L. Zimmermann , E. Füri , J. Boulliung, and J. M. Saxton
Geochemistry, Geophysics, Geosystems – METHOD 10.1029/2025GC012247
Voir en ligne : https://doi.org/10.1029/2025GC012247
The Noblesse–HR noble gas mass spectrometer was designed for multicollection analyses of different sets of noble gas isotopes with a fixed detector array under static conditions. At the Centre de Recherches Pétrographiques et Géochimiques (CRPG, Nancy, France), we developed a novel procedure to measure nitrogen (N2) abundance and isotope ratio (28N2/29N2) using the 3 Faraday–4 Multiplier (3F4M)0 system. This procedure simultaneously acquires ion signals for 14N14N+ (Fa2), 15N14N+ (Fa1), and 15N15N+(IC0). An in‐house‐built purification system ensures ultra‐low blank levels (≤1 × 10 12 mol N2), while air standard measurements monitor detector sensitivity and instrumental mass fractionation. Here, we assess the effects of the source and zoom optics settings on mass resolution (MR), mass resolving power (MRP), and peak alignment, and identify potential contributions from interfering species. The performance of the Noblesse–HR for multicollection Ne‐Ar‐N2 analyses was evaluated over several months and across varying gas quantities introduced into the mass spectrometer. Average sensitivities, with 1σ relative scatter, were 5.05 × 10 5 A/Torr ±1.02% for 20Ne, 2.86 × 10 4 A/Torr ±1.37% for 36Ar, and 1.18 × 10 4 A/Torr ±1.90% for N2. Corresponding isotopic ratios were 20Ne/22Ne = 9.80 ± 0.34%, 21Ne/22Ne = 2.90 × 10 2 ± 1.53%, 40Ar/36Ar = 296.19 ± 0.10% (over 20 days), 38Ar/36Ar = 0.1876 ± 0.28%, and 28N2/29N2 = 135.92 ± 0.05%. These results demonstrate that the 3F4M Noblesse–HR provides precise, accurate, and reproducible data, adapted for studying planetary materials.