Search

Your search keyword '"Hambsch, Franz-Josef"' showing total 456 results
Start Over Author "Hambsch, Franz-Josef"
456 results on '"Hambsch, Franz-Josef"'

201. The 2015 superoutburst of QZVirginis: Detection of growing superhumps between the precursor and main superoutburst.

Author

Akira IMADA, Taichi KATO, Keisuke ISOGAI, HAMBSCH, Franz-Josef, DUBOVSKY, Pavol A., KUDZEJ, Igor, PICKARD, Roger D., Hidehiko AKAZAWA, Kiyoshi KASAI, Hiroshi ITOH, COOK, Lewis M., and Seiichiro KIYOTA

Subjects
STELLAR photometry, METEOR showers, DWARF novae, ACCRETION disks, TEMPERATURE
Abstract

We report on time-resolved photometry of the 2015 February-March superoutburst of QZVirginis. The superoutburst consisted of a separated precursor, main superoutburst, and rebrightening. We detected superhumps with a period of 0.061181(42) d between the precursor and main superoutburst. Based on analyses of period changes and amplitudes of superhumps, the observed superhumps were identified as growing superhumps (stage A superhumps). The duration of the stage A superhumps was about 5 d, unusually long for SUUMa-type dwarf novae. Using the obtained stage A superhump period, we estimated the mass ratio of QZ Vir to be 0.108(3). This value suggests that QZ Vir is an SUUMa-type dwarf nova evolving toward the period minimum. Based on the present and previous observations regarding long-lasting stage A superhumps, the time scale for stage A superhumps is likely to be determined by the mass ratio of the system and the temperature of the accretion disk. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

202. Study of negative and positive superhumps in ER Ursae Majoris

Author

Ohshima, Tomohito, primary, Kato, Taichi, additional, Pavlenko, Elena, additional, Akazawa, Hidehiko, additional, Imamura, Kazuyoshi, additional, Tanabe, Kenji, additional, de Miguel, Enrique, additional, Stein, William, additional, Itoh, Hiroshi, additional, Hambsch, Franz-Josef, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Krajci, Thomas, additional, Baklanov, Alex, additional, Samsonov, Denis, additional, Antonyuk, Oksana I., additional, Malanushenko, Viktor, additional, Andreev, Maksim V., additional, Noguchi, Ryo, additional, Ogura, Kazuyuki, additional, Nomoto, Takashi, additional, Ono, Rikako, additional, Nakagawa, Shin’ichi, additional, Taniuchi, Keisuke, additional, Aoki, Tomoya, additional, Kawabata, Miho, additional, Kimura, Hitoshi, additional, Masumoto, Kazunari, additional, Kobayashi, Hiroshi, additional, Matsumoto, Katsura, additional, Shiokawa, Kazuhiko, additional, Shugarov, Sergey Yu., additional, Katysheva, Natalia, additional, Voloshina, Irina, additional, Zemko, Polina, additional, Kasai, Kiyoshi, additional, Ruiz, Javier, additional, Maehara, Hiroyuki, additional, Virnina, Natalia, additional, Virtanen, Jani, additional, Miller, Ian, additional, Boitnott, Boyd, additional, Littlefield, Colin, additional, James, Nick, additional, Tordai, Tamas, additional, Robert, Fidrich, additional, Padovan, Stefano, additional, and Miyashita, Atsushi, additional

Published
2014
Full Text
View/download PDF

203. Survey of period variations of superhumps in SU UMa-type dwarf novae. V. The fifth year (2012–2013)

Author

Kato, Taichi, primary, Hambsch, Franz-Josef, additional, Maehara, Hiroyuki, additional, Masi, Gianluca, additional, Nocentini, Francesca, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Imamura, Kazuyoshi, additional, Ogi, Minako, additional, Tanabe, Kenji, additional, Akazawa, Hidehiko, additional, Krajci, Thomas, additional, Miller, Ian, additional, de Miguel, Enrique, additional, Henden, Arne, additional, Noguchi, Ryo, additional, Ishibashi, Takehiro, additional, Ono, Rikako, additional, Kawabata, Miho, additional, Kobayashi, Hiroshi, additional, Sakai, Daisuke, additional, Nishino, Hirochika, additional, Furukawa, Hisami, additional, Masumoto, Kazunari, additional, Matsumoto, Katsura, additional, Littlefield, Colin, additional, Ohshima, Tomohito, additional, Nakata, Chikako, additional, Honda, Satoshi, additional, Kinugasa, Kenzo, additional, Hashimoto, Osamu, additional, Stein, William, additional, Pickard, Roger D., additional, Kiyota, Seiichiro, additional, Pavlenko, Elena P., additional, Antonyuk, Oksana I., additional, Baklanov, Aleksei V., additional, Antonyuk, Kirill, additional, Samsonov, Denis, additional, Pit, Nikolaj, additional, Sosnovskij, Aleksei, additional, Oksanen, Arto, additional, Harlingten, Caisey, additional, Tyyskä, Jenni, additional, Monard, Berto, additional, Shugarov, Sergey Yu., additional, Chochol, Drahomir, additional, Kasai, Kiyoshi, additional, Maeda, Yutaka, additional, Hirosawa, Kenji, additional, Itoh, Hiroshi, additional, Sabo, Richard, additional, Ulowetz, Joseph, additional, Morelle, Etienne, additional, Michel, Raúl, additional, Suárez, Genaro, additional, James, Nick, additional, Dvorak, Shawn, additional, Voloshina, Irina B., additional, Richmond, Michael, additional, Staels, Bart, additional, Boyd, David, additional, Andreev, Maksim V., additional, Parakhin, Nikolai, additional, Katysheva, Natalia, additional, Miyashita, Atsushi, additional, Nakajima, Kazuhiro, additional, Bolt, Greg, additional, Padovan, Stefano, additional, Nelson, Peter, additional, Starkey, Donn R., additional, Buczynski, Denis, additional, Starr, Peter, additional, Goff, William N., additional, Denisenko, Denis, additional, Kochanek, Christopher S., additional, Shappee, Benjamin, additional, Stanek, Krzysztof Z., additional, Prieto, José L., additional, Itagaki, Koh-ichi, additional, Kaneko, Shizuo, additional, Stubbings, Rod, additional, Muyllaert, Eddy, additional, Shears, Jeremy, additional, Schmeer, Patrick, additional, Poyner, Gary, additional, and Rodríguez-Marco, Miguel, additional

Published
2014
Full Text
View/download PDF

204. WZ Sge-Type Dwarf Novae with Multiple Rebrightenings: MASTER OT J211258.65+242145.4 and MASTER OT J203749.39+552210.3

Author

Nakata, Chikako, primary, Ohshima, Tomohito, additional, Kato, Taichi, additional, Nogami, Daisaku, additional, Masi, Gianluca, additional, de Miguel, Enrique, additional, Ulowetz, Joseph, additional, Littlefield, Colin, additional, Goff, William N., additional, Krajci, Thomas, additional, Maehara, Hiroyuki, additional, Stein, William, additional, Sabo, Richard, additional, Noguchi, Ryo, additional, Ono, Rikako, additional, Kawabata, Miho, additional, Furukawa, Hisami, additional, Matsumoto, Katsura, additional, Ishibashi, Takehiro, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Dvorak, Shawn, additional, HAMBSCH, Franz-Josef, additional, Pickard, Roger D., additional, Morelle, Etienne, additional, Muyllaert, Eddy, additional, Padovan, Stefano, additional, and Henden, Arne, additional

Published
2013
Full Text
View/download PDF

207. BK Lyncis: the oldest old nova and a Bellwether for cataclysmic variable evolution

Author

Patterson, Joseph, primary, Uthas, Helena, additional, Kemp, Jonathan, additional, de Miguel, Enrique, additional, Krajci, Thomas, additional, Foote, Jerry, additional, Hambsch, Franz-Josef, additional, Campbell, Tut, additional, Roberts, George, additional, Cejudo, David, additional, Dvorak, Shawn, additional, Vanmunster, Tonny, additional, Koff, Robert, additional, Skillman, David, additional, Harvey, David, additional, Martin, Brian, additional, Rock, John, additional, Boyd, David, additional, Oksanen, Arto, additional, Morelle, Etienne, additional, Ulowetz, Joseph, additional, Kroes, Anthony, additional, Sabo, Richard, additional, and Jensen, Lasse, additional

Published
2013
Full Text
View/download PDF

208. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV. The Fourth Year (2011–2012)

Author

Kato, Taichi, primary, Hambsch, Franz-Josef, additional, Maehara, Hiroyuki, additional, Masi, Gianluca, additional, Miller, Ian, additional, Noguchi, Ryo, additional, Aakasaka, Chihiro, additional, Aoki, Tomoya, additional, Kobayashi, Hiroshi, additional, Matsumoto, Katsura, additional, Nakagawa, Shinichi, additional, Nakazato, Takuma, additional, Nomoto, Takashi, additional, Ogura, Kazuyuki, additional, Ono, Rikako, additional, Taniuchi, Keisuke, additional, Stein, William, additional, Henden, Arne, additional, De miguel, Enrique, additional, Kiyota, Seiichiro, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Imamura, Kazuyoshi, additional, Akazawa, Hidehiko, additional, Takagi, Ryosuke, additional, Wakabayashi, Yuya, additional, Ogi, Minako, additional, Tanabe, Kenji, additional, Ulowetz, Joseph, additional, Morelle, Etienne, additional, Pickard, Roger D., additional, Ohshima, Tomohito, additional, Kasai, Kiyoshi, additional, Pavlenko, Elena P., additional, Antonyuk, Oksana I., additional, Baklanov, Aleksei V., additional, Antonyuk, Kirill, additional, Samsonov, Denis, additional, Pit, Nikolaj, additional, Sosnovskij, Aleksei, additional, Littlefield, Colin, additional, Sabo, Richard, additional, Ruiz, Javier, additional, Krajci, Thomas, additional, Dvorak, Shawn, additional, Oksanen, Arto, additional, Hirosawa, Kenji, additional, Goff, William N., additional, Monard, Berto, additional, Shears, Jeremy, additional, Boyd, David, additional, Voloshina, Irina B., additional, Shugarov, Sergey Yu., additional, Chochol, Drahomir, additional, Miyashita, Atsushi, additional, Pietz, Jochen, additional, Katysheva, Natalia, additional, Itoh, Hiroshi, additional, Bolt, Greg, additional, Andreev, Maksim V., additional, Parakhin, Nikolai, additional, Malanushenko, Viktor, additional, Martinelli, Fabio, additional, Denisenko, Denis, additional, Stockdale, Chris, additional, Starr, Peter, additional, Simonsen, Mike, additional, Tristram, Paul J., additional, Fukui, Akihiko, additional, Tordai, Tamas, additional, Fidrich, Robert, additional, Paxson, Kevin B., additional, Itagaki, Koh-ichi, additional, Nakashima, Youichirou, additional, Yoshida, Seiichi, additional, Nishimura, Hideo, additional, Kryachko, Timur V., additional, Samokhvalov, Andrey V., additional, Korotkiy, Stanislav A., additional, Satovski, Boris L., additional, Stubbings, Rod, additional, Poyner, Gary, additional, Muyllaert, Eddy, additional, Gerke, Vladimir, additional, Macdonald, Walter, additional, Linnolt, Michael, additional, Maeda, Yutaka, additional, and Hautecler, Hubert, additional

Published
2013
Full Text
View/download PDF

209. Preface

Author

Hambsch, Franz-Josef, primary and Carjan, Nicolae, additional

Published
2013
Full Text
View/download PDF

210. Survey of period variations of superhumps in SUUMa-type dwarf novae. VIII. The eighth year (2015-2016).

Author

Taichi KATO, Hambsch, Franz-Josef, Monard, Berto, Vanmunster, Tonny, Yutaka Maeda, Miller, Ian, Itoh, Hiroshi, Seiichiro Kiyota, Keisuke Isogai, Mariko Kimura, Akira Imada, Tordai, Tamás, Hidehiko Akazawa, Kenji Tanabe, Noritoshi Otani, Minako Ogi, Kazuko Ando, Naoki Takigawa, Dubovsky, Pavol A., and Kudzej, Igor

Subjects
*NOVAE (Astronomy), *CATACLYSMIC variable stars, *METEOR showers, *RESONANCE, *ASTROPHYSICS
Abstract

Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 128 SUUMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, and the relation between period variations and the rebrightening type in WZSge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, and ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3 : 1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSSJ074859.55+312512.6, and CRTS J200331.3-284941 are newly identified eclipsing SUUMa-type (or WZ Sge-type) dwarf novae. ASASSN- 15cy has a short (~0.050 d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN- 15hn, ASASSN-15kh, and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06 d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines on how to organize observations of various superoutbursts. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

211. Discovery of Negative Superhumps during a Superoutburst of 2011 January in ER Ursae Majoris

Author

Ohshima, Tomohito, primary, Kato, Taichi, additional, Pavlenko, Elena P., additional, Itoh, Hiroshi, additional, de Miguel, Enrique, additional, Krajci, Thomas, additional, Akazawa, Hidehiko, additional, Shiokawa, Kazuhiko, additional, Stein, William, additional, Baklanov, Alex, additional, Samsonov, Denis, additional, Antonyuk, Oksana, additional, Andreev, Maksim V., additional, Imamura, Kazuyoshi, additional, Hambsch, Franz-Josef, additional, Maehara, Hiroyuki, additional, Ruiz, Javier, additional, Nakagawa, Shin'ichi, additional, Kasai, Kiyoshi, additional, Boitnott, Boyd, additional, Virtanen, Jani, additional, and Miller, Ian, additional

Published
2012
Full Text
View/download PDF

212. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. III. The Third Year (2010–2011)

Author

Kato, Taichi, primary, Maehara, Hiroyuki, additional, Miller, Ian, additional, Ohshima, Tomohito, additional, de Miguel, Enrique, additional, Tanabe, Kenji, additional, Imamura, Kazuyoshi, additional, Akazawa, Hidehiko, additional, Kunitomi, Nanae, additional, Takagi, Ryosuke, additional, Nose, Mikiha, additional, Hambsch, Franz-Josef, additional, Kiyota, Seiichiro, additional, Pavlenko, Elena P., additional, Baklanov, Aleksei V., additional, Antonyuk, Oksana I., additional, Samsonov, Denis, additional, Sosnovskij, Aleksei, additional, Antonyuk, Kirill, additional, Andreev, Maksim V., additional, Morelle, Etienne, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Oksanen, Arto, additional, Masi, Gianluca, additional, Krajci, Thomas, additional, Pickard, Roger D., additional, Sabo, Richard, additional, Itoh, Hiroshi, additional, Stein, William, additional, Dvorak, Shawn, additional, Henden, Arne, additional, Nakagawa, Shinichi, additional, Noguchi, Ryo, additional, Iino, Eriko, additional, Matsumoto, Katsura, additional, Nishitani, Hiroki, additional, Aoki, Tomoya, additional, Kobayashi, Hiroshi, additional, Akasaka, Chihiro, additional, Bolt, Greg, additional, Shears, Jeremy, additional, Ruiz, Javier, additional, Shugarov, Sergey Yu., additional, Chochol, Drahomir, additional, Parakhin, Nikolai A., additional, Monard, Berto, additional, Shiokawa, Kazuhiko, additional, Kasai, Kiyoshi, additional, Staels, Bart, additional, Miyashita, Atsushi, additional, Starkey, Donn R., additional, Ögmen, Yenal, additional, Littlefield, Colin, additional, Katysheva, Natalia, additional, Sergey, Ivan M., additional, Denisenko, Denis, additional, Tordai, Tamas, additional, Fidrich, Robert, additional, Goranskij, Vitaly P., additional, Virtanen, Jani, additional, Crawford, Tim, additional, Pietz, Jochen, additional, Koff, Robert A., additional, Boyd, David, additional, Brady, Steve, additional, James, Nick, additional, Goff, William N., additional, Itagaki, Koh-ichi, additional, Nishimura, Hideo, additional, Nakashima, Youichirou, additional, Yoshida, Seiichi, additional, Stubbings, Rod, additional, Poyner, Gary, additional, Maeda, Yutaka, additional, Korotkiy, Stanislav A., additional, Sokolovsky, Kirill V., additional, and Ueda, Seiji, additional

Published
2012
Full Text
View/download PDF

213. Author Correction: A planetary collision afterglow and transit of the resultant debris cloud

Author

Kenworthy, Matthew, Lock, Simon, Kennedy, Grant, van Capelleveen, Richelle, Mamajek, Eric, Carone, Ludmila, Hambsch, Franz-Josef, Masiero, Joseph, Mainzer, Amy, Kirkpatrick, J. Davy, Gomez, Edward, Leinhardt, Zoë, Dou, Jingyao, Tanna, Pavan, Sainio, Arttu, Barker, Hamish, Charbonnel, Stéphane, Garde, Olivier, Le Dû, Pascal, Mulato, Lionel, Petit, Thomas, and Rizzo Smith, Michael

Published
2023
Full Text
View/download PDF

214. An Update of the Nuclear Data Standards Activities

Author

Carlson, Allan D., primary, Pronyaev, Vladimir G., additional, Hambsch, Franz-Josef, additional, Mannhart, Wolf, additional, Mengoni, Alberto, additional, Nelson, Ronald O., additional, Talou, Patrick, additional, Tagesen, Siegfried, additional, and Vonach, Herbert, additional

Published
2011
Full Text
View/download PDF

216. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II The Second Year (2009–2010)

Author

Kato, Taichi, primary, Maehara, Hiroyuki, additional, Uemura, Makoto, additional, Henden, Arne, additional, De Miguel, Enrique, additional, Miller, Ian, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Kiyota, Seiichiro, additional, Hambsch, Franz-Josef, additional, Tanabe, Kenji, additional, Imamura, Kazuyoshi, additional, Kunitomi, Nanae, additional, Takagi, Ryosuke, additional, Nose, Mikiha, additional, Akazawa, Hidehiko, additional, Masi, Gianluca, additional, Nakagawa, Shinichi, additional, Iino, Eriko, additional, Noguchi, Ryo, additional, Matsumoto, Katsura, additional, Fujii, Daichi, additional, Kobayashi, Hiroshi, additional, Ogura, Kazuyuki, additional, Ohtomo, Sachi, additional, Yamashita, Kousei, additional, Yanagisawa, Hirofumi, additional, Itoh, Hiroshi, additional, Bolt, Greg, additional, Monard, Berto, additional, Ohshima, Tomohito, additional, Shears, Jeremy, additional, Ruiz, Javier, additional, Imada, Akira, additional, Oksanen, Arto, additional, Nelson, Peter, additional, Gomez, Tomas L., additional, Staels, Bart, additional, Boyd, David, additional, Voloshina, Irina B., additional, Krajci, Thomas, additional, Crawford, Tim, additional, Stockdale, Chris, additional, Richmond, Michael, additional, Morelle, Etienne, additional, NovÁk, Rudolf, additional, Nogami, Daisaku, additional, Ishioka, Ryoko, additional, Brady, Steve, additional, Simonsen, Mike, additional, Pavlenko, Elena P., additional, Ringwald, Frederick A., additional, Kuramoto, Tetsuya, additional, Miyashita, Atsushi, additional, Pickard, Roger D., additional, Hynek, Tomáš, additional, Dvorak, Shawn, additional, Stubbings, Rod, additional, and Muyllaert, Eddy, additional

Published
2010
Full Text
View/download PDF

217. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae

Author

Kato, Taichi, primary, Imada, Akira, additional, Uemura, Makoto, additional, Nogami, Daisaku, additional, Maehara, Hiroyuki, additional, Ishioka, Ryoko, additional, Baba, Hajime, additional, Matsumoto, Katsura, additional, Iwamatsu, Hidetoshi, additional, Kubota, Kaori, additional, Sugiyasu, Kei, additional, Soejima, Yuichi, additional, Moritani, Yuuki, additional, Ohshima, Tomohito, additional, Ohashi, Hiroyuki, additional, Tanaka, Junpei, additional, Sasada, Mahito, additional, Arai, Akira, additional, Nakajima, Kazuhiro, additional, Kiyota, Seiichiro, additional, Tanabe, Kenji, additional, Imamura, Kazuyoshi, additional, Kunitomi, Nanae, additional, Kunihiro, Kenji, additional, Taguchi, Hiroki, additional, Koizumi, Mitsuo, additional, Yamada, Norimi, additional, Nishi, Yuichi, additional, Kida, Mayumi, additional, Tanaka, Sawa, additional, Ueoka, Rie, additional, Yasui, Hideki, additional, Maruoka, Koichi, additional, Henden, Arne, additional, Oksanen, Arto, additional, Moilanen, Marko, additional, Tikkanen, Petri, additional, Aho, Mika, additional, Monard, Berto, additional, Itoh, Hiroshi, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Dancikova, Radka, additional, Vanmunster, Tonny, additional, Pietz, Jochen, additional, Bolt, Greg, additional, Boyd, David, additional, Nelson, Peter, additional, Krajci, Thomas, additional, Cook, Lewis M., additional, Torii, Ken’ichi, additional, Starkey, Donn R., additional, Shears, Jeremy, additional, Jensen, Lasse-Teist, additional, Masi, Gianluca, additional, Hynek, Tomáš, additional, Novák, Rudolf, additional, Kocián, Radek, additional, Král, Lukáš, additional, Kučáková, Hana, additional, Kolasa, Marek, additional, Šťastný, Petr, additional, Staels, Bart, additional, Miller, Ian, additional, Sano, Yasuo, additional, Ponthière, Pierre de, additional, Miyashita, Atsushi, additional, Crawford, Tim, additional, Brady, Steve, additional, Santallo, Roland, additional, Richards, Tom, additional, Martin, Brian, additional, Buczynski, Denis, additional, Richmond, Michael, additional, Kern, Jim, additional, Davis, Stacey, additional, Crabtree, Dustin, additional, Beaulieu, Kevin, additional, Davis, Tracy, additional, Aggleton, Matt, additional, Morelle, Etienne, additional, Pavlenko, Elena P., additional, Andreev, Maksim, additional, Baklanov, Alexander, additional, Koppelman, Michael D., additional, Billings, Gary, additional, Urbančok, L’ubomír, additional, Ögmen, Yenal, additional, Heathcote, Bernard, additional, Gomez, Tomas L., additional, Voloshina, Irina, additional, Retter, Alon, additional, Mularczyk, Krzysztof, additional, Złoczewski, Kamil, additional, Olech, Arkadiusz, additional, Kedzierski, Piotr, additional, Pickard, Roger D., additional, Stockdale, Chris, additional, Virtanen, Jani, additional, Morikawa, Koichi, additional, Hambsch, Franz-Josef, additional, Garradd, Gordon, additional, Gualdoni, Carlo, additional, Geary, Keith, additional, Omodaka, Toshihiro, additional, Sakai, Nobuyuki, additional, Michel, Raul, additional, Cárdenas, A. A., additional, Gazeas, Kosmas D., additional, Niarchos, Panos G., additional, Yushchenko, Alexander V., additional, Mallia, Franco, additional, Fiaschi, Marco, additional, Good, Gerry A., additional, Walker, Stan, additional, James, Nick, additional, Douzu, Ken-ichi, additional, Julian, Wm Mack, additional, Butterworth, Neil D., additional, Shugarov, Sergey Yu., additional, Volkov, Igor, additional, Chochol, Drahomir, additional, Katysheva, Natalia, additional, Rosenbush, Alexander E., additional, Khramtsova, Maria, additional, Kehusmaa, Petri, additional, Reszelski, Maciej, additional, Bedient, James, additional, Liller, William, additional, Pojmański, Grzegorz, additional, Simonsen, Mike, additional, Stubbings, Rod, additional, Schmeer, Patrick, additional, Muyllaert, Eddy, additional, Kinnunen, Timo, additional, Poyner, Gary, additional, Ripero, Jose, additional, and Kriebel, Wolfgang, additional

Published
2009
Full Text
View/download PDF

218. Photo-fission at the S-DALINAC

Author

Göök, Alf, primary, Barday, Roman, additional, Chernykh, Maksym, additional, Eckardt, Christian, additional, Eichhorn, Ralf, additional, Enders, Joachim, additional, Hambsch, Franz-Josef, additional, von Neumann-Cosef, Peter, additional, Oberstedt, Andreas, additional, Oberstedt, Stephan, additional, Poltoratska, Yuliya, additional, Richter, Achim, additional, Wagner, Markus, additional, Chatillon, Audrey, additional, Faust, Herbert, additional, Fioni, Gabriele, additional, Goutte, Dominique, additional, and Goutte, Héloise, additional

Published
2009
Full Text
View/download PDF

221. An international neutron cross section standards evaluation

Author

Carlson, Allan, primary, Badikov, Sergey, additional, Zhenpeng, Chen, additional, Gai, Evgenij, additional, Hale, Gerald, additional, Hambsch, Franz-Josef, additional, Hofmann, Hartmut, additional, Kawano, Toshihiko, additional, Larson, Nancy, additional, Oh, Soo-Youl, additional, Pronyaev, Vladimir, additional, Smith, Donald, additional, Tagesen, Siegfried, additional, and Vonach, Herbert, additional

Published
2007
Full Text
View/download PDF

222. PHOTOMETRY OF HIGH-AMPLITUDE DELTA SCUTI STARS IN 2014.

Author

WILS, PATRICK, HAMBSCH, FRANZ-JOSEF, VANLEENHOVE, MAARTEN, LAMPENS, PATRICIA, VAN CAUTEREN, PAUL, VAN DE STADT, INGE, PICKARD, ROGER D., VAN WASSENHOVE, JEROEN, BAILLIEN, ANTOINE, DUBOIS, FRANKY, LOGIE, LUDWIG, RAU, STEVE, VANAVERBEKE, SIEGFRIED, NIEUWENHOUT, FRANS, BENAVIDES PALENCIA, RAFAEL, ROBERTSON, C. W., AYIOMAMITIS, ANTHONY, GONZALEZ CARBALLO, JUAN-LUIS, and KANTOLA, TIMO

Subjects
*PHOTOMETRY, *DELTA Scuti stars, *CHARTS, diagrams, etc.
Abstract

Several tables are presented related to photometry of High-Amplitude Delta Scuti (HADS) stars, along with the information on star name, uncertainty of the epoch, and filter used for the observations.

Published
2015

223. AR Ser: PHOTOMETRIC OBSERVATIONS OF A BLAZHKO STAR.

Author

BONNARDEAU, MICHEL and HAMBSCH, FRANZ-JOSEF

Subjects
*ECLIPSING binaries, *BINARY stars, *STAR observations, *ASTRONOMICAL observations, *STELLAR oscillations
Abstract

The article presents a study of the photometric observations of a Blazhko star. Methods in determining the magnitude and pulsation frequency as well as the residual of the pulsation are offered. Results in which an uncertainty pulsation and two modulations of comparable amplitude observed in a Blazhko star are discussed.

Published
2015

224. ASASSN-14cc: A likely helium analog of RZ Leonis Minoris.

Author

Taichi KATO, HAMBSCH, Franz-Josef, and MONARD, Berto

Subjects
*DWARF novae, *ASTRONOMICAL photometry, *HELIUM, *MASS transfer, *CATACLYSMIC variable stars, *ACCRETION disks
Abstract

We identified that ASASSN-14cc is a very active dwarf nova spending approximately 60% of the time in outburst. Our long-term photometry revealed that the object shows long outbursts recurring with a period of 21-33 d and very brief short outbursts lasting less than 1 d. The maximum fading rate exceeds 2.8 mag d-1. The duration of the long outbursts is 9-18 d, comprising 50%-60% of the recurrence time of long outbursts. We detected 0.01560-0.01562 d (22.5min)modulations during long outbursts, whichwe identified as superhumps. These features indicate thatASASSN-14cc has outburst parameters very similar to the extremely unusual dwarf nova RZ LMi but with a much shorter superhump period. All the observations can be naturally understood, considering that this object is a helium analog (AMCVn-type object) of RZ LMi. The highest outburst activity among AMCVn-type objects can be understood as the high-mass transfer rate expected for the orbital period giving a condition close to the stability limit of the accretion disk. In contrast to RZ LMi, this object shows little evidence for premature quenching of the superoutburst, which has been proposed to explain the unusual outburst parameters in RZ LMi. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

225. Survey of period variations of superhumps in SU UMa-type dwarf novae. VI. The sixth year (2013-2014).

Author

Taichi KATO, DUBOVSKY, Pavol A., KUDZEJ, Igor, HAMBSCH, Franz-Josef, MILLER, Ian, Tomohito OHSHIMA, Chikako NAKATA, Miho KAWABATA, Hirochika NISHINO, Kazunari MASUMOTO, Sahori MIZOGUCHI, Masayuki YAMANAKA, Katsura MATSUMOTO, Daisuke SAKAI, Daiki FUKUSHIMA, Minami MATSUURA, Genki BOUNO, Megumi TAKENAKA, Shinichi NAKAGAWA, and Ryo NOGUCHI

Subjects
DWARF novae, ACCRETION (Astrophysics), DISKS (Astrophysics), FLUCTUATIONS (Physics), COSMIC ray variations, ECLIPSING binaries
Abstract

Continuing the project undertaken by Kato et al. (2009), we collected times of superhump maxima for 56 SU UMa-type dwarf novae mainly observed during the 2013-2014 season and characterized these objects. We detected negative superhumps in VW Hyi and indicated that the low number of normal outbursts in some supercycles can be interpreted as a result of disk tilt. This finding, combined with the Kepler observation of V1504 Cyg and V344 Lyr, suggests that disk tilt is responsible for modulating the outburst pattern in SU UMa-type dwarf novae. We also studied the deeply eclipsing WZ Sge-type dwarf nova MASTER OT J005740.99+443101.5 and found evidence of a sharp eclipse during the phase of early superhumps. The profile can be reproduced by a combination of the eclipse of the axisymmetric disk and the uneclipsed light source of early superhumps. This finding shows the lack of evidence for a greatly enhanced hot spot during the early stage of WZ Sge-type outburst. We detected growing (stage A) superhumps in MN Dra and give a suggestion that some of SU UMa-type dwarf novae situated near the critical condition of tidal instability may show long-lasting stage A superhumps. The large negative period derivatives reported in such systems can be understood as a result of the combination of stage A and B superhumps. Two WZ Sge-type dwarf novae, AL Com and ASASSN-13ck, showed a long-lasting (plateau-type) rebrightening. In the early phase of their rebrightenings, both objects showed a precursor-like outburst, suggesting that the long-lasting rebrightening is triggered by a precursor outburst. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

236. Measurements of Prompt Neutron Multiplicity Distributions in Correlation with Mass-Energy Distribution of Fission Fragments in Spontaneous Fission of252Cf,244Cm and248Cm

Author

Kalinin, Valeri, primary, Dushin, Victor, additional, Hambsch, Franz-Josef, additional, Jakovlev, Vladimir, additional, Kraev, Il’ya, additional, Laptev, Alexander, additional, Petrov, Boris, additional, Petrov, Guennady, additional, Pleva, Yuri, additional, Shcherbakov, Oleg, additional, Sokolov, Vladimir, additional, and Vorobyev, Alexander, additional

Published
2002
Full Text
View/download PDF

237. Possible Fine Structure in the Delayed Neutron Yields in the Resonance Region for Pu-239.

Author

Ohsawa, Takaaki, Hambsch, Franz-Josef, and Torii, Takayuki

Subjects
*NEUTRONS, *NUCLEAR fission, *NUCLEAR reactions, *THERMAL neutrons, *NUCLEAR reactors, *NUCLEAR physics
Abstract

A method of analysis of fluctuation in the delayed neutron yield on the basis of the multimodal fission model was applied to the low-energy resolved resonances for Pu-239. The present calculation using recent data of the fluctuation of the mode branching ratios for the resolved resonances showed both positive and negative resonance structure in the delayed neutron yield relative to the thermal neutron value. This is in contrast to the U-235 case, for which mainly negative dips of about -3.5% were predicted. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2005
Full Text
View/download PDF

238. Status of the International Neutron Cross-Section Standards File.

Author

Pronyaev, Vladimir G., Badikov, Sergei A., Chen Zhenpeng, Carlson, Allan D., Gai, Evgeny V., Hale, Gerald M., Hambsch, Franz-Josef, Hofmann, Hartmut M., Larson, Nancy M., Smith, Donald L., Soo-Youl Oh, Tagesen, Siegfried, and Vonach, Herbert

Subjects
NEUTRON cross section standards, NEUTRON cross sections, COLLISIONS (Nuclear physics), FISSION cross sections, NUCLEAR reactions, NUCLEAR physics, PHYSICS
Abstract

A report is given of the progress achieved in an IAEA Co-ordinated Research Project (CRP) to improve the cross-section standards. The objectives of the CRP, started in 2002, were initially the understanding of the origin of the strong uncertainty reduction in R-matrix model fits and the improvement of the evaluation methodology. These aims were extended in 2003 to the preparation of new evaluations for the standard 6Li(n,t), 10B(n,α), 10B(n,α1), 197Au(n,γ), 235U(n,f), and 238U(n,f) reactions. The methodology, codes, and experimental database developed by Poenitz and Hale for the ENDF/B-VI standards evaluation were taken as the basis for the new evaluation. The major results achieved by the CRP participants include the testing and intercomparison of a number of codes that can be used in the standards evaluation, updating the database of experimental results, analysis of the reasons leading to the strong uncertainty reduction in model fits, and a study of the bias in evaluated data caused by the Peelles’s Pertinent Puzzle (PPP) effect, which has been widely discussed in the nuclear data community since the ENDF/B-VI standards evaluation was completed. Preliminary results of the new standards evaluation are shown. The use of the new 235U(n,f) cross section leads to better consistency in calculations of some important integral experiments. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2005
Full Text
View/download PDF

239. The orbital and superhump periods of the deeply eclipsing dwarf nova PU UMa.

Author

Shears, Jeremy, Hambsch, Franz-Josef, Littlefield, Colin, MIeller, Ian, Pickard, Roger, Pietz, Jochen, Sabo, Richard, and Morlle, Etinne

Subjects
*PHOTOMETRY, *METEOR showers, *ECLIPSES, *NOVAE (Astronomy), *AMPLITUDE estimation, *MAGNITUDE estimation
Abstract

We report unfiltered photometry during superoutbursts of PU UMa in 2009 and 2012. The amplitude was 4.5 magnitudes above mean quiescence and lasted at least 9 to 10 days. Superhumps were present with a peak-to peak amplitude of up to ~0.3 mag, thereby confirming PU UMa to be a member of the SU UMa family of dwarf novae. The mean superhump period during the later part of the 2012 outburst was Psh = 0.08076(40)d. Analysis of the eclipse times of minimum, supplemented with data from other researchers, revealed an orbital period of Porb= 0.077880551(17)d. The superhump period excess was e= 0.037(5). During the 2012 outburst, which was the better observed of the two, the FWHM eclipse duration gradually declined from 9.5 to 5 min. The eclipse depth was up to 1.7 magnitudes. [ABSTRACT FROM AUTHOR]

Published
2013

240. An Interpretation of Energy Dependence of Delayed Neutron Yields in the Resonance Region for 235U and 239Pu

Author

Ohsawa, Takaaki and Hambsch, Franz-Josef

Abstract

AbstractPossible fluctuation in the delayed neutron yields (DNYs) in the resonance region was predicted on the basis of experimental data of mass distribution of fission fragments at resonances. Analyzed according to the multimodal random neck rupture model of fission, the small variations in the experimental mass distribution were attributed to fluctuations in the branching ratios to different modes of fission. Using the results of analysis of measured data for 235U and 239Pu, the DNYs were calculated for each resonance by the summation method, considering 271 precursors and evaluated data of delayed neutron emission probability. It was found that the DNYs should have local dips for 235U and spikes for 239Pu at resonances.

Published
2004
Full Text
View/download PDF

241. Methodology of a Study of Correlations Between Neutron Multiplicity, Mass and Kinetic Energy of Fission Fragments

Author

Vorobyev, Alexander, Dushin, Victor, Hambsch, Franz-Josef, Jakovlev, Vladimir, Kalinin, Valeri, Kraev, Il’ya, Laptev, Alexander, Petrov, Boris, Petrov, Guennadi, Pleva, Yuri, Shcherbakov, Oleg, and Sokolov, Vladimir

Abstract

The description of an experimental set-up for the study of the excitation energy distribution of fission fragments by means of coincident measurement of fission neutrons is presented. For every fission event the kinetic energy and mass of both fragments are registered simultaneously with the number of prompt neutrons emitted by each of the complementary fission fragments. With this set-up, the fission fragments are detected by a twin ionization chamber and the neutrons - by two large Gd-loaded liquid scintillator tanks.

Published
2002
Full Text
View/download PDF

242. Fission of 239Pu with resonance neutrons

Author

Hambsch, Franz-Josef, Demattè, Luca, Bax, Hugo, and Ruskov, Ivan

Abstract

A measurement of fission fragment energy and mass distributions in the 239Pu(n, f) resolved resonance region has been performed applying the twin Frisch-gridded ionization chamber technique. An improved pile-up rejection system has been developed to cope with the strong α background.The results for the mass and mean total kinetic energy (TKE) distributions for resolved resonances do not show any strong ‘pattern’ of fluctuations, unlike it was the case for 235U(n, f) in the same neutron energy region. This can be explained in the frame of existing theoretical models, according to which the only possible low-energy spin states available (Jπ=0+, 1+) belong to two well separated (~1.25 MeV) transition state bands with given fission fragment properties. An anti-correlation between TKE and ⊽pwas found to be not significant. The obtained small spin dependence of TKE of about 70 keV is in agreement with literature values. A slight correlation was found between TKE versus 1/Γf. But also this was considered not to be significant.

Published
2002
Full Text
View/download PDF

243. Measurements of Prompt Neutron Multiplicity Distributions in Correlation with Mass-Energy Distribution of Fission Fragments in Spontaneous Fission of 252Cf, 244Cm and 248Cm

Author

Kalinin, Valeri, Dushin, Victor, Hambsch, Franz-Josef, Jakovlev, Vladimir, Kraev, Il’ya, Laptev, Alexander, Petrov, Boris, Petrov, Guennady, Pleva, Yuri, Shcherbakov, Oleg, Sokolov, Vladimir, and Vorobyev, Alexander

Abstract

The number of prompt neutrons emitted in the fission event have been measured separately for each complementary fragment in coincidence with fragment mass and kinetic energies in spontaneous fission of 252Cf, 244Cm and 248Cm. Two high efficient Gd-loaded liquid scintillator tanks were used for the neutron registration. Approximately 3 106fission events coincident with prompt neutron emission have been accumulated for each isotope. The mean neutron multiplicity, the dispersion and the covariance of the multiplicity distributions have been obtained as a function of fission fragment mass and kinetic energy. The neutron multiplicity data have been corrected for neutron registration efficiency, background and pile-up. Dependencies of the moments of the multiplicity distributions on the fragment mass and total kinetic energy for different mass bins, as well as mass and total kinetic energy distributions of the fission fragments are presented, discussed and compared for the different isotopes investigated. The results showed a different behavior of the moments of the multiplicity distribution depending on the fragment mass asymmetry that reflects changes in the dynamical effects for different fission modes.

Published
2002
Full Text
View/download PDF

244. The standard branching ratio 10B(n, α0) to 10B(n, α1)

Author

Hambsch, Franz-Josef and Bax, Hugo

Abstract

The 10B(n, α) standard cross sections have received considerable attention in recent years due to their relatively poor database available at higher incident neutron energies (above 100 keV) and the problems they caused in the ENDF/B-VI standards evaluation process. In view of a forthcoming new evaluation of the standard cross sections and the demand from the standards sub-group of the WPEC, IRMM has conducted a new measurement of the branching ratio.A Frisch gridded ionization chamber has been used as detector to measure the α-particles from the reaction. The advantage of this set-up is the nearly full coverage of the 2πangular cone. The 10B-samples (~30 μg/cm2) have been prepared by our sample preparation group. Our GELINA white spectrum neutron source has been used to deliver the neutrons in the energy region from eV to 1 MeV.The preliminary data analysis seems at a first glance to be in better agreement with the ENDF/B-VI evaluation than with the most recent measurement of the branching ratio by Weston and Todd. Also the angular distribution has been measured over the full neutron energy range showing strong fluctuations of the anisotropy for the first exited state transition 10B(n, α1γ) above about 300 keV incident neutron energy.

Published
2002
Full Text
View/download PDF

245. IW And-type state in IM Eridani.

Author

Kato, Taichi, Wakamatsu, Yasuyuki, Kojiguchi, Naoto, Kimura, Mariko, Ohnishi, Ryuhei, Isogai, Keisuke, Niijima, Keito, Yoshitake, Tomohiro, Sugiura, Yuki, Sumiya, Sho, Ito, Daiki, Nikai, Kengo, Matsumoto, Hanami, Matsumoto, Katsura, Vanmunster, Tonny, Hambsch, Franz-Josef, Itoh, Hiroshi, Babina, Julia V, Antonyuk, Oksana I, and Baklanov, Alex V

Subjects
DWARF novae, PHASE oscillations, DWARF stars, ACCRETION disks, CATACLYSMIC variable stars, NOVAE (Astronomy)
Abstract

IW And stars are a recently recognized group of dwarf novae which are characterized by a repeated sequence of brightening from a standstill-like phase with damping oscillations followed by a deep dip. Kimura et al. (2019, PASJ, submitted) recently proposed a model based on thermal-viscous disk instability in a tilted disk to reproduce the IW And-type characteristics. IM Eri experienced the IW And-type phase in 2018 and we recorded three cycles of the (damping) oscillation phase terminated by brightening. We identified two periods during the IW And-type state: 4–5 d small-amplitude (often damping) oscillations and a 34–43 d long cycle. This behavior is typical for an IW And-type star. The object gradually brightened within the long cycle before the next brightening, which terminated the (damping) oscillation phase. This observation agrees with the increasing disk mass during the long cycle predicted by the Kimura et al. model of thermal-viscous disk instability in a tilted disk. We did not, however, succeed in detecting negative superhumps, which are considered to be the signature of a tilted disk. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

246. Optical and soft X-ray light-curve analysis during the 2022 eruption of U Scorpii: Structural changes in the accretion disk.

Author

Muraoka, Katsuki, Kojiguchi, Naoto, Ito, Junpei, Nogami, Daisaku, Kato, Taichi, Tampo, Yusuke, Taguchi, Kenta, Isogai, Keisuke, Arranz, Teofilo, Blackwell, John, Blane, David, Brincat, Stephen M, Coates, Graeme, Cooney, Walter, Dvorak, Shawn, Galdies, Charles, Glomski, Daniel, Hambsch, Franz-Josef, Harris, Barbara, and Hodge, John

Subjects
*SOFT X rays, *WHITE dwarf stars, *NOVAE (Astronomy), *LIGHT curves, *ACCRETION disks, *OBSERVATORIES
Abstract

We present our optical photometric observations of the 2022 eruption of the recurrent nova U Scorpii (U Sco) using 49152 data points over 70 d following the optical peak. We have also analyzed its soft X-ray (0.3–1 keV) light curve by the Neil Gehrels Swift Observatory. During the 2022 eruption, the optical plateau stage started 13.8–15.0 d and ended 23.8–25.0 d after the optical peak. The soft X-ray stage started 14.6–15.3 d and ended 38.7–39.5 d after the optical peak. Both stages started later and had shorter durations, and the soft X-ray light curve peaked earlier and was less luminous compared to those during the U Sco 2010 eruption. These points suggest that there were differences in the envelope mass between the different cycles of the nova eruption. Furthermore, we have analyzed the optical eclipses during the 2022 eruption. The primary eclipse was first observed 10.4–11.6 d after the optical peak, earlier than the beginning of the optical plateau stage. This sequence of events can be explained by the receding ejecta photosphere associated with the expanding nova ejecta. We have determined the ingress and egress phases of the primary eclipses and estimated the outer radius of the optical light source centered at the white dwarf (WD). During the optical plateau stage, the source radius remained ∼1.2 times larger than the Roche volume radius of the primary WD, being close to the L1 point. When the optical plateau stage ended, the source radius drastically shrank to the tidal truncation radius within a few orbital periods. This previously unresolved phenomenon can be interpreted as a structural change in U Sco where the temporarily expanded accretion disk due to the nova wind returned to a steady state. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

247. Preface.

Author

Hambsch, Franz-Josef, Ruskov, Ivan, and Carjan, Nicolae

Subjects
*NUCLEAR fission, *GAMMA rays
Published
2018
Full Text
View/download PDF

248. Third-nearest WZ Sge-Type dwarf nova candidate ASASSN-14dx classified on the basis of Gaia Data Release 2.

Author

Isogai, Keisuke, Kato, Taichi, Imada, Akira, Ohshima, Tomohito, Kojiguchi, Naoto, Ohnishi, Ryuhei, Hambsch, Franz-Josef, Monard, Berto, Kiyota, Seiichiro, Nishimura, Hideo, and Nogami, Daisaku

Subjects
DWARF novae, STAR formation, STELLAR evolution, ACCRETION (Astrophysics), CATACLYSMIC variable stars
Abstract

ASASSN-14dx showed an extraordinary outburst whose features are a small outburst amplitude (∼2.3 mag) and long duration (>4 yr). Because we found a long observational gap of 123 d before the outburst detection, we propose that the main outburst plateau was missed and that this outburst is just a "fading tail" often seen after the WZ Sge-type super-outbursts. In order to distinguish between WZ Sge and SU UMa-type dwarf novae (DNe), we investigated Gaia Data Release 2 (DR2) statistically. We applied a logistic regression model and succeeded in classifying by using absolute Gaia magnitudes MG and Gaia colors G BP– G RP. Our new classifier also suggests that ASASSN-14dx is the best candidate of a WZ Sge-type DN. We estimated distances from the Earth of known WZ Sge stars by using Gaia DR2 parallaxes. The result indicates that ASASSN-14dx is the third-nearest WZ Sge star (next to WZ Sge and V455 And), and hence the object can show the third-brightest WZ Sge-type super-outburst whose maximum is V = 8–9 mag. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

249. Evaluation of the Neutron Data Standards

Author

Carlson, Allan D., Pronyaev, Vladimir G., Capote, Roberto, Hale, Gerald M., Chen, Zhenpeng, Duran, Ignacio, Hambsch, Franz Josef, Kunieda, Satoshi, Mannhart, Wolf, Marcinkevicius, B., Nelson, Ronald O., Neudecker, Denise, Noguere, Gilles, Paris, Mark W., Simakov, Stanislav P., Schillebeeckx, Pieter, Smith, D. L., Tao, Xi, Trkov, Andrej, Wallner, A., and Wang, Wenming

Subjects
7. Clean energy
Abstract

With the need for improving existing nuclear data evaluations, (e.g., ENDF/B-VIII.0 and JEFF-3.3 releases) the first step was to evaluate the standards for use in such a library. This new standards evaluation made use of improved experimental data and some developments in the methodology of analysis and evaluation. In addition to the work on the traditional standards, this work produced the extension of some energy ranges and includes new reactions that are called reference cross sections. Since the effort extends beyond the traditional standards, it is called the neutron data standards evaluation. This international effort has produced new evaluations of the following cross section standards: the H(n,n), 6Li(n,t), 10B(n,α), 10B(n,), natC(n,n), Au(n,γ), 235U(n,f) and 238U(n,f). Also in the evaluation process the 238U(n,γ) and 239Pu(n,f) cross sections that are not standards were evaluated. Evaluations were also obtained for data that are not traditional standards: the Maxwellian spectrum averaged cross section for the Au(n,γ) cross section at 30 keV; reference cross sections for prompt γ-ray production in fast neutron-induced reactions; reference cross sections for very high energy fission cross sections; the 252Cf spontaneous fission neutron spectrum and the 235U prompt fission neutron spectrum induced by thermal incident neutrons; and the thermal neutron constants. The data and covariance matrices of the uncertainties were obtained directly from the evaluation procedure.

250. Neutron-induced fission cross section of Pu-240 from 0.5 MeV to 3 MeV

Author

Salvador Castiñeira, Paula Genoveva, Brys, Tomasz, Eykens, Roger, Hambsch, Franz Josef, Gook, A., Moens, André, Oberstedt, Stephan, Sibbens, Geodele, Vanleeuw, David, Vidali, Marzio, Pretel Sánchez, Carme, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group

Subjects
Energies::Energia nuclear [Àrees temàtiques de la UPC], Chamber, U-235, Energy-range, Science, Energia nuclear, Nuclear energy, Energies::Energia nuclear::Reactors nuclears de fissió [Àrees temàtiques de la UPC], 240PU, Fissió nuclear
Abstract

Pu-240 has recently been pointed out by a sensitivity study of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA) to be one of the isotopes whose fission cross section lacks accuracy to meet the upcoming needs for the future generation of nuclear power plants (GEN-IV). In the High Priority Request List (HPRL) of the OECD, it is suggested that the knowledge of the Pu-240(n, f) cross section should be improved to an accuracy within 1-3 %, compared to the present 5%. A measurement of the Pu-240 cross section has been performed at the Van de Graaff accelerator of the Joint Research Center (JRC) Institute for Reference Materials and Measurements (IRMM) using quasi-monoenergetic neutrons in the energy range from 0.5 MeV to 3 MeV. A twin Frisch-grid ionization chamber (TFGIC) has been used in a back-to-back configuration as fission fragment detector. The Pu-240(n, f) cross section has been normalized to three different isotopes: Np-237(n, f), U-235(n, f), and U-238(n, f). Additionally, the secondary standard reactions were benchmarked through measurements against the primary standard reaction U-235(n, f) in the same geometry. A comprehensive study of the corrections applied to the data and the associated uncertainties is given. The results obtained are in agreement with previous experimental data at the threshold region. For neutron energies higher than 1 MeV, the results of this experiment are slightly lower than the ENDF/B-VII.1 evaluation, but in agreement with the experiments of Laptev et al. (2004) as well as Staples and Morley (1998).

Catalog

Books, media, physical & digital resources
See catalog results