Helion magnetic moment to nuclear magneton ratio

$μₕ/μ_N$ = −2.127 625 3498(17)

Value: −2.127 625 3498
Standard uncertainty: 1.7 × 10⁻⁹
Relative uncertainty: 8.0 × 10⁻¹⁰ (799 parts per trillion)
Status: Measured
Symbol: $μₕ/μ_N$
Source: CODATA 2022 via NIST · NIST entry

Use in a calculation

# helion magnetic moment to nuclear magneton ratio, CODATA 2022 (NIST)
helion_magnetic_moment_to_nuclear_magnet = -2.1276253498  # standard uncertainty 1.7e-9

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

What it is

The magnetic moment of the helion, the nucleus of helium-3 (two protons and one neutron), expressed in nuclear 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	−2.127 625 3498(17)	8.0 × 10⁻¹⁰	−1.7 σ of 2018
2018	−2.127 625 307(25)	1.2 × 10⁻⁸	+0.0 σ of 2014
2014	−2.127 625 308(25)	1.2 × 10⁻⁸	−0.1 σ of 2010
2010	−2.127 625 306(25)	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).