Asset Details
Do you wish to reserve the book?
Impact of pear-shaped fission fragments on mass-asymmetric fission in actinides
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Impact of pear-shaped fission fragments on mass-asymmetric fission in actinides
Do you wish to request the book?
Impact of pear-shaped fission fragments on mass-asymmetric fission in actinides
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Impact of pear-shaped fission fragments on mass-asymmetric fission in actinides
2018
Overview
Nuclear fission of heavy (actinide) nuclei results predominantly in asymmetric mass splits
1
. Without quantum shell effects, which can give extra binding energy to their mass-asymmetric shapes, these nuclei would fission symmetrically. The strongest shell effects appear in spherical nuclei, such as the spherical ‘doubly magic’ (that is, both its atomic and neutron numbers are ‘magic’ numbers) nucleus
132
Sn, which contains 50 protons and 82 neutrons. However, a systematic study of fission
2
has shown that heavy fission fragments have atomic numbers distributed around
Z
= 52 to
Z
= 56, indicating that the strong shell effects in
132
Sn are not the only factor affecting actinide fission. Reconciling the strong spherical shell effects at
Z
= 50 with the different
Z
values of fission fragments observed in nature has been a longstanding puzzle
3
. Here we show that the final mass asymmetry of the fragments is also determined by the extra stability provided by octupole (pear-shaped) deformations, which have been recently confirmed experimentally around
144
Ba (
Z
= 56)
4
,
5
, one of very few nuclei with shell-stabilized octupole deformation
6
. Using a quantum many-body model of superfluid fission dynamics
7
, we find that heavy fission fragments are produced predominantly with 52 to 56 protons, which is associated with substantial octupole deformation acquired on the way to fission. These octupole shapes, which favour asymmetric fission, are induced by deformed shells at
Z
= 52 and
Z
= 56. By contrast, spherical magic nuclei are very resistant to octupole deformation, which hinders their production as fission fragments. These findings may explain surprising observations of asymmetric fission in nuclei lighter than lead
8
.
Quantum many-body calculations of superfluid fission dynamics reveal that heavy fragments from asymmetric fission of actinides are associated with considerable octupole (pear-shaped) deformation acquired on the way to fission.
