The
Theexperiment
experiment“FIASCO”
“FIASCO”
Florentine
FlorentineInitiative
InitiativeAfter
AfterSuperconducting
SuperconductingCyclotron
Cyclotron
Opening
Opening
M.
M.Bini,
Bini, G.
G.Casini,
Casini, P.R.
P.R.Maurenzig,
Maurenzig, A.
A.Olmi,
Olmi, G.
G.Pasquali,
Pasquali,
S.
Piantelli,
G.
Poggi,
A.A.
Stefanini
and
N.
Taccetti
S. Piantelli, G. Poggi, A.A. Stefanini and N. Taccetti
Università
UniversitàdidiFirenze
Firenze- -Dipartimento
DipartimentodidiFisica
Fisica
I.N.F.N.
Sezione
di
Firenze
I.N.F.N. - Sezione di Firenze
Heavy-ion
≈≈80-130
Heavy-ion reactions
reactions with
with projectiles
projectiles of
of mass
mass A≈
A≈
80-130
at
at bombarding
bombarding energies
energiesof
of 15
15- -40
40AAMeV
MeV
delivered
delivered by
by the
the Superconducting
Superconducting Cyclotron
Cyclotron
of
of the
the “Laboratori
“Laboratori Nazionali
Nazionali del
del Sud”
Sud” of
of INFN
INFN in
in Catania
Catania
The
The investigation
investigation concentrates
concentrates on
on aspects
aspects of
of the
the reactions
reactions
indicating
indicating the
the presence
presence of
of non-equilibrium
non-equilibrium effects
effects (related
(related to
to
the
thedynamics
dynamicsof
ofthe
theinteraction),
interaction),which
whichare
areexpected
expectedto
tobecome
become
enhanced
enhancedwith
withincreasing
increasingbombarding
bombardingenergy.
energy.
The
Thephysics
physicsissues
issuesconcern,
concern,among
amongothers,
others,the
thestudy
studyof
of
excitation
excitationenergy
energy(and
(andangular
angularmomentum)
momentum)sharing
sharing
non
nonstatistical
statisticalemission
emissionof
oflight
lightcharged
chargedparticles
particles
isospin
isospineffects
effectsin
incollision
collisionand
anddecay
decayof
ofexcited
excitednuclei
nuclei
time
timescales
scalesfrom
fromdistorsions
distorsionsin
inthe
thesequential
sequentialdecay
decay
“mid-velocity”
“mid-velocity”emission
emissionof
ofIMF’s
IMF’sfrom
fromthe
thecontact
contact zone
zone
The
“FIASCO”
Theexperimental
experimentalsetup
setupof
of“FIASCO”
24
24 parallel
parallel plate
plate avalanche
avalanche gas
gas detectors
detectors (PPAD)
(PPAD)
(20cm
Ω ≅≅ 75%
75% of
of forward
forward 2π)
2π)
(20cm xx 20cm
20cm or
or 30cm
30cm xx 30cm
30cm each,
each, Ω
measure:
measure: x,
of projectileprojectile- and
and target-like
target-like fragments
fragments (PLF,
(PLF, TLF)
TLF)
x, y,
y, Tof
Tof of
→
X (cm )
vv
kinematic analysis
primary
, A TLF,, TKE,...
primary quantities
quantities of
of PLF
PLF and
and TLF:
TLF: AAPLF
TKE,...
PLF, ATLF
Very
Very low
low thresholds
thresholds (≤
(≤ 0.1
0.1 AMeV)
AMeV) for
for TLF
TLF detection
detection allow
allow
aa clean
and
efficient
selection
of
very
peripheral
collisions
clean and efficient selection of very peripheral collisions
10 0
80
60
40
20
0
BBeam
EAM
-20
-40
-60
Target
-80
-100
T O P V IE W
-100
-50
0
50
10 0
150
200
250
300
350
400
B eam -axis Z (cm )
96
∆Ε−Ε silicon
µm)
96 ∆Ε−Ε
silicon telescopes
telescopes (200
(200 ++ 500
500 µm)
(3
(3 xx 33 cm
cm each,
each, mounted
mounted behind
behind the
the most
most forward
forward gas
gas detectors)
detectors)
secondary
, Z and A
secondary quantities
quantities of
of PLF
PLF :: EELab
Lab, Z and A
160
160 phoswich
phoswich scintillators
scintillators (fast
(fast plastic
plastic ++ CsI
CsI ,, fast+slow
fast+slow plastic
plastic ++ CsI)
CsI)
(64
(64 xx 64mm
64mm each,
each, behind
behind gas
gas detectors
detectors and
and at
at backward
backward angles)
angles)
→
Z,
Z, A,
A, vv of
of light
light charged
charged particles
particles (LCP)
(LCP)
→
Z,
Z, vv
of
of intermediate
intermediate mass
mass fragments
fragments (IMF)
(IMF)
First
“FIASCO”
Firstresults
resultsof
of“FIASCO”
93Nb+116Sn
@ 30 A· MeV
S.Piantelli et al submitted to PRL
"!$#%&"'
Experiment (corr.)
Statistical Simulation
TKEL = 160-320 MeV
b≈
≈ 9÷
÷10 fm
Comparison
Comparisonbetween
between
experimental
experimental (left)
(left)and
and
calculated
(right)
calculated
(right)
yields
of
LCP’s
yields of LCP’sand
andIMF’s
IMF’s
evidence
evidencefor
forsignificant
significant
“mid-velocity”
“mid-velocity”emission
emission
INDRA
results
The
Theemission
emissionpattern
patterncan
cangive
giveinformation
informationon
onthe
the
time-space
configuration
of
the
emitting
system:
time-space configuration of the emitting system:
Coulomb- trajectory calculations show that a sizeable number
Coulomb- trajectory calculations show that a sizeable number
of IMF come from phase space regions near to PLF or TLF
of IMF come from phase space regions near to PLF or TLF
The
Themidvelocity
midvelocityIMF
IMF
emission
largely
emission largely
overcomes
overcomes the
the
statistical
one
statistical one
New measurements (Jan - July 2001) together with Hodoscope of “Temperature”
93Nb+116Sn

 @ 17, 23, 30, 38 A· MeV
116Sn+ 93Nb 
⇐ Calibration in progress