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Gruppo SIS dal 1989-94 dal 1995-99 SIS-1 dal 2000-2002 SIS-2

Explore research activities, instrumentation, and findings in nuclear physics from 1989-2002. Discover methodologies like HBT Interferometry and Uncorrelated Background Determination.

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Gruppo SIS dal 1989-94 dal 1995-99 SIS-1 dal 2000-2002 SIS-2

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  1. Gruppo SIS dal 1989-94dal 1995-99 SIS-1dal 2000-2002 SIS-2 Chi siamo. Stumentazione Disponibile. Attività di Ricerca:Risultati e Prospettive. Progetto FRIBs @LNS. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  2. CHI SIAMO • G.Immè • G.Raciti • C.Sfienti Assegnista (2002-2006) • A.Saja Dottorando • M.DeNapoli Laureando • S.Rascunà “ • E.Rapisarda “ • L.Spezzi “ G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  3. Strumentazione • HODO96:(96 tripli telescopi: Si(50mm) +Si(300mm) +Csi(6 cm) PD read-out; 3x3 cm2) • HODO80:(80 doppi telescopi: Si(300mm) +Csi(10 cm) PD read-out; 1x1 cm2) • MICROSTRIP X-Y. 12 detectors 5x5 cm2 con 16x16 strips • con i rispettivi: • PREAMPLIFICATORI (1-45-90 mv/MeV) • AMPLIFICATORI (-10 Volts Max) con uscite ECL (L.E. e Zero Crossing) • STRETCHERS • QDC FASTBUS ,Crate,SFI(adattatore FB-VME),CPU VME,VSB-VME (per accoppiamento Front-End) G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  4. HODO96+HODO80+Strips Ca+Sc 40AMeV LNS1997 G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  5. GSI -CaveB -ALADiN 1995 Au+Au 1000AMeV  Target Spectator Fragmentation 50÷200 AMeV  Participant Fragmentation • TOF & ZDO • b selection • HODOSCOPES • Coincidences G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  6. MSU-NSCL (1996) G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  7. LNS-Ciclope (2000-2001) FIASCO-HODO G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  8. Grandezze Misurabili: • Separazione Isotopica (Z<10) • Spettri Energetici • Correlazioni (particella-particella e frammento-frammento) DQ=2 MeV/c • su un angolo solido di Necessita di: Filtro Informazioni G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  9. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  10. Sn+Sn 40 AMeV SIS-FIASCO Experiment LNS 2001 G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  11. The Isotopic Thermometer … under chemical equilibrium ... S.Albergo et al. Il Nuovo Cimento A (1985) 3 - sources fit Moving Sources: Expanding Participant + Projectile + Target Isotopic Yield • Calibration Theoretical Models • Corrections Sequential Decay G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  12. Experimental Method Uncorrelated Background determination  Event-Mixing technique + Geometry Reproduction Koonin-Pratt Formalism Without efficiency With efficiency G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  13. The Excited-State Thermometer • Coincidences’ spectrum • Event Mixing • Correlation function • Background Subtraction Emission Temperature Calibration- Curve • Montecarlo Simulation • Efficiency Function G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  14. The Excited-State Thermometer Particle-Particle Coincidence Measurements G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  15. HBT Interferometry • Intensity Interferometry Hanbury-Brown-Twiss Nature, 177, 27 (1956) h  R-3 2 He-Resonance Uncorrelated Emission q>>1/R  R(q)1 h Coulomb Antisymmetrization G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  16. Calculation of Two-Particle Correlation r+v G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  17. Longitudinal .vs. Transverse Correlation Definition of Coordinates: • Possible Effects: • Long  (Side,Out)  Source Deformation • Long  Side  Life-Time Effects G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  18. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  19. Unlike-Particle Correlations D.Boal and J.Shillock PRC33(1986)549 • Unknown Two-Particle wave function • Unfolded numerical results are available • Experimental setup efficiency •  Cross comparison between experimental and calculated integrals G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  20. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  21. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  22. PHYSICS • Multifragmentation • Calorimetry • Temperature & Density Measurements • Open Problems: • Caloric Curves • Emission vs Isotopic Temperatures • Excitation Energies G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  23. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  24. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  25. Spectator Matter • Multifragmentation pattern independent on: • Incident Energy Multifrag. Evaporation Vaporization • Projectile Mass • Target Mass Universality of Spectator Fragmentation G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  26. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  27. Nuclear Caloric Curve Centrality J.Pochodzalla et al. Phys.Rev.Lett 1995 Similarity with the H2O bulk CC ... 1st order Liquid-Gas Phase Transition in Nuclear Matter? G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  28. Open Problem #1 “ … As with all interesting physics, in the beginning there's a lot of controversy, and we don't know who's right yet..." Indra and EOS Collaboration G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  29. ... Size Effect A = Cost CENTRAL Collisions A @ 170 -180 (Kr+Nb) A @ 80 (Ca + Sc) A=82 A177 Projectile Fragmentation A  35 • Size Effects • Theoretical Models • Experimental Evidences G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  30. ... Size Effect M.Schimidt et al. Nature (1998) Irregular Variation in the melting point of Size-Selected atomic clusters. + Na 192 Cluster Size G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  31. ... Size Effect Dynamic Statistical Multifragmentation Model • C.B.Das and L. Satpathy PRC57(1998)35 Kink for A120 Other models predict A100 Static Thomas-Fermi prescription • J.N. De et al., PRC55(1997)1641 The kink in the CC is related to a well-defined peaked structure for the specific heat G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  32. ... Size Effect Binding Energy Surface Energy • Surface Effectrather than Volume Effect G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  33. Open Problem #2 G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  34. Breakup Temperatures More evidence for equilibration EBeam invariance of THeLi • New Thermometer TBeLi • Rise-Independence on the specific 3He/4He properties Statistical decay of Equilibrated breakup configuration ?? G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  35. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  36. Emission Time-Ordered • Expansion • Cooling Central CollisionsRadial Flow Adiabatic Expansion of an ideal gas Expansion bFlow .. time ? More Cooling G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  37. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  38. Radii Measurements G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  39. Probing Low Density Nuclear Matter • Zero-Lifetime approximation • … large variation for the spectator masses ... • Agreement with the SMM predictions • Breakup configuration of low density G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  40. OPEN PROBLEM #3- Excitation Energy Calorimetryrequires a complete knowledge of all decay products, including their atomic numbers, masses and kinetic energies • X.Campi et al. PRC50(1994)2680 • Only neutron data were available • Assumptions about the N/Z ratio of spectator matter • EBeam dependence  Ekin(n) dependence • SMM values always smaller than the measured ones G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  41. Caloric Curve for Spectator Decay Simple underestimation? Does the whole proton energy contribute to the thermal behaviour? Influence of the Energy Spectra on the excitation energy determination • Open points : SMM predictions • Solid points: Experim. spectra. G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  42. Target Spectator Spectra • Very high temperature values from the maxwellian fits. • Goldhaber Idea: • Product Momenta in fast fragmentation have their origin in the nucleonic Fermi motion within the colliding nuclei • As a thermalized system with high temperature pF265MeV/c T=15MeV G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  43. Fermi Energies • Nucleon momentum distribution at temperature TIN: W.Bauer, PRC 51, 803 (1995) • Fragment momentum = sum of momenta of nucleons in it • Problem equivalent to solving Pearson random walk in momentum space • Fragment slope Temperature Teff is not equal to TIN but is a monotonous function of it • Rise as a consequence of the THeLi rising G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  44. ISOTOPE TEMPERATURE vs SPECTRA TEMPERATURE • where • W.Bauer Phys Rev C 51(95)803 • r/r0=0.07 G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  45. Conclusions • From thesystematic Study of the Nuclear Caloric Curve: • THe-Li and TBe-Li thermometers give consistent results • The “plateau” like behaviour of the Nuclear Caloric Curve exhibit Dependence on the Size of the system • Probing Thermodynamics of Finite System • The “Latent heat” deduced from C.C. of different systems indicate a dependence on the Surface • Nuclear Thermometers Cross Comparison • Energy Spectra and the Role of Fermi Momentum • Emission .vs. Isotope Temperature as clock • HBT Interferometry • Source radii can be deduced and Density determined if the system mass is known. • “Imaging” analysis under development • Temperature -Density measurements might enable us to sample the thermodynamic evolution of nuclear systems G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  46. F R I BsIn Flight Radioactive Ion Beams June 2001 LNS G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  47. RIBs Production Methods G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  48. In Flight Laboratory Accelerators RIB Separator RIB Energies GANIL NSCL-MSU GSI RIKEN DUBNA LANZHOU C Cyclotrons C Cyclotrons SIS Cyclotron C Cyclotrons Cyclotron <95 A MeV <200 A MeV <1.2 A GeV <150 A MeV <100 A MeV <80 A MeV SISSI+LISE A1200 FRS or ESR RIPS ACCULINNA&COMBAS RIBLL ETNA(1994) LNS-Project ISOL Laboratory Driver Accel. Post Accel. RIB Energies Louvain-le Neuve SPIRAL-GANIL ISOLDE-CERN TRIUMF-Vancouver ORNL Oak Ridge ANL Argonne Cyclotron C Cyclotrons PS Booster Syncrotron Cyclotron Cyclotron K110 Cyclotron CIME LINAC LINAC TANDEM ATLAS 0.2-12 A MeV 2-25 A MeV <2.2 A MeV 1.5-6.5 A MeV 25 MVolt 6-15 A MeV LNS-Project EXYCT(1994) RIBs Facilities G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  49. RIBs FACILITIES-2001 G.Raciti, I- Meeting NUCLEX Firenze, October 2001

  50. GOAL • Minor Modification of the existing Beam Line with • a final improvement of transport degree of freedom. • Only commercially available devices. • Reasonable Budget (<150 Keuro) • Ready in one year. • Primary Beam currents in the enA range. • Primary Beam Energy in the present CS range. • No Competition with other RIBs Facilities But • Competitive experiments with the existing • 4p Detectors: • MEDEA+MULTICS+MACISTE • CHIMERA • FIASCO+HODO G.Raciti, I- Meeting NUCLEX Firenze, October 2001

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