The Inverse Kinematics Resonance Elastic Scattering Reaction of 10,11,12Be+p

Liu Yingdu(刘应都 ) PHD candidate

Advisor：Wang Hongwei, Ma Yugang

2013.01.10

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 i

n recent nuclear physics experiments, because it can provide us mor

e important information about the nuclear structure and inter-action, i

ncreasing our understanding on the behavior of nuclear matter at the

extreme neutron to proton ratios.

The interesting nuclei 10Be,11Be and 12Be resonance elastic scatt

ering reaction

The energy structure and width of 11B determination still exists debate;

H.T.Fortune, Phys. Rev. C 74,034328 (2006);

F.C.Barker, Phys. Rev. C 76,027602 (2007);

Taken from :http://www.tunl.duke.edu/nucldata

No experimental result has been No experimental result has been reported in 10Be+p resonance elastic reported in 10Be+p resonance elastic scattering reactionscattering reaction Energy level data come from Energy level data come from TTUNL UNL and capture reaction and capture reaction

Measurement of Excitation function 10Be+pMeasurement of Excitation function 10Be+p→11B(11Be)→11B(11Be)

Simulation by R-matrix Simulation by R-matrix depends on these datadepends on these data

According to R-Matrix calculationAccording to R-Matrix calculation ，， for first resonance statefor first resonance state ，， if its spin-parity is if its spin-parity is 2+2+ （（ excited state energy is 14.82MeVexcited state energy is 14.82MeV ），）， the orbit angular momentum number is the orbit angular momentum number is L=2L=2 ，， the single particle energy level width the single particle energy level width is is 5.7keV5.7keV ，， the calculated resonant the calculated resonant statestate is a very sharpis a very sharp peak peak, and second will be flat peak , and second will be flat peak at at L=0L=0 ，， J=0+J=0+..

Until now , No resonance elastic scattering data have been reportedUntil 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+pMeasurement of Excitation function 11Be+p→12B(12Be)→12B(12Be)

13Be is a13Be is ann unbound n unbound neutron emitter, theoreeutron emitter, theoretical predict it has a tical predict it has a very low S wavevery low S wave （ Jπ=1/2+ ） or or P waveP wave （ Jπ=1/2- ） ground state state. . But untill now, itBut untill now, itss e energy level ,spin-parinergy level ,spin-parity are not confirmed ity are not confirmed in experiment.n experiment.

Measurement of Excitation function 1Measurement of Excitation function 122Be+pBe+p→13B(13Be)→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

Low-Z re

coil

The 10Be(p,10Be)p is an inverse kinematical resonant elastical reaction using the TTIK method!!!

QEE

EA

AE

cmx

plab

cm

2cos4

1

Experimental MethodExperimental Method

Parameters of RIBLL1

HIRFL HIRFL 1818OO8+8+

59.62MeV/59.62MeV/uu ，， 200enA200enA

Target BeTarget Be4616um4616um

Wedge AlWedge Al3060um3060umHomogeneousHomogeneous TOF startTOF start

CC99HH1010 50um 50um

C1 -SlitC1 -Slit 10 mm10 mm

C2- SlitC2- Slit 15 15 mmmm

10,1110,11BeBe7.2MeV/u7.2MeV/u

2012 RIBLL1 10Be+p main parameters ： 主束能量： 18o, 59.62MeV/u

初级靶 ： 9Be, 4616um ； 降能片 ： Al, 3060um ； 次级束 : 10Be,~7.2MeV/u ； 次级靶 : CH2, 41.85mg/cm2

Experiment Introduction

Experiment Introduction

Setup of Experiment 10Be+p

Some pictures

BeamBeam

Position Sensitive silicon detector→ position calibration Position Sensitive silicon detector→ position calibration

PPAC calibrationPPAC calibration

Data Analysis

Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon background4 ） Energy loss correction in PE target

Figure1: ∆E-ToF scattering plot

Figure2: PID of experiment and TOF cut ， 10Be purity ~92%

1010Be Beam TunningBe Beam Tunning

1212Be Beam TunningBe Beam Tunning

1212BeBe

1111BeBe1010BeBe

99LiLi

66HeHe

88LiLi77LiLi66LiLi

44HeHe

88HeHe

1414BB

1313BB1212BB

1111BB

No enough time for 12Be in tNo enough time for 12Be in this beam time.his beam time.

Can't be selectCan't be selecteded by simple by simple TOF cut, thin silicon ΔE detectoTOF cut, thin silicon ΔE detector must be used.r must be used.

At the same time, At the same time, bbig Accelerig Accelerator question, Beam Stop. Silicoator question, Beam Stop. Silicon detector Deadn detector Dead..

Give upGive up

Test Result: 100Test Result: 100 Count/s foCount/s for 12Be beam, purity about 60r 12Be beam, purity about 60%.%.

Include : 1 ） PID befor target 2 ） PID after target 3 ） Subtract of Carbon bkg4 ） Energy loss correction in PE

target

1111LiLi

1414CC

1155CC

Data Analysis of 10Be

Compare with Lise++ calculationRed 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 bkg4 ） Energy loss correction in PE target

Data Analysis

c

ch

beamc

beamchp n

n

N

NN 2

_

_2

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 bkg4 ） 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 bkg4 ） Energy loss correction in PE target

Data Analysis

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

mmmm 28.012

1

)

||||

arccos(

scav

sca

vbeam

vbeamvsca

Data Analysis---Scattering angle

1. Beam direction were determined by the PPACs

sca

2. Recoil protons direction was determined by the Position Sensitive Silicon Detectors '

mmmm 9.012

125.3

Data Analysis-Ecm

psca

Hcm E

M

MME

Be

Be

2cos4 10

10

Preliminary resultPreliminary result

More work need to do....More work need to do....

Thank you! 请多指教 !!