Relative sensitivities of Bayard–Alpert gauges and a quadrupole mass spectrometer for hydrogen isotope molecules

Abstract

To apply mass spectrometers and ionization gauges to thermonuclear fusion devices such as pressure gauges, we measured the relative sensitivities (normalized to H2) of Bayard–Alpert (B–A) gauges (UGD‐1S and UGS‐1A, ANELVA Co.) and a quadrupole mass spectrometer (MSQ‐150A, ULVAC Co.) for hydrogen isotopes. In the case of the B–A gauges, the relative sensitivities were determined as RHDB=1.07, RD2B=0.99, RHTB=1.03, RDTB=0.97, and RT2B =0.95. In the case of the quadrupole mass spectrometer, they were RHDM =1.09, RD2M =0.99, RHTM =1.06, RDTM =0.96, and RT2M =0.88. These values agreed quite well with those observed by Dibeler et al. for the mass spectrometer of the magnetic deflection type. It was revealed that the relative sensitivities of the quadrupole mass spectrometer were essentially the same as those for the B–A gauges except T2.