Chopped Cold Neutron Beam Activation Analysis

Area of Science:

• Nuclear Physics
• Analytical Chemistry
• Materials Science

Background:

• Prompt Gamma Activation Analysis (PGAA) traditionally requires sample transfer for analyzing neutron capture products.
• Short-lived isotopes pose challenges due to their rapid decay, necessitating rapid analysis techniques.
• Existing methods may lack the precision for quantitative analysis of specific isotopes.

Purpose of the Study:

• To design and implement a linear fast neutron beam chopper for in-beam activation analysis.
• To enable the analysis of short-lived neutron capture products without sample transfer.
• To demonstrate the system's capability for quantitative analysis and peak separation.

Main Methods:

• Deployment of a linear fast neutron beam chopper at a PGAA instrument.
• In-beam activation analysis of short-lived isotopes (T1/2 > ~10 ms).
• Optimization of chopper timing for specific isotopes (Se-77, Yb-175m, Dy-165).
• Utilizing time-stamped list mode data acquisition for peak separation.

Main Results:

• Successful in-beam activation analysis of short-lived isotopes was achieved.
• The system demonstrated quantitative analysis capabilities through linear response to mass increments.
• Optimized chopper timing showed advantages for specific isotope analysis.
• Separation of overlapping energy peaks was demonstrated using list mode data.

Conclusions:

• The linear fast neutron beam chopper effectively enables in-beam activation analysis of short-lived isotopes.
• The system is suitable for quantitative analysis and offers advantages in isotope-specific measurements.
• Time-stamped data acquisition aids in resolving complex spectra.