High Energy Primary Ions Research Articles

Recent Advances in Single-Cell Metabolomics Based on Mass Spectrometry

Recent Advances in Single-Cell Metabolomics Based on Mass Spectrometry

Examination of ion beam induced damage on polymer surface using Ar clusters

The damage of polymer surfaces caused by the high energy primary ion beams of TOF‐SIMS was examined using Ar cluster ions. Polymer damage, the damage of secondary ions detected from the polystyrene surface and the damage layer formed by the Bi3 primary ion beam have previously been studied. In this study, the damage observed in the secondary ions was studied by using Ar cluster primary ions. The secondary ions were mainly classified into two types, ions reflecting the polystyrene structure and cyclized ions, generated by excessive energy, which are not useful for qualitative analysis. The layer damaged by irradiation of the Bi3 primary ion regarding PS samples was confirmed using Ar cluster sputtering beams. The depth of the layer that has chemical damage in the PS main chain caused by 30 kV Bi3++ (ion dose: 5 × 1012 ions/cm2) irradiation was approximately 50–60 nm. The Ar cluster ion sputter rate in PS decreases with the Bi3 ion irradiation. Micro PS particles that are not able to be detected by a conventional TOF‐SIMS measurement can be effectively analyzed by accumulating the secondary ions over the static limit using Ar cluster sputtering. Copyright © 2016 John Wiley & Sons, Ltd.

Total and Partial Fragmentation Cross-Section of 500 MeV/nucleon Carbon Ions on Different Target Materials

By using an experimental setup based on thin and thick double-sided microstrip silicon detectors, it has been possible to identify the fragmentation products due to the interaction of very high energy primary ions on different targets. Here we report total and partial cross-sections measured at GSI (Gesellschaft fur Schwerionenforschung), Darmstadt, for 500 MeV/n energy $^{12}C$ beam incident on water (in flasks), polyethylene, lucite, silicon carbide, graphite, aluminium, copper, iron, tin, tantalum and lead targets. The results are compared to the predictions of GEANT4 (v4.9.4) and FLUKA (v11.2) Monte Carlo simulation programs.

One Hundred Years of Isotope Geochronology, and Counting

In 1913, Frederick Soddy's research on the fundamentals of radioactivity led to the discovery of “isotopes.” Later that same year, Arthur Holmes published his now famous book The Age of the Earth, in which he applied this new science of radioactivity to the quantification of geologic time. Combined, these two landmark events did much to establish the field of “isotope geochronology” – the science that underpins our knowledge of the absolute age of most Earth (and extraterrestrial) materials. In celebrating the centenary, this issue brings together modern perspectives on the continually evolving field of isotope geochronology – a discipline that reflects and responds to the demands of studies ranging from the early evolution of the Solar System to our understanding of Quaternary climate change, and the 4.5 billion years in between. * Accuracy : The closeness of agreement between a measured quantity value and a true quantity value Decay constant (λ) : The reciprocal value of the average lifetime of a radionuclide, which is the time over which a population of parent radionuclides is reduced by 1/e times its initial value. The half-life of a radionuclide is equal to ln(2)/λ. Isotope dilution thermal ionisation mass spectrometry (ID-TIMS) : A method of isotopic analysis in which an artificial or enriched isotopic tracer is added to a dissolved sample (e.g. zircon) to make a homogeneous isotopic mixture, the isotopic composition of which is analysed using TIMS. This technique is currently the form of isotopic measurement with the highest precision and accuracy, but it requires complete dissolution of the sample. LA–ICP–MS (laser ablation inductively coupled plasma mass spectrometry) : A microanalytical method that employs a focused laser beam to ablate material from samples. The ejected matter is ionised using a plasma before being passed through to a mass spectrometer. MSWD (mean squared weighted deviation) : A goodness of fit statistic that compares the sum of the squares of the deviations of a set of measurements from their mean value to the corresponding sum of the variances of each measurement Precision : The closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under specified conditions Secondary ion mass spectrometry (SIMS) : Also referred to as an ion microprobe or microscope, SIMS measures the chemical or isotopic composition of small sample volumes by focusing a beam of high-energy primary ions onto a polished sample surface, ablating atoms and molecules, and generating secondary ions that are analysed by mass spectrometry. The high spatial resolution offered by SIMS (commonly <30 μm wide and <1 μm deep during analysis of geological materials) allows in situ analysis of geological materials. The method is relatively non-destructive, allowing multiple analyses to be performed within single grains or zones within grains, but has lower analytical precision than ID-TIMS. Radioactive decay : Nuclear reactions by which an atomic nucleus transforms via emission of ionising particles and electromagnetic radiation. Radioactive decay is a stochastic (i.e. random) process at the level of single atoms, in that it is impossible to predict when a given atom will decay. However, the probability that a given atom will decay is constant over time. Uncertainty (of measurements) : A parameter characterising the dispersion of the quantity values being attributed to the subject of a measurement, which can include components arising from both random and systematic measurement errors. Random errors are those that in replicate measurements vary in an unpredictable manner; systematic errors are those that remain constant or vary in a predictable manner across replicate measurements.

Considerations in Zircon Geochronology by SIMS

Research Article| January 02, 2003 Considerations in Zircon Geochronology by SIMS Trevor R. Ireland; Trevor R. Ireland Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, trevor.ireland@anu.edu.au Search for other works by this author on: GSW Google Scholar Ian S. Williams Ian S. Williams Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, trevor.ireland@anu.edu.au Search for other works by this author on: GSW Google Scholar Author and Article Information Trevor R. Ireland Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, trevor.ireland@anu.edu.au Ian S. Williams Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, trevor.ireland@anu.edu.au Publisher: Mineralogical Society of America First Online: 03 Mar 2017 © The Mineralogical Society Of America Reviews in Mineralogy and Geochemistry (2003) 53 (1): 215–241. https://doi.org/10.2113/0530215 Article history First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Trevor R. Ireland, Ian S. Williams; Considerations in Zircon Geochronology by SIMS. Reviews in Mineralogy and Geochemistry 2003;; 53 (1): 215–241. doi: https://doi.org/10.2113/0530215 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyReviews in Mineralogy and Geochemistry Search Advanced Search Secondary ion mass spectrometry (SIMS) is a versatile technique for measuring the chemical and isotopic composition of solid materials on a scale of a few microns. A beam of high-energy primary ions is focused onto the polished target surface, sputtering (ablating) atoms and molecules, and in the process ionizing a small fraction. These secondary ions, which reflect the target composition, are analyzed by mass spectrometry. The SIMS instrument most common in geoscience is the ion microprobe, which uses a focused primary ion beam in either static or scanning mode to sample target areas usually 10- to 50-μm diameter. Total sampling... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Beryllium Analyses by Secondary Ion Mass Spectrometry

Secondary ion mass spectrometry (SIMS, or ion microprobe) represents an extremely sensitive technique for the microanalysis of beryllium. Positive ions of beryllium are readily formed and its analysis by SIMS is not overly complicated. Matrix effects appear to be small (<20%). In this chapter I will describe SIMS instrumentation, the problems facing Be analysis, solutions to these problems, calibrations for Be and limits of detection. As of the writing of this chapter (mid-2000), SIMS instruments broadly useful to geochemists are commercially available from two companies. Australian Scientific Instruments (ASI, at www.anutech.com.au/asi/shrimpii.htm) sells the SHRIMP (Super High Resolution Ion Micro Probe). The SHRIMP was designed to allow high transmission of secondary ions at high mass resolution and permits U-Pb ages on zircons to be determined. Beryllium analyses are possible on the SHRIMP, but none have been obtained to date (Vickie Bennett and Ian Williams, Australian National University, pers. comm.). Cameca Instruments Inc. (www.cameca.fr) markets an instrument (the IMS 3f-6f series) that focuses on the needs of the semiconductor industry, and is also the most common SIMS instrument in earth science laboratories. A second Cameca instrument (IMS 1270) is designed for applications demanding high transmission at high mass resolving power (as in the SHRIMP). A tutorial on SIMS can be found on the world-wide web (www.cea.com), but a brief description follows. In SIMS, a high-energy primary ion beam is directed at a sample. The impacts of these ions with the target result in the ejection of atoms from the top two or three monolayers of the target surface (Dumke et al. 1983). Some of the ejected atoms are ionized during these collisions, and these “secondary ions” can then be accelerated into a mass spectrometer for isotope selection and analysis. Below I describe primary ion beams and the path followed by secondary ions …

Sample and plume luminescence in fast heavy ion induced desorption

The luminescence arising in 252Cf-fission fragment induced desorption events has been measured using the time-correlated single photon counting technique. Photons emitted from the sample have been guided from a plasma desorption ion source to a photodetector by an optical fibre. Spectra and decay functions have been obtained using thin layers of Coronene or POPOP as samples. The results are strongly dependent on the acceleration field applied for ion extraction. Approximately 10 photons per fission fragment have been produced when applying no accelerating voltage. The results clearly show that these photons come from radiative electronic relaxations of molecules in the solid sample. Considerably more photons per fission fragment have been produced when applying a positive acceleration voltage. The intensity increases almost linearly for acceleration fields below 10 kv/cm and saturates at a nearly 10-fold higher value when compared to no acceleration. The intensity is also affected by the homogeneity of the accelerating field. These additional photons are attributed to radiative electronic relaxations of desorbed neutral molecules in the plume excited by inelastic collisions with accelerated positive ions. No additional photons have been observed when extracting negative ions. The negative ions produced do obviously not hit and/or excite desorbed neutral molecules, presumably due to their specific desorption characteristics. The experimental data have been analyzed by comparing with the cw and time-resolved sample luminescence obtained by optical excitation. The findings demonstrate that valuable information on ion-solid interactions, on specific desorption quantities and on processes in the plume can be obtained by measuring and analyzing the luminescence induced by the impact of high energy primary ions.

Topographic modifications on the graphite surface induced by high energy single-ion impact

Argon ions of 50 keV energy were implanted into graphite at doses ranging from 10 11 to 10 15 ions cm −2. The implanted graphite surface was studied using scanning tunneling microscopy. Isolated single ion-impacts were imaged, showing the formation of a small bump at the point of impact. This characteristic bump is attributed to residual damage and defect-induced stresses which take place after the ion collision cascade, around the ion track. Images obtained for increasing ion doses suggest that the collision cascade initiated by the high energy primary ion determines the first stages of evolution of the surface morphology.

Variation of yield with thickness in SIMS and PDMS: Measurements of secondary ion emission from organized molecular films

The influence of organic film thickness on secondary ion emission has been studied with both low energy (keV) and high energy (MeV) primary ions, i.e. in SIMS (secondary ion mass spectrometry) and PDMS (plasma desorption mass spectrometry). The Langmuir-Blodgett technique was used to prepare well organized films from one monolayer up to 12 monolayers on metal substrates. The time-of-flight mass spectra of Cd stearate Langmuir-Blodgett films on Au are similar in SIMS and PDMS. The deprotonated stearic acid ion peak (MH) − is the most prominent feature in the spectra. However the behavior of the (MH) − yield as a func of the film thickness is different in the two cases. In SIMS the maximum yield is achieved around 1–2 monolayers (25–50 Å); it decreases for subsequent coverage and is constant after ∼ 8 monolayers (200 Å). In PDMS the yield increases with the thickness, reaching a plateau for coverage higher than 6 to 8 monolayers (150–200 Å). The results show clearly that different processes are involved in dissipating and transporting the energy lost by low and high energy primary ions in thin films. Ions from the metal substrate are prominent in SIMS for monolayer coverage but decrease with increasing coverage; these ions are absent altogether in PDMS. In SIMS analysis, the metal substrate also influences the production of ions from the organic films. On Ag and Au the Cd stearate is deposited without any change in structure, but on Al a cation transfer probably takes place in the first 1 to 3 monolayers. This gives a large decrease in the (MH) − yield.

Comparison of biomolecule desorption yields for low and high energy primary ions

Ion induced desorption yields of molecular ions from samples of cesium iodide, glycylglcine, ergosterol, bleomycin and a trinucleoside diphosphate have been studied using primary beams of 54 MeV 63Cu 9+ and 3 keV 133Cs +. Mass analysis was performed with a time-of-flight technique. Each sample was studied with the same spectrometer for both low and high energy primary ions and without opening of the vacuum chamber in between the measurements. The results show that fast heavy ions give larger yields for all samples studied and that the yield ratios for high to low energy desorption increase with the mass of the sample molecule.