Bologna, Firenze, Napoli, Padova Apparati Sperimentali @LNL Esperimento NUCL-EX Rappresentanti Nazionali: M. Bruno (BO) G. Casini (FI) Bologna, Firenze, Napoli, Padova 30 Ricercatori (25 FTE) Collaborazioni: Ganil, Jyvaskyla, Dubna (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 GARFIELD 8pLP RIPEN Apparati Sperimentali @LNL FAZIA Dem. 1
Particle emission from unstable states of primary fragments GARFIELD @ ALPI 14.5 AMeV De-excitation of «hot» fragments produce a «staggering» effect in the isotopic distributions M. D’Agostino et al. Nucl.Phys. A 861 (2011) 47 Measurement of the population of unstable states towards particle emission through the method of correlation functions (GARFIELD + Rco) M. D’Agostino et al. Nucl.Phys. A 875 (2012) 139 d+ p+7Li p+12C 8Be* 13N* 6Li* 2
Evidence of Strong deformation in alpha-like nuclei 24Mg+24Mg @92 MeV, (8pLP + PPAC modules) a detected in 8pLP, Residue detected in PPACs a-Residue angular correlation E F G BALL detector number a-Residues Angular correlation is better reproduced by assuming an Higly Deformed nucleus indicating a possible a-clustering stucture A. Di Nitto et al., EPJ Web of Conferences 21, 02002 (21012) CNR*11 Int. Conf., September 19-23, 2011 Prague, Czech Republic
Activities 2012-2013 Ideas for proposals at TANDEM-ALPI: 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, massdistributions 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 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 The aim of the present work is to perform an accurate high-statistics measurement of the 8B production cross section and angular distribution 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
Neutron emission angle in CM (deg) RIPEN @ CN Van de Graaf accelerator V.L. Kravchuk et al., To be published in Phys Rev. Special Topic – Accelerators and Beams 6 MeV 3He+6Li 8B + n 8Bg.s. 12C(3He, n)14O 8B* ds/dW (mb/Sr) Counts 6Li(3He,np)7Be g TOF (ns) 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 Medium-range plan 2012-2015 Coupling FAZIA + INDRA 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 Basic BLOCK: 4x4 telescopes WITH STABLE BEAMS & 1st DAY EXP with SPIRAL2 Transport properties of isospin asymmetric nuclear matter: neck emission and isospin drift 40,48Ca+40,48Ca at 15, 25, 35AMeV, 58Ni+58Ni at 30-45AMeV 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 2 KE (Riunioni collaborazione, turni LNS ) Missioni Estere 2 KE (riunioni analisi Ganil, Assemblaggio dimostratore Ganil) Consumo 1 KE (lavorazioni meccaniche, materiale test laboratorio) 8
SPARES
Fragments and Light Particles identification 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
RIPEN @ CN Produzione di 8B per studio di fattibilità di beta beam tramite la reazione 6Li(3He,n)8B RIPEN @ CN Positron Counting Technique Neutron TOF measurement P. Van Der Merwe et al., NPA 103 (1967) 474 Precedenti misure effettuate con tecniche diverse hanno dato valori di s di produzione del 8B differenti di un fattore 3 Misura ad alta statistica della distribuzione angolare e della sezione d’urto di produzione del 8B 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 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 Dq ≈ ±2o 7 6 1H 8 BC501 detectors covering angles from 15o to 140o in LAB 6LiF (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 Rutherford scattering of the beam on the Au backing is used as normalization to determine the 8B production absolute cross section