Esperimento NUCL-EX Rappresentanti Nazionali: M. Bruno (BO) G. Casini (FI) Bologna (5 Ric), Firenze (9 Ric), LNL (6 Ric), Napoli (9 Ric), Padova (1 Ric) 30 Ricercatori (25 FTE) Collaborazioni: Ganil, Jyvaskyla, Dubna, Nevsehir Univ. Turkey (BARC,TAMU, Moskow State Univ., Ohio State Univ.) • Dinamica e Termodinamica Nucleare • Formazione e Decadimento di sistemi nucleari (Fusione – Fissione, Pre-equilibrio, Clustering) • Fisica dell’Isospin verso SPES (Densità dei Livelli, Energia di Simmetria) • FAZIA project Apparati Sperimentali @LNL FAZIA Dem. GARFIELD 8pLP RIPEN Evidence of Strong deformation in alpha-like nuclei 24Mg+24Mg @92 MeV, (8pLP + PPAC modules) a detected in 8pLP, Residue detected in PPACs E a-Residue angular correlation F G BALL detector number a-Residues Angular correlation is better reproduced by assuming an Highly Deformed nucleus indicating a possible a-clustering stucture A. Di Nitto et al., EPJ Web of Conferences 21, 02002 (2012) CNR*11 Int. Conf., September 19-23, 2011 Prague, Czech Republic GARFIELD + RING Counter: Central collisions: we expect that close to the multifragmentation threshold, the produced fragments will be relatively cold. The experimental reconstruction through correlation techniques of secondary decays in such moderately excited fragments will allow us to trace back the primary fragmentation pattern minimizing the model dependence of the procedure. 32S+40Ca 17.7MeV/A 32S+48Ca 17.7MeV/A Level densities at low excitation energy are known to exhibit important isotopic and odd-even effects, resulting in staggering effects in different isotopic observables. Analysis in progress Sorting the events: • Peripheral collisions: many sources, • Central collision one source Activities 2012-2013 2012/2013: Two experiments approved by the LNL PAC: 1. Study of a-clustering using pre-equilibrium emission (V.L. Kravchuk) 2. Probing the Statistical decay in N=Z light nuclei (G. Baiocco) One approved experiment at TAMU: 1. Study of nuclear level density at moderate excitation energy (A. Voinov) Ideas for proposals at TANDEM-ALPI: Jacobi and Poincare shapes of Ba isotopes vs. mass asymmetry of fission fragments A. Maj, Cracow Role of the entrance channel in the production of complex fragments in fusion-fission and quasifission reactions in the framework of the dinuclear system model G. Adamian, Dubna Study of fusion-fission dynamics through fission fragment angular, Mass distributions and neutron multiplicity measurements S. Appannababu, LNL and Delhi RIPEN @ CN Van de Graaf accelerator 24 BC501 cylindrical Liquid Scintillators 2 V1720 digitizer from CAEN (12 bit, 250 MS/s) in the 8 channels VME version communicating with a standard PC via a VME bridge (CAEN V1718). • Energy release of impinging particle • Time of flight and Palse Shape Discrimination between neutron and g 8B production in the reaction 6Li(3He,n)8B via neutron angular distribution measurement C. Rubbia et al., NIM A 568 (2006) 475 C.R. McClenahan et al., PRC 11 (1975) 370 R.E. Marrs et al.,PRC 8 (1973) 427 P. Van Der Merwe et al., NPA 103 (1967) 474 8B g.s. 12C(3He, Counts Previous experiments using two different experimental techniques (Positron Counting technique and Neutron Time of Flight) give very different results for the 8B production cross section varying by a factor of 3 n)14O 8B* 6Li(3He,np)7Be g TOF (ns) RIPEN @ CN Van de Graaf accelerator V.L. Kravchuk et al., To be published in Phys Rev. Special Topic – Accelerators and Beams ds/dW (mb/Sr) 12 6 MeV 3He+6Li 8B + n 10 g.s. 8 6 4 1st exc. 2 Total cross section Reference (68 ± 7) mb (g.s.) (35 ± 7) mb (1st exc.) Experimental result 65 mb (g.s.) E3He=5.6 MeV (neutron TOF) 75 mb (g.s.) DWUCK4 calculation (20 ± 3) mb Positron counting 0 0 50 100 150 Neutron emission angle in CM (deg) Test experiment scheduled from July 26 to August 3, 2012 in view of an experimental campaign at the CN Definition of Physics Cases for coupling the neutron detectors with LCP detectors (modules from 8PLP) and/or gamma detectors (GALILEO) FAZIA: Phase II The 192 telescopes of FAZIA demonstrator will be ready at the end of 2013. Initially they will be coupled with : INDRA Then with: GARFIELD@LNL, RIPEN@LNL and CHIMERA@LNS Coupling FAZIA + INDRA WITH STABLE BEAMS & 1st DAY EXP with SPIRAL2 Basic BLOCK: 4x4 telescopes Transport properties of isospin asymmetric nuclear matter: neck emission and isospin drift 40,48Ca+40,48Ca 58Ni+58Ni at 30-45AMeV at 15, 25, 35AMeV, Related to deep-inelastic processes, isospin equilibration and drift; isoscaling for massive ejectiles 78,86Kr+40,48Ca ---> 20-60AMeV Related to the surface or volume expansion in central collisions Richieste finanziarie per 2013 • Missione Interne 1 KE Riunioni collaborazione + 1 KE s.j turni LNS • Missioni Estere 2 KE riunioni analisi Texas, riunioni Fazia, Assemblaggio dimostratore Ganil • Consumo 1 KE lavorazioni meccaniche, materiale test laboratorio • Inventario 1 KE PC per analisi SPARES GARFIELD Fragments and Light Particles identification • 2 Drift chambers : 180 micro-strip detectors + 180 CsI(Tl) ( = 300 – 1500) • Ring Counter: annular telescope, Ionization Chamber + Si + CsI(Tl) ( = 60 – 180) • Time of Flight system: 4 Position Sensitive Parallel Plate Avalanche Counters Drift Chamber 14.5 MeV/A 32S+64Ni THE 8pLP SPECTROMETER 11 The Experimental set-up: The TOF Apparatus 6 MeV 3He+6Li 8B + n 40 pnA, pulsed beam 333 ns rep. rate with 2 ns resolution DE (15 mm) – E (200 mm) Silicon Telescope pickup beam 1 2 3 4 8 3He 5 2 m Flight path DW ≈ 3 mSr D ≈ ±2o 6 7 1H 8 BC501 detectors covering angles from 15o to 140o in LAB (500 mg/cm2) on Au (500 mg/cm2) Background measurements: 1)7LiF (500 mg/cm2) on Au (500 mg/cm2) 2)12C (70 mg/cm2) & 3) without target 6LiF Rutherford scattering of the beam on the Au backing is used as normalization to determine the 8B production absolute cross section