Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Manipulated Gamma Spectroscopy:
Methodologies and Applications
Saed Dababneh•Al-Balqa Applied University, JORDAN.• Forschungszentrum Karlsruhe, GERMANY.• University of Notre Dame, USA.• Joint Institute for Nuclear Astrophysics, USA.• CERN.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Why … ?• Efficiency• Signal-to-Background Ratio• Correction Factors• Interference• True Coincidence (Summing)• Random Coincidences• …
For What…?• Nuclear Structure• Environmental• Material• Nuclear Astrophysics• Medical• Industrial• …
• Composite detectors• Online vs. offline histogramming• Coincidence/anticoincidence• …
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
“Classical” Compton Suppression
• Online signal processing and hardware gating.• Anticoincidences. Kill good events !!!
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detector Spheres• Cost• Room• Availability• Passive Shielding
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detector Spheres
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
“Chronic” Corrections
• Geometry (Extended Source)• Self Absorption• True Coincidence Summing• Random Coincidences
Last Year !!
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Stellar Evolution (Overview)
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Thermonuclear Resonant Reactions
Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept. 2007.
Energy
Cro
ss s
ecti
on
EC
Resonance Strength
Low energy ?Barrier penetration
Yield 2 2 Background ??
QTarget
Projectile
Compound Nucleus
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Specific ProblemNeutron sources for the s-process
14N(, )18F(+)18O(, )22Ne(,n)
12C(p, )13N(+)13C(,n)
At temperatures of interest:• Reaction rate is dominated by 2 resonances; 470 & 566 keV.• Never observed directly !• Estimated resonance strengths. • Now: Improved detection sensitivity.• Measured resonance strengths.
18O +
770750660566470
22Ne
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
How … ?• Close Geometry • Granularity (if available)• Offline Analysis• Timing• Cosmic Suppression• Random Coincidences• Cascade Coincidences• Measured Corrections• Simulated Corrections• Avoid Calculations based on assumptions• …
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Experimental Setup for Accelerators
BGO
L ead shield
Beam
BGOClover
T arget
P las tic sc intillator
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Multiplicities
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Cosmic Suppression
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Random Coincidences
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Addback vs. Direct Mode
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Addback vs. Direct Mode
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Summing-in and -out
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Doppler Correction
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Various Modes of OperationIgnore scintillation No suppression.AnticoincidencesUse Pl. Scintillator Cosmic suppression.Use BGO Compton suppression.Coincidences (w/o cosmic suppression)Window on Clover + BGO Q-value gating.BGO window Cascade coincidences. Clover addback window Summing-in.Clover crystal window Summing-out.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Ultimate Data Reduction• Cosmic suppression.• Cascade coincidences. • Random coincidences.• Signal-to-background ratio…!!!
Offline
01.27
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detection Sensitivity
• Low-energy ultra-weak resonance.• 10 days beam on target.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detection Sensitivity
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detection Sensitivity
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Detailed Coincidences
R
1.27
1 2 3 4
• Modes 1 & 2 are accounted for. Partial strength.• Bypasses over first excited state?
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
3-D Spectra
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
So what ?
• Improved detection sensitivity.• Bypass verification.• Weakest resonances detected.• Target stability.• Quantified reaction rate. Physical Review C 68, 025801 (2003)
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Setup for Small SamplesSample measured with 2 Clover detectors in close geometry.• Each Clover consists of 4 HPGe crystals.• Nearly 4π geometry High efficiency.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Singles vs. Coincidences
Phys. Rev. C
69 025803 (2004)
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
• Close geometry summing.• Classical correction needs TOTAL efficiency • MC total efficiency• If MC why not MC Summing correction
Validate MCWhat about e
fficiency
for c
oincidence
s??
Monte Carlo (Remember 2006…!!)
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Correction Factor using Experimental Data
16 % in Direct Mode
Confirmed by MC
Nuclear Instruments and Methods in Physics ResearchA 517 (2004) 230-239
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Finally …
Get spirit of ideasand
apply to your setup
Invest in yourself
www.dababneh.com/yarmouk07
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Many Thanks
www.dababneh.com/yarmouk07
Acknowledgement
Franz Käppeler, Michael Heil, Rene Reifarth, Ralf Plag, Iris Dillmann, Michael Wiescher, Joachim Görres, Nikolas Patronis, Shawn
O’Brien.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.
2007.
Again: Addback vs. Direct