14be 库仑破裂实验准备
DESCRIPTION
14Be 库仑破裂实验准备. 哈尔滨工程大学 RIBLL 合作组会议 @ 兰州 2013.08 宋玉收. 内容提要. 背景 事件产生与探测器建模 靶厚与 PID 讨论 实验事件预估 总结. 库仑破裂研究丰中子核. M. Labiche et. al, prl86.600.2001. 库仑破裂应用. R rms (exp.) →. S 2n (exp.) and. 14Be 库仑破裂研究现状 实验数据有限,存在矛盾 数据与 11Li 、 6He 不同. S 2n =0.9MeV. S 2n =1.34MeV. 库仑破裂优势 - PowerPoint PPT PresentationTRANSCRIPT
14Be 14Be 库仑破裂实库仑破裂实验准备验准备
哈尔滨工程大学RIBLL 合作组会议 @ 兰州
2013.08宋玉收
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内容提要内容提要• 背景• 事件产生与探测器建模• 靶厚与 PID 讨论• 实验事件预估• 总结
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库仑破裂研究丰中子核库仑破裂研究丰中子核• 库仑破裂应用
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M. Labiche et. al, prl86.600.2001
• 14Be 库仑破裂研究现状o 实验数据有限,存在矛盾o 数据与 11Li 、 6He 不同
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S2n (exp.) andRrms (exp.) →
S2n=0.9MeV S2n=1.34MeV
• 库仑破裂优势o 针对滴线核束流弱,截面大;o 外围碰撞,产物前向运动,可以前向角布置探测器;
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实验装置示意图
Nuclear reaction in G4Nuclear reaction in G4• G4 nuclear reaction models
o Binary Cascadeo Abrasion & Ablationo QMDo EMD
• Not feasible for our problem
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14Be
Kinematics Kinematics
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Pb
14Be
14Be*12Be
2n
12Be+n+n
14Be*
Inelastic scatteringInelastic
scattering
DissociationDissociation
S2n
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The inelastic scattering of 14Be on Pb target
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The breakup of excited 14Be
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12Be kinematic information
2n kinematic information
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14Be before EMD14Be before EMD• Reaction position• Momentum direction• Kinetic energy
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z
P
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M. Labiche et. al, prl86.600.2001 570mg/cm2 ~500 m
Position distribution
r
Z
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Spectrum SettingSpectrum Setting
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Target thicknessTarget thickness
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M. Labiche et. al, prl86.600.2001 : 0.503 mm
beam profile
energy smearing (8MeV, ~1.6%)
Incident direction
Target thickness (mm)
Ion telescope resolution
Neutron wall resolution & threshold
N Y N 0.5 Y N
N Y N 1.0 Y N
N Y N 1.5 Y N
N Y N 1.8 Y N
Influence on PIDInfluence on PID
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12Be
14Be
Time of Flight
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Pb Target 0.5mm
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incident TOF TOF&E-E
12Be 600,000 55911 54898
14Be 15,000,000 6441 1366
According to EMD cross section:(1)The purity of 12Be with the PID cut is
80%=54898/(54898+13660)(2)12Be loss rate because of E-E Cut is ignorable
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Pb Target 1mm
Particle Identification becomes more difficult
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Pb Target 1.5mm
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Pb Target 1.8mm
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14Be
14Be*
12Be+n+nS2n
2120 2 cmmE nBe
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Pb Target 0.5mm
Pb Target 1mm
Red: spectrum setBlack: spectrum reconstructed
Red: spectrum setBlack: spectrum reconstructed
PRELIMINARY
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200enA 的 18O 作为入射初级束, 3500um 的 9Be 作为初级靶,降能器为 2000um 的 Al ,分离提纯后的 14Be ,能量为 35AMeV ,能量展宽约 8MeV ( ~1.6% ),流强约为 20 pps.
24 23N 2.3 10 20 3600 0.6 / 207.2 6.022 10 9%
26.0 (/ )hour
==
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2.3 10 14Be dissociation cross section (2.3b)
20 3600 14Be beam intensity 20pps
0.6 / 207.2 6.022 10
thickness of Pb target 0.6g/cm ,
Pb
360
mass number 207
0 /s h
.2g/mol
9% two-neutron efficiency of MuNCos
26.0/hour*100hour=2600
20Ne ( 80AMeV, 100enA )
SummarySummary• M. Labiche et. Al (prl86.600.2001) chose the
target with a thickness of 570mg/cm2 ~500 m;• According to our simulation 1mm is still a feasible
thickness;• Thicker target will crack the reconstructed
spectrum;• To be done:
o Real three-body kinematic calculation;o Create GEANT4 Physics process to handle EMD reaction of 14Be on Pb
target;o Considering optical process of neutron wall and CsI;o Considering neutron wall in more detail;
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谢谢!谢谢!
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