Half-life of ⁵¹Mn

Area of Science:

• Nuclear Physics
• Radioactive Decay Studies

Background:

• Accurate half-life measurements are crucial for nuclear science and applications.
• Previous values for the half-life of Manganese-51 (51Mn) may lack sufficient precision.

Purpose of the Study:

• To precisely determine the half-life of the isotope 51Mn.
• To provide an updated and highly accurate value for 51Mn half-life, potentially resolving discrepancies with existing data.

Main Methods:

• Serial gamma spectrometry was employed, focusing on the 511-keV annihilation photon from beta-plus (β+) decay.
• Data acquisition involved collecting counts every 100 seconds over extended periods (100,000–230,000 seconds).
• Analysis incorporated corrections for detector dead time, radioactive decay, and background contaminants like Cobalt-55 (55Co) using least-squares regression.

Main Results:

• The measured half-life of 51Mn was determined to be 45.59 ± 0.07 minutes.
• This represents the highest precision measurement of the 51Mn half-life achieved to date.
• The result shows a statistically significant deviation (over 6σ) from the currently accepted value in the Nuclear Data Sheets.

Conclusions:

• The precise half-life of 51Mn is 45.59 ± 0.07 minutes.
• This new value necessitates a revision of the official Nuclear Data Sheets for 51Mn.
• The high precision achieved underscores the reliability of the experimental methodology.