PRISMA-FIDES 2013-2016
Heavy-ion reactions from grazing collisions to complete fusion
G.Montagnoli (100%), D.Montanari (100%), F.Scarlassara (50%)
(Univ. and INFN - Padova)  2.5 FTE
A.M. Stefanini (100%), L. Corradi (80%), E.Fioretto (100%), Huiming Jia (100%)
(INFN - LNL)
 3.8 FTE
G.Pollarolo (50%) (Univ. and INFN – Torino)  0.5 FTE
6.8 FTE overall
  Joint work with the experiments EXOTIC and GAMMA
  Collaboration with GSI (D.Ackermann), Zagreb (S.Szilner,T.Mijatovic), Dubna
(N.Kondratiev, R.Sagaidak), Strasbourg (F.Haas, S.Courtin), Cracow (J.Grebosz)
July 2012
The PRISMA 2 experiment at LNL
Traditionally, our group has always been involved in 2 lines of research:
HI fusion reactions
around VB presently focused at E << VB
using the electrostatic beam separator
PISOLO
2-body reactions
pair transfer enhancement
(transfer coupling to fusion
n-rich isotope production
....)
using the magnetic
spectrometer
PRISMA
PRISMA-2
•
Heavy-ion reactions from grazing collisions to complete fusion: recent
experiments on sub-barrier transfer and on fusion hindrance at very low
energies
•
The AGATA demonstrator: nuclear structure of n-rich nuclei identified
with PRISMA. At LNL until end of 2011. A small array of LaBr3:Ce
detectors.
•
Heavy beams at LNL (Tandem, ALPI, PIAVE) and complementary
experiments at other facilities (GANIL, ANL)
Detection of (light) target like ions in inverse kinematics with PRISMA
beam direction
96Zr
40Ca
20o
Prisma
acceptance
Nucleon transfer channels have been measured down to 25 % below the
Coulomb barrier
Sub-barrier transfer for 96Zr (beam) + 40Ca
+1n well reproduced by theory
in slope and absolute value
Same slope of +2n between
theory and experiment
+2n enhancement due to the
presence of other excited
states?
Absorption reproduced by
theory
2n transfer to g.s.
2n transfer to 0+ (5,76MeV)
(2n in p3/2)
L. Corradi et al., Phys. Rev. C 84, 034603 (2011)
The experiment 116Sn + 60Ni (Feb. 2012)
Slopes for 116Sn + 60Ni
Preliminary data
Data under analysis
+1n and +2n slopes are in
agreement with those
expected from binding
energies
P1
P2≈3(P1)2
LNL results on 58Ni + 54Fe
Log slope
Fus. x-sects.
S-factor
Ec.m. (MeV)
A.M.Stefanini et al., PR C81, 037601 (2010)
Recent measurements on 40Ca+40Ca, 40Ca+48Ca and 48Ca+48Ca
have investigated fusion hindrance and nuclear structure
effects at sub-barrier energies
(Fusion-evaporation residues detected using the electrostatic beam deflector at LNL)
G.Montagnoli et al., PRC 85, 024607 (2012)
C.L.Jiang et al., PRC 82, 041601(R) (2010) A.M.Stefanini et al., PLB 679, 95 (2009)
Our recent results
on 32S + 48Ca
by coupling schematically
a Q>0 transfer channel,
the data are well fit
the logarithmic derivative is rather low
and keeps increasing below the barrier
the barrier distribution is
very wide and shows
an unusual shape
PRISMA-FIDES
•
Study of nucleon-nucleon correlations (particle-vibration couplings,
pairing vibrations, sub-barrier transfer) in binary reactions near the
barrier
•
Couplings effects and fusion hindrance far below the barrier – fusion
cross sections in light heavy-ion systems
•
Developments for Prisma: the new scattering chamber with a second
TOF arm for kinematic coincidences, a new PPAC for light heavy-ions,
better tracking of ion trajectories for higher A resolution
•
Test of γ-particle coincidences in Galileo and of the EXOTIC set-up for very
low fusion x-sects. measurements
•
All this will allow us to use the future exotic SPES beams with great
efficiency
Detection of coincident
fragments (MCP,TOF,DE-E)
Heavy partner :
low Z,A resolution
Via high resolution kinematic
coincidence we can also deduce
the fission probability of
associated heavy partners,
determined as function of Z,A
(light partner) and Q-value of the
reaction
beam
L.Corradi et al,
Phys.Rev.C66(2002)024606
PRISMA
Light partner : high
Z,A resolution
Astrophysical S factors for several systems
measured in the last few years
Fusion of medium-light systems
Measurements of very low
fusion cross sections need
high efficiency and low
background.
Tests using the EXOTIC line
and g-particle coincidences
with GALILEO are being
considered
Spese ordinarie
Investimenti
II braccio Prisma
(coinc. cinem.)
Coinc. γ-particelle
(in Galileo)
Miglior. tracking
Previsioni di spesa 2013 - PD
•
•
•
•
Inventariabile:
Consumo:
Missioni estere:
Missioni interne:
TOTALE :
56 k€
26 k€
6 k€
5 k€
93 k€
(per tutta la collaborazione circa 189 k€)
Richieste ai servizi Padova per il 2013
Servizio
Lavoro richiesto
Tempo
(mesi uomo)
Ufficio Tecnico
2 flangie di adattamento
Sliding seal per secondo braccio
e alloggiamento rivelatori γ LaBr3
2
Officina Meccanica
Completamento camera sliding seal,
installazione e allineamenti
6
Laboratorio Elettronica
Ottimizzazione fast ampl. + HV
per i due PPAC
2
Richieste ai servizi LNL per il 2013
Servizio
Lavoro richiesto
Officina meccanica
Completamento camera sliding seal,
installazione e allineamenti
Installazione II braccio
6
Sviluppo, install. e collaudo del
controllo PLC del vuoto Pisolo
Upgrading controllo x II braccio
3
Servizio Utenti
(Supporto App. Sperim.)
Tempo
(mesi uomo)
1
1
Sliding-seal scattering chamber
Beam line
Prisma
Target
Secondo Braccio
End
Electrostatic separator and E-ΔE-ToF telescope to detect
evaporation residues at ≈ Oo
scattering chamber
MCP, IC & Si detectors
beam
E-ΔE-ToF telescope
detecting ER
HV
target
_
_
+
+
HV
12/21/2015
PAC-meeting 2008
20
Very different behaviors
Milestones PRISMA-2 2011-2012
1) July 31, 2011 to conclude the experimental campaign of PRISMAAGATA measurements
→ AGATA stayed at LNL until December 2011- milestone reached 100%
2) December 15, 2011 to organize a measurement of sub-barrier transfer
reactions involving superfluid nuclei
→ milestone reached 100%
3) June 30, 2012 to perform the sub-barrier fusion experiment on Ca+Zr
systems
→ milestone reached 80%
4) June 30, 2012 to complete the installation of the new scattering
chamber for PRISMA
→ milestone reached 30%
5) June 30, 2012 to define the scientific program using PRISMA and
Pisolo spectrometers for the next few years
→ milestone reached 100%
6) December 30, 2012 to complete the R&D studies of PRISMA
upgradings for the next few years
Milestones PRISMA-FIDES 2013
1) July 31, 2013 to extend the sub-barrier fusion experiments to
medium-light systems
1) July 31, 2013 to study sub-barrier transfer in 92Mo+54Fe or in
another proton-rich system
2) .Sep. 30, 2013 to install and test the new gas pumping and
vacuum control of PISOLO
1) Dec. 20, 2013 to measure nucleon transfer channels in Ca+Ca
systems
1) Dec. 20, 2013 to complete the tests of new detectors and DAQ
upgrading for the second arm of PRISMA
New sliding seal scattering chamber
New large angle «coincidence arm»
MCP + PPAC + IC?
EFB
EFB
Sub-barrier transfer for 96Zr (beam) + 40Ca
L.Corradi et al., Phys. Rev. C84, 034603 (2011)