Copper x unit = 1.002 076 97 × 10−13 m

Value
1.002 076 97 × 10−13
Unit
m
Uncertainty
0.000 000 28 × 10⁻¹³
Copy-ready
1.00207697e-13

The copper x unit, an X-ray wavelength unit defined from the copper Kα₁ line.

Used to read older X-ray diffraction literature quoted in x units.

NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.

Electrical, thermal and X-ray constants

Angstrom starConductance quantumCopper x unitElectron charge to mass quotientFermi coupling constantFirst radiation constantHartree energyJosephson constantLattice parameter of siliconLattice spacing of ideal Si (220)Loschmidt constant (273.15 K, 101.325 kPa)Magnetic flux quantumMolar mass constantMolar mass of carbon-12Molar Planck constantMolar volume of siliconMolybdenum x unitNeutron-proton mass differenceProton charge to mass quotientQuantum of circulationSackur-Tetrode constant (1 K, 101.325 kPa)Second radiation constantVon Klitzing constantWeak mixing angleWien frequency displacement law constantW to Z mass ratio

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All physical constants

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