Construction of a Newly Designed Small-Size Mass Spectrometer for Helium Isotope Analysis: Toward the Continuous Monitoring Of 3He/4He Ratios In Natural Fluids

Bajo, K.; Sumino, Hirochika; Toyoda, Michisato; Okazaki, Ryuji; Osawa, Takahiro; Ishihara, Morio; Katakuse, Itsuo; Notsu, Kenji; Igarashi, George; Nagao, Keisuke

doi:10.5702/massspectrometry.a0009

Cited by 4 publications

(1 citation statement)

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“…In order to apply the infiTOF for on-site helium isotope analysis in the future, removal of other gas species and improvement of the sensitivity defined by (helium count rate)/(helium flow rate into the ion source) is necessary. A simple helium separation system from a gas/water sample using a hot silica glass wall, as demonstrated by Bajo et al, 26 is a good prospect for this purpose.…”

Section: ■ Methodsmentioning

confidence: 99%

Instrumentation and Method Development for On-Site Analysis of Helium Isotopes

et al. 2017

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Helium isotope determination may be useful in measuring volcanic activity and issuing earlier warnings of possible eruptions. A method is presented for measuring the He/He ratio in a gas sample using a multiturn time-of-flight mass spectrometer "infiTOF". In contrast to conventional waveform averaging, peaks are determined by counting ion pulses from each time-of-flight trigger. Samples were also measured by conventional magnetic-sector mass spectrometry for comparison. Magnetic sector results were used to designate a standard for infiTOF measurement and to calculate a ratio for each sample measured by infiTOF. Mass assignment error for ultrapure He standard was 4.30 × 10 Da. Mass assignment error of He and He for sample cylinders was 3.00 × 10 Da and 2.25 × 10 Da, respectively. Abundance ratios determined by infiTOF were found to be within 2% of the abundance ratios determined by magnetic-sector mass spectrometry. Mass drift was <50 × 10 Da over 10 h. Sample flow rate was not found to affect the results as long as the reference sample was analyzed under the same conditions. Results indicate that the infiTOF system may be a viable tool for measuring helium isotopes, which may eventually lead to earlier warnings of volcanic activity.

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Section: ■ Methodsmentioning

confidence: 99%

Instrumentation and Method Development for On-Site Analysis of Helium Isotopes

et al. 2017

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Differential Diffusion of Helium Isotopes in Glass, Quantum-tunneling 3He Enrichment, and Portable 3He/4He Monitoring of Mantle Processes

McMurtry

DeLuze²,

Hilton

et al. 2019

Sci Rep

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While studying the scientific and engineering aspects of a field-portable 3He/4He ratio detector, we found elevated ratios at comparatively lower temperatures that appear to result from differential diffusion of these isotopes in pure quartz glass. The 3He enrichment relative to 4He in lab air, expressed as the ratio R and normalized to the accepted 3He/4He ratio of 1.40 E-06 (Ra), ranges from peak values of about 200 to 600 in dry static samples. Even at the maximum classical 3He/4He diffusivity ratio of 1.15, the expected R would be only 1.61 E-06. Within a narrow temperature window, the air value in our experimental set up with pure quartz glass can range from about 2.70 to 8.20 E-04, or nearly 1000 times the expected enrichment based upon classical fractionation. When plotted versus temperature, the narrow 3He net partial pressure peak reveals at least three sharper embedded peaks that may be quantized vibrational entrance states in quartz glass which are temperature specific. This discovery has implications for relatively low-energy industrial enrichment of scarce 3He from natural sources on Earth, and for radiogenic and cosmogenic helium dating assumptions in natural glasses. It also has bearing upon designs for field portable 3He/4He ratio detectors aimed at earthquake and volcanic eruption studies, and monitoring of nuclear sites.

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Deep‐Seated Fluids in Thermal Waters Before and After the 2016 Kumamoto Earthquakes

Tsunomori,

Morikawa,

Takahashi

2024

Groundwater

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Noble gases, oxygen‐hydrogen isotope ratios, and ion compositions were measured at three sampling points (KUM, OTN, and ASO) from December 2013 to July 2021. The 3He/4He values at the three sampling points remained stable in the range of 3–4 Ra throughout the observation period, suggesting that the supply of deep‐seated gases to the aquifer was stable. The 4He/20Ne values of KUM and OTN indicate that the supply of surface‐source fluids to the aquifer decreased relative to that of deep‐seated fluids at KUM and OTN. In contrast, in the ASO site, both the surface‐ and deep‐seated fluids supplied to the aquifer were stable. The δD–δ18O relationship indicated the supply of deep‐seated water to the KUM and OTN aquifers but not to the ASO aquifer. Nevertheless, the δD–δ18O relationship remained stable throughout the observation period, suggesting that the supply of deep‐seated water to the three stations was stable. The Li/Cl and 1/Cl relationships for the three sampling points were plotted within a narrow range throughout the observation period, suggesting that the groundwater recharge was stable. Neither spikes nor step changes owing to the 2016 Kumamoto earthquake were observed in any of the data. These results indicate that the KUM and OTN aquifers are constantly supplied with deep fluids from the fluid‐rich zone beneath the Kumamoto region, and that only deep‐seated gas was supplied to the ASO aquifer. We also confirmed that these supply conditions were unaffected by the 2016 Kumamoto earthquake or the subsequent aftershock activity.

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Construction of a Newly Designed Small-Size Mass Spectrometer for Helium Isotope Analysis: Toward the Continuous Monitoring Of 3He/4He Ratios In Natural Fluids

Cited by 4 publications

References 20 publications

Instrumentation and Method Development for On-Site Analysis of Helium Isotopes

Instrumentation and Method Development for On-Site Analysis of Helium Isotopes

Differential Diffusion of Helium Isotopes in Glass, Quantum-tunneling 3He Enrichment, and Portable 3He/4He Monitoring of Mantle Processes

Deep‐Seated Fluids in Thermal Waters Before and After the 2016 Kumamoto Earthquakes

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