LISE development : application to Coulomb fission

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LISE development application to Coulomb
fission
The code operates under MS Win-dows
environment and provides a highly user-friendly
interface. It can be freely downloaded from the
fol-lowing internet addresses
http//www.nscl.msu/edu/lise http//dnr080.jinr.ru
/lise
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Introduction
Application
The program 1)  has been developed to
calculate the transmission and yields of
fragments and fusion residues 2) produced and
collected in a spectrometer. This code allows to
simulate an experiment, beginning from the
parameters of the reaction mechanism and
finishing with the registration of products
selected by a spectrometer. An application
of transport integral 3) lies in the basis of
fast calculations of the program for the
estimation of temporary evolution of phase space
distributions. 1) D.Bazin, M.Lewitowicz,
O.Sorlin, O.Tarasov, Nucl.Instr. and Meth. A 482
(2002) 314. O.B.Tarasov, D.Bazin, 
M.Lewitowicz, O.Sorlin , Nuclear Physics A  701
(2002)  661-665.  2) O.Tarasov and D.Bazin,
NIM B 204 (2003) 174-178. 3) D.Bazin and
B.Sherrill, Phys.Rev.E50 (1994) 4017-4021.
The LISE code may be applied at low-energy,
medium-energy and high-energy facilities
(fragment- and recoil-separators with
electrostatic and/or magnetic selections). A
number of these facilities, like LISE3,
SISSI/LISE3 and SPEG at GANIL, FRS at GSI, COMBAS
and ACCULINA at Dubna, A1900 and S800 at NSCL,
and RIPS at RIKEN, based on the separation of
projectile-like fragments are included or might
be easily added to the existing optical
configuration files. LISE is the new
generation of the LISE  code, which allows the
creation of a spectrometer through the use of
different blocks. A block can be a dipole
(dispersive block), a material (i.e. a given
thickness for a detector), a piece of beampipe,
etc.
Number of blocks in the spectrometer is limited
by operating memory of Your PC and Your
imagination
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Main features

• Fast analytical calculations(Monte Carlo method
  is applied just for two-dimensional plots
• Highly userfriendly environment
• Reaction mechanisms projectile fragmentation,
  fusion-evaporation, Coulomb fission(fusion-fissio
  n abrasion-fission under construction)
• Optics ( Transport matrices are used)
• Ion charge state distribution calculations (4
  methods)
• Range and energy loss in material calculations (4
  methods)
• Contribution of secondary reactions in the target
• Different selection methods (Brho, Wedge,
  velocity, Erho)
• In-built help support
• In-built powerful tools

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In action
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Examples dE-TKE plot
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Coulomb Fission
High-energy secondary-beam facilities such as
GSI, RIA, and RIBF provide the technical
equipment for a new kind of fission experiment .
A new model of fast analytical calculation of
fission fragment transmission through a fragment
separator has been developed in the framework of
the LISE code. Using the LISE code now we can
establish the parameters for the RIA fragment
separator (see the next talk) .
In the development of Coulomb fission in the
LISE framework it is possible to distinguish
the following principal directions
Kinematics of reaction products Production
cross-section of fragments Spectrometer tuning
to the fragment of interest to produce maximal
rate (or purification).
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Fission fragment kinematics at intermediate and
high energies
The kinematics of the fission process is
characterized by the fact that the velocity
vectors of the fission residues populate a narrow
shell of a sphere in the frame of the fissioning
nucleus. The radius of this sphere Vf is defined
by the Coulomb repulsion between both fission
fragments. In the case of reactions induced by
relativistic heavy ions, the transformation into
the laboratory frame leads to an ellipsoidal
distribution which will characterize the angular
distribution of fission residues 1,2 (see
Figure).
Two different methods for fission fragment
kinematics are available in LISE MCmethod and
DistrMethod. DistrMethod is the fast analytical
method applied to calculate the fragment
transmission through all optical blocks of the
spectrometer. MCmethod (Monte Carlo) has been
developed for a qualitative analysis of fission
fragment kinematics and utilized in the
Kinematics calculator.
Fig.a) Schematic view of the experimental
parameters shaping the measured velocity spectrum
in the frame of the fissioning system. Vf the
fission-fragment velocity. b) Velocity spectrum
of 128Te in the frame of the fissioning system.
The velocity V 0 refers to the projectile
frame 3).
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Fission kinematics by Monte Carlo method
All reaction settings (projectile, target,
setting fragment) and excitation energies can be
entered in the Kinematics calculator dialog. In
the 2D fragment plot dialog (see Figure) it was
possible to set
The energy, horizontal and vertical angular
emittances The angular acceptance shape The
horizontal and vertical angular values and their
variance The center of energy silts and their
size in .
Fig. The 2D fragment plot dialog. Initial
excitation energy of fissioning nucleus 238U is
equal to 50 MeV
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Fission kinematics by Monte Carlo method
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Fission kinematics by LISE analytical
Distribution method
The Monte Carlo method is a powerful tool for
modeling, but sometimes the amount of time spent
to get enough statistics makes it more beneficial
to use fast analytical methods.
The forward intensity matrix after cutting by a
horizontal rectangle shape acceptance equal to
?12 mrad.
The forwardenergy matrix.
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Spectrometer settings in the case of fission
The two new settings mode (left peak and right
peak) have been developed for the case of
fission reactions (see screen-shot of the
dialog). The default method to tune the
spectrometer in the fission case is right peak
(as on more intense peak). Figure. Horizontal
spatial selection of fission fragments by the
slits S1. The spectrometer is set to the right
peak of 130Te momentum distribution.
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Projections (Comparison of different calculation
methods)
LISE DistrMethod
LISE MCmethod
MOCADI
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Coulomb fission fragment production
cross-sections
References 1. J.Benlliure et al., Nuclear Physics
A 628 (1998) 458-478. 2. O.Tarasov and D.Bazin,
NIM B204 (2003) 174-178. 3. M.G.Itkis et al.,
Yad.Fiz. 43 (1986) 1125. 4. M.G.Itkis et al.,
Fiz.Elem.Chastits At.Yadra 19 (1988) 701.
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Electromagnetic excitation

• A well-known review of the processes generated by
  the electromagnetic interaction in relativistic
  nuclear, and atomic collisions, by C.Bertulani
  and G.Baur Physics Report 163 (1988) 299-408
  has been used to obtain the excitation energy
  function for fission.

Differential cross-sections of GDR (red solid
curve), GQR(IS) (blue dashed curve), and GQR(IV)
(black dot curve) excitations in 238U as
calculated from the equivalent photon spectrum
representing a 208Pb projectile nucleus at 600
MeV/u.
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Deexcitation channels
Deexcitation channels for 238U nuclei at 600
MeV/u excited by a lead target. The solid red
curve represents fission decay. The blue dashed
line represents 1n-decay channel, black dotted
and green dot-dashed curves respectively 2n- and
3n-decay channels.
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A semi-empirical model of the fission-fragment
properties
A semi-empirical model of the fission-fragment
properties
Figure. LISEs calculation of potential energy at
the fission barrier for 238U, as a function of
mass asymmetry expressed by the neutron number.
References Ben98 J.Benlliure et al., Nuclear
Physics A 628 (1998) 458-478. Itk86 M.G.Itkis
et al., Yad.Fiz. 43 (1986) 1125. Itk88
M.G.Itkis et al., Fiz.Elem.Chastits At.Yadra 19
(1988) 701.
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Cross Sections
LISEs plots for Coulomb fission mode
Calculated fission fragment differential cross
sections for the fissile nucleus 238U for
excitation energies left 12 MeV, right 80 MeV.
The total fission cross-section is normalized to
10 mb.
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Total Kinetic Energy
LISEs plots for Coulomb fission mode
Calculated kinetic energies of both final
fragments for the fissile nucleus 238U for
excitation energies left 15.4 MeV, right 80 MeV.
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Number of emitted nucleons (dA,dN,dZ)
LISEs plots for Coulomb fission mode
Calculated number of emitted nucleons from one
excited fragment for the fissile nucleus 238U
excitation energies left 15.4 MeV, right 80 MeV.
Now you dont need any semi-empirical
systematic!
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Cross Sections
Comparisons with experimental data
Experimental production cross-section of cesium
isotopes (black squares) with a uranium beam
(1GeV/u) in a lead target Enq99. Cross sections
calculated with the TXE method to set 1
(Qvalue). See details on plots. Fragmentation
parameterization EPAX2.15 is shown by blue
dotted-dash line. Enq99 T. Enqvist et
al., Nucl.Phys. A658
(1999) 47-66.
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Total Kinetic Energy
Comparisons with experimental data
The total kinetic energy as a function of the
nuclear charge of the fission fragments.
Experi-mental (black circles) values of every
element correspond to fission of 233U having
passed the lead target at 420 MeV/u Sch00.
Calculations were done the excitation energy
equal to 13.1 MeV what corresponds to the average
energy of the EM fission excitation function in
the reaction 233U(420 MeV/u) Pb. See details for
calculated curves in plots Sch00
K.-H.Schmidt et al., Nucl.Phys.
A665 (2000) 221-267.
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Thank You for Your attention and Welcome in the
LISE site to see details!

• Register in LISEs sites to get informationabout
  new versions of the codehttp//www.nscl.msu.edu/l
  ise or http//dnr080.jinr.ru/lise

The authors thank for the help in
developingCoulomb fission model in the
program Carlos Bertulani (NSCL/MSU) Alexandra
Gade (NSCL/MSU) Brad Sherrill (NSCL/MSU)
Michael Thoennessen (NSCL/MSU) Mikhail Itkis
(FLNR/JINR, Dubna) Valery Zagrebaev (FLNR/JINR,
Dubna) J.Benlliure (University of Santiago de
Compostela) Helmut Weick (GSI) and DOE and NSF
grants
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In-built tools

• Physical Calculator
• Nuclide Database utilities
• Relativistic Reaction Kinematics Calculations
• Curved degrader calculation
• PACE4 evaporation Monte Carlo code for Windows
• The spectrometric handbook of J.Kantele Units
  converter
• Codes Global Charge (charge state
  distributions)
• Range optimization utility
• Brho analyzer
• Transport envelope packet package
• Evaporation calculator
• Automatical search of two-dimensional peaks in
  experimental spectra
• LISE for Excel

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