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β-delayed neutron spectroscopy using trapped radioactive ions.
R M Yee1, N D Scielzo, P F Bertone
1Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Physical Review Letters
|March 19, 2013
Summary
A new method uses trapped ions for beta-delayed neutron spectroscopy, reconstructing neutron energies from nuclear recoil. This technique overcomes challenges in direct neutron detection for improved accuracy in nuclear physics research.
Area of Science:
- Nuclear Physics
- Atomic Physics
- Spectroscopy
Background:
- Beta-delayed neutron emission is crucial for understanding nuclear structure and reactions.
- Traditional neutron spectroscopy faces challenges like detector backgrounds and complex response functions.
- Trapped ion techniques offer novel approaches for precision measurements in nuclear science.
Purpose of the Study:
- To demonstrate a novel technique for beta-delayed neutron spectroscopy using trapped ions.
- To reconstruct the neutron-energy spectrum by measuring nuclear recoil time-of-flight.
- To overcome limitations of conventional neutron detection methods.
Main Methods:
- Utilized a linear Paul trap to confine Iodine-137 (137I(+)) ions from a Californium-252 (252Cf) source.
- Measured the time-of-flight of nuclear recoil ions following neutron emission.
- Detected beta(-) and recoil ions in coincidence with surrounding radiation detectors.
Main Results:
- Successfully demonstrated beta-delayed neutron spectroscopy with trapped ions.
- Reconstructed the neutron-energy spectrum by analyzing nuclear recoil kinematics.
- Determined the branching ratio through three independent methods to explore systematic effects.
Conclusions:
- The trapped ion technique provides a viable alternative to direct neutron detection for spectroscopy.
- This method mitigates challenges related to scattered neutrons, gamma rays, and detector response functions.
- Future improvements can enhance detection efficiency, energy resolution, and lower the neutron energy threshold.
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