Transcript Slide 1

Low density matter
probed in multifragmentation reactions
W. Trautmann
GSI Helmholtzzentrum, Darmstadt, Germany
Workshop „Simulating the Supernova Neutrinosphere
with Heavy Ion Collisions“
ECT* Trento, April 2014
ALADIN 1990-2004
historical and personal
MUSIC III
ToF
V. Serfling
Lynen
Lühning
Müller
Pochodzalla
Sann
Schwarz
Sfienti
et al.
multifragmentation of relativistic projectiles
K. Turzó
isospin dependent multifragmentation of
relativistic projectiles
main result:
reduced symmetry energy
required for
liquid drop description of
fragments at freeze-out
K. Turzó
the nuclear phase diagram
as we explore it with multifragmentation
critical points from
Jaqaman et al., PRC 27 (1983) 2782
Müller & Serot, PRC 52 (1995) 2072
Schnack & Feldmeier, PLB B 409 (1997) 6
NN2000 Strasbourg
astrophysical motivation
dashed:
adiabatic evolution,
e.g., collapse
(along constant
entropy per
baryon S/B)
ALADiN spectrometer
Z resolution
full acceptance for projectile fragments at E>400 A MeV
dynamic range from Z<2 to Z=93 with good resolution
ALADiN
Magnet
TP-MUSIC IV
107Sn
HodoCT
Target
TOFWall
LAND
2m
main topic: projectile (multi)fragmentation
correlation functions with hodoscopes
(160 elements) in coincidence
A. Schüttauf et al., NPA 607, 457 (1996)
A resolution
124Sn
5Li
discrete states from correlations
V. Serfling et al.,
PRL 80 (1998)
Au+Au
50-200 A MeV
central, 10% σreact
150 A MeV
secondary decay effects
with QSM at T=5 MeV
He4
Li5
Li6
Be8-1
Be8-2
Be8-3
kinematic
acceptance
5Li
4He
8Be
g.s. vs. 20.21+
g.s. vs. 16.66
2.19 vs. 4.31+5.65
g.s. vs. 3.04
g.s. vs. 17.64+
17.64+ vs. 3.04
HeLi
Hedt
5Li
T=5 MeV
universal
and limit
can fragments survive
in the hot environment?
Au+Au@1000
lines from Typel et al. (2010)
chemical freeze-out
THeLi
thermal freeze-out 4He, 5Li
Zmax
ALADiN
Mott points
determined experimentally
using equilibrium assumptions
for cluster emissions
from 40Ar, 64Zn + 112,124Sn @ 47AMeV
Hagel et al., PRL108 (2012)
Zbound
T=5 MeV for excited state
temperatures (thermal freeze-out)
W.T. et al., PRC76 (2007)
isotopic effects in chemical freeze-out
from double isotope yield ratios: THeLi (3,4He,6,7Li)
(Albergo's formula)
TBeLi (7,9Be,6,8Li)
C. Sfienti et al., PRL 102 (2009)
isotopic effects in chemical freeze-out
from double isotope yield ratios: THeLi (3,4He,6,7Li)
(Albergo's formula)
TBeLi (7,9Be,6,8Li)
issue:
dynamical compound stability
vs. fragmentation phase space
C. Sfienti et al., PRL 102 (2009)
temperatures from SMM ensemble calculations
experimental isotope temperatures
mean microcanonical temperatures
p+p
densities from correlations
without filter
S. Fritz et al.,
PLB 461 (1999)
Au+Au
1 A GeV
RAu=6.7 fm
R≈8 fm
ρ/ρ0 = 0.1 – 0.4
from radius of sphere and
number of spectator nucleons
R≈10 fm
R≈9.5 fm
densities
from moving source fits
U. Milkau et al.,
PRC 44 (1991)
Coulomb energies according to
the fission systematics for
decaying nuclei
of Z=79 and Z = 39
inclusive reactions on Au
density in dynamical approaches
QMD with simulated annealing clusterization algorithm (Aichelin, Puri et al.)
ALADIN data
SACA
60 fm/c
MST
figures from Vermani and Puri, EPL 85 (2009)
SACA method identifies fragments at 60 fm/c and ρ/ρ0 ≈ 0.6
fragment modifications
ALADiN experiment S254
Z resolution
Projectile fragmentation of
neutron-rich and neutron-poor
projectiles: 124Sn, 107Sn, 124La (1.14 ≤ N/Z)
ALADiN
Magnet
TP-MUSIC IV
107Sn
HodoCT
Target
TOFWall
LAND
2m
main result: reduced symmetry energy
of fragments in the hot environment;
will affect neutron capture rates in SN
C. Sfienti et al., PRL 102 (2009), R. Ogul et al., PRC 83 (2011)
A resolution
124Sn
SMM ensemble calculations
used for analysis
meant to reproduce
participant-spectator
geometry
(SMM: Statistical Multifragmentation Model)
mass variation with excitation
energy taken into account;
fixed to reproduce exclusive yields
Zbound = ΣZi with Zi≥2
and model study of sensitivities
A.S. Botvina, N. Buyukcizmeci, R. Ogul et al.
Statistical Multifragmentation Model
SMM
R. Ogul et al.,
PRC 83 (2011)
main result:
neutron-rich fragment yields
require low symmetry energy
standard
modified
exp
124Sn
standard
124La
exp
standard
Isoscaling:
Experiment vs. SMM
25
14
8
surface alone
4
experiment
symmetry term reduced
at chemical freeze-out
in multifragmentation reactions
S. Bianchin, K. Kezzar, A. Le Fèvre, J. Lühning, J. Lukasik,
U. Lynen, W.F.J. Müller, H. Orth, A.N. Otte, H. Sann,
C.Schwarz, C. Sfienti, W. Trautmann, J. Wiechula,
M.Hellström, D. Henzlova, K. Sümmerer, H. Weick,
P.Adrich, T. Aumann, H. Emling, H. Johansson, Y. Leifels,
R. Palit, H. Simon, M. De Napoli, G. Imme', G.Raciti,
E.Rapisarda, R. Bassini, C. Boiano, I. Iori, A. Pullia,
W.G.Lynch, M. Mocko, M.B. Tsang, G. Verde, M. Wallace,
C.O. Bacri, A. Lafriakh, A. Boudard, J-E. Ducret,
E.LeGentil, C. Volant, T. Barczyk, J. Brzychczyk, Z. Majka,
A. Wieloch, J. Cibor, B. Czech, P. Pawlowski, A. Mykulyak,
B. Zwieglinski, A. Chbihi, J. Frankland and A.S. Botvina
memory of earlier stages
<MIMF>
The largest
fragment as order
parameter
percolation
describes the partitions well
Kreutz et al., Nucl. Phys. A556 (1993)
early fragment recognition
and persistence
classical molecular dynamics
X. Campi et al., Phys. Rev. C 67, 044610 (2003)
Fermi motion
momentum widths in projectile fragmentation
ALADIN and FRS at GSI
prop.√Z
T ≈ 15 MeV
Schüttauf et al., NPA 607, 457 (1996)
σ0 = 115 MeV
T ≈ 14 MeV
Föhr et al., PRC 84, 054605 (2011)
T = 15 MeV expected for cold Au in the Goldhaber model
kinetic temperatures in projectile fragmentation
interpreted within the „hot“ Goldhaber model of Bauer
prop.√Z
T ≈ 15 MeV
Odeh et al., PRL 84, 4557 (2000) with analysis following Bauer, PRC 51, 803 (1995)
Bauer‘s numerical solution for ρ/ρ0 = 1
for ρ/ρ0 = 0.3
control of the composition
ALADIN experiment S254
"Mass and isospin effects in multifragmentation"
secondary beams
from 142Nd
107Sn, 124La
124Sn, 197Au
600 A MeV
A=124
Z
contour lines represent
limiting temperatures
following
temperature dependent
Hartree-Fock calculations
using Skyrme forces
N
evaporation attractor line
R.J. Charity, PRC 58, 1073 (1998)
nuclear structure and memory effects
ALADIN
experiment
S254
SMM ensemble
calculations by
A.S. Botvina,
R. Ogul et al.
lines SMM
symbols exp
124Sn
124La
107Sn
nuclear structure and memory effects
ALADIN
experiment
S254
SMM ensemble
calculations by
A.S. Botvina,
R. Ogul et al.
lines SMM
U, Fe from FRS
symbols exp
124Sn
238U
107Sn
124Sn
124La
56Fe
107Sn
projectile fragmentation
at 1 AGeV (FRS at GSI)
112Sn
+
124Sn +
112Sn
124Sn
SMM calculations
with ensembles from ALADIN study
A/Z of the initial projectiles
2.24 vs. 2.48
data: V. Föhr et al., PRC 84, 054605 (2011)
analysis: H. Imal et al., arXiv:1403.4786 [nucl-th]
collaborations
present outlook on FAIR
April 2014
INDRA at GSI
Z = 3 at 100 A MeV central
γβ
y
Systems:
Au + Au 40 to 150 AMeV
Xe + Sn 50 to 250 AMeV
C + Au 95 to 1800 AMeV
November 1997 – April 1999
INDRA at GSI
Z = 3 at 100 A MeV peripheral
γβ
y
Systems:
Au + Au 40 to 150 AMeV
Xe + Sn 50 to 250 AMeV
C + Au 95 to 1800 AMeV
November 1997 – April 1999
INDRA at GSI
From the Fermi
to the relativistic
domain
Invariant
cross sections
for Au + Au
at peripheral
impact
parameters
summary of S254
1. secondary beams essential to enhance effects
2. small changes of global observables with N/Z
important for isolating isospin effects
3. isotope distributions exhibit
memory and structure effects
4. isoscaling obeyed with high accuracy;
reduced symmetry term for hot fragments
5. N/Z dependence of nuclear caloric curve
indicates phase-space driven instability
rather than Coulomb instability
6. spectator neutron source with T=4 MeV,
invariant with system N/Z.