WFRF:(Hambsch Franz Josef)
Sökning: WFRF:(Hambsch Franz Josef) > Measurements of the...
- Al-Adili, AliUppsala universitet,Tillämpad kärnfysik (författare)
Measurements of the 234U(n,f) Reaction with a Frisch-Grid Ionization Chamber up to En=5 MeV
- BokEngelska2013
Förlag, utgivningsår, omfång ...
- Uppsala :Acta Universitatis Upsaliensis,2013
- 109 s.
- electronicrdacarrier
Nummerbeteckningar
- LIBRIS-ID:oai:DiVA.org:uu-185306
- ISBN:9789155485542
- https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-185306URI
Kompletterande språkuppgifter
- Språk:engelska
- Sammanfattning på:engelska
Ingår i deldatabas
- SwePubSwePub
Klassifikation
Serie
- Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology,1651-6214 ;1002
Anmärkningar
- This study on the neutron-induced fission of 234U was carried out at the 7 MV Van de Graaff accelerator of IRMM in Belgium. A Twin Frisch-Grid Ionization Chamber (TFGIC) was used to study 234U(n,f) between En = 0.2 and 5.0 MeV. The reaction is important for fission modelling of the second-chance fission in 235U(n,f). The fission fragment (FF) angular-, energy and mass distributions were determined using the 2E-method highlighting especially the region of the vibrational resonance at En = 0.77 MeV.The experiment used both conventional analogue and modern digital acquisition systems in parallel. Several advantages were found in the digital case, especially a successful pile-up correction. The shielding limitations of the Frisch-grid, called "grid-inefficiency", result in an angular-dependent energy signal. The correction of this effect has been a long-standing debate and a solution was recently proposed using the Ramo-Shockley theorem. Theoretical predictions from the latter were tested and verified in this work using two different grids. Also the neutron-emission corrections as a function of excitation energy were investigated. Neutron corrections are crucial for the determination of FF masses. Recent theoretical considerations attribute the enhancement of neutron emission to the heavier fragments exclusively, contrary to the average increase assumed earlier. Both methods were compared and the impact of the neutron multiplicities was assessed. The effects found are significant and highlight the importance of further experimental and theoretical investigation.In this work, the strong angular anisotropy of 234U(n,f ) was confirmed. In addition, and quite surprisingly, the mass distribution was found to be angular-dependent and correlated to the vibrational resonances. The anisotropy found in the mass distribution was consistent with an anisotropy in the total kinetic energy (TKE), also correlated to the resonances. The experimental data were parametrized assuming fission modes based on the Multi-Modal Random Neck-Rupture model. The resonance showed an increased yield from the Standard-1 fission mode and a consistent increased TKE. The discovered correlation between the vibrational resonances and the angular-dependent mass distributions for the asymmetric fission modes may imply different outer fission-barrier heights for the two standard modes.
Ämnesord och genrebeteckningar
- NATURVETENSKAP Fysik Subatomär fysik hsv//swe
- NATURAL SCIENCES Physical Sciences Subatomic Physics hsv//eng
- Fission
- U-234
- Neutron
- Uranium
- Resonance
- Ionization Chamber
- Frisch-grid
- Fysik med inriktning mot tillämpad kärnfysik
- Physics with specialization in Applied Nuclear Physics
Biuppslag (personer, institutioner, konferenser, titlar ...)
- Stephan, PompUppsala universitet,Tillämpad kärnfysik (preses)
- Hambsch, Franz-JosefIRMM - JRC - EC (preses)
- Österlund, MichaelUppsala universitet,Institutionen för fysik och astronomi (preses)
- Patrick, TalouLos Alamos National Lab, US (opponent)
- Uppsala universitetTillämpad kärnfysik (creator_code:org_t)
Internetlänk
Hitta via bibliotek
- Measurements of the 234U(n,f) Reaction with a Frisch-Grid Ionization Chamber up ... (Sök publikationen i LIBRIS)
Till lärosätets databas
Hitta mer i SwePub
- Av författaren/redakt...
- Al-Adili, Ali
- Stephan, Pomp
- Hambsch, Franz-J ...
- Österlund, Micha ...
- Patrick, Talou
- Om ämnet
-
- NATURVETENSKAP
- NATURVETENSKAP
- och Fysik
- och Subatomär fysik
- Delar i serien
- Digital Comprehe ...
- Av lärosätet
- Uppsala universitet
Sök utanför SwePub
- Sök vidare i:
- Google Book Search
- Google Scholar
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
- Copyright © LIBRIS - Nationella bibliotekssystem
- LIBRIS.kb.se
