Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC), for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n-TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered. © Owned by the authors, published by EDP Sciences, 2013.

Angular distribution in the neutron-induced fission of actinides / Leong, L.S.; Tassan-Got, L.; Tarrio, D.; Audouin, L.; Paradela, C.; Duran, I.; Le Naour, C.; Altstadt, S.; Andrzejewsky, J.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M.A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A.R.; Giubrone, G.; Gómez-Hornillos, M.B.; Gonçalves, I.F.; González, Romero; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Jenkins, D.G.; Jericha, E.; Kadi, E.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Kroll, J.; Krtička, M.; Langer, C.; Lederer, C.; Leeb, H.; Losito, R.; Manousos, A.; Marganiec, J.; Massimi, C.; Martínez, T.; Mastinu, P.F.; Mastromarco, M.; Meaze, M.; Mengon, A.; Mendoza, E.; Milazzo, P.M.; Mingrone, T.; Mirea, M.; Mondelaers, W.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J.M.; Rauscher, T.; Reifhart, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Taín, J.L.; Tagliente, G.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, V.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; Zç, Gec. - In: EPJ WEB OF CONFERENCES. - ISSN 2101-6275. - ELETTRONICO. - 62:(2013), pp. 08003.08003-08003.08006. (Intervento presentato al convegno 5th International Workshop on Nuclear Fission and Fission Product Spectroscopy, Fission 2013 tenutosi a Caen, fra nel 2013) [10.1051/epjconf/20136208003].

Angular distribution in the neutron-induced fission of actinides

MASSIMI, CRISTIAN;VANNINI, GIANNI;
2013

Abstract

Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC), for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n-TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered. © Owned by the authors, published by EDP Sciences, 2013.
2013
EPJ Web of Conferences
08003
08006
Angular distribution in the neutron-induced fission of actinides / Leong, L.S.; Tassan-Got, L.; Tarrio, D.; Audouin, L.; Paradela, C.; Duran, I.; Le Naour, C.; Altstadt, S.; Andrzejewsky, J.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M.A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A.R.; Giubrone, G.; Gómez-Hornillos, M.B.; Gonçalves, I.F.; González, Romero; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Jenkins, D.G.; Jericha, E.; Kadi, E.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Kroll, J.; Krtička, M.; Langer, C.; Lederer, C.; Leeb, H.; Losito, R.; Manousos, A.; Marganiec, J.; Massimi, C.; Martínez, T.; Mastinu, P.F.; Mastromarco, M.; Meaze, M.; Mengon, A.; Mendoza, E.; Milazzo, P.M.; Mingrone, T.; Mirea, M.; Mondelaers, W.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J.M.; Rauscher, T.; Reifhart, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Taín, J.L.; Tagliente, G.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, V.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; Zç, Gec. - In: EPJ WEB OF CONFERENCES. - ISSN 2101-6275. - ELETTRONICO. - 62:(2013), pp. 08003.08003-08003.08006. (Intervento presentato al convegno 5th International Workshop on Nuclear Fission and Fission Product Spectroscopy, Fission 2013 tenutosi a Caen, fra nel 2013) [10.1051/epjconf/20136208003].
Leong, L.S.; Tassan-Got, L.; Tarrio, D.; Audouin, L.; Paradela, C.; Duran, I.; Le Naour, C.; Altstadt, S.; Andrzejewsky, J.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M.A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A.R.; Giubrone, G.; Gómez-Hornillos, M.B.; Gonçalves, I.F.; González, Romero; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Jenkins, D.G.; Jericha, E.; Kadi, E.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Kroll, J.; Krtička, M.; Langer, C.; Lederer, C.; Leeb, H.; Losito, R.; Manousos, A.; Marganiec, J.; Massimi, C.; Martínez, T.; Mastinu, P.F.; Mastromarco, M.; Meaze, M.; Mengon, A.; Mendoza, E.; Milazzo, P.M.; Mingrone, T.; Mirea, M.; Mondelaers, W.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J.M.; Rauscher, T.; Reifhart, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Taín, J.L.; Tagliente, G.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, V.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; Zç, Gec
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/571884
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 1
social impact