Download presentation
Presentation is loading. Please wait.
1
GAMMA-PARTICLE ARRAY FOR DIRECT REACTION STUDIES SIMULATIONS
2
PHYSICS CASE : DIRECT REACTION STUDIES Key experiments: Mapping of single-particle energies using transfer reactions 78 Ni(d,p) 79 Ni @ 10 MeV/u 132 Sn(d,p) 133 Sn @ 10 MeV/u Reactions : Elastic and inelastic scattering Transfer reactions A SUB-TASK: SINGLE-PARTICLES and COLLECTIVE PROPERTIES Integrated particle and gamma detection system : Direct reactions studies
3
Detection challenges for (d,p) reactions 78 Ni(d,p) 79 Ni @ 10 MeV/u A Challenges: Kinematics compression ->Ep good resolution States separated by 1 MeV ->~200 keV in Ep Covers large range in θ _lab(deg) ->4pi ang cover Deposit of low Energy->Threshold problems Doppler Broadening Measurements->Obervables Ep and/or E ->Ex θ p -> d σ/d -> (l, SF) θ _lab(deg) Energy (MeV)
4
B. Integrated particle and gamma detection system : Direct reactions studies PARTICLES TO BE DETECTED : Beam-like particles Spectrometer Charged Particles Particle Array Solid-angle of 4 PID with ( x~0.1,0.5 mm and ~ 1-5 mrad) Large dynamic range with PID to Z=10 Gamma and fast charged particles Gamma Array Solid-angle of 4 Best efficiency and resolution PID with ( x~0.1,0.5 mm and ~ 1-5 mrad) Particle Array Gamma Array RIBs Ancillary detectors: Spectrometer, Neutron array, …
5
78 Ni(d,p) 79 Ni @ 10 AMeV Particle array (Simulations)
6
PARTICLE ARRAY: Simple Geometry Distance to (0,0,0) = 5 cm Box of 4 Silicon detectors : Area =10*10 cm2 Detector Thickness =400um Isotropic source: protons kinematics from reaction placed at (0,0,0) No target X Z Y INPUT: Energy Resolution Strip pitch size Thickness detector (punch through) Target thickness effect STUDY of the θ and Ex
7
PARTICLE ARRAY: Energy Resolution Energy (MeV) θ _lab(deg) 10 keV 50 keV100 keV Energy and angle correlated -> need to fix one variable, Eproton Ep=2,3,4,5,6 MeV -> θ and Ex (FWHM) E= 50 keV reasonable value
8
PARTICLE ARRAY: Angular Resolution Unnoticeable dependence with the strip sizes explored. If Strip pitch ~ 1mm ->number of channels for 10 cm detector 100*100=10000 6 detectors =6x10000 channels (pad-type detector)
9
200 μm thick 400 μm thick 15000 μm thick ~ 40 times thicker t The tickness determines the upper limit in Total energy and angle before the particles punch-through. The energy rises steadily and therefore not much gain in angular distributions PARTICLE ARRAY: Thickness detector
10
PARTICLE ARRAY: Ex Resolution Ex=f(Ep, θ ) Strip size small influence on the Ex resolution
11
PARTICLE ARRAY: Target Effect Effect of the angular and energy loss straggling on the θ, Ex X Y Z Target thickness 0.5 mg/cm2 1 mg/cm2 2 mg/cm2 Isotropic source of protons @ (0,0,0) Strip pitch and thickness fixed = 1mm, 400μm
12
PARTICLE ARRAY: Angular Resolution (target in) At high energies, emission angles close to 90 degrees, protons see more material
13
PARTICLE ARRAY: Ex Resolution (target in) Ex ~ 140 keV (0.5mg/cm2) Ex ~ 170 keV (1mg/cm2) Ex ~ 225 keV (2mg/cm2) for 4MeV
14
PARTICLE ARRAY: Excited States (no target) 79 Ni 1 MeV 2 MeV 78 Ni(d,p) 79 Ni * (Ex=1,2 MeV)
15
PARTICLE ARRAY: Excited States (target in) 79 Ni 1 MeV 2 MeV 78 Ni(d,p) 79 Ni * (Ex=1,2 MeV) 0.5 mg/cm21 mg/cm22 mg/cm2 Effect of the target thickness in the Energy- Angle distributions: Punch-through at lower Ep Low the Ep due to the energy loss ->threshold Increases the Ep -> difficult to separate states
16
PARTICLE ARRAY: Excited States (target in) Thicker target worsens the resolution in Ex
17
FURTHER WORK Study of the influence of the interaction point Full geometry implementation of the integrated charge particle and gamma particle Cross Sections implementation Reconstruction with CsI
18
78 Ni(d,p) 79 Ni at 10 AMeV Gamma array (simulations)
19
GAMMA ARRAY: VALUES OF GAMMA RAYS IN THE LAB : DOPPLER SHIFT Θ lab(degrees) ~ 0.2 -> 10 AMeV E =4 MeV -> [3.4,4.8] MeV ~ 0.3 -> 35 AMeV E =4 MeV -> [2.9,5.4] MeV E /E tot ~ E /E int + E /E dop
20
GAMMA ARRAY: RESOLUTION: DOPPLER BROADENING Θ lab(degrees) E /E (%) E lab = f( θ, ) -> E /E dop ~ f( θ ) E /E ~ 0.5 % E=1MeV -> 5 keV θ ~ 2 o D=8 cm Crystal Size θ 2.8 mm 2 o 3mm for a detector size of 12cm ->40x40 =1600 ch detector 6 detectors ->6x 1600=9600 channels
21
GAMMA ARRAY: RESOLUTION: INTRINSIC E /E int ~ F. Notaristefani NIM A480 (2002) 423-430 Other materials: LaBr3(Ce),LaCl2 To be studied E /E int ~ 50 keV
22
Distance to (0,0,0) = 8 cm Array of CsI detectors : Area =10*10 cm2 Detector Thickness = 20 cm Isotropic source gammas 1MeV at (0,0,0) GAMMA ARRAY: Simple Geometry
23
FURTHER WORK Study of different materials Influence of the particle detector in the gamma detection system
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.