#
APS April Meeting 2010

## Volume 55, Number 1

##
Saturday–Tuesday, February 13–16, 2010;
Washington, DC

### Session S2: Fusion, Fission and Super Heavy Element Production

3:30 PM–5:18 PM,
Monday, February 15, 2010

Room: Thurgood Marshall East

Sponsoring
Unit:
DNP

Chair: Daniel Shapira, Oak Ridge National Laboratory

Abstract ID: BAPS.2010.APR.S2.3

### Abstract: S2.00003 : Hot fusion or cold fusion, best route to the SHEs?*

4:42 PM–5:18 PM

Preview Abstract
Abstract

####
Author:

Walter Loveland

(Oregon State University)

Elements 102-113 have been synthesized using cold fusion
reactions (Pb or
Bi target nuclei, massive projectiles., E*=13 MeV, high survival
probabilities,significant fusion hindrance). The production cross
sections
decrease with increasing Z$_{CN}$ with a cross section of 27 fb
being
measured for element 113. Synthesis of elements 102-108 by hot
fusion
reactions (actinide target nuclei, intermediate mass projectiles,
E*=30-50
MeV, low survival probability, small fusion hindrance) shows
decreasing
production cross sections for Z=102 to Z=108 and then the cross
sections
level out at a few pb out to Z=118. Upper limit cross sections
for the
production of Z=120 nuclei in hot fusion reactions are $\sim $
0.1 pb.
How should one go forward to make nuclei with Z $>$ 120 or with
large
neutron numbers, N $\sim $ 184? The cross section for the
production of an
evaporation residue, $\sigma _{EVR}$, is $\sigma _{EVR} =\sigma
_{CN}
W_{sur} $ where $\sigma _{CN}$ is the complete fusion cross
section and
W$_{sur}$ is the survival probability of the completely fused
system. The
complete fusion cross section can be written as $\sigma _{CN}
=\sum\limits_{J=0}^{J_{\max } } {\sigma _{capture} (E_{c.m.}
,J)P_{CN} (}
E_{c.m.} ,J)$
where $\sigma _{capture} (E_{c.m.} ,J)$ is the capture cross
section and
P$_{CN}$ is the probability that the projectile-target system
will evolve
inside the fission saddle point to form a completely fused system
rather
than reseparating (quasifission). I have used this formalism to make
estimates of the best reactions to make new heavy nuclei using
stable and
radioactive beams. I conclude that stable beams offer the best
opportunities
to make new chemical elements and that radioactive beams offer new
opportunities to make nuclei to study the atomic physics and
chemistry of
the heaviest elements. The radioactive beam reactions involve the
light
neutron-rich projectiles interacting in hot fusion reactions. If
time
permits I will also discuss recent experiments to make heavy
nuclei using
multi-nucleon transfer reactions.

*Work supported in part by USDOE Grant No. DE-FG06-97ER41026.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.APR.S2.3