First Results on a Scanning Ion Microprobe Equipped with an EHD-Type Indium Primary Ion Source

We have shown the feasibility of 20 nm lateral resolution in both topographic and elemental imaging using probes of this size from a liquid metal ion source (LMIS) scanning ion microprobe (SIM). This performance, which approaches the intrinsic resolution limits of secondary ion mass spectrometry (SIMS), was attained by limiting the size of the beam defining aperture (5μm) to subtend a semiangle at the source of 0.16 mr. The ensuing probe current, in our chromatic-aberration limited optical system, was 1.6 pA with Ga+ or In+ sources. Although unique applications of such low current probes have been demonstrated,) the stringent alignment requirements which they imposed made their routine use impractical. For instance, the occasional tendency of the LMIS to shift its emission pattern caused severe misalignment problems.

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An Ion Source for the HVEE 14C Isotope Ratio Mass Spectrometer for Biomedical Applications

Radiocarbon ◽

10.1017/s0033822200018154 ◽

1997 ◽

Vol 40 (1) ◽

pp. 283-288 ◽

Cited By ~ 7

Author(s):

Dirk J. W. Mous ◽

Wim Fokker ◽

Rein Van Den Broek ◽

Ron Koopmans ◽

Christopher Bronk Ramsey ◽

...

Keyword(s):

Biomedical Research ◽

Biomedical Applications ◽

Ion Source ◽

User Friendliness ◽

The Past ◽

Widespread Acceptance ◽

First Results ◽

Order Of Magnitude ◽

Isotope Ratio Mass Spectrometer ◽

Near Future

During the past two decades, accelerator mass spectrometry (AMS) has allowed major developments in many areas of geosciences and archaeology. In the near future, AMS should realize a similar potential in the field of biomedical research, leading ultimately to clinical applications. For such applications, the required instrument differs significantly from that presently used in the field of 14C dating. Whereas the needed accuracy and sensitivity is more than an order of magnitude less demanding than that for present state-of-the-art 14C instrumentation, the widespread acceptance of 14C AMS in biomedical research will require AMS spectrometers that are small, simple to operate and capable of handling CO2 samples. In order to satisfy these demands, HVEE has developed a compact 14C AMS spectrometer dedicated to biomedical research. The instrument consists of a compact accelerator with a footprint of 2.25 × 1.25 m and an ion source that features direct CO2 acceptance and optimal user friendliness. Having previously described the layout and design of the accelerator, we here discuss progress on the accelerator and present the design and first results of the CO2 ion source.

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Sensitive High Resolution Ion Microprobe (SHRIMP IIe/MC) of the Institute of Geosciences of the University of São Paulo, Brazil: analytical method and first results

Geologia USP Série Científica ◽

10.5327/z1519-874x201400030001 ◽

2014 ◽

Vol 14 (3) ◽

pp. 3-18 ◽

Cited By ~ 45

Author(s):

Kei Sato ◽

Colombo Celso Gaeta Tassinari ◽

Miguel Angelo Stipp Basei ◽

Oswaldo Siga Júnior ◽

Artur Takashi Onoe ◽

...

Keyword(s):

High Resolution ◽

Analytical Method ◽

Sao Paulo ◽

São Paulo ◽

Ion Microprobe ◽

First Results ◽

The University

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The quest for AMS of 182Hf – why poor gas gives pure beams

EPJ Web of Conferences ◽

10.1051/epjconf/202023202003 ◽

2020 ◽

Vol 232 ◽

pp. 02003

Author(s):

Martin Martschini ◽

Johannes Lachner ◽

Silke Merchel ◽

Alfred Priller ◽

Peter Steier ◽

...

Keyword(s):

Detection Efficiency ◽

Ion Source ◽

Negative Ion ◽

Complete Suppression ◽

Buffer Gas ◽

Novel Approach ◽

First Results ◽

Ion Laser ◽

R Process ◽

Ion Yields

The long-lived radioisotope 182Hf (T1/2 = 8.9 Ma) is of high astrophysical interest as its potential abundance in environmental archives would provide insight into recent r-process nucleosynthesis in the vicinity of our solar system. Despite substantial efforts, it could not be measured at natural abundances with conventional AMS so far due to strong isobaric interference from stable 182W. Equally important is an increase in ion source efficiency for the anions of interest. The new Ion Laser InterAction Mass Spectrometry (ILIAMS) technique at VERA tackles the problem of elemental selectivity in AMS with a novel approach. It achieves near-complete suppression of isobar contaminants via selective laser photodetachment of decelerated anion beams in a gas-filled radio-frequency quadrupole (RFQ) ion cooler. The technique exploits differences in electron affinities (EA) within elemental or molecular isobaric systems neutralizing anions with EAs smaller than the photon energy. Alternatively, these differences in EA can also facilitate anion separation via chemical reactions with the buffer gas. We present first results with this approach on AMS-detection of 182Hf. With He +O2 mixtures as buffer gas in the RFQ, suppression of 182WF5− vs 180HfF 5− by >105 has been demonstrated. Mass analysis of the ejected anion beam identified the formation of oxyfluorides as an important reaction channel. The overall Hf-detection efficiency at VERA presently is 1.4% and the W-corrected blank value is 182Hf/180Hf = (3.4 ± 2.1)×10−14. In addition, a survey of different sample materials for highest negative ion yields of HfF 5− with Cs-sputtering has been conducted.

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