The ¹²C(n, 2n)¹¹C cross section from threshold to 26.5 MeV

Area of Science:

• Nuclear Physics
• Nuclear Reactions
• Neutron Cross Section Measurements

Background:

• Accurate nuclear reaction data is crucial for applications in nuclear energy, medicine, and fundamental science.
• Previous measurements of the ¹²C(n, 2n)¹¹C reaction have shown significant discrepancies, falling into distinct upper and lower bands.
• Understanding neutron interactions with carbon is important for reactor physics and neutron dosimetry.

Purpose of the Study:

• To precisely measure the ¹²C(n, 2n)¹¹C cross section over a wide energy range.
• To resolve discrepancies in existing experimental data for this reaction.
• To provide reliable nuclear data for ¹¹C production and related applications.

Main Methods:

• Utilized a Pelletron accelerator to produce monoenergetic neutrons via the ³H(d,n)⁴He reaction.
• Irradiated polyethylene and graphite targets with neutrons, ranging from near threshold to 26.5 MeV.
• Measured ¹¹C activation by detecting positron annihilations and gamma rays using NaI detectors in coincidence and singly.
• Determined incident neutron flux indirectly by measuring elastically scattered protons from polyethylene (¹H(n,p)).

Main Results:

• The measured ¹²C(n, 2n)¹¹C cross section data were obtained from just below the reaction threshold up to 26.5 MeV.
• The experimental results are in good agreement with the upper band of previously reported measurements.
• This study provides a new, consistent dataset for the ¹²C(n, 2n)¹¹C reaction.

Conclusions:

• The findings help to resolve ambiguities in the existing experimental database for the ¹²C(n, 2n)¹¹C cross section.
• The data supports the upper band of previous measurements, offering a more refined understanding of this nuclear reaction.
• This work contributes valuable cross-section data for nuclear astrophysics, medical isotope production, and fundamental nuclear physics research.