Helion magnetic moment to Bohr magneton ratio

$μₕ/μ_B$ = −1.158 740 980 83(94) × 10⁻³

Value: −1.158 740 980 83 × 10⁻³
Standard uncertainty: 9.4 × 10⁻¹³
Relative uncertainty: 8.1 × 10⁻¹⁰ (811 parts per trillion)
Status: Measured
Symbol: $μₕ/μ_B$
Source: CODATA 2022 via NIST · NIST entry

Use in a calculation

# helion magnetic moment to Bohr magneton ratio, CODATA 2022 (NIST)
helion_magnetic_moment_to_bohr_magneton_ = -1.15874098083e-3  # standard uncertainty 9.4e-13

# SciPy: scipy.constants.physical_constants['helion mag. mom. to Bohr magneton ratio']

What it is

The magnetic moment of the helion, the nucleus of helium-3 (two protons and one neutron), expressed in Bohr magnetons.

How the value changed, 1998–2022

Each point is one CODATA adjustment, plotted as its difference from the 2022 value; the bars show one standard uncertainty (an arrowhead means the bar runs off the chart).

Relative uncertainty

CODATA	Value (uncertainty)	Relative uncertainty	Change from previous
2022	−1.158 740 980 83(94) × 10⁻³	8.1 × 10⁻¹⁰	−1.6 σ of 2018
2018	−1.158 740 958(14) × 10⁻³	1.2 × 10⁻⁸	+0.0 σ of 2014
2014	−1.158 740 958(14) × 10⁻³	1.2 × 10⁻⁸	+0.0 σ of 2010
2010	−1.158 740 958(14) × 10⁻³	1.2 × 10⁻⁸

“Change from previous” is the shift in the value divided by the standard uncertainty of the previous adjustment. Earlier values are converted into the current unit where NIST changed it (for example J s to J Hz⁻¹).