The Inverse Kinematics Resonance Elastic Scattering Reaction of 10,11,12 Be+p Liu Yingdu( 刘应都 ) PHD candidate Advisor ： Wang Hongwei, Ma Yugang Shanghai Institute of Applied Physics(SINAP), CAS

Outline  Motivation;  The Experiment Introduction;  Data Analysis and the Preliminary Result;

Motivation  The study of exotic light nuclei far from the stability is a major issue in recent nuclear physics experiments, because it can provide us more important information about the nuclear structure and inter- action, increasing our understanding on the behavior of nuclear matter at the extreme neutron to proton ratios.  The interesting nuclei 10Be,11Be and 12Be resonance elastic scattering reaction

 The energy structure and width of 11 B determination still exists debate;  H.T.Fortune, Phys. Rev. C 74, (2006); F.C.Barker, Phys. Rev. C 76, (2007); Taken from :

 No experimental result has been reported in 10Be+p resonance elastic scattering reaction  Energy level data come from TUNL and capture reaction Measurement of Excitation function 10Be+p→11B(11Be) Simulation by R-matrix depends on these data

According to R-Matrix calculation ， for first resonance state ， if its spin-parity is 2+ （ excited state energy is 14.82MeV ）， the orbit angular momentum number is L=2 ， the single particle energy level width is 5.7keV ， the calculated resonant state is a very sharp peak, and second will be flat peak at L=0 ， J=0+. Until now, No resonance elastic scattering data have been reported.  Only two energy levels exist above 14MeV, and their spin-parities are still not clear Measurement of Excitation function 11Be+p→12B(12Be)

13Be is an unbound neutron emitter, theoretical predict it has a very low S wave or 13Be is an unbound neutron emitter, theoretical predict it has a very low S wave （ Jπ=1/2+ ） or P wave state. P wave （ Jπ=1/2- ） ground state. But untill now, its energy level,spin-parity are not confirmed in experiment. Measurement of Excitation function 12Be+p→13B(13Be)

 Thick Target Inverse Kinematics Method (TTIK) is a powfull tool for studying unstable neutron- riched nulei  (developed by K.P.Artemov et al. in 1990,Sov.J.Nucl.Phys.52,480(1990) ) Heavy Ion Beam Low-Z recoil The 10Be(p,10Be)p is an inverse kinematical resonant elastical reaction using the TTIK method!!! Experimental Method

Parameters of RIBLL1 HIRFL 18 O MeV/u ， 200enA Target Be 4616um Wedge Al 3060umHomogeneous TOF start C 9 H 10 50um C1 -Slit  10 mm C2- Slit  15 mm 10,11 Be 7.2MeV/u   2012 RIBLL1 10Be+p main parameters ：   主束能量： 18 o, 59.62MeV/u   初级靶 ： 9 Be, 4616um ；   降能片 ： Al, 3060um ；   次级束 : 10 Be,~7.2MeV/u ；   次级靶 : CH2, 41.85mg/cm2 Experiment Introduction

Setup of Experiment 10Be+p

Some picturesBeam

Position Sensitive silicon detector→ position calibration PPAC calibration

Data Analysis  Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon background 4 ） Energy loss correction in PE target Figure1: ∆E-ToF scattering plot Figure2: PID of experiment and TOF cut ， 10Be purity ~92% 10 Be Beam Tunning

12 Be Beam Tunning 12 Be 11 Be 10 Be 9 Li 6 He 8 Li 7 Li 6 Li 4 He 8 He 14 B 13 B 12 B 11 B  No enough time for 12Be in this beam time.  Can't be selected by simple TOF cut, thin silicon ΔE detector must be used.  At the same time, big Accelerator question, Beam Stop. Silicon detector Dead.  Give up  Test Result: 100 Count/s for 12Be beam, purity about 60%.   Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon bkg 4 ） Energy loss correction in PE target 11 Li 14 C 15C15C15C15C

Data Analysis of 10 Be Compare with Lise++ calculation Red point: Lise++ ； Brown point: experimental data Compare with GEANT4 Simulation. Red Point: Geant4 ； Brown point: Experimental data.   Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon bkg 4 ） Energy loss correction in PE target

D ata Analysis protons come from ： (a) 10Be + H (b) 10Be + C and other material around (c) other particles + C and material around deduction method ： 10Be+C exp. ; deducted per energy bin. the relationship of energy bins and mass thickness Carbon Background spectrum   Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon bkg 4 ） Energy loss correction in PE target

Data Analysis -Underconstruction  proton energy loss in PE target correction proton elastic, detector (CH2)n ∆Ep Ep Figure: ∆Ep-Ep relationship (not the final result )   Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon bkg 4 ） Energy loss correction in PE target

Data Analysis Ene Loss cal ： Gean4 & Lise++ 、 difference < 5%

Data Analysis---Scattering angle 1. Beam direction were determined by the PPACs 2. Recoil protons direction was determined by the Position Sensitive Silicon Detectors '

Data Analysis-Ecm Preliminary result More work need to do....

Thank you! 请多指教 !!