huber, Daniel, Huesler, Joseph, Hui-Bon-Hoa, Alain, Huygen, Rik, Huynh, Duc-Dat, Iro, Nicolas, Irwin, Jonathan, Irwin, Mike, Izidoro, André, Jacquinod, Sophie, Jannsen, Nicholas Emborg, Janson, Markus, Jeszenszky, Harald, Jiang, Chen, Mancebo, Antonio José Jimenez, Jofre, Paula, Johansen, Anders, Johnston, Cole, Jones, Geraint, Kallinger, Thomas, Kálmán, Szilárd, Kanitz, Thomas, Karjalainen, Marie, Karjalainen, Raine, Karoff, Christoffer, Kawaler, Steven, Kawata, Daisuke, Keereman, Arnoud, Keiderling, David, Kennedy, Tom, Kenworthy, Matthew, Kerschbaum, Franz, Kidger, Mark, Kiefer, Flavien, Kintziger, Christian, Kislyakova, Kristina, Kiss, László, Klagyivik, Peter, Klahr, Hubert, Klevas, Jonas, Kochukhov, Oleg, Köhler, Ulrich, Kolb, Ulrich, Koncz, Alexander, Korth, Judith, Kostogryz, Nadiia, Kovács, Gábor, Kovács, József, Kozhura, Oleg, Krivova, Natalie, Kučinskas, Arunas, Kuhlemann, Ilyas, Kupka, Friedrich, Laauwen, Wouter, Labiano, Alvaro, Lagarde, Nadege, Laget, Philippe, Laky, Gunter, Lam, Kristine Wai Fun, Lambrechts, Michiel, Lammer, Helmut, Lanza, Antonino Francesco, Lanzafame, Alessandro, Martiz, Mariel Lares, Laskar, Jacques, Latter, Henrik, Lavanant, Tony, Lawrenson, Alastair, Lazzoni, Cecilia, Lebre, Agnes, Lebreton, Yveline, Etangs, Alain Lecavelier des, Leinhardt, Zoe, Leleu, Adrien, Lendl, Monika, Leto, Giuseppe, Levillain, Yves, Libert, Anne-Sophie, Lichtenberg, Tim, Ligi, Roxanne, Lignieres, Francois, Lillo-Box, Jorge, Linsky, Jeffrey, Liu, John Scige, Loidolt, Dominik, Longval, Yuying, Lopes, Ilídio, Lorenzani, Andrea, Ludwig, Hans-Guenter, Lund, Mikkel, Lundkvist, Mia Sloth, Luri, Xavier, Maceroni, Carla, Madden, Sean, Madhusudhan, Nikku, Maggio, Antonio, Magliano, Christian, Magrin, Demetrio, Mahy, Laurent, Maibaum, Olaf, Malac-Allain, LeeRoy, Malapert, Jean-Christophe, Malavolta, Luca, Maldonado, Jesus, Mamonova, Elena, Manchon, Louis, Mann, Andrew, Mantovan, Giacomo, Marafatto, Luca, Marconi, Marcella, Mardling, Rosemary, Marigo, Paola, Marinoni, Silvia, Marques, Érico, Marques, Joao Pedro, Marrese, Paola Maria, Marshall, Douglas, Perales, Silvia Martínez, Mary, David, Marzari, Francesco, Masana, Eduard, Mascher, Andrina, Mathis, Stéphane, Mathur, Savita, Figueiredo, Ana Carolina Mattiuci, Maxted, Pierre F. L., Mazeh, Tsevi, Mazevet, Stephane, Mazzei, Francesco, McCormac, James, McMillan, Paul, Menou, Lucas, Merle, Thibault, Meru, Farzana, Mesa, Dino, Messina, Sergio, Mészáros, Szabolcs, Meunier, Nadége, Meunier, Jean-Charles, Micela, Giuseppina, Michaelis, Harald, Michel, Eric, Michielsen, Mathias, Michtchenko, Tatiana, Miglio, Andrea, Miguel, Yamila, Milligan, David, Mirouh, Giovanni, Mitchell, Morgan, Moedas, Nuno, Molendini, Francesca, Molnár, László, Mombarg, Joey, Montalban, Josefina, Montalto, Marco, Monteiro, Mário J. P. F. G., Morales, Juan Carlos, Morales-Calderon, Maria, Morbidelli, Alessandro, Mordasini, Christoph, Moreau, Chrystel, Morel, Thierry, Morello, Guiseppe, Morin, Julien, Mortier, Annelies, Mosser, Benoît, Mourard, Denis, Mousis, Olivier, Moutou, Claire, Mowlavi, Nami, Moya, Andrés, Muehlmann, Prisca, Muirhead, Philip, Munari, Matteo, Musella, Ilaria, Mustill, Alexander James, Nardetto, Nicolas, Nardiello, Domenico, Narita, Norio, Nascimbeni, Valerio, Nash, Anna, Neiner, Coralie, Nelson, Richard P., Nettelmann, Nadine, Nicolini, Gianalfredo, Nielsen, Martin, Niemi, Sami-Matias, Noack, Lena, Noels-Grotsch, Arlette, Noll, Anthony, Norazman, Azib, Norton, Andrew J., Nsamba, Benard, Ofir, Aviv, Ogilvie, Gordon, Olander, Terese, Olivetto, Christian, Olofsson, Göran, Ong, Joel, Ortolani, Sergio, Oshagh, Mahmoudreza, Ottacher, Harald, Ottensamer, Roland, Ouazzani, Rhita-Maria, Paardekooper, Sijme-Jan, Pace, Emanuele, Pajas, Miriam, Palacios, Ana, Palandri, Gaelle, Palle, Enric, Paproth, Carsten, Parro, Vanderlei, Parviainen, Hannu, Granado, Javier Pascual, Passegger, Vera Maria, Pastor-Morales, Carmen, Pätzold, Martin, Pedersen, May Gade, Hidalgo, David Pena, Pepe, Francesco, Pereira, Filipe, Persson, Carina M., Pertenais, Martin, Peter, Gisbert, Petit, Antoine C., Petit, Pascal, Pezzuto, Stefano, Pichierri, Gabriele, Pietrinferni, Adriano, Pinheiro, Fernando, Pinsonneault, Marc, Plachy, Emese, Plasson, Philippe, Plez, Bertrand, Poppenhaeger, Katja, Poretti, Ennio, Portaluri, Elisa, Portell, Jordi, de Mello, Gustavo Frederico Porto, Poyatos, Julien, Pozuelos, Francisco J., Moroni, Pier Giorgio Prada, Pricopi, Dumitru, Prisinzano, Loredana, Quade, Matthias, Quirrenbach160, ndreas, Reina6, Julio Arturo Rabanal, Soares, Maria Cristina Rabello, Raimondo, Gabriella, Rainer, Monica, Rodón, Jose Ramón, Ramón-Ballesta, Alejandro, Zapata, Gonzalo Ramos, Rätz, Stefanie, Rauterberg, Christoph, Redman, Bob, Redmer, Ronald, Reese, Daniel, Regibo, Sara, Reiners, Ansgar, Reinhold, Timo, Renie, Christian, Ribas, Ignasi, Ribeiro, Sergio, Ricciardi, Thiago Pereira, Rice, Ken, Richard, Olivier, Riello, Marco, Rieutord, Michel, Ripepi, Vincenzo, Rixon, Guy, Rockstein, Steve, Rodríguez, María Teresa Rodrigo, Díaz, Luisa Fernanda Rodríguez, Garcia, Juan Pablo Rodriguez, Rodriguez-Gomez, Julio, Roehlly, Yannick, Roig, Fernando, Rojas-Ayala, Bárbara, Rolf, Tobias, Rørsted, Jakob Lysgaard, Rosado, Hugo, Rosotti, Giovanni, Roth, Olivier, Roth, Markus, Rousseau, Alex, Roxburgh, Ian, Roy, Fabrice, Royer, Pierre, Ruane, Kirk, Mastropasqua, Sergio Rufini, de Galarreta, Claudia Ruiz, Russi, Andrea, Saar, Steven, Saillenfest, Melaine, Salaris, Maurizio, Salmon, Sebastien, Saltas, Ippocratis, Samadi, Réza, Samadi, Aunia, Samra, Dominic, da Silva, Tiago Sanches, Carrasco, Miguel Andrés Sánchez, Santerne, Alexandre, Santoli, Francesco, Santos, Ângela R. G., Mesa, Rosario Sanz, Sarro, Luis Manuel, Scandariato, Gaetano, Schäfer, Martin, Schlafly, Edward, Schmider, François-Xavier, Schneider, Jean, Schou, Jesper, Schunker, Hannah, Schwarzkopf, Gabriel Jörg, Serenelli, Aldo, Seynaeve, Dries, Shan, Yutong, Shapiro, Alexander, Shipman, Russel, Sicilia, Daniela, Sanmartin, Maria Angeles Sierra, Sigot, Axelle, Silliman, Kyle, Silvotti, Roberto, Simon, Attila E., Napoli, Ricardo Simoyama, Skarka, Marek, Smalley, Barry, Smiljanic, Rodolfo, Smit, Samuel, Smith, Alexis, Smith, Leigh, Snellen, Ignas, Sódor, Ádám, Sohl, Frank, Solanki, Sami K., Sortino, Francesca, Sousa, Sérgio, Southworth, John, Souto, Diogo, Sozzetti, Alessandro, Stamatellos, Dimitris, Stassun, Keivan, Steller, Manfred, Stello, Dennis, Stelzer, Beate, Stiebeler, Ulrike, Stokholm, Amalie, Storelvmo, Trude, Strassmeier, Klaus, Strøm, Paul Anthony, Strugarek, Antoine, Sulis, Sophia, Švanda, Michal, Szabados, László, Szabó, Róbert, Szabó, Gyula M., Szuszkiewicz, Ewa, Talens, Geert Jan, Teti, Daniele, Theisen, Tom, Thévenin, Frédéric, Thoul, Anne, Tiphene, Didier, Titz-Weider, Ruth, Tkachenko, Andrew, Tomecki, Daniel, Tonfat, Jorge, Tosi, Nicola, Trampedach, Regner, Traven, Gregor, Triaud, Amaury, Trønnes, Reidar, Tsantaki, Maria, Tschentscher, Matthias, Turin, Arnaud, Tvaruzka, Adam, Ulmer, Bernd, Ulmer-Moll, Solène, Ulusoy, Ceren, Umbriaco, Gabriele, Valencia, Diana, Valentini, Marica, Valio, Adriana, Guijarro, Ángel Luis Valverde, Van Eylen, Vincent, Van Grootel, Valerie, van Kempen, Tim A., Van Reeth, Timothy, Van Zelst, Iris, Vandenbussche, Bart, Vasiliou, Konstantinos, Vasilyev, Valeriy, de Mascarenhas, David Vaz, Vazan, Allona, Nunez, Marina Vela, Velloso, Eduardo Nunes, Ventura, Rita, Ventura, Paolo, Venturini, Julia, Trallero, Isabel Vera, Veras, Dimitri, Verdugo, Eva, Verma, Kuldeep, Vibert, Didier, Martinez, Tobias Vicanek, Vida, Krisztián, Vigan, Arthur, Villacorta, Antonio, Villaver, Eva, Aparicio, Marcos Villaverde, Viotto, Valentina, Vorobyov, Eduard, Vorontsov, Sergey, Wagner, Frank W., Walloschek, Thomas, Walton, Nicholas, Walton, Dave, Wang, Haiyang, Waters, Rens, Watson, Christopher, Wedemeyer, Sven, Weeks, Angharad, Weingril, Jörg, Weiss, Annita, Wendler, Belinda, West, Richard, Westerdorff, Karsten, Westphal, Pierre-Amaury, Wheatley, Peter, White, Tim, Whittaker, Amadou, Wickhusen, Kai, Wilson, Thomas, Windsor, James, Winter, Othon, Winther, Mark Lykke, Winton, Alistair, Witteck, Ulrike, Witzke, Veronika, Woitke, Peter, Wolter, David, Wuchterl, Günther, Wyatt, Mark, Yang, Dan, Yu, Jie, Sanchez, Ricardo Zanmar, Osorio, María Rosa Zapatero, Zechmeister, Mathias, Zhou, Yixiao, Ziemke, Claas, and Zwintz, Konstanze

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2 R_(Earth)) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5 %, 10 %, 10 % for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO's target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile at the beginning of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.

Published
2024

2. TESS and CHEOPS Discover Two Warm Sub-Neptunes Transiting the Bright K-dwarf HD 15906

Author

Tuson, Amy, Queloz, Didier, Osborn, Hugh P., Wilson, Thomas G., Hooton, Matthew J., Beck, Mathias, Lendl, Monika, Olofsson, Göran, Fortier, Andrea, Bonfanti, Andrea, Brandeker, Alexis, Buchhave, Lars A., Cameron, Andrew Collier, Ciardi, David R., Collins, Karen A., Gandolfi, Davide, Garai, Zoltan, Giacalone, Steven, da Silva, João Gomes, Howell, Steve B., Patel, Jayshil A., Persson, Carina M., Serrano, Luisa M., Sousa, Sérgio G., Ulmer-Moll, Solène, Vanderburg, Andrew, Ziegler, Carl, Alibert, Yann, Alonso, Roi, Anglada, Guillem, Bárczy, Tamas, Navascues, David Barrado, Barros, Susana C. C., Baumjohann, Wolfgang, Beck, Thomas, Benz, Willy, Billot, Nicolas, Bonfils, Xavier, Borsato, Luca, Broeg, Christopher, Cabrera, Juan, Charnoz, Sébastien, Conti, Dennis M., Csizmadia, Szilard, Cubillos, Patricio E., Davies, Melvyn B., Deleuil, Magali, Delrez, Laetitia, Demangeon, Olivier D. S., Demory, Brice-Olivier, Dragomir, Diana, Dressing, Courtney D., Ehrenreich, David, Erikson, Anders, Essack, Zahra, Farinato, Jacopo, Fossati, Luca, Fridlund, Malcolm, Furlan, Elise, Gill, Holden, Gillon, Michaël, Gnilka, Crystal L., Gonzales, Erica, Güdel, Manuel, Günther, Maximilian N., Hoyer, Sergio, Isaak, Kate G., Jenkins, Jon M., Kiss, Laszlo L., Laskar, Jacques, Latham, David W., Law, Nicholas, Etangs, Alain Lecavelier des, Curto, Gaspare Lo, Lovis, Christophe, Luque, Rafael, Magrin, Demetrio, Mann, Andrew W., Maxted, Pierre F. L., Mayor, Michel, McDermott, Scott, Mecina, Marko, Mordasini, Christoph, Mortier, Annelies, Nascimbeni, Valerio, Ottensamer, Roland, Pagano, Isabella, Pallé, Enric, Peter, Gisbert, Piotto, Giampaolo, Pollacco, Don, Pritchard, Tyler, Ragazzoni, Roberto, Rando, Nicola, Ratti, Francesco, Rauer, Heike, Ribas, Ignasi, Ricker, George R., Rieder, Martin, Santos, Nuno C., Savel, Arjun B., Scandariato, Gaetano, Schwarz, Richard P., Seager, Sara, Ségransan, Damien, Shporer, Avi, Simon, Attila E., Smith, Alexis M. S., Steller, Manfred, Stockdale, Chris, Szabó, Gyula M., Thomas, Nicolas, Torres, Guillermo, Tronsgaard, René, Udry, Stéphane, Ulmer, Bernd, Van Grootel, Valérie, Vanderspek, Roland, Venturini, Julia, Walton, Nicholas A., Winn, Joshua N., and Wohler, Bill

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of two warm sub-Neptunes transiting the bright (G = 9.5 mag) K-dwarf HD 15906 (TOI 461, TIC 4646810). This star was observed by the Transiting Exoplanet Survey Satellite (TESS) in sectors 4 and 31, revealing two small transiting planets. The inner planet, HD 15906 b, was detected with an unambiguous period but the outer planet, HD 15906 c, showed only two transits separated by $\sim$ 734 days, leading to 36 possible values of its period. We performed follow-up observations with the CHaracterising ExOPlanet Satellite (CHEOPS) to confirm the true period of HD 15906 c and improve the radius precision of the two planets. From TESS, CHEOPS and additional ground-based photometry, we find that HD 15906 b has a radius of 2.24 $\pm$ 0.08 R$_\oplus$ and a period of 10.924709 $\pm$ 0.000032 days, whilst HD 15906 c has a radius of 2.93$^{+0.07}_{-0.06}$ R$_\oplus$ and a period of 21.583298$^{+0.000052}_{-0.000055}$ days. Assuming zero bond albedo and full day-night heat redistribution, the inner and outer planet have equilibrium temperatures of 668 $\pm$ 13 K and 532 $\pm$ 10 K, respectively. The HD 15906 system has become one of only six multiplanet systems with two warm ($\lesssim$ 700 K) sub-Neptune sized planets transiting a bright star (G $\leq$ 10 mag). It is an excellent target for detailed characterisation studies to constrain the composition of sub-Neptune planets and test theories of planet formation and evolution., Comment: 30 pages, 20 figures, 11 tables (including appendix). Published in MNRAS

Published
2023
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3. Two Warm Neptunes transiting HIP 9618 revealed by TESS & Cheops

Author

Osborn, Hugh P., Nowak, Grzegorz, Hébrard, Guillaume, Masseron, Thomas, Lillo-Box, J., Pallé, Enric, Bekkelien, Anja, Florén, Hans-Gustav, Guterman, Pascal, Simon, Attila E., Adibekyan, V., Bieryla, Allyson, Borsato, Luca, Brandeker, Alexis, Ciardi, David R., Cameron, Andrew Collier, Collins, Karen A., Egger, Jo A., Gandolfi, Davide, Hooton, Matthew J., Latham, David W., Lendl, Monika, Matthews, Elisabeth C., Tuson, Amy, Ulmer-Moll, Solène, Vanderburg, Andrew, Wilson, Thomas G., Ziegler, Carl, Alibert, Yann, Alonso, Roi, Anglada, Guillem, Arnold, Luc, Asquier, Joel, Navascues, David Barrado y, Baumjohann, Wolfgang, Beck, Thomas, Belinski, Alexandr A., Benz, Willy, Biondi, Federico, Boisse, Isabelle, Bonfils, Xavier, Broeg, Christopher, Buchhave, Lars A., Bárczy, Tamas, Barros, S. C. C., Cabrera, Juan, Guillen, Carlos Cardona, Carleo, Ilaria, Castro-González, Amadeo, Charnoz, Sébastien, Christiansen, Jessie, Cortes-Zuleta, Pia, Csizmadia, Szilard, Dalal, Shweta, Davies, Melvyn B., Deleuil, Magali, Delfosse, Xavier, Delrez, Laetitia, Demory, Brice-Olivier, Dunlavey, Ava B., Ehrenreich, David, Erikson, Anders, Fernandes, Rachel B., Fortier, Andrea, Forveille, Thierry, Fossati, Luca, Fridlund, Malcolm, Gillon, Michaël, Goeke, Robert F., Goliguzova, Maria V., Gonzales, Erica J., Günther, M. N., Güdel, Manuel, Heidari, Neda, Henze, Christopher E., Howell, Steve, Hoyer, Sergio, Frey, Jonas Immanuel, Isaak, Kate G., Jenkins, Jon M., Kiefer, Flavien, Kiss, Laszlo, Korth, Judith, Maxted, Pierre F. L., Laskar, Jacques, Etangs, Alain Lecavelier des, Lovis, Christophe, Lund, Michael B., Luque, Rafa, Magrin, Demetrio, Almenara, Jose Manuel, Martioli, Eder, Mecina, Marko, Medina, Jennifer V., Moldovan, Daniel, Morales-Calderón, María, Morello, Giuseppe, Moutou, Claire, Murgas, Felipe, Jensen, Eric L. N., Nascimbeni, Valerio, Olofsson, Göran, Ottensamer, Roland, Pagano, Isabella, Peter, Gisbert, Piotto, Giampaolo, Pollacco, Don, Queloz, Didier, Ragazzoni, Roberto, Rando, Nicola, Rauer, Heike, Ribas, Ignasi, Ricker, George, Demangeon, Olivier D. S., Smith, Alexis M. S., Santos, Nuno, Scandariato, Gaetano, Seager, Sara, Sousa, Sergio G., Steller, Manfred, Szabó, Gyula M., Ségransan, Damien, Thomas, Nicolas, Udry, Stéphane, Ulmer, Bernd, Van Grootel, Valerie, Vanderspek, Roland, Walton, Nicholas, and Winn, Joshua N.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

HIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright ($G=9.0$ mag) solar analogue. TESS photometry revealed the star to have two candidate planets with radii of $3.9 \pm 0.044$ $R_\oplus$ (HIP 9618 b) and $3.343 \pm 0.039$ $R_\oplus$ (HIP 9618 c). While the 20.77291 day period of HIP 9618 b was measured unambiguously, HIP 9618 c showed only two transits separated by a 680-day gap in the time series, leaving many possibilities for the period. To solve this issue, CHEOPS performed targeted photometry of period aliases to attempt to recover the true period of planet c, and successfully determined the true period to be 52.56349 d. High-resolution spectroscopy with HARPS-N, SOPHIE and CAFE revealed a mass of $10.0 \pm 3.1 M_\oplus$ for HIP 9618 b, which, according to our interior structure models, corresponds to a $6.8\pm1.4\%$ gas fraction. HIP 9618 c appears to have a lower mass than HIP 9618 b, with a 3-sigma upper limit of $< 18M_\oplus$. Follow-up and archival RV measurements also reveal a clear long-term trend which, when combined with imaging and astrometric information, reveal a low-mass companion ($0.08^{+0.12}_{-0.05} M_\odot$) orbiting at $26^{+19}_{-11}$ au. This detection makes HIP 9618 one of only five bright ($K<8$ mag) transiting multi-planet systems known to host a planet with $P>50$ d, opening the door for the atmospheric characterisation of warm ($T_{\rm eq}<750$ K) sub-Neptunes., Comment: 19 pages, 16 figures, 9 tables. Accepted at MNRAS. CHEOPS, RV and ground-based photometric data is available on CDS at https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/523/3069

Published
2023
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4. Back scatter imaging with megavoltage radiation

Author

Ulmer, Bernd

Subjects
539.7, Nuclear physics & particle accelerators
Abstract

This thesis presents a novel radiographic technique for imaging radiographically dense materials using photon-induced positron annihilation radiation (PIPAR). Back-scattering experiments with X-ray tubes have been carried out to show the principal limitations of the Compton back-scatter imaging. The results are compared with simulations with the EGS4 Monte-Carlo code and generally good agreement is obtained. Simulations of higher incident energies (up to 10 MeV) show a rapid increase of the single to total scatter ratio (S/T) by extracting the 511 keV annihilation line. This new PIPAR technique extends significantly the inspection depth of materials which may be investigated with gamma rays in the reflection geometry. EGS4 simulations of the PIPAR principle have been carried out to optimize the relevant parameters for the use of a PIPAR scanner. A possible radiation source and detector system are discussed and a scanner for use in the field is proposed. The maximum inspection depths for a cavity in sand, water and concrete are estimated. Preliminary experimental results showing the feasibility of PIPAR imaging are presented in this work. These were obtained with megavoltage radiation from a linear accelerator exciting positrons in elemental samples through the pair production effect. The 511 keV annihilation line was extracted from the back-scattered radiation using a plastic scintillator detector and a difference filter technique. The experimental arrangement is described and potential applications are briefly discussed.

Published
1998

6. PLATO DPS: State of the art on-board data processing for Europe's next planet-hunter

Author

Ziemke, Claas, Witteck, Ulrike, Peter, Gisbert, Plasson, Philippe, Galli, Emanuele, Ulmer, Bernd, Ottensamer, Roland, Ottacher, Harald, and Windsor, James

Subjects
obdp2021, obdp, on-board processing
Abstract

State-of-the-art optical space instruments are capable of producing data rates that considerably exceed the available down-link capacities. The potential data rates are increasing as the sensor technologies progress. These trends require a signifi-cant data reduction on-board, most appropriately at the source of the data, the in-strument. Furthermore, the high availability needed to fulfill the science goals re-quire a high degree of autonomy. In this presentation we will discuss these trends using the example of the architecture of the data processing system of the PLATO payload. PLATO (PLAnetary Transits and Oscillations of stars) is the third medium (M3) mission in ESA’s Cosmic Vision programme. The goal of the PLATO mission is to detect terrestrial exoplanets in the habitable zone of so-lar-type stars and characterize their bulk properties. The PLATO instrument is comprised of 24 identical refracting telescopes each equipped with 4 CCDs, plus 2 additional telescopes which aid the space-craft fine-pointing. Altogether the PLATO payload is comprised of over 27 CPU cores, over 30 FPGAs and 6 Space-Wire Routers. In order to master this complex system of interacting soft-ware and hardware we use standardized protocols, pre-qualified operating sys-tems, Model-Based Systems-Engineering tools and techniques, code-generation, and on-board control procedures. We will give an overview of the aforemen-tioned tools and techniques, discuss their benefits and pitfalls and share the les-sons learnt so far in the development of the PLATO instrument. Finally, we will propose architectural considerations that could potentially improve the perfor-mance of similar instrument designs in the future.

Published
2021
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7. Evaluating the performance of the MErcury Radiometer and Thermal Infrared imaging Spectrometer (MERTIS) after the Moon and the first Venus flyby

Author

Helbert, Jörn, primary, D'Amore, Mario, additional, Maturilli, Alessandro, additional, Peter, Gisbert, additional, Säuberlich, Thomas, additional, Ulmer, Bernd, additional, Knollenberg, Jörg, additional, Varatharajan, Indhu, additional, Bauch, Karin, additional, Wohlfarth, Kay, additional, Wöhler, Christian, additional, Schmedemann, Nico, additional, Arnold, Gabriele E., additional, Haus, Rainer, additional, and Hiesinger, Harald, additional

Published
2021
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8. A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express

Author

Drossart, P., Piccioni, G., Gerard, J. C., Lopez-Valverde, M. A., Sanchez-Lavega, A., Zasova, L., Hueso, R., Taylor, F. W., Bezard, B., Adriani, A., Angrilli, F., Arnold, G., Baines, K. H., Bellucci, G., Benkhoff, J., Bibring, J. P., Blanco, A., Blecka, M. I., Carlson, R. W., Coradini, A., Di Lellis, A., Encrenaz, T., Erard, S., Fonti, S., Formisano, V., Fouchet, T., Garcia, R., Haus, R., Helbert, J., Ignatiev, N. I., Irwin, P., Langevin, Y., Lebonnois, S., Luz, D., Marinangeli, L., Orofino, V., Rodin, A. V., Roos-Serote, M. C., Saggin, B., Stam, D. M., Titov, D., Visconti, G., Zambelli, M., Tsang, C., Ammannito, Eleonora, Barbis, Alessandra, Berlin, Rainer, Bettanini, Carlo, Boccaccini, Angelo, Bonnello, Guillaume, Bouye, Marc, Capaccioni, Fabrizio, Cardesin, Alejandro, Carraro, Francesco, Cherubini, Giovanni, Cosi, Massimo, Dami, Michele, De Nino, Maurizio, Del Vento, Davide, Di Giampietro, Marco, Donati, Alessandro, Dupuis, Olivier, Espinasse, Sylvie, Fabbri, Anna, Fave, Agnes, Ficai Veltroni, Iacopo, Filacchione, Gianrico, Garceran, Katia, Ghomchi, Yamina, Giustizi, Maurizio, Gondet, Brigitte, Hello, Yann, Henry, Florence, Hofer, Stefan, Huntzinger, Gerard, Kachlicki, Juergen, Knoll, Rene, Kouach, Driss, Mazzoni, Alessandro, Melchiorri, Riccardo, Mondello, Giuseppe, Monti, Francesco, Neumann, Christian, Nuccilli, Fabrizio, Parisot, Jerome, Pasqui, Claudio, Perferi, Stefano, Peter, Gisbert, Piacentino, Alain, Pompei, Carlo, Reess, Jean-Michel, Rivet, Jean-Pierre, Romano, Antonio, Russ, Natalie, Santoni, Massimo, Scarpelli, Adelmo, Semery, Alain, Soufflot, Alain, Stefanovitch, Douchane, Suetta, Enrico, Tarchi, Fabio, Tonetti, Nazzareno, Tosi, Federico, and Ulmer, Bernd

Subjects
Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): P. Drossart (corresponding author) [1]; G. Piccioni [2]; J. C. Gérard [4]; M. A. Lopez-Valverde [5]; A. Sanchez-Lavega [6]; L. Zasova [7]; R. Hueso [6]; F. W. Taylor [8]; [...]

Published
2007
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9. South-polar features on Venus similar to those near the north pole

Author

Piccioni, G., Drossart, P., Sanchez-Lavega, A., Hueso, R., Taylor, F. W., Wilson, C. F., Grassi, D., Zasova, L., Moriconi, M., Adriani, A., Lebonnois, S., Coradini, A., Bezard, B., Angrilli, F., Arnold, G., Baines, K. H., Bellucci, G., Benkhoff, J., Bibring, J. P., Blanco, A., Blecka, M. I., Carlson, R. W., Di Lellis, A., Encrenaz, T., Erard, S., Fonti, S., Formisano, V., Fouchet, T., Garcia, R., Haus, R., Helbert, J., Ignatiev, N. I., Irwin, P. G. J., Langevin, Y., Lopez-Valverde, M. A., Luz, D., Marinangeli, L., Orofino, V., Rodin, A. V., Roos-Serote, M. C., Saggin, B., Stam, D. M., Titov, D., Visconti, G., Zambelli, M., Ammannito, Eleonora, Barbis, Alessandra, Berlin, Rainer, Bettanini, Carlo, Boccaccini, Angelo, Bonnello, Guillaume, Bouye, Marc, Capaccioni, Fabrizio, Cardesin Moinelo, Alejandro, Carraro, Francesco, Cherubini, Giovanni, Cosi, Massimo, Dami, Michele, De Nino, Maurizio, Del Vento, Davide, Di Giampietro, Marco, Donati, Alessandro, Dupuis, Olivier, Espinasse, Sylvie, Fabbri, Anna, Fave, Agnes, Veltroni, Iacopo Ficai, Filacchione, Gianrico, Garceran, Katia, Ghomchi, Yamina, Giustini, Maurizio, Gondet, Brigitte, Hello, Yann, Henry, Florence, Hofer, Stefan, Huntzinger, Gerard, Kachlicki, Juergen, Knoll, Rene, Driss, Kouach, Mazzoni, Alessandro, Melchiorri, Riccardo, Mondello, Giuseppe, Monti, Francesco, Neumann, Christian, Nuccilli, Fabrizio, Parisot, Jerome, Pasqui, Claudio, Perferi, Stefano, Peter, Gisbert, Piacentino, Alain, Pompei, Carlo, Reess, Jean-Michel, Rivet, Jean-Pierre, Romano, Antonio, Russ, Natalie, Santoni, Massimo, Scarpelli, Adelmo, Semery, Alain, Soufflot, Alain, Stefanovitch, Douchane, Suetta, Enrico, Tarchi, Fabio, Tonetti, Nazzareno, Tosi, Federico, and Ulmer, Bernd

Subjects
Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): G. Piccioni (corresponding author) [1]; P. Drossart [4]; A. Sanchez-Lavega [5]; R. Hueso [5]; F. W. Taylor [6]; C. F. Wilson [6]; D. Grassi [4]; L. Zasova [7]; M. [...]

Published
2007
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10. The Mercury Radiometer and Thermal Infrared Imaging Spectrometer (MERTIS) Onboard Bepi Colombo: First Inflight Calibration Results

Author

D'Amore, Mario, Helbert, Jörn, Maturilli, Alessandro, Varatharajan, Indhu, Ulmer, Bernd, Berlin, Rainer, Peter, Gisbert, Walter, Ingo, and Hiesinger, H.

Subjects
MERTIS, Weltrauminstrumente, Thermal, BepiColombo, Calibration, Leitungsbereich PF, Mercury, Radiometer, Inflight, Infrared, Spectrometer, Imaging
Abstract

MErcury Radiometer and Thermal Infrared Spectrometer (MERTIS) is an instrument to study the mineralogy and temperature distribution of Mercury’s surface in unprecedented detail. During the nominal mission, MERTIS will map the whole surface at 500 m scale, combining a push broom IR grating spectrometer (TIS) with a radiometer (TIR) sharing the same optics, instrument electronics and inflight calibration components for the whole wavelength range of 7-14µm (TIS) and 7-40µm (TIR) [1]. The instrument successfully completed the Near Earth Commissioning Phase (NECP) in November 2018. Calibrated data shows performances comparable with ground based measurements and very small changes in sensitivity.

Published
2019

12. Data processing of the Mercury radiometer and thermal infrared imaging spectrometer (MERTIS) onboard Bepi Colombo

Author

D'Amore, Mario, primary, Helbert, Joern, primary, Maturilli, Alessandro, primary, Varatharajan, Indhu, primary, Ulmer, Bernd, primary, Säuberlich, Thomas, primary, Berlin, Rainer, primary, Peter, Gisbert, primary, Hiesinger, Harald, primary, Martinez, Santa, primary, Casale, Mauro, primary, Ortiz de Landaluce, Inaki, primary, and Walter, Ingo, primary

Published
2018
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13. The design of the instrument control unit and its role within the data processing system of the ESA PLATO Mission

Author

Focardi, Mauro, primary, Pezzuto, Stefano, primary, Cosentino, Rosario, primary, Giusi, Giovanni, primary, Di Giorgio, Anna Maria, primary, Biondi, David, primary, Steller, Manfred, primary, del Vecchio Blanco, Carlo, primary, Serafini, Luca, primary, Plasson, Philippe, primary, Jeszenszky, Harald, primary, Ottacher, Harald, primary, Ottensamer, Roland, primary, Pancrazzi, Maurizio, primary, Noce, Vladimiro, primary, Pace, Emanuele, primary, Westerdorff, Karsten, primary, Peter, Gisbert, primary, Ulmer, Bernd, primary, Pagano, Isabella, primary, Berlin, Rainer, primary, Tommasi, Elisabetta, primary, Natalucci, Silvia, primary, Laky, Gunter, primary, Vangelista, Donatella, primary, Kerschbaum, Franz, primary, and Guedel, Manuel, primary

Published
2018
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17. South polar features on Venus similar to those near the north pole

Author

Piccioni, Giuseppe, Drossart, Pierre, Sanchez-Lavega, A., Hueso, R., Taylor, F. W., Wilson, C. F., Grassi, D., Zasova, L., Moriconi, M., Adriani, A., Lebonnois, Sébastien, Coradini, A., Bézard, B., Angrilli, F., Virtis Venus Express, T., Arnold, G., Baines, K. H., Bellucci, G., Benkhoff, J., Bibring, J. P., Blecka, M. I., Blanco, A., Carlson, R. W., Di Lellis, A., Encrenaz, T., Erard, S., Fonti, S., Formisano, V., Fouchet, T., Garcia, R., Haus, R., Helbert, J., Ignatiev, N. I., Irwin, P. G. J., Langevin, Y., Lopez-Valverde, M. A., Luz, D., Marinangeli, L., Rodin, A. V., Orofino, V., Roos-Serote, M. C., Saggin, B., Stam, D. M., Titov, D., Visconti, G., Zambelli, M., Ammannito, Eleonora, Barbis, Alessandra, Berlin, Rainer, Luiz, D., Bettanini, Carlo, Boccaccini, Angelo, Bonnello, Guillaume, Bouye, Marc, Capaccioni, Fabrizio, Cardesin Moinelo, Alejandro, Carraro, Francesco, Cherubini, Giovanni, Cosi, Massimo, Dami, Michele, De Nino, Maurizio, Del Vento, Davide, Di Giampietro, Marco, Donati, Alessandro, Dupuis, Olivier, Espinasse, Sylvie, Fabbri, Anna, Veltroni, Iacopo Ficai, Fave, Agnes, Filacchione, Gianrico, Garceran, Katia, Ghomchi, Yamina, Giustini, Maurizio, Gondet, Brigitte, Hello, Yann, Henry, Florence, Hofer, Stefan, Huntzinger, Gerard, Kachlicki, Juergen, Knoll, René, Driss, Kouach, Mazzoni, Alessandro, Melchiorri, Riccardo, Mondello, Giuseppe, Monti, Francesco, Neumann, Christian, Nuccilli, Fabrizio, Parisot, Jerome, Pompei, Carlo, Pasqui, Claudio, Reess, Jean-Michel, Perferi, Stefano, Rivet, Jean-Pierre, Peter, Gisbert, Romano, Antonio, Piacentino, Alain, Russ, Natalie, Santoni, Massimo, Scarpelli, Adelmo, Semery, Alain, Soufflot, Alain, Stefanovitch, Douchane, Suetta, Enrico, Tarchi, Fabio, Tonetti, Nazzareno, Tosi, Federico, Be' Zard, B., Ulmer, Bernd, and A.-L., Et

Subjects
Physics::Atmospheric and Oceanic Physics, Astrophysics::Galaxy Astrophysics
Abstract

Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole (1–4). The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.

Published
2007

19. Back Scatter Imaging with Megavoltage Radiation

Author

Ulmer, Bernd.

Abstract

This thesis presents a novel radiographic technique for imaging radiographically dense materials using photon-induced positron annihilation radiation (PIPAR). Back-scattering experiments with X-ray tubes have been carried out to show the principal limitations of the Compton back-scatter imaging. The results are compared with simulations with the EGS4 Monte-Carlo code and generally good agreement is obtained. Simulations of higher incident energies (up to 10 MeV) show a rapid increase of the single to total scatter ratio (S/T) by extracting the 511 keV annihilation line. This new PIPAR technique extends significantly the inspection depth of materials which may be investigated with gamma rays in the reflection geometry. EGS4 simulations of the PIPAR principle have been carried out to optimize the relevant parameters for the use of a PIPAR scanner. A possible radiation source and detector system are discussed and a scanner for use in the field is proposed. The maximum inspection depths for a cavity in sand, water and concrete are estimated. Preliminary experimental results showing the feasibility of PIPAR imaging are presented in this work. These were obtained with megavoltage radiation from a linear accelerator exciting positrons in elemental samples through the pair production effect. The 511 keV annihilation line was extracted from the back-scattered radiation using a plastic scintillator detector and a difference filter technique. The experimental arrangement is described and potential applications are briefly discussed.

Published
1998

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