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Sample records for accelerator mass spectrometer

  1. The AMS [Accelerator Mass Spectrometer] program at LLNL

    Livermore will have an operational Accelerator Mass Spectrometer (AMS) by mid-1989 as part of its new Multi-user Tandem Laboratory. The spectrometer was designed primarily for applications in archaeology and the geosciences and was co-funded by the University of California Regents. Radiological control for personnel protection, ion sources and injection systems, the tandem and all beam handling hardware are operated with a distributed processor computer control system. The Tandem is the former University of Washington injector FN which has been upgraded with Dowlish tubes, pelletron charging and SF6 gas. Design goals for the AMS system, computer aided operation, automated measurement capability, initial results and some of our intended applications will be presented. 5 refs., 2 figs

  2. Installation of a tandem-type accelerator mass spectrometer

    Mizushima, Toshihiko; Togawa, Orihiko; Mizutani, Yoshihiko [Japan Atomic Energy Research Inst., Mutsu, Aomori (Japan). Mutsu Establishment; Kabuto, Shoji [Mutsu Marine Laboratory, Japan Marine Science Foundation, Mutsu, Aomori (Japan); Yamamoto, Tadatoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-02-01

    Tandem-type accelerator mass spectrometer (hereinafter referred to as Tandetron) was installed at the Ominato Facility of Mutsu Establishment, JAERI in April, 1997. The objective of its installation is to investigate the mechanism of the mixing and circulation of seawater in the ocean, by collecting seawater samples around Japan and analyzing the horizontal and vertical distributions of {sup 14}C contained in the samples. The Tandetron consists of two lines to measure isotopic ratios of carbon and those of heavier iodine. The adjustment for the carbon line was finished and the measurements of seawater samples were started. The iodine line, on the other hand, is on the final step of its adjustment and performance tests are being carried out with a TOF (Time of Flight) detector. The iodine line will be used to analyze {sup 129}I released from a spent nuclear fuel reprocessing plant and other nuclear facilities. In this report, we summarize the status of installation of the carbon and iodine lines for the Tandetron. The report describes the situations of their adjustments until now, the outline of the Tandetron, tests of measurement performance, evaluation and inspection of shielding performance, problems and their solutions, and so on. (author)

  3. The distributed control system of Shanghai mini-cyclotron accelerator mass spectrometer (SMCAMS)

    It is mainly introduced the composition, structure, hardware and software designing, function, and the method of communication between the host computer and the ADAM modules of the distributed control system on Shanghai Mini-cyclotron Accelerator Mass Spectrometer (SMCAMS). Some detail problems such as controlling the devices staying on high voltage by ADAM-4541 (RS-485 to Fiber Optic Convertor) and optical fiber are also introduced

  4. Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

    Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

    2015-10-01

    The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

  5. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

    2016-03-01

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  6. Design of virtual double-parameter multichannel analyzer to measure 14C on the accelerator mass spectrometer

    The author introduces the design of the virtual double-parameter multichannel analyzer based on PC DAQ board and LabVIEW, the graphical development platform, and the use of it to measure the double-parameter ΔE-Er spectrum of 14C on the accelerator mass spectrometer

  7. 129I level in seawater near a nuclear power plant determined by accelerator mass spectrometer

    129I concentration in the seawater samples near a nuclear power plant was determined in the Xi'an Accelerator Mass Spectrometer (AMS) Center. Isotope dilution method was used via addition of excessive amount of stable iodine (127I) in the sample before separation, and iodine in the seawater was separated by solvent extraction, and the back extracted iodine in iodide form was precipitated as AgI, which was used as AMS target for 129I measurement. 125I tracer was added to monitor the recovery of iodine in the whole separation process. 129I/127I ratios in the prepared target were determined by AMS. The concentration of 127I in seawater samples was determined by inductively coupled plasma mass spectrometry. The results show that the 129I/127I atomic ratios in the seawater range from 8.29x10-11 to 9.45x10-10, approximately one order of magnitude higher than that in seaweed collected in the pre-nuclear era, but fall in the environmental level of global fallout.

  8. Mass Spectrometer Studies of Ion Sources for One Shot AcceleratorTube

    Brumbaugh, R.; Pon, W.; Seaman, W.; Wiegand, C.

    1951-12-12

    A simple mass spectrometer using 60 degree focusing was set up to study the (illegible) of the ions produced by various types of sources. A schematic diagram of the apparatus is shown in Fig. 1, which is to a large extent self-explanatory. The isolation transformer was simply a piece of RG (illegible) cable about three feet long and was used in order to operate the source at high accelerating voltage allowing the collector to be at essentially ground potential. The collimating slits were 0.05 (illegible) wide and were space 4 (illegible-cm?) apart. The coarse slit immediately preceding the collector cup was 0.3 (illegible) wide. The electrometer was the integrating type which indicated the potential due to the charge collected on known capacitance. The vacuum tube voltmeter indicated the potential of the 0.5 (illegible) capacitor due to the total charge reaching the slit system. It thus served as a monitor of the source output for each firing. The neon lamp was a protection for the condenser against breakdown discharges of the tube.

  9. Cyclotrons as mass spectrometers

    Clark, D.J.

    1984-04-01

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures.

  10. Cyclotrons as mass spectrometers

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures

  11. Automated transportable mass spectrometer

    The need has been identified for a Mass Spectrometer (MS) which can be conveniently transported among several facilities for rapid verification of the isotopic composition of Special Nuclear Material. This requirement for a light weight, transportable MS for U and Pu mass analysis was met by deleting the gas chromatograph (GC) portions of a Hewlett-Packard (H-P) Model 5992 Quadrupole GCMS and substituting a vacuum lock sample entry system. A programmable power supply and vacuum gauge were added and circuitry modifications were made to enable use of the supplied software. The single rhenium filament plug-in source is loaded with either a nominal microliter of sample solution and evaporated, or with a prepared resin bead. Using a resin bead in a specially dimpled filament, copious sensitivity is obtained with 30 nanogram uranium samples. After sample insertion the analysis is completely controlled by an H-P Model 9825 calculator. Source vacuum of 2 x 10-7 torr or better is regained within 2 minutes after sample insertion, and total time for a complete analysis is about 7 minutes. Accuracy is better than 1% for isotope ratios less than 20 and better than 2% for ratios of 100. Ions are accelerated at about 1.8 volts into the mass filter which has pole pieces of hyperbolic cross section. Collection is by a Galileo Channeltron multiplier into a log preamp. During a normal run, 1.4 x 106 data point are observed and averaged. Weight of the instrument excluding the calculator is 88 Kg which allows relatively easy transportation over short distances by two persons. The instrument can be carried into a facility and be ready to analyze samples in less than 3 hours

  12. Magnetron mass spectrometer

    A magnetron mass-spectrometer characterized by increased sensitivity at low power is described. The mass-spectrometer contains ion source cylindrical analyzer located on its axis, ion collector and magnetic system. For decreasing consumed power the ion source is fixed at the end of the analyzer and it represents two coaXial cylinders located between plane electrodes, in one of which a ring slot takes place and the other one is connected with positive terminal of discharge voltage source. The magnetic system represents ring-form magnets fixed by similar poles to each other and separated by washers of magnetic-soft material, the washers being placed in the plane of the ion source. The analyzed ions in the described mass-spectrometer are obtained mainly at the expense of resonance recharge that increases accuracy of measurements due to decrease of fragment peak intensity

  13. Mass spectrometers: instrumentation

    Cooks, R. G.; Hoke, S. H., II; Morand, K. L.; Lammert, S. A.

    1992-09-01

    Developments in mass spectrometry instrumentation over the past three years are reviewed. The subject is characterized by an enormous diversity of designs, a high degree of competition between different laboratories working with either different or similar techniques and by extremely rapid progress in improving analytical performance. Instruments can be grouped into genealogical charts based on their physical and conceptual interrelationships. This is illustrated using mass analyzers of different types. The time course of development of particular instrumental concepts is illustrated in terms of the s-curves typical of cell growth. Examples are given of instruments which are at the exponential, linear and mature growth stages. The prime examples used are respectively: (i) hybrid instruments designed to study reactive collisions of ions with surfaces: (ii) the Paul ion trap; and (iii) the triple quadrupole mass spectrometer. In the area of ion/surface collisions, reactive collisions such as hydrogen radical abstraction from the surface by the impinging ion are studied. They are shown to depend upon the chemical nature of the surface through the use of experiments which utilize self-assembled monolayers as surfaces. The internal energy deposited during surface-induced dissociation upon collision with different surfaces in a BEEQ instrument is also discussed. Attention is also given to a second area of emerging instrumentation, namely technology which allows mass spectrometers to be used for on-line monitoring of fluid streams. A summary of recent improvements in the performance of the rapidly developing quadrupole ion trap instrument illustrates this stage of instrument development. Improvements in resolution and mass range and their application to the characterization of biomolecules are described. The interaction of theory with experiment is illustrated through the role of simulations of ion motion in the ion trap. It is emphasized that mature instruments play a

  14. Effective mass spectrometer

    The history and major accomplishments of the Effective Mass Spectrometer (EMS) are described. In the eight years since the EMS turned on, 21 experiments have been completed by groups from nine institutions in 32 months of operation. Over 400 million triggers have been recorded on magnetic tape, resulting in 29 journal publications to date. A list of experimental proposals for the EMS and a sampling of results are presented. 12 figures, 4 tables

  15. In Situ Mass Spectrometer Project

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  16. Improvements to mass spectrometers

    This invention concerns mass spectrometers and, specifically, an ion beam analyser that facilitates the use of these spectrometers. Its object is to provide an improved apparatus for determining the desorption characteristics by field effect of a sample. It also aims to provide an improved system for carrying out sample analyses by using field effect desorption. Under the invention, facilities are added to the analyser to put out of action a part at least of the separation facilities so that the ion beam coming from the source of ions is not deflected. Detection means are located along the non deflected ion beam to detect the ions of the sample when they effectively appear and finally, actuating facilities are coupled to the out-of-action system so that the mass separation facilities may be brought back into action. This enables the operator to vary the parameters, such as the position of the source (emitter), the temperature and the electric field intensity until ions are released by the unknown sample

  17. Implementation of a mass spectrometer operating in the external beam of a proton accelerator. Application to the study of short-lived isotopes produced by uranium fission

    Implementation and use of a mass spectrometer operating directly in the external beam of a proton accelerator has proven to be a very fruitful way to study short-lived nuclides in both areas covered: measuring production cross sections and nuclear spectroscopy. The results obtained in this work are only a first step and can be developed in different directions in which the study was discussed and an extension to elements other than alkali may be considered. (author)

  18. A new LabVIEW-based control system for the Naval Research Laboratory Trace Element Accelerator Mass Spectrometer

    A new LabVIEW-based control system for the existing tandem accelerator and new AMS components has been implemented at the Trace Element Accelerator Mass Spectrometry (TEAMS) facility at the Naval Research Laboratory. Through the use of Device Interfaces (DIs) distributed along a fiber optic network, virtually every component of the accelerator system can be controlled from any networked computer terminal as well as remotely via modem or the internet. This paper discusses the LabVIEW-based control software, including remote operation, automatic calculation of ion optical component parameters, beam optimization, and data logging and retrieval

  19. High-resolving mass spectrographs and spectrometers

    Wollnik, Hermann, E-mail: hwollnik@gmail.com [New Mexico State University, Department of Chemistry & Biochemistry (United States)

    2015-11-15

    Discussed are different types of high resolving mass spectrographs and spectrometers. In detail outlined are (1) magnetic and electric sector field mass spectrographs, which are the oldest systems, (2) Penning Trap mass spectrographs and spectrometers, which have achieved very high mass-resolving powers, but are technically demanding (3) time-of-flight mass spectrographs using high energy ions passing through accelerator rings, which have also achieved very high mass-resolving powers and are equally technically demanding, (4) linear time-of-flight mass spectrographs, which have become the most versatile mass analyzers for low energy ions, while the even higher performing multi-pass systems have only started to be used, (5) orbitraps, which also have achieved remarkably high mass-resolving powers for low energy ions.

  20. High-resolving mass spectrographs and spectrometers

    Wollnik, Hermann

    2015-11-01

    Discussed are different types of high resolving mass spectrographs and spectrometers. In detail outlined are (1) magnetic and electric sector field mass spectrographs, which are the oldest systems, (2) Penning Trap mass spectrographs and spectrometers, which have achieved very high mass-resolving powers, but are technically demanding (3) time-of-flight mass spectrographs using high energy ions passing through accelerator rings, which have also achieved very high mass-resolving powers and are equally technically demanding, (4) linear time-of-flight mass spectrographs, which have become the most versatile mass analyzers for low energy ions, while the even higher performing multi-pass systems have only started to be used, (5) orbitraps, which also have achieved remarkably high mass-resolving powers for low energy ions.

  1. Biopolymer mass spectrometer with cryogenic particle detectors

    A novel type of biopolymer mass spectrometer is proposed for massive proteins, polypeptides and DNA-fragments by replacing standard ionizing detectors with cryogenic particle detectors. The detection efficiency in ionizing detectors decreases rapidly with increasing biopolymer mass owing to the biopolymer's decreasing velocity. Cryogenic particle detectors, however, record the total kinetic energy deposited by the accelerated biopolymer. In a given electric acceleration field, this kinetic energy is independent of mass and depends only on the biopolymer's charged state. Using the intrinsic properties of cryogenic particle detectors and their specific fabrication techniques, a mass spectrometer has been designed specifically for high-throughput DNA-sequencing. The calculated DNA-fragment separation rate would be increased by several orders of magnitude as compared to standard gel-electrophoresis DNA-sequencers. (orig.)

  2. Imaging mass spectrometer with mass tags

    Felton, James S.; Wu, Kuang Jen J.; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2013-01-29

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  3. New schemes of static mass spectrometers

    Baisanov, O.A. [Military Institute of Air Defense Forces, Aktobe (Kazakhstan); Doskeyev, G.A. [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan); Spivak-Lavrov, I.F., E-mail: baisanov@mail.ru [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan)

    2011-07-21

    Different possibilities to increase the 'quality', or Q-quantity, of static mass spectrometers by expanding the ion beam before it enters the magnetic field are analyzed. The design of mass spectrometers using a cone-shaped achromatic prism is discussed. Different variants of achromatic mass spectrometers using electrostatic prisms and sector magnetic fields are also considered.

  4. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    Chastagner, P.

    2001-08-01

    This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

  5. New schemes of static mass spectrometers

    Different possibilities to increase the 'quality', or Q-quantity, of static mass spectrometers by expanding the ion beam before it enters the magnetic field are analyzed. The design of mass spectrometers using a cone-shaped achromatic prism is discussed. Different variants of achromatic mass spectrometers using electrostatic prisms and sector magnetic fields are also considered.

  6. AixMICADAS, the accelerator mass spectrometer dedicated to 14C recently installed in Aix-en-Provence, France

    Bard, Edouard; Tuna, Thibaut; Fagault, Yoann; Bonvalot, Lise; Wacker, Lukas; Fahrni, Simon; Synal, Hans-Arno

    2015-10-01

    A compact AMS system dedicated to measuring 14C in ultra-small samples was installed at the CEREGE in Aix-en-Provence at the end of March 2014, together with an automated graphitization system. AixMICADAS operates at around 200 kV with carbon ion stripping in helium leading to a transmission of about 47%. The hybrid ion source works with graphite targets and CO2 gas. It is coupled to a versatile gas interface system that ensures stable gas measurements from different sources: a cracker for CO2 in glass ampoules, an elemental analyzer for combusting organic matter and an automated system to handle carbonate by wet chemistry. The analyses performed during the first half-year of operation show that a precision of about 2‰ is reached on modern samples of about 1 mg of carbon. Measurements of IAEA reference materials of various 14C ages show a good agreement with consensus values. Direct measurements of geological graphites indicate a machine background equivalent to an age of 68,000 years BP. AixMICADAS is thus limited solely by the 14C contamination of samples in the field and in the laboratory. The performances of the gas ion source and its gas interface system were tested with two CO2 production units: the elemental analyzer and the automated carbonate hydrolysis unit. These tests show that samples ranging between 10 and 100 μg C can produce a 12C- ion beam of the order of 10-15 μA during time spans ranging from 3 to 30 min depending on the sample mass. Coupling the automated hydrolysis system to the gas ion source of AixMICADAS, enables us to develop a method involving sequential leaching of carbonate samples with direct 14C measurements of the leached fractions and the residual sample. The main advantage is that all of steps leaching and hydrolysis are performed in the same vial for a particular sample. A sequential leaching was applied to a young carbonate sample (ca. 6600 years BP) whose 14C age agrees with previous determination and which shows no sign of

  7. Multidetector calibration for mass spectrometers

    The International Atomic Energy Agency's Safeguards Analytical Laboratory has performed calibration experiments to measure the different efficiencies among multi-Faraday detectors for a Finnigan-MAT 261 mass spectrometer. Two types of calibration experiments were performed: (1) peak-shift experiments and (2) peak-jump experiments. For peak-shift experiments, the ion intensities were measured for all isotopes of an element in different Faraday detectors. Repeated measurements were made by shifting the isotopes to various Faraday detectors. Two different peak-shifting schemes were used to measure plutonium (UK Pu5/92138) samples. For peak-jump experiments, ion intensities were measured in a reference Faraday detector for a single isotope and compared with those measured in the other Faraday detectors. Repeated measurements were made by switching back-and-forth between the reference Faraday detector and a selected Faraday detector. This switching procedure is repeated for all Faraday detectors. Peak-jump experiments were performed with replicate measurements of 239Pu, 187Re, and 238U. Detector efficiency factors were estimated for both peak-jump and peak-shift experiments using a flexible calibration model to statistically analyze both types of multidetector calibration experiments. Calculated detector efficiency factors were shown to depend on both the material analyzed and the experimental conditions. A single detector efficiency factor is not recommended for each detector that would be used to correct routine sample analyses. An alternative three-run peak-shift sample analysis should be considered. A statistical analysis of the data from this peak-shift experiment can adjust the isotopic ratio estimates for detector differences due to each sample analysis

  8. The Varian MAT-250 mass spectrometer. Steady isotopes laboratory

    This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)

  9. Low Power Mass Spectrometer employing TOF Project

    National Aeronautics and Space Administration — A low power Mass Spectrometer employing multiple time of flight circuits for parallel processing is possible with a new innovation in design of the Time of flight...

  10. Mass Spectrometer for Airborne Micro-Organisms

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  11. Time of flight spherotron mass spectrometer

    The possibility of using the spherotron, the mass spectrometer with crossed spherical electric and inhomogeneous magnetic fields, as a TOF mass spectrometry instrument has been analyzed. The possibility of achieving triple isochronous focusing has been shown. The estimates for the mass dispersion and resolutions are derived. (author)

  12. Evaluation of Small Mass Spectrometer Systems

    Arkin, C. Richard; Griffin, Timothy P.; Ottens, Andrew K.; Diaz, Jorge A.; Follistein, Duke W.; Adams, Fredrick W.; Helms, William R.; Voska, N. (Technical Monitor)

    2002-01-01

    Various mass analyzer systems were evaluated. Several systems show promise, including the Stanford Research Systems RGA-100, Inficon XPR-2, the University of Florida's Ion Trap, and the Compact Double Focus Mass Spectrometer. Areas that need improvement are the response time, recovery time, system volume, and system weight. Future work will investigate techniques to improve systems and will evaluate engineering challenges.

  13. ELECTRONICS UPGRADE OF HIGH RESOLUTION MASS SPECTROMETERS

    Mcintosh, J; Joe Cordaro, J

    2008-03-10

    High resolution mass spectrometers are specialized systems that allow researchers to determine the exact mass of samples to four significant digits by using magnetic and electronic sector mass analyzers. Many of the systems in use today at research laboratories and universities were designed and built more than two decades ago. The manufacturers of these systems have abandoned the support for some of the mass spectrometers and parts to power and control them have become scarce or obsolete. The Savannah River National Laboratory has been involved in the upgrade of the electronics and software for these legacy machines. The Electronics Upgrade of High Resolution Mass Spectrometers consists of assembling high-end commercial instrumentation from reputable manufacturers with a minimal amount of customization to replace the electronics for the older systems. By taking advantage of advances in instrumentation, precise magnet control can be achieved using high resolution current sources and continuous feedback from a high resolution hall-effect probe. The custom equipment include a precision voltage divider/summing amplifier chassis, high voltage power supply chassis and a chassis for controlling the voltage emission for the mass spectrometer source tube. The upgrade package is versatile enough to interface with valve control, vacuum and other instrumentation. Instrument communication is via a combination of Ethernet and traditional IEEE-488 GPIB protocols. The system software upgrades include precision control, feedback and spectral waveform analysis tools.

  14. Laser resonance ionization mass spectrometer

    The setup is elaborated for the trace detection of transuranium elements by the three-step laser resonance ionization combined with the time-of-flight mass spectrometry. The setup efficiency for detection of plutonium was measured to be about 0.5 centre dot 10-8 ion/atom, and its selectivity relative to atoms of another elements has the order of 1013 atom/atom

  15. Small system for tritium accelerator mass spectrometry

    Roberts, Mark L.; Davis, Jay C.

    1993-01-01

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  16. High-precision accelerator-mass-spectrometer radiocarbon dating of buried tidal-marsh soils - An approach to estimating the frequency and coastal extent of subduction zone earthquakes in Oregon and Washington

    Accurate and precise radiocarbon dating of buried tidal-marsh soils in estuarine stratigraphic sequences in the Pacific Northwest can help distinguish soils submerged during regional plate-boundary earthquakes from soils submerged during local upper-plate earthquakes or by non-tectonic processes. More precise ages than those resulting from conventional methods of radiocarbon analysis can be obtained by averaging multiple accelerator-mass-spectrometer (AMS) 14C ages of rigorously selected and pretreated plant macrofossils at the abrupt upper contacts of tidal-marsh soils. An initial test of this method in Coos Bay, Oregon, shows that standard deviations on AMS ages can be reduced to ± 25-40 radiocarbon years. But consideration of the total analytical errors in AMS analysis and age differences due to variations in the rate of 14C production in the atmosphere over time indicate that 95% confidence limits on calendar-corrected ages for submergence events range from 50 to 450 years

  17. 21 CFR 862.2860 - Mass spectrometer for clinical use.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mass spectrometer for clinical use. 862.2860... Instruments § 862.2860 Mass spectrometer for clinical use. (a) Identification. A mass spectrometer for... by means of an electrical and magnetic field according to their mass. (b) Classification. Class...

  18. Automation of a thermal ionisation mass spectrometer

    A thermal ionization mass spectrometer was upgraded in order to be monitored by a PC. A PC-LMP-16 National Instruments data acquisition board was used for the ion current channel and the Hall signal channel. A dedicated interface was built to allow commands from the computer to the current supply of the analyzing magnet and to the high voltage unit of the mass spectrometer. A software application was worked out to perform the adjustment of the spectrometer, magnetic scanning and mass spectra acquisition, data processing and isotope ratio determination. The apparatus is used for isotope ratio 235 U/238 U determination near the natural abundance. A peak jumping technique is applied to choose between the 235 U and 238 U signal, by switching the high voltage applied to the ion source between two preset values. This avoids the delay between the acquisition of the peaks of interest, a delay that would appear in the case of a 'pure' magnetic scanning. Corrections are applied for the mass discrimination effects and a statistical treatment of the data is achieved. (authors)

  19. Measuring transfer of 14C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

    Environmental pollutants pose a substantial risk to nursing infants. Many of these toxicants (i.e. PCBs, PBDEs, mercury) are passed from the maternal diet to the nursing infant in breast milk. Determining the toxicokinetics has been difficult to measure due to ethical limitations. Since extremely small amounts of 14C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14C-labeled PCB (2,2',4,4',5,5'-hexachlorobiphenyl-UL-14C) that could be given to a lactating animal and traced into the milk. An oral dose of 66 nCi/kg body weight (1.84 μg PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of 14C label reached a peak value of 1.71 ng/ml PCB equivalents in the milk on day 2 and then declined to about 135 pg/ml PCB equivalents in the milk at 3 weeks. A second goat was administered a smaller dose (22 nCi/kg bw; 616 ng PCB/kg bw). A peak concentration of 485 pg PCB equivalents/ml milk occurred at 3 days and declined to 77.6 pg PCB equivalents/ml milk by 3 weeks. Our results indicated that an even lower dosage of labeled-PCB could be used due to the extreme sensitivity of AMS measurement. Extrapolating from current data it is estimated that the dose could be reduced by a factor of 20 (31 ng PCB/kg bw; 1.1 nCi/kg bw) and still be detectable after 2 months. Thus, the potential exists for developing protocols for studying toxicokinetics in humans using radiologically- and toxicologically-benign doses of labeled environmental toxicants

  20. Accelerator mass spectrometry: state of the art

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.

  1. Mass spectrometer for the analyses of gases

    A 6-in-radius, 600 magnetic-sector mass spectrometer (designated as the MS-200) has been constructed for the quantitative and qualitative analyses of fixed gases and volatile organics in the concentration range from 1 ppM (by volume) to 100%. A partial pressure of 1 x 10-6 torr in the inlet expansion volume is required to achieve a useful signal at an electron-multiplier gain of 10,000

  2. Double focussing stigmatic image mass spectrometer

    The mass spectrometer for the analysis of ions, which occur in matetial pulverisation by a radiation micro probe, contains one lens a 450 spherical condenser lens, from which the ion beam emerhes as a parallel beam, an intermediate shutter, a 900 magnetic field and an outlet shutter. The angle of entry and energy bandwidth can be set independently of each other. An optimum transmission is obtained with the least possible image errors. (DG)

  3. Effective mass spectrometer. [History and accomplishments

    Ayres, D.

    1979-10-12

    The history and major accomplishments of the Effective Mass Spectrometer (EMS) are described. In the eight years since the EMS turned on, 21 experiments have been completed by groups from nine institutions in 32 months of operation. Over 400 million triggers have been recorded on magnetic tape, resulting in 29 journal publications to date. A list of experimental proposals for the EMS and a sampling of results are presented. 12 figures, 4 tables.

  4. Progress with the PENTATRAP mass spectrometer

    Bekker, Hendrik; Crespo Lopez-Urrutia, Jose; Doerr, Andreas; Eliseev, Sergey; Goncharov, Mikhail; Repp, Julia; Rischka, Alexander; Roux, Christian; Sturm, Sven; Blaum, Klaus [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Boehm, Christine [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); ExtreMe Matter Institute EMMI, Helmholtz Gemeinschaft, 64291 Darmstadt (Germany); Novikov, Yuri [PNPI, Gatchina, 188300 St. Petersburg (Russian Federation)

    2014-07-01

    The five-trap mass spectrometer PENTATRAP has been constructed and is currently being characterized at the Max-Planck-Institut fuer Kernphysik, Heidelberg. It aims for high-precision mass ratio measurements with a relative mass uncertainty of a few 10{sup -12}. Long-lived and stable, highly charged nuclides with masses up to uranium will be addressed to perform e.g. stringent tests of quantum electrodynamics and neutrino oriented mass measurements. The main part of the experiment is a stack of five cylindrical cryogenic Penning traps. An ultra-stable voltage source is required to supply the Penning trap electrodes with appropriate and stable potentials. Therefore, an elaborated source was developed and built at MPIK. Recently, first ions have been successfully trapped. Details about the progress of the installation, especially the status of the voltage source and first ion signals are presented in the talk.

  5. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  6. Recent exploits of the ISOLTRAP mass spectrometer

    Kreim, S; Naimi, S; Blaum, K; Breitenfeldt, M; Rossel, R E; Fink, D; Stanja, J; Atanasov, D; Borgmann, Ch; Cocolios, T E; Zuber, K; Wolf, R N; George, S; Neidherr, D; Nicol, T; Rosenbusch, M; Lunney, D; Boehm, Ch; Manea, V; Herlert, A; Koester, U; Beck, D; Wienholtz, F; Kellerbauer, A; Ramirez, E Minaya; Schweikhard, L

    2013-01-01

    The Penning-trap mass spectrometer ISOLTRAP, located at the isotope-separator facility ISOLDE (CERN), is presented in its current form taking into account technical developments since 2007. Three areas of developments are presented. The reference ion sources have been modified to guarantee a sufficient supply of reference ions for mass measurements and systematic studies. Different excitation schemes have been investigated for manipulation of the ion motion in the Penning trap, to enhance either the purification or measurement process. A multi-reflection time-of-flight mass separator has been implemented and can now be routinely used for purification and as a versatile tool for beam analysis. (C) 2013 Elsevier B.V. All rights reserved.

  7. Recent exploits of the ISOLTRAP mass spectrometer

    Highlights: • Update on ISOLTRAP. • Reference carbon clusters for heavy species. • Ion-beam yield analysis with MR-TOF MS. Q -- Abstract: The Penning-trap mass spectrometer ISOLTRAP, located at the isotope-separator facility ISOLDE (CERN), is presented in its current form taking into account technical developments since 2007. Three areas of developments are presented. The reference ion sources have been modified to guarantee a sufficient supply of reference ions for mass measurements and systematic studies. Different excitation schemes have been investigated for manipulation of the ion motion in the Penning trap, to enhance either the purification or measurement process. A multi-reflection time-of-flight mass separator has been implemented and can now be routinely used for purification and as a versatile tool for beam analysis

  8. Symposium on accelerator mass spectrometry

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  9. Symposium on accelerator mass spectrometry

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base

  10. MEMS mass spectrometers: the next wave of miniaturization

    Syms, Richard R. A.; Wright, Steven

    2016-02-01

    This paper reviews mass spectrometers based on micro-electro-mechanical systems (MEMS) technology. The MEMS approach to integration is first briefly described, and the difficulties of miniaturizing mass spectrometers are outlined. MEMS components for ionization and mass filtering are then reviewed, together with additional components for ion detection, vacuum pressure measurement and pumping. Mass spectrometer systems containing MEMS sub-components are then described, applications for miniaturized and portable systems are discussed, and challenges and opportunities are presented.

  11. MEMS mass spectrometers: the next wave of miniaturization

    This paper reviews mass spectrometers based on micro-electro-mechanical systems (MEMS) technology. The MEMS approach to integration is first briefly described, and the difficulties of miniaturizing mass spectrometers are outlined. MEMS components for ionization and mass filtering are then reviewed, together with additional components for ion detection, vacuum pressure measurement and pumping. Mass spectrometer systems containing MEMS sub-components are then described, applications for miniaturized and portable systems are discussed, and challenges and opportunities are presented. (topical review)

  12. Resolution of time-of-flight mass spectrometers evaluated for secondary neutral mass spectrometry

    Kato, Makoto; Mogami, Akinori; Naito, Motohiro; Ichimura, Shingo; Shimizu, Hazime

    1988-09-01

    Mass resolution of a time-of-flight mass spectrometer with a two-stage electrostatic reflector is calculated for secondary neutral mass spectrometry. The instrument parameters are optimized for energy and space focusing: correcting the flight time difference due to the energy width ΔE of sputtered particles and the spatial width Δs of an ionizing laser beam. The effect of Δs can be compensated by applying an acceleration field to the ionizing region, and the maximum resolution becomes about 1000 for ΔE=10 eV and Δs=1.0 mm.

  13. Zinc isotope discrimination effect in inductively coupled plasma mass spectrometer

    Inductively coupled plasma mass spectrometry (ICPMS) has recently been used for isotope ratio analysis. The isotope discrimination effect in the mass spectrometer is a primary factor contributing to loss of precision and accuracy in isotope ratio analysis. The discrimination effect of zinc isotopes was investigated by comparing the results obtained using a quadrupole type ICPMS with those obtained using a thermal ionization mass spectrometer

  14. Passive neutron dosemeter-spectrometer for high-energy accelerators

    A passive neutron dosemeter-spectrometer (PNDS) with fission fragments converters is described. The results obtained show that it is a convenient and reliable instrument for neutron dose equivalent measurement in the calibration performing and response investigations of personnel dosemeters in mixed radiation fields behind accelerator shielding. Because of the possibility of neutron spectrum estimation in a wide energy range PNDS using is promissing in the neutron radiation fields research and also as an accidental neutron dosemeter. 23 refs.; 10 figs.; 4 tabs

  15. Analysis of corrosive materials on GD-150 mass spectrometer

    A study has been made to extend the use of Varian Mat GD-150 mass/spectrometer for the corrosive gas analysis. Chlorine, bromine and thiophosgene have been used for this purpose. The feasibility studies, calibration of mass spectrometer and the measuring techniques have been discussed for the aforesaid analysis. (author)

  16. Estimation of the Beam Width in Magnetic Mass Spectrometer

    O.N. Peregudov

    2010-01-01

    Full Text Available A method for estimation of the beam width in magnetic sector mass spectrometers is proposed. This method consists in the restoration of the initial ion density distribution function in a beam cross-section before the receiving collector slit and can be used for the qualitative estimation of the mass spectrometer ion-optical scheme.

  17. Accelerator mass spectrometry programme at Mumbai pelletron accelerator facility

    The Accelerator Mass Spectrometry (AMS) programme and the related developments based on the Mumbai Pelletron accelerator are described. The initial results of the measurement of the ratio, 36Cl / Cl in water samples are presented. (author)

  18. Neuroscience and Accelerator Mass Spectrometry

    Palmblad, M N; Buchholz, B A; Hillegonds, D J; Vogel, J S

    2004-08-02

    Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.

  19. Mass spectrometer experiments for the European space probe Giotto

    Neumann, G.

    The Particulate Impact Analyzer (PIA) and Neutral Mass Spectrometer (NMS) experiments to be carried on board the Giotto cometary probe are presented. The NMS is designed to determine the chemical composition of gases and ions in the coma of Halley's Comet based on the ue of two spectrometers: an electrostatic parallel-plate analyzer, and a similar analyzer coupled with a magnetic analyzer with double-focusing geometry. The sensor structure consists of a monolithic multi-rib milled body with integral fixation points, with provisions for electromagnetic and thermal isolation, and dust protection. The PIA is intended for the measurement of the physical and chemical characteristics of cometary dust particles. It is based on an instrument comprising an entrance baffle and shutter unit, a target unit at which the dust is ionized, a light flash detector marking the flash of ionization, an acceleration grid sending the ions into the time-of-flight unit, and a multiplier unit for recording the time of flight spectrum. A microprocessor-based electronics system housed in a separate case next to the sensor performs tasks of power supply, signal processing, data processing and flow control.

  20. Multiple-ion-beam time-of-flight mass spectrometer

    An innovative approach to increase the throughput of mass spectrometric analyses using a multiple-ion-beam mass spectrometer is described. Two sample spots were applied onto a laser desorption/ionization target and each spot was simultaneously irradiated by a beam of quadrupled Nd:YLF laser radiation (261.75 nm) to produce ions by laser-desorption ionization. Acceleration of the ions in an electric field created parallel ion beams that were focused by two parallel einzel lens systems. After a flight path of 2.34 m, the ions were detected with a microchannel plate-phosphor screen assembly coupled with a charge coupled device camera that showed two resolved ion beams. Time-of-flight mass spectra were also obtained with this detector. Experiments were performed using both metal atom cations (Ti+ and Cr+) produced by laser desorption/ionization and the molecular ions of two different proteins (myoglobin and lysozyme), created by matrix assisted laser desorption/ionization using an excess of nicotinic acid as matrix

  1. Miniature Mass Spectrometer for Earth Science Research Project

    National Aeronautics and Space Administration — By drastically reducing the physical footprint of a mass spectrometer to the size of a beverage can, Ceramitron could set a new performance/price standard in the...

  2. Quadrupole Time-of-Flight Mass Spectrometer

    Federal Laboratory Consortium — FUNCTION: The system generates superior quality mass spectrometry (MS) and tandem mass spectrometry (MS/MS) data from both atmospheric pressure ionization (API) and...

  3. Mass spectrometers based on a cone-shaped acromatic prism

    We have elaborated a mass spectrometer without lenses consisting of one conic achromatic prism. It has a specific mass dispersion which is equal to 67.5 mm/m per 1% change of mass. (By specific dispersion we mean linear dispersion related to the main path.) The pass of charged particles with different emittance is investigated with the help of integrating precise equations for tracks of charged particles in natural curvilinear coordinates. We have calculated the resolving power and aberration of a mass spectrometer for different beams of particles. It is evident that the mass spectrometer is particularly effective in use when we deal with rather wide ion beams having an insignificant angular divergence in the mean plane. (orig.)

  4. Mass spectrometers based on a cone-shaped acromatic prism

    Spivak-Lavrov, I.F. [Pedagogical Inst. of Aktyubinsk (Kazakhstan)

    1995-09-01

    We have elaborated a mass spectrometer without lenses consisting of one conic achromatic prism. It has a specific mass dispersion which is equal to 67.5 mm/m per 1% change of mass. (By specific dispersion we mean linear dispersion related to the main path.) The pass of charged particles with different emittance is investigated with the help of integrating precise equations for tracks of charged particles in natural curvilinear coordinates. We have calculated the resolving power and aberration of a mass spectrometer for different beams of particles. It is evident that the mass spectrometer is particularly effective in use when we deal with rather wide ion beams having an insignificant angular divergence in the mean plane. (orig.).

  5. Real time spectrometer for thermal neutrons from radiotherapic accelerators

    Mozzanica, A. [Universita degli Studi di Brescia e INFN sezione di Pavia (Italy)], E-mail: mozzanica@bs.infn.it; Bartesaghi, G.; Bolognini, D.; Conti, V.; Mascagna, V.; Prest, M.; Scazzi, S. [Universita degli Studi dell' Insubria e INFN sezione di Milano/Milano Bicocca (Italy); Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A. [Fisica Sanitaria, Ospedale S. Anna di Como (Italy); Bevilacqua, R.; Giannini, G.; Totaro, P.; Vallazza, E. [INFN, sezione di Trieste e Universita degli Studi di Trieste (Italy)

    2007-10-15

    Radiotherapy accelerators can produce high energy photon beams for deep tumour treatments. Photons with energies greater than 8 MeV produce neutrons via photoproduction. The PHONES (PHOto NEutron Source) project is developing a neutron moderator to use the photoproduced neutrons for BNCT (Boron Neutron Capture Therapy) in hospital environments. In this framework we are developing a real time spectrometer for thermal neutrons exploiting the bunch structure of the beam. Since the beam is produced by a linear accelerator, in fact, particles are sent to the patient in bunches with a rate of 150-300 Hz depending on the beam type and energy. The neutron spectrum is usually measured with integrating detectors such as bubble dosimeters or TLDs, which integrate over a time interval and an energy one. We are developing a scintillator detector to measure the neutron spectrum in real time in the interval between bunches, that is in the thermal region. The signals from the scintillator are discriminated and sampled by a dedicated clock in a Cyclone II FPGA by Altera, thus obtaining the neutron time of flight spectrum. The exploited physical process in ordinary plastic scintillators is neutron capture by H with a subsequent {gamma} emission. The measured TOF spectrum has been compared with a BF{sub 3} counter one. A dedicated simulation with MCNP is being developed to extract the energy spectrum from the TOF one. The paper will present the results of the prototype measurements and the status of the simulation.

  6. Design of the multi-reflection time-of-flight mass spectrometer for the RAON facility

    Yoon J. W.

    2014-03-01

    Full Text Available Electrodes design for the multi-reflection time-of-flight mass spectrometer (MR-TOF-MS has been performed for the high precision mass measurement system in RAON accelerator facility, which will be constructed in Korea. Calculated mass resolution is 105 for the condition of an energy spread of ± 30 eV and an emittance of 0.75 π mm mrad. MR-TOF-MS will be used for the isobar separation and the mass measurement for very short-lived isotopes.

  7. Development of an ion mobility spectrometer for use in an atmospheric pressure ionization ion mobility spectrometer/mass spectrometer instrument for fast screening analysis

    Sysoev, A; Adamov, A; Vildanoja, J; Ketoja, RA; Kostiainen, R; Kotiaho, T

    2004-01-01

    An ion mobility spectrometer that can easily be installed as an intermediate component between a commercial triple-quadrupole mass spectrometer and its original atmospheric pressure ionization (API) sources was developed. The curtain gas from the mass spectrometer is also used as the ion mobility sp

  8. Glow discharge electron impact ionization source for miniature mass spectrometers.

    Gao, Liang; Song, Qingyu; Noll, Robert J; Duncan, Jason; Cooks, R Graham; Ouyang, Zheng

    2007-05-01

    A glow discharge electron impact ionization (GDEI) source was developed for operation using air as the support gas. An alternative to the use of thermoemission from a resistively heated filament electron source for miniature mass spectrometers, the GDEI source is shown to have advantages of long lifetime under high-pressure operation and low power consumption. The GDEI source was characterized using our laboratory's handheld mass spectrometer, the Mini 10. The effects of the discharge voltage and pressure were investigated. Design considerations are illustrated with calculations. Performance is demonstrated in a set of experimental tests. The results show that the low power requirements, mechanical ruggedness, and quality of the data produced using the small glow discharge ion source make it well-suited for use with a portable handheld mass spectrometer. PMID:17441220

  9. Double focusing mass spectrometers of second order

    The resolution of the on-line mass spectrograph is normally several hundred and this is sufficient to separate nuclei having different mass number A. If the nuclei to be analyzed have the same A but different charge number Z, they can not be separated by this amount of resolution. However, the complete separation of nuclei (both A and Z) can be possible if the resolution is raised by about hundred times, that is, up to several ten thousands. The resolving power of about 30,000 would be sufficient to resolve all nuclei far from the valley of beta-stability. Besides, the direct mass measurement of short lived nuclei would be possible with such a high resolution mass spectrograph. The determination of masses of nuclei far from beta-stability is also a very interesting and important problem. For this purpose, a mass spectrograph which can collect many ions and still has a high resolution is necessary. In order to satisfy such conditions, it is essentially necessary to realize good focusing. Therefore, the possibility of correcting for second order image aberrations of a double focusing instrument is investigated and several suitable designs are found by computer calculation

  10. Shotgun lipidomics on a LTQ Orbitrap mass spectrometer by successive switching between acquisition polarity modes

    Schuhmann, K.; Almeida, R.; Baumert, M.;

    2012-01-01

    accuracy. Here, we report on a method to rapidly acquire high-resolution spectra in both polarity modes with sub-ppm mass accuracy and demonstrate that it not only simplifies and accelerates shotgun lipidomics analyses but also improves the lipidome coverage because more lipid classes and more individual......Topdown shotgun lipidomics relies on direct infusion of total lipid extracts into a high-resolution tandem mass spectrometer and implies that individual lipids are recognized by their accurately determined m/z. Lipid ionization efficiency and detection specificity strongly depend on the acquisition...... polarity, and therefore it is beneficial to analyze lipid mixtures in both positive and negative modes. Hybrid LTQ Orbitrap mass spectrometers are widely applied in topdown lipidomics; however, rapid polarity switching was previously unfeasible because of the severe and immediate degradation of mass...

  11. Enrichment of rare isotopes using a quadrupole mass spectrometer

    A small quadrupole mass spectrometer was operated in the static mode to enrich selected rare gas isotopes. Memory effects in the apparatus were observed and attributed to the re-emission of atoms implanted by the electron-impact ion source. Studies of the pumping mechanism led to a practical means for reducing the rate of noble gas pumping. (author)

  12. Cherenkov detectors and a new effective-mass spectrometer method

    Hladký, Jan

    2006-01-01

    Roč. 75, - (2006), s. 854-855. ISSN 0969-806X Institutional research plan: CEZ:AV0Z10100502 Keywords : Cherenkov radiation * spectrometer * effective mass method Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.868, year: 2006

  13. SMAD-2A mass spectrometer core isotopic analysis of water

    SMAT-2A is a small mass spectrometer for water isotopes analysis, double collector method (HD/H2 ratio). Improvements in maintenance automation data acquisition and processing are presented. Analyses of liquid and gaseous samples were made and internal reproducibility and precision are calculated. (Author)

  14. The History of Planetary Exploration Using Mass Spectrometers

    Mahaffy, Paul R.

    2012-01-01

    At the Planetary Probe Workshop Dr. Paul Mahaffy will give a tutorial on the history of planetary exploration using mass spectrometers. He will give an introduction to the problems and solutions that arise in making in situ measurements at planetary targets using this instrument class.

  15. Micro mass spectrometer on a chip.

    Cruz, Dolores Y.; Blain, Matthew Glenn; Fleming, James Grant

    2005-11-01

    The design, simulation, fabrication, packaging, electrical characterization and testing analysis of a microfabricated a cylindrical ion trap ({mu}CIT) array is presented. Several versions of microfabricated cylindrical ion traps were designed and fabricated. The final design of the individual trap array element consisted of two end cap electrodes, one ring electrode, and a detector plate, fabricated in seven tungsten metal layers by molding tungsten around silicon dioxide (SiO{sub 2}) features. Each layer of tungsten is then polished back in damascene fashion. The SiO{sub 2} was removed using a standard release processes to realize a free-hung structure. Five different sized traps were fabricated with inner radii of 1, 1.5, 2, 5 and 10 {micro}m and heights ranging from 3-24 {micro}m. Simulations examined the effects of ion and neutral temperature, the pressure and nature of cooling gas, ion mass, trap voltage and frequency, space-charge, fabrication defects, and other parameters on the ability of micrometer-sized traps to store ions. The electrical characteristics of the ion trap arrays were determined. The capacitance was 2-500 pF for the various sized traps and arrays. The resistance was in the order of 1-2 {Omega}. The inductance of the arrays was calculated to be 10-1500 pH, depending on the trap and array sizes. The ion traps' field emission characteristics were assessed. It was determined that the traps could be operated up to 125 V while maintaining field emission currents below 1 x 10{sup -15} A. The testing focused on using the 5-{micro}m CITs to trap toluene (C{sub 7}H{sub 8}). Ion ejection from the traps was induced by termination of the RF voltage applied to the ring electrode and current measured on the collector electrode suggested trapping of ions in 1-10% of the traps. Improvements to the to the design of the traps were defined to minimize voltage drop to the substrate, thereby increasing trapping voltage applied to the ring electrode, and to

  16. A microelectromechanical systems-enabled, miniature triple quadrupole mass spectrometer.

    Wright, Steven; Malcolm, Andrew; Wright, Christopher; O'Prey, Shane; Crichton, Edward; Dash, Neil; Moseley, Richard W; Zaczek, Wojciech; Edwards, Peter; Fussell, Richard J; Syms, Richard R A

    2015-03-17

    Miniaturized mass spectrometers are becoming increasingly capable, enabling the development of many novel field and laboratory applications. However, to date, triple quadrupole tandem mass spectrometers, the workhorses of quantitative analysis, have not been significantly reduced in size. Here, the basis of a field-deployable triple quadrupole is described. The key development is a highly miniaturized ion optical assembly in which a sequence of six microengineered components is employed to generate ions at atmospheric pressure, provide a vacuum interface, effect ion guiding, and perform fragmentation and mass analysis. Despite its small dimensions, the collision cell efficiently fragments precursor ions and yields product ion spectra that are very similar to those recorded using conventional instruments. The miniature triple quadrupole has been used to detect thiabendazole, a common pesticide, in apples at a level of 10 ng/g. PMID:25708099

  17. Laser Proton acceleration from mass limited silicon foils

    Zeil, K.; Kraft, S.; Richter, T.; Metzkes, J.; Bussmann, M.; Schramm, U.; Sauerbrey, R.; Cowan, T. E.; Fuchs, J.; Buffechoux, S.

    2009-11-01

    We present recent studies on laser proton acceleration experiments using mass limited silicon targets. Small micro machined silicon foils with 2 μm thickness and 20x20 μm2 to 100x100μm2 size mounted on very tiny stalks were shot with the 100 TW LULI Laser (long pulse 150 fs) and with the new 150 TW DRACO Laser facility (short pulse 30 fs) of the Research Centre Dresden-Rossendorf. The experiments were carried out using high contrast levels. Proton spectra have been measured with magnetic spectrometers and radio chromic film stacks.

  18. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  19. Preliminary results from LADEE's Neutral Mass Spectrometer (NMS)

    Benna, Mehdi; Mahaffy, Paul; Hodges, Richard

    2014-05-01

    The Neutral Mass Spectrometer (NMS) of the Lunar Atmosphere and Dust Environment Explorer (LADEE) Mission is a high sensitivity quadrupole mass spectrometer designed to measure the composition and variability of the tenuous lunar atmosphere. The instrument has been observing the lunar exosphere since 10/17/2013, initially from a near circular 250 km altitude orbit and since 11/11/2013 from an elliptical orbit that reaches to 30-60 km altitude near the sunrise terminator. During its first four months in orbit, the NMS instrument successfully detected exospheric helium, argon and neon and mapped their spatial and temporal variability. Furthermore, the NMS instrument was able to establish new upper limits for many other exospheric species either sputtered or thermally evolved from the lunar surface. This talk will summarize these preliminary results from the NMS measurements.

  20. A high efficiency thermal ionization source adapted to mass spectrometers

    A tungsten crucible thermal ionization source mounted on a quadrupole mass spectrometer is described. The crucible is a disposable rod with a fine hole bored in one end; it is heated by electron bombardment. The schematic design of the assembly, including water cooling, is described and depicted. Historically, the design is derived from that of ion sources used on ion separators at Los Alamos and Dubna, but the crucible is made smaller and simplified. 10 refs., 4 figs

  1. Commissioning of the AEI MS702 mass spectrometer

    The setting-up and commissioning of the AEI MS702 mass spectrometer is described. Its individual components and their use are discussed, as well as the sample preparation, analysis, and reduction of data. A comprehensive list is given of instrumental breakdowns, and the application of the technique to several matrices is outlined. Improvements and modifications to the technique, including the use of a minicomputer, are suggested

  2. Determining gaseous composition of fluid inclusions with quadrupole mass spectrometer

    朱和平; 王莉娟

    2002-01-01

    Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD, n = 6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical re-sults meet the requirement of geological study.

  3. A new computerized mass spectrometer for isotopic analyses of solids

    VARIAN MAT's new MAT 260 mass spectrometer system which is intended for automatic precision analysis of isotope ratios in solids (U, Pu, Rb, Sr, Pb and others) is described. The MAT 260 features exceptional performance for exceeding previous standards. The programmable desk calculator and the exceptionally sensitive ion source which contribute to the excellent standard of the system are discussed. The specifications and the applications to which the system can be put are also discussed. (K.B.)

  4. Method development of gas analysis with mass spectrometer

    Dissolved gas content in deep saline groundwater is an important factor, which has to be known and taken into account when planning the deep repository for the spent nuclear fuel. Posiva has investigated dissolved gases in deep groundwaters since the 1990's. In 2002 Posiva started a project that focused on developing the mass spectrometric method for measuring the dissolved gas content in deep saline groundwater. The main idea of the project was to analyse the dissolved gas content of both the gas phase and the water phase by a mass spectrometer. The development of the method started in 2003 (in the autumn). One of the aims was to create a parallel method for gas analysis with the gas chromatographic method. The starting point of this project was to test if gases could be analysed directly from water using a membrane inlet in the mass spectrometer. The main objective was to develop mass spectrometric methods for gas analysis with direct and membrane inlets. An analysis method for dissolved gases was developed for direct gas inlet mass spectrometry. The accuracy of the analysis method is tested with parallel real PAVE samples analysed in the laboratory of Insinoeoeritoimisto Paavo Ristola Oy. The results were good. The development of the membrane inlet mass spectrometric method still continues. Two different membrane materials (silicone and teflon) were tested. Some basic tests (linearity,repeatability and detection limits for different gases) will be done by this method. (orig.)

  5. Augmenting Ion Trap Mass Spectrometers Using a Frequency Modulated Drift Tube Ion Mobility Spectrometer.

    Morrison, Kelsey A; Siems, William F; Clowers, Brian H

    2016-03-15

    Historically, high pressure ion mobility drift tubes have suffered from low ion duty cycles and this problem is magnified when such instrumentation is coupled with ion trap mass spectrometers. To significantly alleviate these issues, we outline the result from coupling an atmospheric pressure, dual-gate drift tube ion mobility spectrometer (IMS) to a linear ion trap mass spectrometer (LIT-MS) via modulation of the ion beam with a linear frequency chirp. The time-domain ion current, once Fourier transformed, reveals a standard ion mobility drift spectrum that corresponds to the standard mode of mobility analysis. By multiplexing the ion beam, it is possible to successfully obtain drift time spectra for an assortment of simple peptide and protein mixtures using an LIT-MS while showing improved signal intensity versus the more common signal averaging technique. Explored here are the effects of maximum injection time, solution concentration, total experiment time, and frequency swept on signal-to-noise ratios (SNRs) and resolving power. Increased inject time, concentration, and experiment time all generally led to an improvement in SNR, while a greater frequency swept increases the resolving power at the expense of SNR. Overall, chirp multiplexing of a dual-gate IMS system coupled to an LIT-MS improves ion transmission, lowers analyte detection limits, and improves spectral quality. PMID:26854901

  6. Accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator

    Accelerator based mass spectrometry (ABMs) is an ultra sensitive means of counting individual atoms having sufficiently long half life and available in small amount. The 14 U D Pelletron Accelerator is an ideal machine to carry out ABMs studies with heavy isotopes like 36Cl and 129I. Cosmogenic radio isotope 36Cl is widely being detected using ABMs as it has got applications in ground water research, radioactive waste management, atmospheric 36Cl transport mechanism studies of Arctic Alpine ice core etc. As a part of the ongoing ABMs programme at 14UD Pelletron Accelerator Facility at Mumbai, a segmented gas detector developed for identification of 36Cl was tested for performance. Recently a beam chopper required for this measurement has been developed. Further progress made in this programme is discussed in this paper. (author)

  7. Weighing excited nuclear states with a Penning trap mass spectrometer

    We report on high-accuracy mass measurements and isomer identification of 187Pb. In this nuclide, two close-lying isomeric states are known from α-decay studies. With the combined use of the ISOLDE resonance ionization laser ion source and the Penning trap mass spectrometer ISOLTRAP the energy difference of 187Pb and 187mPb was determined to be E = 33(13) keV. This is the lowest isomeric excitation energy ever determined by weighing nuclei. (orig.)

  8. Mass spectrometry by means of tandem accelerators

    Mass spectrometry based on an accelerator allows to measure rare cosmogenic isotopes found in natural samples with isotopic abundances up to 10E-15. The XTU Tandem of Legnaro National Laboratories can measure mean heavy isotopes (36Cl, 41Ca, 129I) in applications interesting cosmochronology and Medicine. The TTT-3 Tandem of the Naples University has been modified in view of precision studies of C14 in Archeology, Paleantology and Geology. In this paper a review is made of principles and methodologies and of some applicationy in the framework of the National Program for mass spectrametry research with the aid of accelerators

  9. The high-precision Penning trap mass spectrometer PENTATRAP

    Doerr, Andreas; Bekker, Hendrik; Blaum, Klaus; Goncharov, Mikhail; Hoekel-Schmoeger, Christian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Fakultaet fuer Physik und Astronomie, Ruprecht-Karls-Universitaet, Heidelberg (Germany); Boehm, Christine [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Fakultaet fuer Physik und Astronomie, Ruprecht-Karls-Universitaet, Heidelberg (Germany); Extreme Matter Institute EMMI, Helmholtz Gemeinschaft, Darmstadt (Germany); Crespo Lopez-Urrutia, Jose; Eliseev, Sergey; Repp, Julia; Roux, Christian; Sturm, Sven [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Novikov, Yuri [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Ulmer, Stefan [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama (Japan)

    2013-07-01

    Currently, the high-precision Penning trap mass spectrometer PENTATRAP is being built up at the Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany. It aims at mass-ratio measurements of medium- to high-Z elements with uncertainties of a few parts in 10{sup 12}. Mass-ratios will be determined by the measurement of cyclotron frequency-ratios in the strong magnetic field of the trap. The experiment will host five identical cylindrical Penning traps and will allow for simultaneous cyclotron frequency determinations in all measurement traps. It will feature access to highly charged ions provided by EBITs. Measurements at PENTATRAP will contribute to various fields of physics. For example, input parameters for neutrino mass determinations will be provided with measurements of Q-values of relevant β-transitions. The current status of the experiment will be outlined in the talk.

  10. Ion mobility analyzer - quadrupole mass spectrometer system design

    Cuna, C; Leuca, M; Lupsa, N; Mirel, V; Cuna, Stela; Cosma, V; Tusa, Florina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Bocos-Bintintan, V, E-mail: cornel.cuna@itim-cj.r [Babes-Bolyai University, Faculty of Environmental Sciences, 3 Fantanele, 400294 Cluj Napoca (Romania)

    2009-08-01

    Because of their extremely high sensitivity for chemicals with elevated electronegativity or high proton affinity the ion mobility analysers are ideal for the ultra-trace detection of toxic or explosive chemicals, most of these situated often at concentration levels of sub-ppb (parts-per-billion). Ion mobility spectrometers (IMS) can be used to identify illicit drugs or environmental pollutants. Since resolution of an IMS is relatively low, to achieve an accurate identification of target analyte it is recommended to couple the IMS with a quadrupole mass spectrometer (QMS) or a time of flight mass spectrometer, acquiring in this way confirmatory information. This coupling is made through a specific interface. In this paper, an experimental model of such a tandem instrument, IMS-QMS is described. Accomplishment of this general purpose will be done, overcoming a series of specific issues. This implies the solving, using innovative solutions, of a series of complex issues: ensuring the stability of the ions beam generated by ion source; transfer with a good efficiency of the ionic current from IMS analyser to QMS; and realization of a special electronic circuitry which will be able to detect both positive and negative ions.

  11. Ion mobility analyzer - quadrupole mass spectrometer system design

    Because of their extremely high sensitivity for chemicals with elevated electronegativity or high proton affinity the ion mobility analysers are ideal for the ultra-trace detection of toxic or explosive chemicals, most of these situated often at concentration levels of sub-ppb (parts-per-billion). Ion mobility spectrometers (IMS) can be used to identify illicit drugs or environmental pollutants. Since resolution of an IMS is relatively low, to achieve an accurate identification of target analyte it is recommended to couple the IMS with a quadrupole mass spectrometer (QMS) or a time of flight mass spectrometer, acquiring in this way confirmatory information. This coupling is made through a specific interface. In this paper, an experimental model of such a tandem instrument, IMS-QMS is described. Accomplishment of this general purpose will be done, overcoming a series of specific issues. This implies the solving, using innovative solutions, of a series of complex issues: ensuring the stability of the ions beam generated by ion source; transfer with a good efficiency of the ionic current from IMS analyser to QMS; and realization of a special electronic circuitry which will be able to detect both positive and negative ions.

  12. Non-accelerator neutrino mass searches

    Zuber, K.

    2000-01-01

    The current status of non-accelerator based searches for effects of a non-vanishing neutrino mass is reviewed. Beside the direct kinematical methods this includes searches for magnetic moments and a discussion of the solar neutrino problem. Double beta decay is not included.

  13. Linear electric field time-of-flight ion mass spectrometer

    Funsten, Herbert O.; Feldman, William C.

    2008-06-10

    A linear electric field ion mass spectrometer having an evacuated enclosure with means for generating a linear electric field located in the evacuated enclosure and means for injecting a sample material into the linear electric field. A source of pulsed ionizing radiation injects ionizing radiation into the linear electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between ionization of atoms or molecules and arrival of an ion out of the ionized atoms or molecules at a predetermined position.

  14. Instruction manual for ORNL tandem high abundance sensitivity mass spectrometer

    Smith, D.H.; McKown, H.S.; Chrisite, W.H.; Walker, R.L.; Carter, J.A.

    1976-06-01

    This manual describes the physical characteristics of the tandem mass spectrometer built by Oak Ridge National Laboratory for the International Atomic Energy Agency. Specific requirements met include ability to run small samples, high abundance sensitivity, good precision and accuracy, and adequate sample throughput. The instrument is capable of running uranium samples as small as 10/sup -12/ g and has an abundance sensitivity in excess of 10/sup 6/. Precision and accuracy are enhanced by a special sweep control circuit. Sample throughput is 6 to 12 samples per day. Operating instructions are also given.

  15. A gas monitoring facility with a quadrupole mass spectrometer for the ZEUS transition-radiation chambers

    A gas analysis facility for the ZEUS transition-radiation chambers based on a quadrupole mass spectrometer is described. After a description of the spectrometer, the vacuum system, and the software, some test results are presented. (HSI)

  16. Accelerator Mass Spectrometry: practice and prospects

    Accelerator mass spectrometry (AMS) is an established technique for detecting rare isotopes, at isotope ratios in the range ∼10-12 to ∼10-15. As the name indicates, the technique uses an accelerator to produce high-energy ion beams, which are then analyzed by mass spectrometry. AMS is not only useful for determining anthropogenic or cosmogenic isotopes, but can also be used for trace element analysis, because every element except In has an isotope for which no other element has a stable isobar. This is significant for semiconductors and mineral analysis. The success of AMS arises from three factors: the use of negative ions at injection, which can suppress isobars (e.g.in the case of C-14); the stripping process at the accelerator terminal, which destroys molecular ions; and the high energy of the accelerated particles, which, by overcoming detector background, permits the use of sensitive particle identification and detection techniques. The 'standard' AMS isotopes are Be-10, C-14, Al-26, Cl-36, Ca-41, Ni-59, I-129. Prospective isotopes include Mn-53, Fe-60, Se-79, Tc-99, Pd-107, Sn-126, Cs-135. The following developed or prospective techniques are briefly discussed: total stripping; resonant ionization; static electric field ionization; the gas-filled magnet; isobaric laundering; negative molecular ions; laser photodetachment; X-ray identification. 9 refs., 4 tabs

  17. One-step membrane feed system for a mass spectrometer

    The data on the gas permeability of membranes made of the Soviet silicon rubber which are used in the feed system for a mass spectrometer to analyze gaseous mixtures and gases dissolved in the liquid at atmospheric and increased pressures, are presented. Membranes of a rubber mixture have been made in the form of tubes with the wall thickness of outer and inner diameters of approximately 0.15 mm and 1 mm, respectively. No alterations in the mumbrane permeability at the measurement accuracy level of 5-10 % have been noticed in the process of investigations into the gaseous mixture composition at the atmospheric pressure during 500 hours with the total exploitation time of one year. The temperature increase from 22 to 35 deg C leads to the increase of nitrogen permeability by 35%. No mutual effect on the permeability is noticed for the mixture of N2, O2, C2 gases. The gas dynamic time constant of membranes is 3-5 s. The results obtained permit to consider one-step membrane feed systems for mass-spectrometers to be perspective when studying the composition of gaseous and liquid media in a wide range of pressures

  18. Accelerator mass spectrometry for radiocarbon dating

    Bronk, Christopher Ramsey.; Hedges, Robert; Robert Hedges

    1987-01-01

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. During this period it has become evident neither the accuracy nor the range of the technique were as great as had originally been hoped. This thesis describes both theoretical work to understand the reasons for this and practical solutions to overcome some of the problems. The production and transport of the ions used in the measurements are found to be the most crucial stages in...

  19. The five-Penning trap mass spectrometer PENTATRAP

    Repp, Julia; Boehm, Christine; Goncharov, Mikhail; Roux, Christian; Blaum, Klaus [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Crespo Lopez-Urrutia, Jose; Eliseev, Sergey [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Doerr, Andreas [Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Novikov, Yuri [St. Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Sturm, Sven [Johannes Gutenberg-Universitaet, Institut fuer Physik, 55099 Mainz (Germany); Ulmer, Stefan [Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Johannes Gutenberg-Universitaet, Institut fuer Physik, 55099 Mainz (Germany)

    2011-07-01

    Currently the new mass spectrometer PENTATRAP is being developed at the Max-Planck-Institut fuer Kernphysik in Heidelberg. Ions of interest are stable and long-lived highly charged nuclides up to uranium. PENTATRAP aims for an accuracy of few parts in 10{sup 12} for mass ratios of mass doublets and a relative uncertainty of {approx} 10{sup -11} for absolute mass ratios. The measured mass values will contribute among others to Q-value determinations of relevant {beta}-processes for neutrino physics, stringent tests of quantum electrodynamics in the regime of extreme fields, and a test of special relativity. The five-trap setup allows to choose an optimal measurement scheme for each ionic species of interest. Main features of PENTATRAP are an access to highly charged ions, highly sensitive cryogenic non-destructive detection systems, a fast exchange between different ions and a continuous monitoring of magnetic field fluctuations. This talk presents the experimental setup and the present status of the PENTATRAP experiment.

  20. Quantitative determination of carbonaceous particle mixing state in Paris using single particle mass spectrometer and aerosol mass spectrometer measurements

    Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.

    2013-04-01

    Single particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been estimated using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulphate and potassium were compared with concurrent measurements from an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal/optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and ten discrete mixing states for carbonaceous particles were identified and quantified. Potassium content was used to identify particles associated with biomass combustion. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorization, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulphate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA/EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidized OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the heterogeneity of primary and

  1. Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

    R. M. Healy

    2013-09-01

    Full Text Available Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC, organic aerosol (OA, ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a thermal–optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC. ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78, and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the

  2. Quantitative determination of carbonaceous particle mixing state in Paris using single particle mass spectrometer and aerosol mass spectrometer measurements

    R. M. Healy

    2013-04-01

    Full Text Available Single particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been estimated using an aerosol time-of-flight mass spectrometer (ATOFMS as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC, organic aerosol (OA, ammonium, nitrate, sulphate and potassium were compared with concurrent measurements from an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a thermal/optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC. ATOFMS-derived mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78, and ten discrete mixing states for carbonaceous particles were identified and quantified. Potassium content was used to identify particles associated with biomass combustion. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorization, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA detected in Paris is associated with two EC-rich mixing states which differ in their relative sulphate content, while fresh biomass burning OA (BBOA is associated with two mixing states which differ significantly in their OA/EC ratios. Aged biomass burning OA (OOA2-BBOA was found to be significantly internally mixed with nitrate, while secondary, oxidized OA (OOA was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the heterogeneity of

  3. Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

    Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.

    2013-09-01

    Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal-optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the temporal

  4. The advantages of orthogonal acceleration in ICP time-of-flight mass spectrometry

    The OptiMass 8000 incorporates an orthogonal acceleration time-of-flight mass spectrometer. A general schematic of the instrument is given. The continuous ion beam is chopped by an orthogonal accelerator. A push out pulse supply is coupled to the accelerator for providing repetitive push-out voltages at a frequency of 30 kHz. The ion packets that are sliced out of the beam then travel within the field free space towards the SMARTGATE ion blanker. Orthogonal accelerator parameters are set to enable temporal-spatial focusing at the SMARTGATE ion blanker, so that iso-mass ion packets are resolved in time. Any ion packets of unwanted specie are ejected from the direction of travel by supplying pulsed voltages onto the deflection plates of the SMARTGATE. The ions to be measured are let through SMARTGATE and travel further down the field free space, to enter the ion reflectron. The ion reflectron increases the resolution of the mass spectrometer by means of temporal-energy focussing. After reflection, the ions travel within the field free space towards the discrete-dynode detector. In comparison to other acceleration geometries used in elemental time-of-flight mass spectrometry the OptiMass 8000 orthogonal acceleration geometry ultimately leads to superior resolution. As the energy spread is about 3 orders of magnitude lower in the time-of-flight direction for an oaTOFMS in comparison to an on-axis system, aberration acquired in the initial stages of acceleration are much lower. As a result the orthogonal acceleration scheme provides superior resolution at the first spatial focus point and the detector. The orthogonal acceleration time-of-flight analyzer of the OptiMass 8000 is able to provide resolution of at least 1800 at mass 238. (author)

  5. Broadband Single-Shot Electron Spectrometer for GeV-Class Laser Plasma Based Accelerators

    Nakamura, K.; Wan, W.; Ybarrolaza, N.; Syversrud, D.; Wallig, J.; Leemans, W.P.

    2008-05-01

    Laser-plasma-based accelerators can provide electrons over a broad energy range and/or with large momentum spread. The electron beam energy distribution can be controlled via accurate control of laser and plasma properties, and beams with energies ranging from'0.5 to 1000 MeV have been observed. Measuring these energy distributions in a single shot requires the use of a diagnostic with large momentum acceptance and, ideally, sufficient resolution to accurately measure energy spread in the case of narrow energy spread. Such a broadband single-shot electron magnetic spectrometer for GeV-class laser-plasma-based accelerators has been developed at Lawrence Berkeley National Laboratory. A detailed description of the hardware and the design concept is presented, as well as a performance evaluation of the spectrometer. The spectrometer covered electron beam energies raging from 0.01 to 1.1 GeV in a single shot, and enabled the simultaneous measurement of the laser properties at the exit of the accelerator through the use of a sufficiently large pole gap. Based on measured field maps and 3rd-order transport analysis, a few percent-level resolution and determination of the absolute energy were achieved over the entire energy range. Laser-plasma-based accelerator experiments demonstrated the capability of the spectrometer as a diagnostic and its suitability for such a broadband electron source.

  6. Multi-stage magnetic induction mass accelerator

    The magnetic induction method of mass acceleration readily lends itself to multi-staging. In the limit of many stages, such an accelerator approaches a distributed energy source system where only closing switches are necessary. We describe the design and performance of a three-stage accelerator, each driven by a separate capacitor bank. This system was modeled using a previously reported computer code. In order to do this the code was modified to calculate projectile acceleration through a succession of driver coils: Thermal conductivity and surface melting models were also added. The former is necessary due to the extended transit time through many stages. The latter is needed in anticipation of the more extreme ohmic heating when the capacitor banks are replaced by explosive-driven, magnetic flux compression generators. The performance goal of this system is to at least double the kinetic energy of a 0.3 kgm copperclad, steel projectile injected at a velocity of 300 m/sec from an explosive-driven gun. We then plan to test the system at the thermal and mechanical limit by using explosive-driven, magnetic flux compression generators as energy sources. We envision a six-stage system driven by three generators

  7. Mass measurements near the $r$-process path using the Canadian Penning Trap mass spectrometer

    Van Schelt, J.; Lascar, D.; G. Savard; Clark, J. A.; Caldwell, S.; Chaudhuri, A.; Fallis, J.; Greene, J. P.; Levand, 1 A. F.; Li, G.; Sharma, K. S.; Sternberg, M. G.; Sun, T.; Zabransky, B. J.

    2012-01-01

    The masses of 40 neutron-rich nuclides from Z = 51 to 64 were measured at an average precision of $\\delta m/m= 10^{-7}$ using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. The measurements, of fission fragments from a $^{252}$Cf spontaneous fission source in a helium gas catcher, approach the predicted path of the astrophysical $r$ process. Where overlap exists, this data set is largely consistent with previous measurements from Penning traps, storage rings, and ...

  8. Actinides analysis by accelerator mass spectrometry

    At the ANTARES accelerator at ANSTO a new beamline has been commissioned, incorporating new magnetic and electrostatic analysers, to optimise the efficiency for Actinides detection by Accelerator Mass Spectrometry (AMS). The detection of Actinides, particularly the isotopic ratios of uranium and plutonium, provide unique signatures for nuclear safeguards purposes. We are currently engaged in a project to evaluate the application of AMS to the measurement of Actinides in environmental samples for nuclear safeguards. Levels of certain fission products, Actinides and other radioactive species can be used as indicators of undeclared nuclear facilities or activities, either on-going or in the past Other applications of ultra-sensitive detection of Actinides are also under consideration. neutron-attenuation images of a porous reservoir rock

  9. Electrical recording system for laser mass spectrometer with double focusing

    Paper describes a system to record ion currents for EMAL-2 laser mass spectrometer with double focusing. The recording system consists of an original geometry multichannel collector, a controlled multiplexer and a data entry circuit. A receiving collector represents a set of metal plates separated by insulator plates of similar thickness. The collector has 384 channels at 38.4 cm length and 0.5 mm thickness of one collector unit. Every collector is put under condenser load. To measure discharge at accumulating systems and to enter data to a computer one applies a multichannel analog-to-digital converter (ADC) and a controlled multiplexer. One elaborated a special software enabling on-line displaying of signals from ADC

  10. Diagnostics aid for mass spectrometer trouble-shooting

    The ''MS Expert'' system provides problem diagnostics for instruments used in the Mass Spectrometry Laboratory (MSL). The most critical results generated on these mass spectrometers are the uranium concentration and isotopic content data used for process control and materials accountability at the Idaho Chemical Processing Plant. The two purposes of the system are: (1) to minimize instrument downtime and thereby provide the best possible support to the Plant, and (2) to improve long-term data quality. This system combines the knowledge of several experts on mass spectrometry to provide a diagnostic tool, and can make these skills avilable on a more timely basis. It integrates code written in the Pascal language with a knowledge base entered into a commercial expert system ''shell.'' The user performs some preliminary status checks, and then selects from among several broad diagnostic categories. These initial steps provide input to the rule base. The overall analysis provides the user with a set of possible solutions to the observed problems, graded as to their probabilities. Besides the trouble-shooting benefits expected from this system, it will also provide structures diagnostic training for lab personnel. In addition, development of the system knowledge base has already produced a better understanding of instrument behavior. Two key findings are that a good user interface is necessary for full acceptance of the tool, and a development system should include standard programming capabilities as well as the expert system shell. 22 refs., 5 figs

  11. Diagnostics aid for mass spectrometer trouble-shooting

    The MS Expert system provides problem diagnostics for instruments used in the Mass Spectrometry Laboratory (MSL). The most critical results generated on these mass spectrometers are the uranium concentration and isotopic content data used for process control and materials accountability at the Idaho General Processing Plant. The two purposes of the system are: (1) to minimize instrument downtime and thereby provide the best possible support to the Plant, and (2) to improve long-term data quality. This system combines the knowledge of several experts on mass spectrometry to provide a diagnostic tool, and can make these skills available on a more timely basis. It integrates code written in the Pascal language with a knowledge base entered into a commercial expert system shell. The user performs some preliminary status checks, and then selects from among several broad diagnostic categories. These initial steps provide input to the rule base. The overall analysis provides the user with a set of possible solutions to the observed problems, graded as to their probabilities. Besides the trouble-shooting benefits expected from this system, it also provides structured diagnostic training for lab personnel. In addition, development of the system knowledge base has already produced a better understanding of instrument behavior. Two key findings are that a good user interface is necessary for full acceptance of the tool, and, a development system should include standard programming capabilities as well as the expert system shell

  12. New directions for accelerator mass spectrometry technology

    The influence on accelerator mass spectrometry (AMS) of developments in other fields is reviewed and three examples are discussed in detail. The appropriate use of electric and magnetic analysers with small AMS systems (129I, for nuclear fuel monitoring and ocean circulation tracer studies. The inclusion of gas chromatography technology extends the capability of AMS to applications which require large numbers of samples with rapid turn-around. The adaptation of chemical reaction cell technology to negative ion beams adds new isobar selection capability to AMS and will permit analyses of isotopes such as 36Cl on small AMS systems. (author)

  13. 10 K Ring Electrode Trap—Tandem Mass Spectrometer for Infrared Spectroscopy of Mass Selected Ions

    Goebbert, Daniel J.; Meijer, Gerard; Asmis, Knut R.

    2009-03-01

    A novel instrumental setup for measuring infrared photodissociation spectra of buffer gas cooled, mass-selected ions is described and tested. It combines a cryogenically cooled, linear radio frequency ion trap with a tandem mass spectrometer, optimally coupling continuous ion sources to pulsed laser experiments. The use of six independently adjustable DC potentials superimposed over the trapping radio frequency field provides control over the ion distribution within, as well as the kinetic energy distribution of the ions extracted from the ion trap. The scheme allows focusing the ions in space and time, such that they can be optimally irradiated by a pulsed, widely tunable infrared photodissociation laser. Ion intensities are monitored with a time-of-flight mass spectrometer mounted orthogonally to the ion trap axis.

  14. 10 K Ring Electrode Trap - Tandem Mass Spectrometer for Infrared Spectroscopy of Mass Selected Ions

    A novel instrumental setup for measuring infrared photodissociation spectra of buffer gas cooled, mass-selected ions is described and tested. It combines a cryogenically cooled, linear radio frequency ion trap with a tandem mass spectrometer, optimally coupling continuous ion sources to pulsed laser experiments. The use of six independently adjustable DC potentials superimposed over the trapping radio frequency field provides control over the ion distribution within, as well as the kinetic energy distribution of the ions extracted from the ion trap. The scheme allows focusing the ions in space and time, such that they can be optimally irradiated by a pulsed, widely tunable infrared photodissociation laser. Ion intensities are monitored with a time-of-flight mass spectrometer mounted orthogonally to the ion trap axis.

  15. Fast mass programming controller for a supersonic gas chromatography mass spectrometer

    In a gas chromatograph mass spectrometer employing a quadrupole mass filter, molecules are ionized and transferred to a mass analyzer, where their mass to charge ratios (m/z) are measured. After the ionization step, the ions pass through a series of ion lenses that focus and guide them into the mass analyzer. The voltages on these lenses can be optimized for each specific m/z value (as the rest of the system is also optimized) to increase the number of ions reaching the mass analyzer. In certain cases, this dynamic mass-dependent optimization of the lenses can increase the signal by a factor of 2 or more. To implement this dynamic optimization, a digital circuit was developed, based on a digital signal controller and high-voltage (HV) amplifiers, that is able to optimize eight independent HV channels ranging between ±150 V at a rate of 100 µs

  16. Accelerator mass spectrometry for radiocarbon dating

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. This thesis describes theoretical work to understand the reasons for low accuracy and range and offers practical solutions. The production and transport of the ions used in the measurements are found to be the most crucial stages in the process. The theories behind ion production by sputtering are discussed and applied to the specific case of carbon sputtered by caesium. Experimental evidence is also examined in relation to the theories. The phenomena of space charge and lens aberrations are discussed along with the interaction between ion beams and gas molecules in the vacuum. Computer programs for calculating phase space transformations are then described; these are designed to help investigations of the effects of space charge and aberrations on AMS measurements. Calculations using these programs are discussed in relation both to measured ion beam profiles in phase space and to the current dependent transmission of ions through the Oxford radiocarbon accelerator. Improvements have been made to this accelerator and these are discussed in the context of the calculations. C- ions are produced directly from carbon dioxide at the Middleton High Intensity Sputter Source. Experiments to evaluate the performance of such a source are described and detailed design criteria established. An ion source designed and built specifically for radiocarbon measurements using carbon dioxide is described. Experiments to evaluate its performance and investigate the underlying physical processes are discussed. (author)

  17. Miniature Ion Optics Towards a Micro Mass Spectrometer

    Chaudhary, Ashish

    This PhD dissertation reports the development of miniature ion optics components of a mass spectrometer (MS) with the ultimate goal to lay the foundation for a compact low-power micromachined MS (microMS) for broad-range chemical analysis. Miniaturization of two specific components a) RF ion traps and b) an ion funnel have been investigated and miniature low-power versions of these components have been developed and demonstrated successfully in lab experiments. Power savings, simpler electronics and packaging schemes required to operate the micro-scale RF cylindrical ion traps have been the key motivation driving this research. Microfabricated cylindrical ion traps (microCITs) and arrays in silicon, silicon-on-insulator and stainless steel substrates have been demonstrated and average power of as low as 55 mW for a low mass range (28 to 136 amu) and mass spectra with better than a unit-mass-resolution have been recorded. For the ion funnel miniaturization effort, simple assembly, small form factor and ease of integration have been emphasized. A simplification of the conventional 3D ion funnel design, called the planar ion funnel, has been developed in a single plate and has been tested to demonstrate ion funneling at medium vacuum levels (1E-5 Torr) using DC voltages and power less than 0.5 W. Miniaturization of these components also enables use of other novel ion optics components, packaging and integration, which will allow a new class of microMS architectures amenable for radical miniaturization.

  18. Determining gaseous composition of fluid inclusions with quadrupole mass spectrometer

    ZHU; Heping

    2002-01-01

    [1]Joseph, R. G., Stephen, E. K., Factors affecting gas analysis of inclusion fluid by quadrupole mass spectrometry, Geo-chimica et Acta, 1995, 59(19): 3977-3986.[2]Masakatsu, S., Takayuki, S., Naoto, T., Analysis of fluid inclusion gases from geothermal systems, using a rapid-scanning quadrupole mass spectrometer, Eur. J. Mineral., 1992, 4: 895-906.[3]Van den Kerkhof, A. M., Isochoric phase diagrams in the systems CO2-CH4 and CO2-N2: Application to fluid inclusions, Geochimica et Cosmochimica Acta, 1990, 54: 621-629.[4]Colin, B., Michael, P. S., Mass spectrometric determination of gases in individual fluid inclusions in natural minerals, Anal. Chem., 1986, 58: 1330-1333.[5]David, I. N., Fredrick, J. S., Analysis of volatiles in fluid inclusions by mass spectrometry, Chemical Geology, 1987, 61: 1-10.[6]Yoichi, M., Ryo, K., Takayuki, S. et al., Gas composition of fluid inclusion from the Mori Geothermal Reservoir, South-western Hokkaido, Japan, Resource Geology, 1997, 47(5): 283-291.[7]Lu Huanzhang, Guo Dijiang, Progress and trends of researches on fluid inclusions, Geological Review, 2000, 46(4): 385-392.[8]Xia Xinyu, Wang Xianbin, Chen Jiangfeng, Geningjie, composition of fluid inclusions and CO2 carbon isotope of ultra-high pressure metamorphic rocks in Shuanghe area, Dabieshan Mountain, Science in China (in Chinese), Ser. D, 1999, 29(4): 314-320.

  19. Recent results from the Penning trap mass spectrometer JYFLTRAP

    Accurate mass determination employing Penning ion traps has gained increasing importance after the installation of several new on-line facilities at accelerator labs. These setups combine unique production possibilities for rare isotopes with elaborate ion-capture and manipulation techniques. Since the final commissioning of the JYFLTRAP setup at the IGISOL facility in Jyvaeskylae, the masses of more than 200 short-lived nuclides have been measured. Their knowledge applies to studies on nuclear structure, the modeling of nucleosynthesis processes, tests of the conserved vector current (CVC) hypothesis and the unitarity of the CKM matrix, and furthermore, can help to assist in ongoing searches of neutrinoless double-beta decays. This presentation focuses on recent highlights studied at JYFLTRAP

  20. Recent results from the Penning trap mass spectrometer JYFLTRAP

    Weber, Christine; Elomaa, Viki-Veikko; Eronen, Tommi; Hakala, Jani; Jokinen, Ari; Kankainen, Anu; Rahaman, Saidur; Rissanen, Juho; Aeystoe, Juha [Department of Physics, (YFL), University of Jyvaeskylae (Finland)

    2009-07-01

    Accurate mass determination employing Penning ion traps has gained increasing importance after the installation of several new on-line facilities at accelerator labs. These setups combine unique production possibilities for rare isotopes with elaborate ion-capture and manipulation techniques. Since the final commissioning of the JYFLTRAP setup at the IGISOL facility in Jyvaeskylae, the masses of more than 200 short-lived nuclides have been measured. Their knowledge applies to studies on nuclear structure, the modeling of nucleosynthesis processes, tests of the conserved vector current (CVC) hypothesis and the unitarity of the CKM matrix, and furthermore, can help to assist in ongoing searches of neutrinoless double-beta decays. This presentation focuses on recent highlights studied at JYFLTRAP.

  1. A New Multi Collector Isotope Ratio Mass Spectrometer

    Appelhans, A. D.; Olson, J. E.; Ward, M. B.; Dahl, D. A.

    2007-12-01

    With the goal of improving the sensitivity of isotope ratio measurements, particularly for actinides, a new magnetic sector mass spectrometer that utilizes up to seven full-sized discrete dynode electron multipliers operating simultaneously has been designed, constructed and is in the early stages of testing. The design is based on a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated by 35 mm; this allows a full-sized discrete dynode pulse counting multiplier to be used for each beam. The ion dispersion lens (US patents 6,297,501 and pending) is a two element electrostatic 90 degree sector device that causes the beam-to-beam dispersion to increase faster than the intra-beam dispersion. Each of the multipliers is housed in an isolated case and is equipped with a deflector/condenser lens at the entrance to optimize pulse generation. The instrument includes a 9-sample filament cartridge mounted on a micro-manipulator X-Y stage that enables adjustment of the filament position with 10 micron resolution within the ion lens. Initial testing has shown that the instrument is performing as predicted by the ion optics model of the design.

  2. Detection electronics at the Penning trap mass spectrometer PENTATRAP

    Doerr, Andreas; Boehm, Christine; Repp, Julia; Roux, Christian; Blaum, Klaus [Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Crespo Lopez-Urrutia, Jose; Eliseev, Sergey; Goncharov, Mikhail [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Novikov, Yuri [St. Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Sturm, Sven [Johannes Gutenberg-Universitaet, Institut fuer Physik, 55099 Mainz (Germany); Ulmer, Stefan [Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Johannes Gutenberg-Universitaet, Institut fuer Physik, 55099 Mainz (Germany)

    2011-07-01

    The ''five Penning trap'' mass spectrometer PENTATRAP is currently under construction at the Max-Planck-Institut fuer Kernphysik in Heidelberg. Measurements of masses of single stable and long lived highly charged ions with a relative uncertainty on the order of 10{sup -11} are aimed at. The experiment is based on the non-destructive detection of image currents the ion induces in the trap electrodes. Essential part of each detection circuit is an inductance, configured either as a copper wire coil or as a superconducting toroid, in both cases mounted in a copper housing. Since signals are small ({proportional_to}fA), low-noise detection electronics is needed to obtain a sufficient signal-to-noise ratio. Therefore the first amplification stage is a cryogenic GaAs amplifier. Currently, we evaluate the possible use of a SQUID based amplifier. Furthermore, an axial frequency down converter providing a high level of sideband rejection has been set up. Further details on the detection electronics mentioned above will be presented in the poster.

  3. Detection electronics at the Penning-trap mass spectrometer PENTATRAP

    Doerr, Andreas; Repp, Julia; Roux, Christian; Blaum, Klaus [Fakultaet fuer Physik und Astronomie, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Boehm, Christine [Fakultaet fuer Physik und Astronomie, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); ExtreMe Matter Institute EMMI, Helmholtz Gemeinschaft, 64291 Darmstadt (Germany); Eliseev, Sergey; Goncharov, Mikhail [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Sturm, Sven [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Ulmer, Stefan [Atomic Physics Laboratory, RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama 351-0198 (Japan)

    2012-07-01

    The five Penning-trap mass spectrometer PENTATRAP is currently being built at the Max-Planck-Institut fuer Kernphysik in Heidelberg. Measurements of masses of single stable and long lived highly charged ions with a relative uncertainty on the order of 10{sup -11} are aimed for. The experiment is based on the non-destructive detection of image currents the ion induces in the trap electrodes. Essential part of each detection circuit is a cryogenic high-Q inductance, configured either as a copper wire coil or as a superconducting toroid, in both cases mounted in a copper housing. The following amplification stages consist of cryogenic GaAs FET amplifiers, which provide high input impedances and have low input-related noise densities. With these cryogenic detection systems, the tiny image currents ({proportional_to}fA) induced by a single ion become detectable. The current status of the detection electronics as well as future perspectives are presented in the talk.

  4. Using a fully automatic mass spectrometer for fissile material control

    The demand for higher accuracy and a shorter delay in the analysis together with better objectifiability and data security needed in safeguards, lead to the automation of a mass spectrometer. Starting with a continuous feeding of samples via a high vacuum lock and including the subsequent heating, focussing and scanning of the samples as well as the final evaluation of the source data (taking alpha spectrometry and the weights required for the isotope dilution technique into account), the mass spectrometric procedure was completely automated. For this purpose, a serial CH-5 instrument of varian mat was modified to be operated by a varian 620/I computer. A newly developed three chamber high vacuum lock was attached to this system and the final evaluation is made with an IBM 370. The system has been used in operation for the isotope analysis of U, Pu and Nd for one year. Major breakdowns of the hardware did not occur, however, the computer programmes had to be steadily improved according to the changing characteristics of the samples. Compared to manual operation, the automat is superior in its throughput and speed of analysing series of similar samples. The automatic procedure objectifies the analysis and the complete evaluation ensures a better data security. (Orig./HP). (author)

  5. High-precision masses of neutron-deficient rubidium isotopes using a Penning trap mass spectrometer

    Kellerbauer, A G; Beck, D; Blaum, K; Bollen, G; Guénaut, C; Herfurth, F; Herlert, A; Kluge, H J; Lunney, D; Schwarz, S; Schweikhard, L; Weber, C; Yazidjian, C

    2007-01-01

    The atomic masses of the neutron-deficient radioactive rubidium isotopes $^{74-77,79,80,83}$Rb have been measured with the Penning trap mass spectrometer ISOLTRAP. Using the time-of-flight cyclotron resonance technique, relative mass uncertainties ranging from $1.6 \\times 10^{-8}$ to $5.6 \\times 10^{-8}$ were achieved. In all cases, the mass precision was significantly improved as compared with the prior Atomic-Mass Evaluation; no significant deviations from the literature values were observed. The exotic nuclide $^{74}$Rb with a half-life of only 65 ms, is the shortest-lived nuclide on which a high-precision mass measurement in a Penning trap has been carried out. The significance of these measurements for a check of the conserved-vector-current hypothesis of the weak interaction and the unitarity of the Cabibbo-Kobayashi-Maskawa matrix is discussed.

  6. High-Precision Mass Measurements of Exotic Nuclei with the Triple-Trap Mass Spectrometer Isoltrap

    Blaum, K; Zuber, K T; Stanja, J

    2002-01-01

    The masses of close to 200 short-lived nuclides have already been measured with the mass spectrometer ISOLTRAP with a relative precision between 1$\\times$10$^{-7}$ and 1$\\times$10^{-8}$. The installatin of a radio-frequency quadrupole trap increased the overall efficiency by two orders of magnitude which is at present about 1%. In a recent upgrade, we installed a carbon cluster laser ion source, which will allow us to use carbon clusters as mass references for absolute mass measurements. Due to these improvements and the high reliability of ISOLTRAP we are now able to perform accurate high-precision mass measurements all over the nuclear chart. We propose therefore mass measurements on light, medium and heavy nuclides on both sides of the valley of stability in the coming four years. ISOLTRAP is presently the only instrument capable of the high precision required for many of the proposed studies.

  7. Mass Spectrometer Sounding of the Turbopause Region on Commercial Vehicles

    Thurairajah, B.; Bailey, S. M.; Syrstad, E. A.; Fish, C. S.; Siskind, D. E.; Russell, J. M.

    2013-12-01

    The turbopause region near 100 km remains one of the most poorly explored yet crucial regions of the upper atmosphere. In the vicinity of this altitude, the atmosphere reaches its lowest temperature and changes from being well mixed to being in diffusive equilibrium. Dynamical energy in the form of tides as well as gravity and planetary waves propagate from the lower atmosphere up to the ionosphere and thermosphere. Some energy and reactive chemical species are transported down across the turbopause to lower altitudes where the impact is significant. There is a significant dearth of composition observations near the turbopause. Few measurement techniques work well at this altitude, and it is too low for satellite orbits. Amazingly, major species with relatively large abundances such as O2, O, and CO2 are all poorly understood at these attitudes. While there are several experiments that measure temperature, the uncertainties in the temperature measurements are large because the techniques that are used rely on knowledge of CO2 or sometimes of O2. The lack of composition information thus hinders those observations that do occur near the turbopause and mesopause and leaves us with an overall poor understanding of this altitude region. We are soon to enter a new era in space exploration. Routine visits to the 100km region by commercial vehicles are on the verge of becoming a reality. The relevant organizations have expressed a willingness and even enthusiasm for including scientific instrumentation with their tourism and related commercial goals. We propose a major step forward in understanding the turbopause region by developing a mass spectrometer capable of being manifested on these commercial vehicles. Such an implantation could ultimately result in daily sounding of the turbopause region and greatly expand the database of measurements there. Our suggested instrument is a cryogenic time-of-flight mass Spectrometer. This technique has heritage, and our

  8. IBM PC based data acquisition and processing package for an organic mass spectrometer (VG micro mass 7070F)

    The manual processing and mass marking of data obtained from mass spectrometer through UV oscillograph is tedious and quite time consuming. This report describes interconnection of an IBM PC through an ADC interface to the mass spectrometer to acquire and store the mass spectral data and offline processing. A menu driven software in Turbo Pascal has been developed for this purpose which is described in detail. (author). 3 refs., 17 figs., 2 tabs

  9. Desorption electrospray ionization using an Orbitrap mass spectrometer: Exact mass measurements on drugs and peptides.

    Hu, Qizhi; Talaty, Nari; Noll, Robert J; Cooks, R Graham

    2006-01-01

    Desorption electrospray ionization (DESI) is implemented on an Orbitrap mass spectrometer. The ion source is described and applications which utilize the high-resolution capabilities of the Orbitrap are emphasized, including the characterization of peptides and active ingredients in pharmaceutical tablets. Measurements are made in less than 1 s at a resolution of 60,000. The implications of the data for the mechanisms of DESI are discussed. PMID:17051609

  10. Radiocarbon dating with accelerator mass spectrometry

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  11. Ambient mass spectrometry with a handheld mass spectrometer at high pressure.

    Keil, Adam; Talaty, Nari; Janfelt, Christian; Noll, Robert J; Gao, Liang; Ouyang, Zheng; Cooks, R Graham

    2007-10-15

    The first coupling of atmospheric pressure ionization methods, electrospray ionization (ESI) and desorption electrospray ionization (DESI), to a miniature hand-held mass spectrometer is reported. The instrument employs a rectilinear ion trap (RIT) mass analyzer and is battery-operated, hand-portable, and rugged (total system: 10 kg, 0.014 m(3), 75 W power consumption). The mass spectrometer was fitted with an atmospheric inlet, consisting of a 10 cm x 127 microm inner diameter stainless steel capillary tube which was used to introduce gas into the vacuum chamber at 13 mL/min. The operating pressure was 15 mTorr. Ions, generated by the atmospheric pressure ion source, were directed by the inlet along the axis of the ion trap, entering through an aperture in the dc-biased end plate, which was also operated as an ion gate. ESI and DESI sources were used to generate ions; ESI-MS analysis of an aqueous mixture of drugs yielded detection limits in the low parts-per-billion range. Signal response was linear over more than 3 orders of magnitude. Tandem mass spectrometry experiments were used to identify components of this mixture. ESI was also applied to the analysis of peptides and in this case multiply charged species were observed for compounds of molecular weight up to 1200 Da. Cocaine samples deposited or already present on different surfaces, including currency, were rapidly analyzed in situ by DESI. A geometry-independent version of the DESI ion source was also coupled to the miniature mass spectrometer. These results demonstrate that atmospheric pressure ionization can be implemented on simple portable mass spectrometry systems. PMID:17867653

  12. Reproducibility of cardioventilatory measurements using a respiratory mass spectrometer.

    Narang, Indra; Rosenthal, Mark; Bush, Andrew

    2007-08-01

    The aim of this study was to assess the within subject reproducibility of cardioventilatory measurements and the maximum permitted 'normal' variability over time at rest and exercise using the respiratory mass spectrometer (RMS). Ten subjects underwent an incremental exercise test on three separate occasions utilising rebreathing (RB) and helium dilution mixed expired gas analysis (HME) functions of the RMS. Measurements included heart rate (HR), oxygen consumption (V(O2)), carbon dioxide excretion (V(VO2)), effective pulmonary blood flow (Q(eff)), stroke volume (SV), arteriovenous oxygen content difference (AVO), transfer factor (Dl(CO)), functional residual capacity (FRC), minute ventilation (VE), tidal volume (VT) and respiratory quotient (RQ). The coefficients of variation for each variable for the 10 subjects were calculated. At rest, the 90th centile variability for measured cardiopulmonary variables (RB only) was <35%. During exercise, the 90th centile for variability for measured cardiopulmonary variables for HME and RB were < or =20 and <40%, respectively. These measurements in healthy adults should inform sample size in research studies. PMID:17188945

  13. SCAPS, a two-dimensional ion detector for mass spectrometer

    Yurimoto, Hisayoshi

    2014-05-01

    Faraday Cup (FC) and electron multiplier (EM) are of the most popular ion detector for mass spectrometer. FC is used for high-count-rate ion measurements and EM can detect from single ion. However, FC is difficult to detect lower intensities less than kilo-cps, and EM loses ion counts higher than Mega-cps. Thus, FC and EM are used complementary each other, but they both belong to zero-dimensional detector. On the other hand, micro channel plate (MCP) is a popular ion signal amplifier with two-dimensional capability, but additional detection system must be attached to detect the amplified signals. Two-dimensional readout for the MCP signals, however, have not achieve the level of FC and EM systems. A stacked CMOS active pixel sensor (SCAPS) has been developed to detect two-dimensional ion variations for a spatial area using semiconductor technology [1-8]. The SCAPS is an integrated type multi-detector, which is different from EM and FC, and is composed of more than 500×500 pixels (micro-detectors) for imaging of cm-area with a pixel of less than 20 µm in square. The SCAPS can be detected from single ion to 100 kilo-count ions per one pixel. Thus, SCAPS can be accumulated up to several giga-count ions for total pixels, i.e. for total imaging area. The SCAPS has been applied to stigmatic ion optics of secondary ion mass spectrometer, as a detector of isotope microscope [9]. The isotope microscope has capabilities of quantitative isotope images of hundred-micrometer area on a sample with sub-micrometer resolution and permil precision, and of two-dimensional mass spectrum on cm-scale of mass dispersion plane of a sector magnet with ten-micrometer resolution. The performance has been applied to two-dimensional isotope spatial distribution for mainly hydrogen, carbon, nitrogen and oxygen of natural (extra-terrestrial and terrestrial) samples and samples simulated natural processes [e.g. 10-17]. References: [1] Matsumoto, K., et al. (1993) IEEE Trans. Electron Dev. 40

  14. A collinear tandem time-of-flight mass spectrometer for infrared photodissociation spectroscopy of mass-selected ions

    WANG GuanJun; CHI ChaoXian; XING XiaoPeng; DING ChuanFan; ZHOU MingFei

    2014-01-01

    An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.

  15. The Time-of-Flight Isochronous (TOFI) spectrometer for direct mass measurements of exotic light nuclei

    A new type of time-of-flight recoil spectrometer designed to measure the masses of neutron-rich light nuclei has recently been completed at LAMPF. The spectrometer relies on an isochronous design that directly correlates an ion's time-of-flight through the spectrometer with it's mass-to-charge ratio. Additional measurements of the ion's velocity and energy enable the charge state of the recoil to be uniquely defined and thus permit precision mass measurements given sufficient statistics. The performance of the spectrometer has been investigated in both off-line (using alpha sources) and on-line tests. The design resolution of Δm/M = 1/2000 (FWHM) has been achieved. Initial performance results of the spectrometer are described with emphasis placed on the techniques used to achieve the overall high mass resolution and large solid angle/momentum acceptance

  16. The time-of-flight isochronous (TOFI) spectrometer for direct mass measurements of exotic light nuclei

    A new type of time-of-flight recoil spectrometer designed to measure the masses of neutron-rich light nuclei has recently been completed at LAMPF. The spectrometer relies on an isochronous design that directly correlates an ion's time-of-flight through the spectrometer with its mass-to-charge ratio. Additional measurements of the ion's velocity and energy enable the charge state of the recoil to be uniquely defined and thus permit precision mass measurements given sufficient statistics. The performance of the spectrometer has been investigated in both-off line (using alpha sources) and on-line tests. The design resolution of ΔM/M=1/2000 (fwhm) has been achieved. Initial performance results of the spectrometer are described with emphasis placed on the techniques used to achieve the overall high mass resolution and large solid angle/momentum acceptance. (orig.)

  17. SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

    Spencer, W; Laura Tovo, L

    2008-07-08

    The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms

  18. "Fast Excitation" CID in Quadrupole Ion Trap Mass Spectrometer

    Murrell, J. [Defence Science and Detection Department (Dstl), Wiltshire, UK; Despeyroux, D. [Defence Science and Detection Department (Dstl), Wiltshire, UK; Lammert, Stephen {Steve} A [ORNL; Stephenson Jr, James {Jim} L [ORNL; Goeringer, Doug [ORNL

    2003-01-01

    Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. ''Fast excitation'' CID deposits (as determined by the intensity ratio of the a{sub 4}/b{sub 4} ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with ''fast excitation'' CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for ''fast excitation'' CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M + 17H){sup 17+} of horse heart myoglobin is also shown to illustrate the application of ''fast excitation'' CID to proteins.

  19. Plasma Desorption Mass Spectrometry using TANDEM accelerator in National Industrial Research Inst. of Nagoya

    Mizota, Takeshi; Nakao, Setsuo; Niwa, Hiroaki; Saito, Kazuo [Particle Beam Sceince Laboratory, Multi-Function Material Science Department, National Industrial Research Inst. of Nagoya, Nagoya (Japan)

    2001-02-01

    Plasma Desorption Mass Spectrometry (PDMS) analysis was studied using TANDEM accelerator. The heavy ions of MeV range emit the secondary ions of atoms, molecules, polymers and clusters from the irradiated samples without destruction. The analysis system of PDMS designed and set-up using a mass spectrometer of Time of Flight and the TANDEM accelerator. The system performance was tested for C-60 fullerene on the surface of the samples using 11.2 MeV {sup 28}Si beams produced by the TANDEM accelerator of 1.7MV. The result shows that the hydrogen and hydrocarbons can be analyzed in the range of 1amu unit. The resolution (M/{delta}M) of the Mass Spectrometry system is confirmed to be about 1000 from the separation of the 720 and 721amu peaks, which is attributed to the C-60 fullerene including {sup 13}C atoms. (H. Katsuta)

  20. Measurement of mass and isotopic fission yields for heavy fission products with the LOHENGRIN mass spectrometer

    In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupled to a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields of the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. To complete and improve the nuclear data libraries, these measurements have been extended in this work to the heavy mass region for the reactions 235U(nth,f), 239Pu(nth,f) and 241Pu(nth,f). For these higher masses an isotopic separation is no longer possible. So, a new method was undertaken with the reaction 239Pu(nth,f) to determine the isotopic yields by spectrometry. These experiments have allowed to reduce considerably the uncertainties. Moreover the ionic charge state and kinetic energy distributions were specifically studied and have shown, among others, nanosecond isomers for some masses. (author)

  1. A Micro Cylindrical Ion Trap (5-CIT) Micro Mass Spectrometer Instrument System (5MSIS) for NASA Planetary Exploration Project

    National Aeronautics and Space Administration — The project aims to develop a miniature packaging platform for the integration of MEMS mass spectrometer components to form the basis of a Micro Mass Spectrometer...

  2. Pluto Integrated Camera-Spectrometer (PICS): A Low Mass, Low Power Instrument for Planetary Exploration

    Beauchamp, Patricia; Brown, Robert; Rodgers, David; Chrisp, Michael; Chen, Gun-Shiog; Fraschetti, George; Krabach, Timothy; Petrick, Walter; Soderblom, Laurance; Yelle, Roger; Benoit, Robert; Curcio, Michael; Glasheen, Richard; Tucker, Theodore; Wang, Dexter

    1994-01-01

    The concept we describe is an integrated instrument (a Pluto Integrated Camera Spectrometer, PICS) that will perform the functions of all three optical instruments required by the Pluto Fast Flyby Mission: the near-IR spectrometer, the camera, and the UV spectrometer. This integrated approach minimizes mass and power use. It also forced us early in the conceptual design to consider integrated observational sequences and integrated power management, thus ensuring compatible duty cycles (i.e. e...

  3. Fundamental studies of MALDI with an orthogonal TOF mass spectrometer

    Qiao, Hui

    The interaction between the matrix and analyte molecules are studied with a high resolution MALDI imaging technique in an orthogonal-injection time of flight (TOF) mass spectrometer. The analyte incorporation and distribution patterns have been clearly demonstrated. Purified protein analytes were found to be homogeneously incorporated in large single crystals of DHB and sinapinic acid matrices, with no evidence for preferred crystal faces. Segregation of some species was observed and appeared to correlate with analyte hydrophobicity, and to a lesser extent analyte mass or mobility. Similar segregation phenomena were observed with confocal laser scanning microscopy of the same analytes labeled with fluorescent dyes in 2,5-DHB single crystals. The above investigations may shed some light on optimizing sample preparation with different matrices. The influence of incident laser parameters on sensitivity in MALDI has been investigated using orthogonal-injection TOF instruments. A qualitative comparison was first made between the beam profiles obtained with a N 2 laser and a Nd:YAG laser using 2-m long optical fibers. The N 2 laser gives better sensitivity, consistent with a more uniform fluence distribution and therefore better coverage of the N2 laser profile. Most of the difference disappears when a 30-m long fiber is used or when the fibers are twisted during irradiation to smooth out the fluence distribution. In more systematic measurements, the total integrated ion yield from a single spot (a measure of sensitivity) was found to increase rapidly with fluence to a maximum, and then saturate or decrease slightly. Thus, the optimum sensitivity is achieved at high fluence. For a fluence near threshold, the integrated yield has a steep (cubic) dependence on the spot size, but the yield saturates at higher fluence for smaller spots. The area dependence is much weaker (close to linear) for fluence values above saturation, with the result that the highest integrated yields

  4. Mass measurement of halo nuclides and beam cooling with the mass spectrometer Mistral

    Halo nuclides are a spectacular drip-line phenomenon and their description pushes nuclear theories to their limits. The most critical input parameter is the nuclear binding energy; a quantity that requires excellent measurement precision, since the two-neutron separation energy is small at the drip-line by definition. Moreover halo nuclides are typically very short-lived. Thus, a high accuracy instrument using a quick method of measurement is necessary. MISTRAL is such an instrument; it is a radiofrequency transmission mass spectrometer located at ISOLDE/CERN. In July 2003 we measured the mass of the Li11, a two-neutron halo nuclide. Our measurement improves the precision by a factor 6, with an error of 5 keV. Moreover the measurement gives a two-neutron separation energy 20% higher than the previous value. This measurement has an impact on the radius of the nucleus, and on the state of the two valence neutrons. At the same time, a measurement of the Be11 was performed with an uncertainty of 4 keV, in excellent agreement with previous measurements. In order to measure the mass of the two-neutron halo nuclide Be14, an ion beam cooling system is presently under development which will increase the sensitivity of the spectrometer. The second part of this work presents the development of this beam cooler using a gas-filled Paul trap. (author)

  5. Search for doubly-charged negative ions via accelerator mass spectrometry

    The Argonne FN tandem accelerator in conjunction with an Enge split-pole magnetic spectrograph has been used as a highly sensitive mass spectrometer to search for doubly charged negative ions of 11B, 12C and 16O. No evidence for the formation of these ions in an inverted sputter source and the subsequent acceleration in the tandem has been found. The following limits for the ratio of doubly-charged to singly-charged ions were measured: X--/X- -15, 11B; -15, 12C; -14, 16O. A relatively abundant formation of the short lived, metastable He- ion in the sputter source has been observed

  6. Large acceptance spectrometers for invariant mass spectroscopy of exotic nuclei and future developments

    Nakamura, T.; Kondo, Y.

    2016-06-01

    Large acceptance spectrometers at in-flight RI separators have played significant roles in investigating the structure of exotic nuclei. Such spectrometers are in particular useful for probing unbound states of exotic nuclei, using invariant mass spectroscopy with reactions at intermediate and high energies. We discuss here the key characteristic features of such spectrometers, by introducing the recently commissioned SAMURAI facility at the RIBF, RIKEN. We also investigate the issue of cross talk in the detection of multiple neutrons, which has become crucial for exploring further unbound states and nuclei beyond the neutron drip line. Finally we discuss future perspectives for large acceptance spectrometers at the new-generation RI-beam facilities.

  7. Continuation of Mass determinations through a Double Focusing Mass Spectrometer on Line with ISOLDE

    2002-01-01

    In a previous experiment (1976-77) we have demonstrated the interest and feasibility of atomic mass determinations from the direct measurements of mass ratios on Rb, Cs and Fr isotopes. Masses of long series of isotopes on both side of stability were determined with an accuracy of a few tens to 300 keV (for th exotic). Interesting nuclear structure features could be observed as for example the indication for an onset of deformation, at N~=~60 for Z~=~37, which stimulated further experiments and theoretical calculations. The many mass values, until then unknown, we obtained in our experiments, gave in addition the possibility to make detailed tests of the nuclear mass predictions. Due to improvements on our mass spectrometer (better transmission and higher resolving power) and increased ISOLDE production yields, some new and valuable measurements can be performed. We plan: \\item a) to continue the measurements towards even heavier isotopes and explore the deformation regions which start at |9|7Rb and |1|4|6Cs;...

  8. Characterization of a time-of-flight mass spectrometer and its applications in the study of solid surfaces; Charakterisierung eines Flugzeitmassenspektrometers und seine Anwendungen in der Festkoerperoberflaechenuntersuchung

    Mazarov, P.

    2006-12-21

    The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the detection of highly molecular particles, a device for post-acceleration of the detected particles by up to 10 keV were inserted directly before the MCP detector. The detection efficiency of positive secondary ions was determined for different post-acceleration voltages for the example of sputtered indium cluster ions. In addition, a new method was developed for the quantitative determination of the spectral ionization probability {alpha}{sup +}({nu}) of sputtered particles as a function of the emission velocity. The next application of the TOF mass spectrometer is the analysis of complicated organic molecules in solid state surfaces. During measurements of the photo-ionization behaviour of neutral tryptophan molecules, it was found out that a stable molecular ion signal is generated in the SNMS spectrum with h{nu}=7.9 eV can only be observed by the use of a continuous ion beam or very long (ms range) ion pulses. (orig.)

  9. A statistical investigation of the mass discrepancy-acceleration relation

    Desmond, Harry

    2016-01-01

    We use the mass discrepancy-acceleration relation (the correlation between the ratio of dark-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 14 statistics which quantify its four most important features: its shape, its scatter, the presence of a "characteristic acceleration scale," and the correlation of its residuals with other galaxy properties. We construct an empirical framework for the galaxy-halo connection in $\\...

  10. Development and Deployment of Retrofit PolarisQ Ion Trap Mass Spectrometer for Isotope Ratio Measurements

    This report describes Oak Ridge National Laboratory's (ORNL) FY15 progress in support of National Nuclear Security Administration's (NNSA) Portable Mass Spectrometer project. A retrofit PolarisQ ion trap mass spectrometer (RPMS) has been assembled from components of two PolarisQ ion trap mass spectrometers used in previous isotope ratio programs. The retrofit mass spectrometer includes a custom Hastelloy vacuum chamber which is about ¼ the size of the standard aluminum vacuum chamber and reduces the instrument weight from the original by nine pounds. In addition, the new vacuum chamber can be independently heated to reduce impurities such as water, which reacts with UF6 to produce HF in the vacuum chamber. The analyzer and all components requiring service are mounted on the chamber lid, facilitating quick and easy replacement of consumable components such as the filament and electron multiplier.

  11. Indigenous realisation of measurement electronics for ion signal from mass spectrometer

    A PC based data measurement electronics has been realised for a Faraday cup detector signal. The Faraday cup detector serves as a complementary to a Daly detector of the thermal ionisation mass spectrometer. This report discusses about its indigenous development

  12. Miniature Time of Flight Mass Spectrometer for Space and Extraterrestrial Applications Project

    National Aeronautics and Space Administration — The PI has developed a miniature time-of-flight mass spectrometer (TOF-MS), which can be op-timized for space and extraterrestrial applications, by using a...

  13. Development and Deployment of Retrofit PolarisQ Ion Trap Mass Spectrometer for Isotope Ratio Measurements

    Thompson, Cyril V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitten, William B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-11-01

    This report describes Oak Ridge National Laboratory’s (ORNL) FY15 progress in support of National Nuclear Security Administration’s (NNSA) Portable Mass Spectrometer project. A retrofit PolarisQ ion trap mass spectrometer (RPMS) has been assembled from components of two PolarisQ ion trap mass spectrometers used in previous isotope ratio programs. The retrofit mass spectrometer includes a custom Hastelloy vacuum chamber which is about ¼ the size of the standard aluminum vacuum chamber and reduces the instrument weight from the original by nine pounds. In addition, the new vacuum chamber can be independently heated to reduce impurities such as water, which reacts with UF6 to produce HF in the vacuum chamber. The analyzer and all components requiring service are mounted on the chamber lid, facilitating quick and easy replacement of consumable components such as the filament and electron multiplier.

  14. Double-arm time-of-flight mass-spectrometer of nuclear fragments

    A double-arm time-of-flight spectrometer of nuclear fragments for the investigation of heavy nuclei photofission in the intermediate energy range is described. The calibration results and working characteristics of the spectrometer, obtained using 252Cf as a source of spontaneous fission, are presented. A mass resolution of σ m ∼2-3 a.m.u. was obtained within the registered fragments mass range of 80-160 a.m.u. The spectrometer was tested in the experiment on the investigation of 238U nuclei fission by Bremsstahlung photons with Eγ max=1.75 GeV

  15. Automatic isotope ratio measurements with a double collector magnetic mass spectrometer

    This paper describes a measuring procedure and the instrumentation of automatic measurements of isotope ratios with double collector magnetic mass spectrometers. This is essentially achieved by discriminating the desired peak plateau for ion current integration during the high voltage variation. The resolution is nearly uneffected by offset drifts of the electronic system. Prior to every isotope ratio measurement the offset values are determined, digitally stored, and finally compensated when the isotope ratio is calculated with an arithmetic unit. Several mass spectrometers have been compared on the basis of an uranium isotope analysis in a long time experiment. The developed system proved reliable and showed the same resolution as more sophisticated spectrometer systems. (orig.)

  16. Radio-tracing 'without' radioactivity: accelerator mass spectrometry in biomedicine

    Accelerator mass spectrometry (AMS) is a form of isotope-ratio mass spectrometry that quantifies concentrations of certain long-lived radioisotopes independently of their radioactive decay. AMS is primarily used in the geosciences for determining the age of a material that contains naturally occurring radioisotopes. AMS uses the same high specificity for enriched levels of these radioisotopes in tracing low chemical doses for long periods in biological systems, including humans. AMS provides the safety of low radiative exposure to experimental subjects and investigators, while obtaining attomole sensitivities that are not possible with stable isotope tracers because of their natural isotopic abundances. AMS isotope tracing was first applied to quantifying the genotoxicity of low level environmental chemicals in animals and later in humans. Physiologic concentrations of 14C-labeled trace nutrients (folate, carotene, and tocopherol) are now measured directly in humans without concern about radiation. The radiative exposure is less than the commonly accepted risks of natural background radiation or the radiation fields found in high altitude air flights. AMS measures very small biological samples (such as 20 microliters of blood) that are easily obtained from human volunteers or model animals at frequent intervals for detailed analysis of kinetic profiles. This high data density enables the construction of compartmental models that elucidate nutrient behavior in tissues that cannot be directly sampled. The pharmaceutical industry is enthusiastic about AMS as a detector for 'micro-dosing' in which the human kinetics of an assuredly non-toxic dose of a candidate drug is tested early in a development project. Molecular tracing uses 3H or 14C as common isotopic labels, but AMS contributes to elemental tracing with certain radioisotopes having very long lives, such as 26AL or 41Ca. Calcium-41 is a particularly useful isotope in biomedical research because it is used to

  17. First direct mass measurements on nobelium and lawrencium with the Penning trap mass spectrometer SHIPTRAP

    Dworschak, Michael Gerhard

    2009-12-08

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt was set up for high-precision mass measurements of heavy radionuclides produced in fusion evaporation reactions and separated from the primary beam by the velocity filter SHIP. It consists of a gas stopping cell for the deceleration of the high energetic reaction products, an RFQ cooler and buncher for cooling and accumulation of the ions, and a double Penning trap system to perform mass measurements. The mass is determined by measuring the cyclotron frequency of the ion of interest in a strong homogeneous magnetic field and comparing it to the frequency of a well-known reference ion. With this method relative uncertainties in the order of 10{sup -8} can be achieved. Recently, mass measurements of the three nobelium isotopes {sup 252-254}No (Z=102) and the lawrencium isotope {sup 255}Lr (Z=103) were performed successfully. These were the first direct mass measurements of transuranium elements ever per- formed. The production rate of the atoms of interest was about one per second or less. The results of the measurements on nobelium confirm the previous mass values which were deduced from Q{sub {alpha}} values. In the case of {sup 255}Lr the mass excess value, which was previously only estimated from systematic trends, was for the first time directly measured. These results mark the first step in the exploration of the region of transuranium elements which is planned at SHIPTRAP. The main objective is to fix the endpoints of {alpha} decay chains which are originating from superheavy elements close to the predicted island of stability. (orig.)

  18. First direct mass measurements on nobelium and lawrencium with the Penning trap mass spectrometer SHIPTRAP

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt was set up for high-precision mass measurements of heavy radionuclides produced in fusion evaporation reactions and separated from the primary beam by the velocity filter SHIP. It consists of a gas stopping cell for the deceleration of the high energetic reaction products, an RFQ cooler and buncher for cooling and accumulation of the ions, and a double Penning trap system to perform mass measurements. The mass is determined by measuring the cyclotron frequency of the ion of interest in a strong homogeneous magnetic field and comparing it to the frequency of a well-known reference ion. With this method relative uncertainties in the order of 10-8 can be achieved. Recently, mass measurements of the three nobelium isotopes 252-254No (Z=102) and the lawrencium isotope 255Lr (Z=103) were performed successfully. These were the first direct mass measurements of transuranium elements ever per- formed. The production rate of the atoms of interest was about one per second or less. The results of the measurements on nobelium confirm the previous mass values which were deduced from Qα values. In the case of 255Lr the mass excess value, which was previously only estimated from systematic trends, was for the first time directly measured. These results mark the first step in the exploration of the region of transuranium elements which is planned at SHIPTRAP. The main objective is to fix the endpoints of α decay chains which are originating from superheavy elements close to the predicted island of stability. (orig.)

  19. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.;

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...... response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m∕Δm > 2500. The system design...

  20. A novel high-capacity ion trap-quadrupole tandem mass spectrometer

    Krutchinsky, Andrew N.; Cohen, Herbert; Chait, Brian T.

    2007-12-01

    We describe a prototype tandem mass spectrometer that is designed to increase the efficiency of linked-scan analyses by >100-fold over conventional linked-scan instruments. The key element of the mass spectrometer is a novel high ion capacity ion trap, combined in tandem configuration with a quadrupole collision cell and a quadrupole mass analyzer (i.e. a TrapqQ configuration). This ion trap can store >106 ions without significant degradation of its performance. The current mass resolution of the trap is 100-450 full width at half maximum for ions in the range 800-4000 m/z, yielding a 10-20 m/z selection window for ions ejected at any given time into the collision cell. The sensitivity of the mass spectrometer for detecting peptides is in the low femtomole range. We can envisage relatively straightforward modifications to the instrument that should improve both its resolution and sensitivity. We tested the tandem mass spectrometer for collecting precursor ion spectra of all the ions stored in the trap and demonstrated that we can selectively detect a phosphopeptide in a mixture of non-phosphorylated peptides. Based on this prototype instrument, we plan to construct a fully functional model of the mass spectrometer for detecting modification sites on proteins and profiling their abundances with high speed and sensitivity.

  1. Mass Spectrometric Analysis of Eight Common Chemical Explosives Using Ion Trap Mass Spectrometer

    Park, Sehwan; Lee, Jihyeon; KIm, Jeongkwon [Chungnam National Univ., Daejeon (Korea, Republic of); Cho, Soo Gyeong; Goh, Eun Mee [Agency for Defense Development, Daejeon (Korea, Republic of); Lee, Sungman; Koh, Sungsuk [Sensor Tech Inc., Seoul (Korea, Republic of)

    2013-12-15

    Eight representative explosives (ammonium perchlorate (AP), ammonium nitrate (AN), trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), cyclonite (RDX), cyclotetramethylenetetranitramine (HMX), pentaerythritol tetranitrate (PETN), and hexanitrostilbene (HNS)) were comprehensively analyzed with an ion trap mass spectrometer in negative ion mode using direct infusion electrospray ionization. MS/MS experiments were performed to generate fragment ions from the major parent ion of each explosive. Explosives in salt forms such as AP or AN provided cluster parent ions with their own anions. Explosives with an aromatic ring were observed as either [M.H]{sup -} for TNT and DNT or [M]{sup ·-}. for HNS, while explosives without an aromatic ring such as RDX, HMX, and PETN were detected as an adduct ion with a formate anion, i. e., [M+HCOO]{sup -}. These findings provide a guideline for the rapid and accurate detection of explosives once portable MS instruments become more readily available.

  2. Mass Spectrometric Analysis of Eight Common Chemical Explosives Using Ion Trap Mass Spectrometer

    Eight representative explosives (ammonium perchlorate (AP), ammonium nitrate (AN), trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), cyclonite (RDX), cyclotetramethylenetetranitramine (HMX), pentaerythritol tetranitrate (PETN), and hexanitrostilbene (HNS)) were comprehensively analyzed with an ion trap mass spectrometer in negative ion mode using direct infusion electrospray ionization. MS/MS experiments were performed to generate fragment ions from the major parent ion of each explosive. Explosives in salt forms such as AP or AN provided cluster parent ions with their own anions. Explosives with an aromatic ring were observed as either [M.H]- for TNT and DNT or [M]·-. for HNS, while explosives without an aromatic ring such as RDX, HMX, and PETN were detected as an adduct ion with a formate anion, i. e., [M+HCOO]-. These findings provide a guideline for the rapid and accurate detection of explosives once portable MS instruments become more readily available

  3. Compact Ion and Neutral Mass Spectrometer with Ion Drifts, Temperatures and Neutral Winds

    Paschalidis, Nikolaos

    2016-07-01

    In situ measurements of atmospheric neutral and ion composition and density, temperatures, ion drifts and neutral winds, are in high demand to study the dynamics of the ionosphere-theremosphere-mesosphere system. This paper presents a compact Ion and Neutral Mass Spectrometer (INMS) with impended ion drifts and temperature, and neutral winds capability for in situ measurements of ions and neutrals H, He, N, O, N2, O2. The mass resolution M/dM is approximately 10 at an incoming energy range of 0-20eV. The goal is to resolve ion drifts in the range 0 to 3000m/sec with a resolution better than 50m/sec, and neutral winds in the range of 0 to 1000m/sec with similar resolution. For temperatures the goal is to cover a dynamic range of 0 to 5000K. The INMS is based on front end optics for ions and neutrals, pre acceleration, gated time of flight, top hat ESA, MCP detectors and compact electronics. The instrument is redundant for ions and neutrals with the ion and neutral sensor heads on opposite sides and with full electronics in the middle. The ion front end includes RPA for temperature scanning and neutral front end includes angular modulation and thermionic ionization and ion blocking grids. The electronics include fast electric gating, TOF electronics, TOF binning and C&DH digital electronics. The data package includes 400 mass bins each for ions and neutrals and key housekeeping data for instrument health and calibration. The data sampling can be commanded from 0.1 to 10 sec with 1sec nominal setting. The instrument has significant onboard storage capability and a data compression scheme. The mass spectrometer version of the instrument has been flown on the Exocube mission. The instrument occupied 1.5U volume, weighed only 560 g and required nominal power of 1.6W The ExoCube mission was designed to acquire global knowledge of in-situ densities of [H], [He], [O] and H+, He+, O+ in the upper ionosphere and lower exosphere in combination with incoherent scatter radar and

  4. Electronics for processing of data from a double collector isotopic ratio mass spectrometer

    The output data available from the mass spectrometer type MS-660 developed in the mass spectrometry section of Technical Physics Division of the Bhabha Atomic Research Centre, Bombay, for the determination of H/D ratios in liquid/gas sample consist of uncompensated mass 3 and mass 2 signals. After the mass 3 signal has been compensated for H3+ formation, the on-line ratio of compensated mass 3 to mass 2 is calculated, displayed, and then printed on a printer for record. The electronic compensation circuit, the discrete voltage-to-frequency (V/F) converter circuit, the ratio calculating system using V/F converters, and a digital interface system for Hindustan Teleprinter to print out the ratios are explained. Results obtained on mass spectrometer MS-660 are presented. (auth.)

  5. High-throughput mass-directed parallel purification incorporating a multiplexed single quadrupole mass spectrometer.

    Xu, Rongda; Wang, Tao; Isbell, John; Cai, Zhe; Sykes, Christopher; Brailsford, Andrew; Kassel, Daniel B

    2002-07-01

    We report on the development of a parallel HPLC/MS purification system incorporating an indexed (i.e., multiplexed) ion source. In the method described, each of the flow streams from a parallel array of HPLC columns is directed toward the multiplexed (MUX) ion source and sampled in a time-dependent, parallel manner. A visual basic application has been developed and monitors in real-time the extracted ion current from each sprayer channel. Mass-directed fraction collection is initiated into a parallel array of fraction collectors specific for each of the spray channels. In the first embodiment of this technique, we report on a four-column semipreparative parallel LC/MS system incorporating MUX detection. In this parallel LC/MS application (in which sample loads between 1 and 10 mg on-column are typically made), no cross talk was observed. Ion signals from each of the channels were found reproducible over 192 injections, with interchannel signal variations between 11 and 17%. The visual basic fraction collection application permits preset individual start collection and end collection thresholds for each channel, thereby compensating for the slight variation in signal between sprayers. By incorporating postfraction collector UV detection, we have been able to optimize the valve-triggering delay time with precut transfer tubing between the mass spectrometer and fraction collectors and achieve recoveries greater than 80%. Examples of the MUX-guided, mass-directed fraction purification of both standards and real library reaction mixtures are presented within. PMID:12141664

  6. Analysis of isotopic ratio 235U/238U of UF6 with quadrupole mass spectrometer

    The uranium enrichment assay is vital to the research and development of uranium enrichment technology. In order to develop a small, light and high speed mass scanning quadrupole mass spectrometer as an on-line mass spectrometer, the design and trial fabrication of the system have been carried out, together with various performance evaluation tests. For the system, it is desirable to select the structure capable of making the preliminary experiments for on-line assay. The essential conditions for the uranium enrichment assay include enough resolution to identify uranium isotopes; good accuracy and precision; and small memory effect. The mass spectrometer fabricated for trial was confirmed to nearly satisfy these requirements. Residual UF6 in the ionization chamber reaches 1/50,000 in three minutes after evacuation, so that the memory effect is negligible. The necessary conditions for the on-line assay include the stable operation of the system for long time and small consumption of UF6. The measurement of reproducibility of isotopic ratio was made by introducing UF6 continuously and operating the system for long time. While the quadrupole mass spectrometer fabricated for trial was judged to be applicable to uranium enrichment test, the applicability as an on-line mass spectrometer will be evaluated in the field test of the cascade in future. (Kobatake, H.)

  7. The development of accelerator mass spectroscopy system

    Mitarai, Shiro; Machida, Atsushi; Iwata, Yasunao; Tsubusaki, Yoshihiro; Tanaka, Katsuhiko; Maeda, Toyokazu; Nakajima, Takao [Kyushu Univ., Fukuoka (Japan)

    2001-02-01

    Inverse PIXE method was applied to the differentiation of Chlorine 36 and Sulfur 36. The contaminated soil from the USSR nuclear test site was measured. Terminal potential of the tandem accelerator was controlled by GVM. A new AMS system, using time-of flight method is under development. The development of beam buncher and beam chopper for the system is briefly described. (A. Yamamoto)

  8. A computer controlled mass spectrometer system for investigating the decomposition of non-metallic materials under atmospheric conditions

    Thompson, J. M.

    1985-01-01

    A PDP 11/23 quadrupole mass spectrometer system was coupled to a nondiscriminating gas inlet system permitting gases at atmospheric pressure to be admitted into a high vacuum chamber containing the ion source of the mass spectrometer without separation of the gaseous components. The resolution of related software problems has resulted in a convenient computer-mass spectrometer system capable of generating masses, relative intensities and related data on the gaseous products resulting from the atmospheric thermal decomposition of nonmetallic materials.

  9. Hybrid micropixel detector at the focal plane of the mass-spectrometer

    Results on testing TimePix micropixel chip as a detector of low energy ions in a focal plane of the laser mass-spectrometer are presented. Two options were tested: hybrid micro-pixel detector as well as metal micro-pixel detector (naked read-out chip with a metal mesh to improve a charge collection). For both cases a response uniformity of pixels over ion mass, energy and detection position has been thoroughly studied. The results obtained illustrate capability of both detector modes to be used for creating 'electronic focal plane' of a mass-spectrometer with obvious advantages of real time devices.

  10. A GPU Accelerated Spring Mass System for Surgical Simulation

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  11. Mass resolution of accelerated ions in LNR cyclotrons

    The possibiliti of separating in cyclotron accelerated ions with different mass-to-charge ratios is considered. The calculations and experiment have demonstrated that mass resolution of accelerated ions for the U-400 cyclotron is approximately 3600; for U-200 cyclotron, approximately 1500. Ion beams which have not been separated in the cyclotron may be separated during beam extraction by means of the charge exchange in thin targets

  12. Studies on reducing the scale of a double focusing mass spectrometer

    Several groups have developed miniaturized sector mass spectrometers with the goal of remote sensing in confined spaces or portability. However, these achievements have been overshadowed by more successful development of man-portable quadrupole and ion trap mass spectrometers. Despite these accomplishments the development of a reduced-scale sector mass spectrometer remains attractive as a potentially low-cost, robust instrument requiring very simple electronics and low power. Previous studies on miniaturizing sector instruments include the use of a Mattauch-Herzog design for a portable mass spectrograph weighing less than 10 kg. Other work has included the use of a Nier-Johnson design in spacecraft-mountable gas chromatography mass spectrometers for the Viking spacecraft as well as miniature sector-based MS/MS instrument. Although theory for designing an optimized system with high resolution and mass accuracy is well understood, such specifications have not yet been achieved in a miniaturized instrument. To proceed further toward the development of a miniaturized sector mass spectrometer, experiments were conducted to understand and optimize a practical, yet nonideal instrument configuration. The sector mass spectrometer studied in this work is similar to the ones developed for the Viking project, but was further modified to be low cost, simple and robust. Characteristics of this instrument that highlight its simplicity include the use of a modified Varian leak detector ion source, source ion optics that use one extraction voltage, and an unshunted fixed nonhomogeneous magnetic sector. The effects of these design simplifications on ion trajectory were studied by manipulating the ion beam along with the magnetic sector position. This latter feature served as an aid to study ion focusing amidst fringing fields as well as nonhomogeneous forces and permitted empirical realignment of the instrument

  13. Time-of-flight mass spectrometer for fullerene and recoil ions: design and construction

    the machining of most components. The entire mass spectrometer will be mounted on a support to rise the mass spectrometer mean plane to the level of the accelerated particle beam. (authors)

  14. Mass separation of deuterium and helium with conventional quadrupole mass spectrometer by using varied ionization energy

    Yu, Yaowei; Hu, Jiansheng; Wan, Zhao; Wu, Jinhua; Wang, Houyin; Cao, Bin

    2016-03-01

    Deuterium pressure in deuterium-helium mixture gas is successfully measured by a common quadrupole mass spectrometer (model: RGA200) with a resolution of ˜0.5 atomic mass unit (AMU), by using varied ionization energy together with new developed software and dedicated calibration for RGA200. The new software is developed by using MATLAB with the new functions: electron energy (EE) scanning, deuterium partial pressure measurement, and automatic data saving. RGA200 with new software is calibrated in pure deuterium and pure helium 1.0 × 10-6-5.0 × 10-2 Pa, and the relation between pressure and ion current of AMU4 under EE = 25 eV and EE = 70 eV is obtained. From the calibration result and RGA200 scanning with varied ionization energy in deuterium and helium mixture gas, both deuterium partial pressures (PD2) and helium partial pressure (PHe) could be obtained. The result shows that deuterium partial pressure could be measured if PD2 > 10-6 Pa (limited by ultimate pressure of calibration vessel), and helium pressure could be measured only if PHe/PD2 > 0.45, and the measurement error is evaluated as 15%. This method is successfully employed in EAST 2015 summer campaign to monitor deuterium outgassing/desorption during helium discharge cleaning.

  15. Mass separation of deuterium and helium with conventional quadrupole mass spectrometer by using varied ionization energy.

    Yu, Yaowei; Hu, Jiansheng; Wan, Zhao; Wu, Jinhua; Wang, Houyin; Cao, Bin

    2016-03-01

    Deuterium pressure in deuterium-helium mixture gas is successfully measured by a common quadrupole mass spectrometer (model: RGA200) with a resolution of ∼0.5 atomic mass unit (AMU), by using varied ionization energy together with new developed software and dedicated calibration for RGA200. The new software is developed by using MATLAB with the new functions: electron energy (EE) scanning, deuterium partial pressure measurement, and automatic data saving. RGA200 with new software is calibrated in pure deuterium and pure helium 1.0 × 10(-6)-5.0 × 10(-2) Pa, and the relation between pressure and ion current of AMU4 under EE = 25 eV and EE = 70 eV is obtained. From the calibration result and RGA200 scanning with varied ionization energy in deuterium and helium mixture gas, both deuterium partial pressures (PD2 ) and helium partial pressure (PHe) could be obtained. The result shows that deuterium partial pressure could be measured if PD2 > 10(-6) Pa (limited by ultimate pressure of calibration vessel), and helium pressure could be measured only if PHe/PD2 > 0.45, and the measurement error is evaluated as 15%. This method is successfully employed in EAST 2015 summer campaign to monitor deuterium outgassing/desorption during helium discharge cleaning. PMID:27036832

  16. Size-exclusion chromatography with organic carbon detection using a mass spectrometer.

    Warton, Ben; Heitz, Anna; Allpike, Bradley; Kagi, Robert

    2008-10-17

    A novel organic carbon detector for size-exclusion chromatography (SEC) is described. The instrument uses the conventional UV-persulfate oxidation method to convert organic carbon to CO(2), which is then detected using a mass spectrometer. This system, using the mass spectrometer, had lower limits of detection (LOD) and limits of quantification (LOQ) than a previously described system using a Fourier transform infrared (FTIR) spectroscopy 'lightpipe' detector (i.e. when quantification was based on calibration using phthalate standards). When used to analyse natural organic matter (NOM) in water, it also had a superior signal-to-noise ratio to the previously described system. The use of a mass spectrometer to detect organic carbon (as CO(2)) enables the possibility of further characterisation of NOM by measuring the stable carbon isotope ratios of the various molecular size fractions of organic carbon, as obtained by SEC. PMID:18790486

  17. The analysis of uranium in environmental sample by mass spectrometer combined with isotopic dilution

    Uranium in the environmental sample was analyzed by mass spectrometer combined with isotopic dilution. Before mass spectrometer analysis, samples were dissolved in a concentrated acidic solution containing HNO3, HF and HClO4 and chemically processed to suit the analysis requirement. Analysis results indicated that the uranium content was 0.08 μg/g in river water, 0.1 μg/g in evergreen foliage, and 5-11 μg/g in surface soil respectively. (authors)

  18. Accelerator mass spectrometry in biomedical research

    Vogel, J.S.; Turteltaub, K.W.

    1993-10-20

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10{sup 9}) or less. Affected biomolecules may be separable in only milligram or microgram quantities. Quantification at attomole sensitivity is needed to study these interactions. AMS measures isotope concentrations to parts per 10{sup 13--15} on milligram-sized samples and is ideal for quantifying long-lived radioisotopic labels that are commonly used to trace biochemical pathways in natural systems. {sup 14}C-AMS has now been coupled to a variety of organic separation and definition technologies. The primary research investigates pharmacokinetics and genotoxicities of toxins and drugs at very low doses. Human subject research using AMS includes nutrition, toxicity and elemental balance studies. {sup 3} H, {sup 41}Ca and {sup 26}Al are also traced by AMS for fundamental biochemical kinetic research. Expansion of biomedical AMS awaits further development of biochemical and accelerator technologies designed specifically for these applications.

  19. Accelerator mass spectrometry in biomedical research

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:109) or less. Affected biomolecules may be separable in only milligram or microgram quantities. Quantification at attomole sensitivity is needed to study these interactions. AMS measures isotope concentrations to parts per 1013--15 on milligram-sized samples and is ideal for quantifying long-lived radioisotopic labels that are commonly used to trace biochemical pathways in natural systems. 14C-AMS has now been coupled to a variety of organic separation and definition technologies. The primary research investigates pharmacokinetics and genotoxicities of toxins and drugs at very low doses. Human subject research using AMS includes nutrition, toxicity and elemental balance studies. 3 H, 41Ca and 26Al are also traced by AMS for fundamental biochemical kinetic research. Expansion of biomedical AMS awaits further development of biochemical and accelerator technologies designed specifically for these applications

  20. Study of Odor Approximation by Using Mass Spectrometer

    Ohno, Masashi; Nihei, Yasunori; Nakamoto, Takamichi

    2011-09-01

    Since a set of odor components to cover wide range of smells has not been revealed yet, we studied the selection of odor components using essential-oil mass spectrum database. Basis vectors were extracted using non-negative matrix factorization method1 and then non-negative least squares method was used to determine the recipe. The odor approximations of three typical essential oils were confirmed by the sensory test. It was found that the mass spectrum data were correlated with the sensory test result. Moreover, this correlation was remarkable in the high m/z region.

  1. Fabrication and testing of recoil mass spectrometer at Mumbai Pelletron

    The main motivation for the recoil mass separator, which has been designed and constructed at the Mumbai Pelletron, has been to study the exotic nuclei far off from the line of β-stability, produced through fusion-evaporation reactions. These have very low cross sections, of the order of a few microbarns and the reaction products recoil in the forward direction along with the beam particles. The recoil mass separator enables one to study these reaction products by separating them from the main beam and from each other

  2. High Energy Collisions on Tandem Time-of-Flight Mass Spectrometers

    Cotter, Robert J.

    2013-05-01

    Long before the introduction of matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), Orbitraps, and any of the other tools that are now used ubiquitously for proteomics and metabolomics, the highest performance mass spectrometers were sector instruments, providing high resolution mass measurements by combining an electrostatic energy analyzer (E) with a high field magnet (B). In its heyday, the four sector mass spectrometer (or EBEB) was the crown jewel, providing the highest performance tandem mass spectrometry using single, high energy collisions to induce fragmentation. During a time in which quadrupole and tandem triple quadrupole instruments were also enjoying increased usage and popularity, there were, nonetheless, some clear advantages for sectors over their low collision energy counterparts. Time-of-flight (TOF) mass spectrometers are high voltage, high vacuum instruments that have much in common with sectors and have inspired the development of tandem instruments exploiting single high energy collisions. In this retrospective, we recount our own journey to produce high performance TOFs and tandem TOFs, describing the basic theory, problems, and the advantages for such instruments. An experiment testing impulse collision theory (ICT) underscores the similarities with sector mass spectrometers where this concept was first developed. Applications provide examples of more extensive fragmentation, side chain cleavages, and charge-remote fragmentation, also characteristic of high energy sector mass spectrometers. Moreover, the so-called curved-field reflectron has enabled the design of instruments that are simpler, collect and focus all of the ions, and may provide the future technology for the clinic, for tissue imaging, and the characterization of microorganisms.

  3. Mass spectrometer for real-time metabolism monitoring during anesthesia

    Elizarov, A. Yu.; Levshankov, A. I.

    2012-06-01

    Mass-spectrometric monitoring of metabolism (CO2/O2) in the inspiration-expiration regime is used to estimate the anesthetic protection of the patient against surgical stimulation during combined anesthesia. A correlation between the anesthetic protection of the patient and the metabolic rate is demonstrated, and the periodic variation of the metabolic rate with time is found. The sevoflurane metabolism products and intravenous analgesic fentanyl are found in the blowing air of the patient during anesthesia.

  4. Method for selective detection of explosives in mass spectrometer or ion mobility spectrometer at parts-per-quadrillion level

    Ewing, Robert G.; Atkinson, David A.; Clowers, Brian H.

    2015-09-01

    A method for selective detection of volatile and non-volatile explosives in a mass spectrometer or ion mobility spectrometer at a parts-per-quadrillion level without preconcentration is disclosed. The method comprises the steps of ionizing a carrier gas with an ionization source to form reactant ions or reactant adduct ions comprising nitrate ions (NO.sub.3.sup.-); selectively reacting the reactant ions or reactant adduct ions with at least one volatile or non-volatile explosive analyte at a carrier gas pressure of at least about 100 Ton in a reaction region disposed between the ionization source and an ion detector, the reaction region having a length which provides a residence time (tr) for reactant ions therein of at least about 0.10 seconds, wherein the selective reaction yields product ions comprising reactant ions or reactant adduct ions that are selectively bound to the at least one explosive analyte when present therein; and detecting product ions with the ion detector to determine presence or absence of the at least one explosive analyte.

  5. Accelerator-mass spectroscopy with fully stripped 36Cl

    The Garching MP tandem-post accelerator-achromator accelerator facility was extended in such way that by it a very backgroundless accelerator mass spectroscopy with fully stripped medium heavy ions was possible. As first applications microscopical amounts of 36Cl (Tsub(1/2)= 301 000 years) were detected. The detection limit lies at 36Cl/CL=4x10-15. In first measurements the method was applied to the age determination of palaeontological samples and to the study of cosmic-radiation induced reactions in the earth crust. (orig.)

  6. Performance results of a mobile high-resolution MR-TOF mass spectrometer for in-situ analytical mass spectrometry

    Lippert, Wayne; Lang, Johannes [Justus-Liebig-Universitaet Giessen (Germany); Ayet San Andres, Samuel [GSI, Darmstadt (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [Justus-Liebig-Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Yavor, Mikhail [RAS St. Petersburg (Russian Federation)

    2014-07-01

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed which provides a mass resolving power exceeding 250,000 and sub-ppm mass accuracy in a transportable format. Thus it allows resolving isobars and enables accurate determination of the composition and structure of biomolecules. Furthermore the device offers high mass resolving MS/MS capability via selective ion re-trapping and collisional-induced dissociation (CID). An atmospheric pressure interface (API) provides for routine measurements with various atmospheric ion sources. All supply electronics, DAQ and control system are mounted with the spectrometer into a single frame with a total volume of only 0.8 m{sup 3}. With the current system many applications like waste water monitoring at hot spots, mass-based classification of biomolecules and breath analysis are possible. In addition the mass spectrometer is readily scalable and can be adopted and simplified for even more specific use like in space science for instance. A characterization and first performance results are shown, and the implementation of MS/MS in combination with CID is discussed.

  7. Performance results of a mobile high-resolution MR-TOF mass spectrometer for in-situ analytical mass spectrometry

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed which provides a mass resolving power exceeding 250,000 and sub-ppm mass accuracy in a transportable format. Thus it allows resolving isobars and enables accurate determination of the composition and structure of biomolecules. Furthermore the device offers high mass resolving MS/MS capability via selective ion re-trapping and collisional-induced dissociation (CID). An atmospheric pressure interface (API) provides for routine measurements with various atmospheric ion sources. All supply electronics, DAQ and control system are mounted with the spectrometer into a single frame with a total volume of only 0.8 m3. With the current system many applications like waste water monitoring at hot spots, mass-based classification of biomolecules and breath analysis are possible. In addition the mass spectrometer is readily scalable and can be adopted and simplified for even more specific use like in space science for instance. A characterization and first performance results are shown, and the implementation of MS/MS in combination with CID is discussed.

  8. MEMS Fabrication of Micro Cylindrical Ion Trap Mass Spectrometer for CubeSats Application

    Zheng, Y.

    2015-10-01

    Microelectromechanical Systems (MEMS) technology is used to fabricate arrays of micro Cylindrical Ion Traps (μCIT) which are integrated into a miniaturized mass spectrometer (MS). The micro μCITs are built from silicon wafers and requires high machining precision, smooth surface, and high dimensional uniformity across the array for optimum mass spectrometer performance. In order to build these 3D miniature structures several MEMS processing techniques were explored and a process was developed and tested. By using the developed MEMS process, the required μCIT 4 x 4 arrays were fabricated. This included a chip design variation in which mechanical locking pits and posts were machined in the Ring Electrode (RE) chip and End Plate (EP) chips respectively, for self-assembly. The size of the assembled μCIT is only 12 mm x 12 mm x 1.5 mm. It is a key component for the miniature mass spectrometer. The micro cylindrical ion trap mass spectrometer has the advantages of low-power operation, simpler electronics and less-stringent vacuum system requirements. The MEMS batch production capabilities will also greatly lower the cost. It is a promising candidate for CubeSat and nanoSats applications for exploration of chemical distributions in space.

  9. Development of a high vacuum sample preparation system for helium mass spectrometer

    A high vacuum sample preparation system for the 3He/4He ratio mass spectrometer (Helix SFT) has been developed to remove all the gaseous constituents excluding helium from the field gases. The sample preparation system comprises of turbo molecular pump, ion pump, zirconium getter, pipettes and vacuum gauges with controller. All these are fitted with cylindrical SS chamber using all metal valves. The field samples are initially treated with activated charcoal trap immersed in liquid nitrogen to cutoff major impurities and moisture present in the sample gas. A sample of 5 ml is collected out of this stage at a pressure of 10−2 mbar. This sample is subsequently purified at a reduced pressure of 10−7 mbar before it is injected into the ion source of the mass spectrometer. The sample pressure was maintained below 10−7 mbar with turbo molecular vacuum pumps and ion pumps. The sample gas passes through several getter elements and a cold finger with the help of manual high vacuum valves before it is fed to the mass spectrometer. Thus the high vacuum sample preparation system introduces completely clean, dry and refined helium sample to the mass spectrometer for best possible analysis of isotopic ratio of helium.

  10. Desorption electrospray ionization with a portable mass spectrometer: in situ analysis of ambient surfaces.

    Mulligan, Christopher C; Talaty, Nari; Cooks, R Graham

    2006-04-28

    Desorption electrospray ionization (DESI) is implemented on a portable mass spectrometer and used to demonstrate in situ detection of active ingredients in pharmaceutical preparations, alkaloids in plant tissues, explosives, chemical warfare agent simulants and agricultural chemicals from a variety of surfaces; air monitoring applications using DESI are also introduced. PMID:16609779

  11. High resolution (GC/MS) mass spectrometer data acquisition and processing system based on microcomputer

    A high resolution (GC/MS) mass spectrometer data acquisition and processing system based on IBM-PC/AT is introduced in this paper. Its hardware design and system software are described simply, and a comparison between two measurement results on standard samples PFK obtained with this system and minicomputer is given

  12. Potentiality evaluation of the MAT 250 UF mass spectrometer for general analysis

    This work presents a study on the potentiality of the MAT 250 UF mass spectrometer. It was formerly used only, for uranium isotopic analysis. It will be used, flow now on, also for the analysis of other gases such as deuterium, helium and hydrogen, as well. (A.C.A.S.)

  13. Ultrasensitive resonance ionization mass spectrometer for evaluating krypton contamination in xenon dark matter detectors

    An ultrasensitive resonance ionization mass spectrometer that can be applied to evaluate krypton (Kr) contamination in xenon (Xe) dark matter detectors has been developed for measuring Kr at the parts-per-trillion (ppt) or sub-ppt level in Xe. The gas sample is introduced without any condensation into a time-of-flight mass spectrometer through a pulsed supersonic valve. Using a nanosecond pulsed laser at 212.6 nm, 84Kr atoms in the sample are resonantly ionized along with other Kr isotopes. 84Kr ions are then mass separated and detected by the mass spectrometer in order to measure the Kr impurity concentration. With our current setup, approximately 0.4 ppt of Kr impurities contained in pure argon (Ar) gas are detectable with a measurement time of 1000 s. Although Kr detection sensitivity in Xe is expected to be approximately half of that in Ar, our spectrometer can evaluate Kr contamination in Xe to the sub-ppt level

  14. Acquisition systems and data elaboration for Varian Mat 1129 mass spectrometers

    The data acquisition equipment to be described is used to capture data deriving from the Varian Mat 1125 mass spectrometer. It is based on a system controlled by the microprocessor 8085 and was designed with the aim of advantegeously replacing the photosensitive paper recorder used originally. (Author)

  15. Frequency-swept detector for ion cyclotron resonance mass spectrometers

    Wronka, J.; Ridge, D. P.

    1982-04-01

    Design, construction, performance, and use of a frequency-swept bridge detector for ion cyclotron resonance mass spectrometry are described. Special features include characterization and simple automatic correction of phase shift to allow broadband detection. The result is a detection system that may be used either at constant field or constant frequency. Drift-mode operation is simplified in that it may be satisfactorily used without the various signal modulation schemes used in previous detectors. In the trapped mode the detector may be pulsed to control the timing of ion detection. This detector makes it possible to do frequency-swept double resonance experiments which provide spectra of all the product ions of a given reactant ion. Circuit schematics and typical frequency- and field-swept spectra are shown.

  16. HD gas analysis with Gas Chromatography and Quadrupole Mass Spectrometer

    Ohta, T; Didelez, J -P; Fujiwara, M; Fukuda, K; Kohri, H; Kunimatsu, T; Morisaki, C; Ono, S; Rouille, G; Tanaka, M; Ueda, K; Uraki, M; Utsuro, M; Wang, S Y; Yosoi, M

    2011-01-01

    A gas analyzer system has been developed to analyze Hydrogen-Deuteride (HD) gas for producing frozen-spin polarized HD targets, which are used for hadron photoproduction experiments at SPring-8. Small amounts of ortho-H$_{2}$ and para-D$_{2}$ gas mixtures ($\\sim$0.01%) in the purified HD gas are a key to realize a frozen-spin polarized target. In order to obtain reliable concentrations of these gas mixtures in the HD gas, we produced a new gas analyzer system combining two independent measurements with the gas chromatography and the QMS. The para-H$_{2}$, ortho-H$_{2}$, HD, and D$_{2}$ are separated using the retention time of the gas chromatography and the mass/charge. It is found that the new gas analyzer system can measure small concentrations of $\\sim$0.01% for the otho-H$_2$ and D$_2$ with good S/N ratios.

  17. Design of Portable Mass Spectrometers with Handheld Probes: Aspects of the Sampling and Miniature Pumping Systems

    Chen, Chien-Hsun; Chen, Tsung-Chi; Zhou, Xiaoyu; Kline-Schoder, Robert; Sorensen, Paul; Cooks, R. Graham; Ouyang, Zheng

    2014-01-01

    Miniature mass spectrometry analytical systems of backpack configuration fitted with sampling probes could potentially be of significant interest for in-field, real-time chemical analysis. In this study, various configurations were explored in which a long narrow tube was used to connect the turbo and backing pumps used to create and maintain vacuum. Also, for the first time we introduced two new types of pumps for miniature mass spectrometers, the Creare 130g drag pump and Creare 350g scroll...

  18. On-line monitoring of continuous flow chemical synthesis using a portable, small footprint mass spectrometer.

    Bristow, Tony W T; Ray, Andrew D; O'Kearney-McMullan, Anne; Lim, Louise; McCullough, Bryan; Zammataro, Alessio

    2014-10-01

    For on-line monitoring of chemical reactions (batch or continuous flow), mass spectrometry (MS) can provide data to (1) determine the fate of starting materials and reagents, (2) confirm the presence of the desired product, (3) identify intermediates and impurities, (4) determine steady state conditions and point of completion, and (5) speed up process optimization. Recent developments in small footprint atmospheric pressure ionization portable mass spectrometers further enable this coupling, as the mass spectrometer can be easily positioned with the reaction system to be studied. A major issue for this combination is the transfer of a sample that is representative of the reaction and also compatible with the mass spectrometer. This is particularly challenging as high concentrations of reagents and products can be encountered in organic synthesis. The application of a portable mass spectrometer for on-line characterization of flow chemical synthesis has been evaluated by coupling a Microsaic 4000 MiD to the Future Chemistry Flow Start EVO chemistry system. Specifically, the Hofmann rearrangement has been studied using the on-line mass spectrometry approach. Sample transfer from the flow reactor is achieved using a mass rate attenuator (MRA) and a sampling make-up flow from a high pressure pump. This enables the appropriate sample dilution, transfer, and preparation for electrospray ionization. The capability of this approach to provide process understanding is described using an industrial pharmaceutical process that is currently under development. The effect of a number of key experimental parameters, such as the composition of the sampling make-up flow and the dilution factor on the mass spectrometry data, is also discussed. PMID:25106707

  19. Development of a GC/Quadrupole-Orbitrap Mass Spectrometer, Part II: New Approaches for Discovery Metabolomics

    Peterson, Amelia C.; Balloon, Allison J.; Westphall, Michael S.; Coon, Joshua J.

    2014-01-01

    Identification of unknown peaks in gas chromatography/mass spectrometry (GC/MS)-based discovery metabolomics is challenging, and remains necessary to permit discovery of novel or unexpected metabolites that may elucidate disease processes and/or further our understanding of how genotypes relate to phenotypes. Here, we introduce two new technologies and an analytical workflow that can facilitate the identification of unknown peaks. First, we report on a GC/Quadrupole-Orbitrap mass spectrometer...

  20. Synchrotron ring as a multi-turn time-of-flight mass spectrometer

    A synchrotron ring can be used as a time-of-flight mass spectrometer under one of the two condition; a) all the particles in the ring are cooled down and have a very small momentum spread: b) the ring is tuned so as to achieve an isochronous condition for particles circulating in the ring. The methods are suited for the on-line mass measurement of short-lived nuclei which are made at an upstream production target before the injection. (author)

  1. Search for doubly-charged negative ions via accelerator mass spectrometry

    Kutschera, W.; Frekers, D.; Pardo, R.; Rehm, K.E.; Smither, R.K.; Yntema, J.L.

    1983-01-01

    The Argonne FN tandem accelerator in conjunction with an Enge split-pole magnetic spectrograph has been used as a highly sensitive mass spectrometer to search for doubly charged negative ions of /sup 11/B, /sup 12/C and /sup 16/O. No evidence for the formation of these ions in an inverted sputter source and the subsequent acceleration in the tandem has been found. The following limits for the ratio of doubly-charged to singly-charged ions were measured: X/sup - -//X/sup -/ < 1 x 10/sup -15/, /sup 11/B; < 2 x 10/sup -15/, /sup 12/C; < 2 x 10/sup -14/, /sup 16/O. A relatively abundant formation of the short lived, metastable He/sup -/ ion in the sputter source has been observed.

  2. Volcanic Gas Emissions Mapping Using a Mass Spectrometer System

    Griffin, Timothy P.; Diaz, J. Andres

    2008-01-01

    The visualization of hazardous gaseous emissions at volcanoes using in-situ mass spectrometry (MS) is a key step towards a better comprehension of the geophysical phenomena surrounding eruptive activity. In-Situ gas data consisting of helium, carbon dioxide, sulfur dioxide, and other gas species, were acquired with an MS system. MS and global position system (GPS) data were plotted on ground imagery, topography, and remote sensing data collected by a host of instruments during the second Costa Rica Airborne Research and Technology Applications (CARTA) mission This combination of gas and imaging data allowed 3-dimensional (3-D) visualization of the volcanic plume end the mapping of gas concentration at several volcanic structures and urban areas This combined set of data has demonstrated a better tool to assess hazardous conditions by visualizing and modeling of possible scenarios of volcanic activity. The MS system is used for in-situ measurement of three-dimensional gas concentrations at different volcanic locations with three different transportation platforms, aircraft, auto, and hand carried. The demonstration for urban contamination mapping is also presented as another possible use for the MS system.

  3. Fast magnetic peak switching for thermal ionization mass spectrometers

    Common practice in thermal ionization mass spectrometry is to make repeated and rapid comparisons between isotopes of interest by switching the magnetic deflection field sequentially between the values required to deflect each isotope through the collector slit. After each step in the field value (peak switch) it is necessary to pause before logging data, in order to allow the system response to settle to the point where it does not affect the precision of the isotopic ratio determination. The dynamics of the field stabilization system are the principle contributors to this delay period. The system characteristics applicable to a field-controlled magnet system are analyzed in this paer. Possible areas where the step response may be improved by the application of modern control theory are outlined. It is shown that any field-stabilized magnet system can be optimized for step response by the synthesis of a discrete control system. Discrete digital control, i.e. a software implementation, allows system optimization without the necessity for hardware modification, which would be difficult, expensive and possibility in some cases impractical. (orig.)

  4. Influence of the Ion Source Operating Conditions on the Characteristics of a Prism Mass Spectrometer With Inhomogeneous Magnetic Field

    P.O. Kuzema

    2010-01-01

    Full Text Available The influence of magnetic field focusing the electron beam in ion source of mass spectrometer on the analytical characteristics of the instrument has been studied. The range of current of ion source's focusing electromagnet providing the optimal performance of the mass spectrometer has been determined.

  5. Mass- and energy-analyses of ions from plasma by means of a miniature Thomson spectrometer

    The paper presents an improved version of a miniature mass-spectrometer of the Thomson-type, which has been adopted for ion analysis near the dense plasma region inside a vacuum chamber. Problems connected with the separation of ions from plasma streams are considered. Input diaphragms and pumping systems, needed to ensure good vacuum inside the analyzing region, are described. The application of the miniature Thomson-type analyzer is illustrated by ion parabolas recorded in plasma-focus facility and rod plasma injector experiment. A quantitative analysis of the recorded ion parabolas is presented. Factors influencing accuracy of the ion analysis are discussed and methods of the spectrometer calibration are described.

  6. Construction status of the three-stage mass spectrometer for plutonium isotope measurements

    The purpose of the three-stage high sensitivity mass spectrometer currently being assembled at the Savannah River Laboratory (SRL) is to provide ultra low-level isotope analyses to support current research programs. Initially, the instrument will measure isotope ratios required for research on plutonium transport in the environment and for determining the characteristics of plutonium-bearing particles. Also, the spectrometer will be expected to support other environmental research, in particular, research programs concerning long-lived fission products in the environment

  7. Accelerator mass spectrometry as a bioanalytical tool for nutritional research

    Vogel, J.S.; Turteltaub, K.W.

    1997-09-01

    Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but recently has been developed for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram- sized samples. Its advantages over non-isotopeic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided.

  8. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    Andersen, T.; Jensen, R.; Christensen, M. K.; Pedersen, T.; Hansen, O.; Chorkendorff, I.

    2012-07-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH3.

  9. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    Andersen, T.; Jensen, R.; Christensen, M. K.; Chorkendorff, I. [Department of Physics, Danish National Research Foundation' s Center for Individual Nanoparticle Functionality (CINF), Technical University of Denmark, Building 312, DK-2800 Kgs. Lyngby (Denmark); Pedersen, T.; Hansen, O. [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech Building 345 East, DK-2800 Kgs. Lyngby (Denmark)

    2012-07-15

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/{Delta}m > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH{sub 3}.

  10. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors.

    Andersen, T; Jensen, R; Christensen, M K; Pedersen, T; Hansen, O; Chorkendorff, I

    2012-07-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH(3). PMID:22852722

  11. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0–5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH3.

  12. High-performance multiple-reflection time-of-flight mass spectrometers for research with exotic nuclei and for analytical mass spectrometry

    Plaß, Wolfgang R.; Dickel, Timo; Ayet San Andres, Samuel; Ebert, Jens; Greiner, Florian; Hornung, Christine; Jesch, Christian; Lang, Johannes; Lippert, Wayne; Majoros, Tamas; Short, Devin; Geissel, Hans; Haettner, Emma; Reiter, Moritz P.; Rink, Ann-Kathrin; Scheidenberger, Christoph; Yavor, Mikhail I.

    2015-11-01

    A class of multiple-reflection time-of-flight mass spectrometers (MR-TOF-MSs) has been developed for research with exotic nuclei at present and future accelerator facilities such as GSI and FAIR (Darmstadt), and TRIUMF (Vancouver). They can perform highly accurate mass measurements of exotic nuclei, serve as high-resolution, high-capacity mass separators and be employed as diagnostics devices to monitor the production, separation and manipulation of beams of exotic nuclei. In addition, a mobile high-resolution MR-TOF-MS has been developed for in situ applications in analytical mass spectrometry ranging from environmental research to medicine. Recently, the MR-TOF-MS for GSI and FAIR has been further developed. A novel RF quadrupole-based ion beam switchyard has been developed that allows merging and splitting of ion beams as well as transport of ions into different directions. It efficiently connects a test and reference ion source and an auxiliary detector to the system. Due to an increase in the kinetic energy of the ions in the time-of-flight analyzer of the MR-TOF-MS, a given mass resolving power is now achieved in less than half the time-of-flight. Conversely, depending on the time-of-flight, the mass resolving power has been increased by a factor of more than two.

  13. Laser Ion Acceleration from Mass-Limited Targets with Preplasma

    Lezhnin, K V; Esirkepov, T Zh; Bulanov, S V; Klimo, O; Weber, S; Korn, G

    2016-01-01

    The interaction of high intensity laser radiation with mass-limited target exhibits significant enhancement of the ion acceleration when the target is surrounded by an underdense plasma corona, as seen in numerical simulations. The self-generated quasistatic magnetic field squeezes the corona causing the intensification of a subsequent Coulomb explosion of the target. The electric field intensification at the target edges and plasma resonance effects result in the generation of characteristic density holes and further contributes to the ion acceleration.The interaction of high intensity laser radiation with mass-limited target exhibits significant enhancement of the ion acceleration when the target is surrounded by an underdense plasma corona, as seen in numerical simulations. The self-generated quasistatic magnetic field squeezes the corona causing the intensification of a subsequent Coulomb explosion of the target. The electric field intensification at the target edges and plasma resonance effects result in...

  14. Mobile high-resolution time-of-flight mass spectrometer for in-situ analytics

    Lang, Johannes; Ebert, Jens [II. Physikalisches Institut, JLU, Giessen (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [II. Physikalisches Institut, JLU, Giessen (Germany); GSI, Darmstadt (Germany)

    2011-07-01

    A compact multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed. For the first time it allows for mass measurements with a resolving power exceeding 100000 and sub ppm accuracy in a mobile device. Thus it allows to resolve isobars and enables to accurately determine the composition and structure of biomolecules. The MR-TOF-MS consists of an atmospheric pressure interface for DESI and REIMS, ion cooler, ion trap, time-of-flight analyzer, MCP detector and DAQ. Vacuum system components, power supplies as well as electronics are mounted together with the ion optical spectrometer parts on a single frame with a total volume of 0.8 m{sup 3}. Applications of the device within the AmbiProbe research program include in-situ mass spectrometry such as real-time tissue recognition in electrosurgery, identification of mycotoxins and analysis of soil samples for environmental studies.

  15. Mobile high-resolution time-of-flight mass spectrometer for in-situ analytics

    A compact multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed. For the first time it allows for mass measurements with a resolving power exceeding 100000 and sub ppm accuracy in a mobile device. Thus it allows to resolve isobars and enables to accurately determine the composition and structure of biomolecules. The MR-TOF-MS consists of an atmospheric pressure interface for DESI and REIMS, ion cooler, ion trap, time-of-flight analyzer, MCP detector and DAQ. Vacuum system components, power supplies as well as electronics are mounted together with the ion optical spectrometer parts on a single frame with a total volume of 0.8 m3. Applications of the device within the AmbiProbe research program include in-situ mass spectrometry such as real-time tissue recognition in electrosurgery, identification of mycotoxins and analysis of soil samples for environmental studies.

  16. Optimization of an indigenous thermal ionization mass spectrometer for field application in a fuel reprocessing plant

    Reprocessing of spent fuels is an important step in the entire nuclear fuel cycle for a sustained nuclear energy programme in our country. Thermal ionization mass spectrometry (TIMS) has been recognized as the most reliable and suitable method for Input Accountability of plutonium and uranium in reprocessing plant. To meet this requirement, a thermal ionization mass spectrometer (TIMS-3) has been developed indigenously by TPPED, BARC, Mumbai, India and is installed at Accountability laboratory of KARP, Kalpakkam. Instrument has been designed based on user specifications which is in line with current generation commercial thermal ionization mass spectrometer. The objective of this present work is to evaluate performance characteristics of the instrument and optimize its capabilities to make it suitable for regular application in the reprocessing plant. Some of the performances of this instrument and the quality of analytical out-put has been already discussed. Present paper discusses the further works carried out in standardizing the instrument with various calibrations and arbitration

  17. A Bragg curve ionization chamber for acceleration mass spectrometry

    An ionization chamber based on the Bragg curve spectrometry method to be used as the final detector in a accelerator mass spectrometry system is described. The first tests with a Cl beam give energy resolution of 1% and Z resolving power of 72 at Z=17

  18. Neutrino mass and mixing, and non-accelerator experiments

    We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

  19. A Method for Estimating Mass-Transfer Coefficients in a Biofilter from Membrane Inlet Mass Spectrometer Data

    Nielsen, Anders Michael; Nielsen, Lars Peter; Feilberg, Anders;

    2009-01-01

    A membrane inlet mass spectrometer (MIMS) was used in combination with a developed computer model to study and improve management of a biofilter (BF) treating malodorous ventilation air from a meat rendering facility. The MIMS was used to determine percentage removal efficiencies (REs) of selected...... sulfur gases and to provide toluene retention profiles for the model to determine the air velocity and overall mass-transfer coefficient of toluene. The mass-transfer coefficient of toluene was used as a reference for determining the mass transfer of sulfur gases. By presenting the model to scenarios of......, knowing the relationship between mass-transfer coefficients and air velocity for a given type of BF allows for an improved dimensioning and managing of this and similar BFs. This research demonstrates that it is possible to estimate mass-transfer coefficients and air velocity in BFs using MIMS in...

  20. Accelerator mass spectrometry at the University of North Texas

    Anthony, J. M.; Matteson, S.; McDaniel, F. D.; Duggan, J. L.

    1989-04-01

    An accelerator mass spectrometry system designed for analysis of electronic materials is being developed and installed on the University of North Texas 3 MV tandem accelerator (National Electrostatics Corporation 9-SDH). High-resolution magnetic (40° deflection, {M}/{ΔM ≈ 350}, maximum mass-energy product 69 MeVu) and electro static (45 ° deflection, E/ q of 4.8 MeV, {E}/{ΔE}≈ 730 ) analysis, coupled with a 1.5 m time-of-flight path and total energy detection (surface barrier detector) forms the basis of the detection system. In order to provide stable element detection capability at the parts-per-trillion level in electronic materials (Si, GaAs, HgCdTe), a custom ion source, incorporating mass analysis of the sputtering beam, ultraclean slits, low cross-contamination and UHV capability, is being constructed.

  1. Solid state magnet control unit for an A.E.I. MS-902 mass spectrometer

    The computerized gas chromatograph-mass spectrometer (GC-MS) technique is used extensively for the study of metabolic disorders. The MS-902 mass spectrometer used by the authors is equipped with a 2-s scanning facility which is used for GC-MS applications. When the spectrometer is operated in a continuous magnetic scanning mode at this scan rate, the magnetic field frequently drifts in the course of a GC analysis. Therefore, it has been impossible to determine automatically the mass peak centroids (usually measured in time from a preset magnetic field) and obtain correct mass to charge (m/z) values for the ions. The instability of the magnetic field arises from the heat generated in the vacuum tube magnet regulator under dynamic scanning conditions. To overcome this problem the vacuum tubes in the regulator must be changed every two to three months. The high cost of some of these tubes, particularly of the three 13 EI control tubes, led to the design and construction of a solid state magnet control unit which is described in this communication. (Auth.)

  2. Direct trace analysis of metals and alloys in a quadrupole ion-trap mass spectrometer

    Song, K S; Yang, M; Cha, H K; Lee, J M; Lee, G H

    1999-01-01

    An ion-trap mass spectrometer adopting a quadrupole ion-trap and laser ablation/ionization method was constructed. The developed system was tested for composition analysis of some metals (Cu, stainless), and alloys (hastalloy C, mumetal) by mass spectrometry. Samples were analyzed by using laser ablation from a sample probe tip followed by a mass analysis with the quadrupole ion-trap. The quadrupole ion-trap was modified to enable laser ablation by a XeCl excimer laser pulse that passed radially through the ring electrode. A mass scan of the produced ions was performed in the mass selective instability mode wherein trapped ions were successively detected by increasing the rf voltage through the ring electrode. Factors affecting the mass resolution, such as pressure of buffer gas and ablation laser power, are discussed.

  3. Accelerating field spectrometer for photons and electrons simultaneous measurement. Application to decay schemes study

    An original spectrometer was built to improve the measurement of the absolute emission intensities of radionuclides with converted low energy gamma transitions. In this spectrometer, the same Si(Li) detector simultaneously measures electrons and photons emitted by the studied radionuclide; an electrostatic field may be established between the source and the detector to modify the electrons energy. This field allows the electron and photon peaks to be separated, and the absorption and energy straggling by detector windows to be decreased. Special attention has been given to determine spectrometer efficiency calibration curves for electrons and photons. 147Nd and 133Ba were used to test the spectrometer improvement and the method used

  4. Recursive least square vehicle mass estimation based on acceleration partition

    Feng, Yuan; Xiong, Lu; Yu, Zhuoping; Qu, Tong

    2014-05-01

    Vehicle mass is an important parameter in vehicle dynamics control systems. Although many algorithms have been developed for the estimation of mass, none of them have yet taken into account the different types of resistance that occur under different conditions. This paper proposes a vehicle mass estimator. The estimator incorporates road gradient information in the longitudinal accelerometer signal, and it removes the road grade from the longitudinal dynamics of the vehicle. Then, two different recursive least square method (RLSM) schemes are proposed to estimate the driving resistance and the mass independently based on the acceleration partition under different conditions. A 6 DOF dynamic model of four In-wheel Motor Vehicle is built to assist in the design of the algorithm and in the setting of the parameters. The acceleration limits are determined to not only reduce the estimated error but also ensure enough data for the resistance estimation and mass estimation in some critical situations. The modification of the algorithm is also discussed to improve the result of the mass estimation. Experiment data on a sphalt road, plastic runway, and gravel road and on sloping roads are used to validate the estimation algorithm. The adaptability of the algorithm is improved by using data collected under several critical operating conditions. The experimental results show the error of the estimation process to be within 2.6%, which indicates that the algorithm can estimate mass with great accuracy regardless of the road surface and gradient changes and that it may be valuable in engineering applications. This paper proposes a recursive least square vehicle mass estimation method based on acceleration partition.

  5. Toward laser ablation Accelerator Mass Spectrometry of actinides

    A project to measure neutron capture cross sections of a number of actinides in a reactor environment by Accelerator Mass Spectrometry (AMS) at the ATLAS facility of Argonne National Laboratory is underway. This project will require the precise and accurate measurement of produced actinide isotopes in many (>30) samples irradiated in the Advanced Test Reactor at Idaho National Laboratory with neutron fluxes having different energy distributions. The AMS technique at ATLAS is based on production of highly-charged positive ions in an electron cyclotron resonance (ECR) ion source followed by acceleration in the ATLAS linac and mass-to-charge (m/q) measurement at the focus of the Fragment Mass Analyzer. Laser ablation was selected as the method of feeding the actinide material into the ion source because we expect it will have higher efficiency and lower chamber contamination than either the oven or sputtering techniques, because of a much narrower angular distribution of emitted material. In addition, a new multi-sample holder/changer to allow quick change between samples and a computer-controlled routine allowing fast tuning of the accelerator for different beams, are being developed. An initial test run studying backgrounds, detector response, and accelerator scaling repeatability was conducted in December 2010. The project design, schedule, and results of the initial test run to study backgrounds are discussed.

  6. Toward laser ablation Accelerator Mass Spectrometry of actinides

    Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Paul, M.; Collon, P.; Deibel, C.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Fonnesbeck, J.; Imel, G.

    2013-01-01

    A project to measure neutron capture cross sections of a number of actinides in a reactor environment by Accelerator Mass Spectrometry (AMS) at the ATLAS facility of Argonne National Laboratory is underway. This project will require the precise and accurate measurement of produced actinide isotopes in many (>30) samples irradiated in the Advanced Test Reactor at Idaho National Laboratory with neutron fluxes having different energy distributions. The AMS technique at ATLAS is based on production of highly-charged positive ions in an electron cyclotron resonance (ECR) ion source followed by acceleration in the ATLAS linac and mass-to-charge (m/q) measurement at the focus of the Fragment Mass Analyzer. Laser ablation was selected as the method of feeding the actinide material into the ion source because we expect it will have higher efficiency and lower chamber contamination than either the oven or sputtering techniques, because of a much narrower angular distribution of emitted material. In addition, a new multi-sample holder/changer to allow quick change between samples and a computer-controlled routine allowing fast tuning of the accelerator for different beams, are being developed. An initial test run studying backgrounds, detector response, and accelerator scaling repeatability was conducted in December 2010. The project design, schedule, and results of the initial test run to study backgrounds are discussed.

  7. A Compact Ion and Neutral Mass Spectrometer for the Exocube Mission

    Jones, S.; Paschalidis, N.; Rodriguez, M.; Sittler, E. C., Jr.; Chornay, D. J.

    2014-12-01

    Demand is high for in situ measurements of atmospheric neutral and ion composition and density, not only for studies of the dynamic ionosphere-theremosphere-mesosphere system but simply to define the steady state background atmospheric conditions. The ExoCube mission is designed to acquire global knowledge of in-situ densities of [H], [He], [O] and [H+], [He+], [O+] in the upper ionosphere and lower exosphere in combination with incoherent scatter radar ground stations distributed in the north polar region. The Heliophysic Division of GSFC has developed a compact Ion and Neutral Mass Spectrometer (INMS) for in situ measurements of ions and neutrals H, He, N, O, N2, O2 with M/dM of approximately 10 at an incoming energy range of 0-50eV. The INMS is based on front end optics, post acceleration, gated time of flight, ESA and CEM or MCP detectors. The compact sensor has a dual symmetric configuration with the ion and neutral sensor heads on opposite sides and with full electronics in the middle. The neutral front end optics includes thermionic emission ionization and ion blocking grids, and the ion front end optics includes spacecraft potential compensation grids. The electronics include front end, fast gating, HVPS, ionizer, TOF binning and full bi directional C&DH digital electronics. The data package includes 400 mass bins each for ions and neutrals and key housekeeping data for instrument health and calibration. The data sampling can be commanded as fast as 10 msec per frame (corresponding to ~80 m spatial separation) in burst mode, and has significant onboard storage capability and data compression scheme. Experimental data from instrument testing with both ions and neutrals will be presented. The instrument is successfully integrated in the CubeSat and passed vibration, thermal and shock testing. The ExoCube mission is scheduled to fly in Nov 2014 in a 445 x 670 km polar orbit with the INMS aperture oriented in the ram direction. This miniaturized instrument (1

  8. The suprathermal ion mass spectrometer (SMS) onboard the Akebono (EXOS-D) satellite

    The suprathermal ion mass spectrometer (SMS) was developed to study the thermal and suprathermal ion distributions in the low altitude magnetosphere. The instrument has a mass and plasma density dynamic range sufficient to measure, on a regular basis, the major and the minor ion distribution functions at apogee as well as at perigee. The instrument is a radio frequency type mass spectrometer and has a programmable mass resolution which is independent of energy and mass selected. The present report gives measurements of the thermal ion mass composition near apogee which show that the composition varies from one dominated by H+ and O+ to one in which the density of 'minor' ions (O++, He+, N+) is comparable to or greater than that of H+ and O+. The report also prevents high time resolution mass/energy/angle observations in the topside ionospheric plasma in or near the cusp region where rapid heating of the bulk of the plasma and the formation of conic distributions is evident. These unique observations are compared with other plasma diagnostrics on the spacecraft to improve the understanding of ionospheric ion production, convection and loss processes as well as low altitude ion energization phenomena. (N.K.)

  9. Toward a Micro Gas Chromatograph/Mass Spectrometer (GC/MS) System

    Wiberg, D. V.; Eyre, F. B.; Orient, O.; Chutjian, A.; Garkarian, V.

    2001-01-01

    Miniature mass filters (e.g., quadrupoles, ion traps) have been the subject of several miniaturization efforts. A project is currently in progress at JPL to develop a miniaturized Gas Chromatograph/Mass Spectrometer (GC/MS) system, incorporating and/or developing miniature system components including turbomolecular pumps, scroll type roughing pump, quadrupole mass filter, gas chromatograph, precision power supply and other electronic components. The preponderance of the system elements will be fabricated using microelectromechanical systems (MEMS) techniques. The quadrupole mass filter will be fabricated using an X-ray lithography technique producing high precision, 5x5 arrays of quadrupoles with pole lengths of about 3 mm and a total volume of 27 cubic mm. The miniature scroll pump will also be fabricated using X-ray lithography producing arrays of scroll stages about 3 mm in diameter. The target detection range for the mass spectrometer is 1 to 300 atomic mass units (AMU) with are solution of 0.5 AMU. This resolution will allow isotopic characterization for geochronology, atmospheric studies and other science efforts dependant on the understanding of isotope ratios of chemical species. This paper will discuss the design approach, the current state-of-the art regarding the system components and the progress toward development of key elements. The full system is anticipated to be small enough in mass, volume and power consumption to allow in situ chemical analysis on highly miniaturized science craft for geochronology, atmospheric characterization and detection of life experiments applicable to outer planet roadmap missions.

  10. The ion optics of a miniature 3He/4He mass spectrometer of high resolution

    To measure the isotopic abundance ratio of 3He and 4He in samples by mass spectrometers is an important detection mean for helium isotope geochemistry research. A symmetrically arranged tandem 3He/4He mass spectrometer is described in the paper. The front stage, used to analyse 3He (including HD and H3) and 4He, is a homogeneous analysing magnet with a bending angle of 90 deg and a bending radius of 6 cm. The end stage, used to analyse 3He, HD and H3, is a non-homogeneous analysing magnet with a bending angle of 180 deg, a bending radius of 15 cm and a magnetic field gradient of 0.75. Because of the use of the non-zero second order coefficient β and curved entrance face of the later magnet for eliminating second order aberrations, the resolving power of the system is notably improved, and theoretically reaches about 3800

  11. The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics

    Osborne, David L.; Zou, Peng; Johnsen, Howard; Hayden, Carl C.; Taatjes, Craig A.; Knyazev, Vadim D.; North, Simon W.; Peterka, Darcy S.; Ahmed, Musahid; Leone, Stephen R.

    2008-08-28

    We have developed a multiplexed time- and photon-energy?resolved photoionizationmass spectrometer for the study of the kinetics and isomeric product branching of gasphase, neutral chemical reactions. The instrument utilizes a side-sampled flow tubereactor, continuously tunable synchrotron radiation for photoionization, a multi-massdouble-focusing mass spectrometer with 100percent duty cycle, and a time- and positionsensitive detector for single ion counting. This approach enables multiplexed, universal detection of molecules with high sensitivity and selectivity. In addition to measurement of rate coefficients as a function of temperature and pressure, different structural isomers can be distinguished based on their photoionization efficiency curves, providing a more detailed probe of reaction mechanisms. The multiplexed 3-dimensional data structure (intensity as a function of molecular mass, reaction time, and photoionization energy) provides insights that might not be available in serial acquisition, as well as additional constraints on data interpretation.

  12. Direct mass measurements of light neutron-rich nuclei using fast recoil spectrometers

    Extensive new mass measurement capabilities have evolved with the development of recoil spectrometers. In the Z = 3 to 9 neutron-rich region alone, 12 neutron-rich nuclei have been determined for the first time by the fast-recoil direct mass measurement method. A recent experiment using the TOFI spectrometer illustrates this technique. A systematic investigation of nuclei that lie along or near the neutron-drip line has provided a valuable first glimpse into the nuclear structure of such nuclei. No evidence for a large single-particle energy gap at N = 14 is observed; however, a change in the two-neutron separation model calculations, and is interpreted in terms of the smaller 1s/sub 1/2/ - 1s/sub 1/2/ interaction compared to that of the 0d/sub 5/2/ - 0d/sub 5/2/ neutron-neutron interaction. 18 refs., 7 figs., 1 tab

  13. Fabrication and testing of the recoil mass spectrometer at Bombay Pelletron

    S Nagaraj; H C Jain; P K Joshi; S D Paul; R Palit; H V Panchal; B S Naidu; A Chatterjee; A Navin

    2001-07-01

    A recoil mass spectrometer (RMS) has been designed, fabricated and installed at the 15°S beam-line of the Pelletron at TIFR. The RMS consists of a quadrupole doublet just after the target chamber followed by an ‘electrostatic deflector’, a magnetic dipole and a second electrostatic deflector. The recoils produced in the 12C+58Ni reaction using 60 MeV 12C beam were focussed with the help of electric and magnetic fields and detected in a strip detector placed at the focal plane of the RMS. Further testing of the spectrometer to obtain mass resolution and efficiency are in progress.

  14. Development and Evaluation of a Variable-Temperature Quadrupole Ion Trap Mass Spectrometer

    Derkits, David; Wiseman, Alex; Snead, Russell F.; Dows, Martina; Harge, Jasmine; Lamp, Jared A.; Gronert, Scott

    2016-02-01

    A new, variable-temperature mass spectrometer system is described. By applying polyimide heating tape to the end-cap electrodes of a Bruker (Bremen, Germany) Esquire ion trap, it is possible to vary the effective temperature of the system between 40 and 100°C. The modification does not impact the operation of the ion trap and the heater can be used for extended periods without degradation of the system. The accuracy of the ion trap temperatures was assessed by examining two gas-phase equilibrium processes with known thermochemistry. In each case, the variable-temperature ion trap provided data that were in good accord with literature data, indicating the effective temperature in the ion trap environment was being successfully modulated by the changes in the set-point temperatures on the end-cap electrodes. The new design offers a convenient and effective way to convert commercial ion trap mass spectrometers into variable-temperature instruments.

  15. Field test of a thermal quadrupole mass spectrometer for safeguards verification

    A thermal ionization quadrupole mass spectrometer (Finnigan MAT) was tested in the Safeguards Analytical Laboratory of the IAEA with a view to evaluating its potential field applications. Several modifications have been introduced by the manufacturer. The instrument is equipped with an electron multiplier system and a Faraday cup detector. It allows fully automated analysis. Loadings of 1 μg U and 50 ng Pu can be measured without any problem. (author)

  16. Performance Characteristics of a New Hybrid Triple Quadrupole Time-of-Flight Tandem Mass Spectrometer

    Andrews, Genna L.; Simons, Brigitte L.; Young, J. Bryce; Hawkridge, Adam M.; David C Muddiman

    2011-01-01

    The TripleTOF 5600 System, a hybrid triple quadrupole time-of-flight mass spectrometer, was evaluated to explore the key figures of merit in generating peptide and protein identifications which included spectral acquisition rates, data quality, proteome coverage, and biological depth. Employing a Saccharomyces cerevisiae tryptic digest, careful consideration of several performance features demonstrated that the speed of the TripleTOF contributed most to the resultant data. The TripleTOF syste...

  17. CologneAMS, a dedicated center for accelerator mass spectrometry in Germany

    Dewald, A., E-mail: dewald@ikp.uni-koeln.de [CologneAMS, Institute of Nuclear Physics, University of Cologne (Germany); Heinze, S.; Jolie, J.; Zilges, A. [CologneAMS, Institute of Nuclear Physics, University of Cologne (Germany); Dunai, T.; Rethemeyer, J.; Melles, M.; Staubwasser, M. [Institute of Geology and Mineralogy, University of Cologne (Germany); Kuczewski, B. [Division of Nuclear Chemistry, University of Cologne (Germany); Richter, J. [Institute of Prehistoric Archaeology, University of Cologne (Germany); Radtke, U. [Institute of Geography, University of Cologne, Germany, Rectorate, University of Duisburg-Essen (Germany); Blanckenburg, F. von [GFZ, German Research Centre for Geosciences, Potsdam (Germany); Klein, M. [HVEE, Amersfoort (Netherlands)

    2013-01-15

    CologneAMS is a new centre for accelerator mass spectrometry (AMS) at University of Cologne. It has been funded by the German Research Foundation (DFG) to improve the experimental conditions especially for those German scientists that apply the AMS technique for their geologic, environmental, nuclear chemical, and nuclear astrophysical research. The new AMS-device has been built by High Voltage Engineering Europe (HVEE) and has been installed in the existing accelerator area of the Institute of Nuclear Physics. The AMS-facility is designed for the spectrometry of {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, {sup 129}I in and heavy ions up to {sup 236}U and {sup 244}Pu. The central part of the AMS-facility is a 6 MV Tandetron Trade-Mark-Sign accelerator. Downstream of the high energy mass spectrometer an additional switching magnet is used as a further filter element which supplies also additional ports for future extensions of the detector systems. The current status of CologneAMS and the results of the first test measurements will be presented.

  18. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    The authors describe the development of a new instrument for the detection of trace amounts of rare isotopes, a Cyclotron Mass Spectrometer (CMS). A compact low energy cyclotron optimized for high mass resolution has been designed and has been fabricated. The instrument has high sensitivity and is designed to measure carbon-14 at abundances of < 10{sup {minus}12}. A novel feature of the instrument is the use of permanent magnets to energize the iron poles of the cyclotron. The instrument uses axial injection, employing a spiral inflector. The instrument has been assembled and preliminary measurements of the magnetic field show that it has a uniformity on the order of 2 parts in 10{sup 4}.

  19. Analytical applications of ion/molecule reactions in a triple quadrupole mass spectrometer

    The development of triple quadrupole mass spectrometers as a means of performing tandem mass spectrometry has provided a versatile instrument on which the ion/molecule reactions of a mass selected ion can be studied. This dissertation details the application of ion/molecule reactions in a triple quadrupole to two analytical problems. Part I. Ion/Molecule Reactions of Ammonia with Translationally Excited C2H5O+/Ions. The ability to impart low center-of-mass translational energies, which upon collision are converted into internal energy, allows the observation of reactions that require energy input. In addition, the systematic variation of the ion kinetic energy, often referred to as energy-resolved mass spectrometer, adds another dimension to the mass spectrum and can allow the observation of thresholds for reactions requiring energy input. This investigation develops methods for determining these thresholds. Part 2. The Use of Ion/Molecule Reactions in selected Reaction Monitoring GC/MSD/MS Analyses. An approach to improving the selectivity of an analysis is to improve the selectivity of the detection method. In GC/MS, one method has been to monitor a selected fragmentation reaction, either metastable or collisionally activated, in a selected reaction monitoring (SRM) analysis. This develops the use of ion/molecule reactions for selected reaction monitoring analyses

  20. Ion-optical studies for improved ion transmission in multistage isotope-ratio mass spectrometers

    Theoretical and experimental ion-optical studies of multistage isotope-ratio mass spectrometers were conducted to determine what improvement in ion transmission efficiency might be attainable through design changes. The computer program GIOS (General Ion Optical Systems) was used to perform theoretical calculations of focusing properties and ion transmission efficiency. Actual transmission through multiple-sector instruments was determined from measurements of the ion beam vertical profile at the focus of each stage. For existing mass spectrometers with tandem magnets of normal geometry, our studies determined a feasible design change that significantly increases ion transmission through the analyzer. The use of a cylindrical einzel lens or an electrostatic quadrupole lens near the focal point between the magnets provides vertical focusing of the ion beam to achieve the improved transmission. We also established a new mass spectrometer design that give 100% transmission through tandem magnetic analyzers and through a third-stage electrostatic analyzer without the use of an intermediate focusing lens. Non-normal magnetic field boundaries provide ion beam focusing in the vertical plant to achieve this complete transmission. 19 refs., 27 figs., 3 tabs

  1. Engineering Sensitivity Improvement of Helium Mass Spectrometer Leak Detection System by Means Global Hard Vacuum Test

    The engineering sensitivity improvement of Helium mass spectrometer leak detection using global hard vacuum test configuration has been done. The purpose of this work is to enhance the sensitivity of the current leak detection of pressurized method (sniffer method) with the sensitivity of 10-3 ∼ 10-5 std cm3/s, to the global hard vacuum test configuration method which can be achieved of up to 10-8 std cm3/s. The goal of this research and development is to obtain a Helium leak test configuration which is suitable and can be used as routine bases in the quality control tests of FPM capsule and AgInCd safety control rod products. The result is an additional instrumented vacuum tube connected with conventional Helium mass spectrometer. The pressure and temperature of the test object during the leak measurement are simulated by means of a 4.1 kW capacity heater and Helium injection to test object, respectively. The addition of auxiliary mechanical vacuum pump of 2.4 l/s pumping speed which is directly connected to the vacuum tube, will reduce 86 % of evacuation time. The reduction of the measured sensitivity due to the auxiliary mechanical vacuum pump can be overcome by shutting off the pump soon after Helium mass spectrometer reaches its operating pressure condition. (author)

  2. Optimized Fast and Sensitive Acquisition Methods for Shotgun Proteomics on a Quadrupole Orbitrap Mass Spectrometer

    Kelstrup, Christian D; Young, Clifford; Lavallee, Richard;

    2012-01-01

    (HCD) tandem mass spectra due to the parallel mode of operation, where the generation, filling, and storage of fragment ions can be performed while simultaneously measuring another ion packet in the Orbitrap mass analyzer. In this study, data-dependent acquisition methods for "fast" or "sensitive......Advances in proteomics are continually driven by the introduction of new mass spectrometric instrumentation with improved performances. The recently introduced quadrupole Orbitrap (Q Exactive) tandem mass spectrometer allows fast acquisition of high-resolution higher-energy collisional dissociation...... h of analysis time. At sample loads below 125 ng, a 156 ms HCD acquisition method improved the sensitivity, mass accuracy, and quality of data and enabled us to identify 30% more proteins and peptides than the faster scanning method. A similar effect was observed when the LC gradient was extended to...

  3. Continuous-flow accelerator mass spectrometry for radiocarbon analysis

    Accelerator Mass Spectrometry (AMS) is a widely used technique for radiocarbon dating of archaeological or environmental samples that are very small or very old (up to 50,000 years before present). Because of the method's extreme sensitivity, AMS can also serve as an environmental tracer and supplements conventional nuclear counting techniques for monitoring 14C emissions from operating nuclear power plants and waste repositories. The utility of present AMS systems is limited by the complex sample preparation process required. Carbon from combusted artefacts must be incorporated into a solid metallic target from which a negative ion beam is produced and accelerated to MeV energies by an accelerator for subsequent analysis. This paper will describe a novel technique being developed by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Laboratory at the Woods Hole Oceanographic Institution for the production of negative carbon ion beams directly from a continuously flowing sample gas stream, eliminating the requirement for a solid target. A key component of the new technique is a microwave-driven, gaseous-feed ion source originally developed at Chalk River Laboratories for the very different requirements of a high current proton linear accelerator. A version of this ion source is now being adapted to serve as an injector for a dedicated AMS accelerator facility at NOSAMS. The paper begins with a review of the fundamentals of radiocarbon dating. Experiments carried out at NOSAMS with a prototype of the microwave ion source are described, including measurements of sample utilization efficiency and sample 'memory' effect. A new version of the microwave ion source, optimized for AMS, is also described. The report concludes with some predictions of new research opportunities that will become accessible to the technique of continuous-flow AMS. (author)

  4. Development of electrospray ionization of biomolecules on a magnetic sector mass spectrometer

    The initial part of this study involves developments made on an electrospray ionization (ESI) source installed on a large-scale double-focusing reverse-geometry two-sector mass spectrometer. The practical considerations and some basic theory have been given in this thesis for each of the improvements made to the ESI source. The process of partial re-designing the ion optical system showed that the ion beam was affected by both gas dynamics and by the field penetration from the lenses of the ion optical system in the region immediately after second skimmer. More than one order magnitude stronger ion signal intensities at the mass spectrometer final detector and easier ESI source operation conditions and stable ion signals has been achieved. Mass-analyzed ion kinetic energy spectroscopy (MIKES) of different charge-states of relatively small peptides (substance P and bradykinin) for collision-induced dissociation (CID) and the metastable dissociation was carried out successfully. The translational energy losses caused shifts in the fragment ion peaks in the CID spectra, compared with fragment ion peaks in the metastable dissociation spectra. A major part of the study concerned effects of ESI source condition on the charge state distributions of mass spectra. It has been shown that the ion optical effect of the potential difference (VHCT-S) between the heated stainless steel capillary (HCT) and the first skimmer in the intermediate-pressure region (capillary-skimmer region or orifice-skimmer region) of the ESI source was the main factor in determining the charge state distribution of the ESI mass spectra. The temperature of the HCT and the potential difference between the first skimmer and the second skimmer has been shown to be also important factors. The collision-induced dissociation (or so-called capillary-skimmer dissociation) effect of VHCT-S has been shown to be relatively low in this sector-mass spectrometer ESI source. (author)

  5. A statistical investigation of the mass discrepancy-acceleration relation

    Desmond, Harry

    2016-01-01

    We use the mass discrepancy-acceleration relation (the correlation between the ratio of dark-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 14 statistics which quantify its four most important features: its shape, its scatter, the presence of a "characteristic acceleration scale," and the correlation of its residuals with other galaxy properties. We construct an empirical framework for the galaxy-halo connection in $\\Lambda$CDM to generate predictions for these statistics, starting with conventional correlations (halo abundance matching; AM) and introducing more where required. Comparing to the SPARC data (Lelli, McGaugh & Schombert 2016), we find: 1) The approximate shape of the MDAR is readily reproduced by AM, and there is no evidence that the acceleration at which dark matter becomes negligible has less spread in the data than in AM mocks; 2) Even under conservative assumptions, AM significantly overpredicts the scatter in the...

  6. Global model of longitude/UT variations in thermospheric composition and temperature based on mass spectrometer data

    Hedin, A. E.; Reber, C. A.; Spencer, N. W.; Brinton, H. C.; Kayser, D. C.

    1979-01-01

    Measurements of N2, O, He, and Ar densities from neutral gas mass spectrometers on four satellites and inferred O2 and H densities from an ion mass spectrometer have been combined to produce a model of longitude/UT variations in thermospheric neutral composition and temperature. The longitude/UT model is an extension of the mass spectrometer-incoherent scatter thermospheric model (Hedin et al., 1977) and uses spherical harmonic terms dependent on geographic latitude, longitude, and UT. The combined longitude and UT variations reflect the influence of the geomagnetic field but indicate that the variations may not simply be represented in magnetic coordinates.

  7. Development of a dedicated isotope mass spectrometer for the noninvasive diagnostics of humans infected with Helicobacter Pylori

    Blashenkov, N. M.; Sheshenya, E. S.; Solov'ev, S. M.; Gall', L. N.; Sachenko, V. M.; Zarutskii, I. V.; Gall', N. R.

    2013-06-01

    A dedicated isotope mass spectrometer for the noninvasive diagnostics of humans infected with Helicobacter Pylori using the isotope respiratory test is developed. A low-aberration mass analyzer is calculated, an input system that makes it possible to eliminate the memory effects is developed, and a small-size ion detector is constructed. The mass spectrometer is created, and the tests are performed. The measurement accuracy of the 13C/12C and 16O/18O isotope ratios are 1.7 and 2.2‰, respectively. Preliminary medical tests show that the spectrometer can be employed for the desired diagnostics.

  8. Preliminary description of a dedicated commercial ultra-sensitive mass spectrometer for direct atom counting of 14C

    A description is presented of a commercial, tandem-accelerator centered secondary ion double mass spectrometer dedicated to 14C/13C/12C ratio measurements. Some design philosophy of the instrument is presented and the performance is described. A scanning cesium ion source with primary beam diameters between 100 to 200 micrometers is used to produce C- beam intensities of 10 to 20μA with the intensities remaining constant to better than 0.1% per minute after the source stabilizes. For recent carbon, these currents correspond to 14C count rates from the ion source of 60 to 120 particles per second. Resolution of the first mass defining system, M/ΔM, is greater than 120 with the capability of rapid mass switching between isotopes. The measured isotopic ratios at the ion source for carbon are constant to better than 0.25%. The virtues of the 3MV parallel-fed Cockroft-Walton accelerator supply are presented. At the operating voltage of 2.5MV, the stability is better than 1:4000 with a terminal ripple 13C3+ and 12C3+ ions which originate from mass-14 molecular ions are measured to be 3.6mm away from the beam axis and so can be completely eliminated by the slits. Isotopic ratios have been measured beyond these slits, and it is shown that these ratios are constant to better than half a percent using recent samples. The final strong focusing magnet has a rejection ratio for unwanted carbon ions greater than 107

  9. Design and realization of a space-borne reflectron time of flight mass spectrometer: electronics and measuring head

    The purpose of this thesis is the design of the electronics of a time of flight mass spectrometer, the making and the vacuum tests of a prototype which can be put onboard a satellite. A particular effort was necessary to decrease to the maximum the mass and electric consumption of the spectrometer, which led to the development of new circuits. The work completed during this thesis initially concerns the electronics of the measuring equipment which was conceived in a concern for modularity. A complete 'reflectron' type mass spectrometer was then designed, simulated and developed. The built prototype, which uses the developed electronics, was exposed to ion flows of different masses and energies in the CESR vacuum chambers. Its measured performances validate the implemented principles and show that an identical mass spectrometer can be put onboard a satellite with profit, for planetary or solar missions. (author)

  10. Report of the consultants' meeting on accelerator mass spectrometry

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. Its use within the IAEA is recommended by the consultants in this meeting. The IAEA programs in which the technology would be useful and beneficial are: safeguards, physical and chemical sciences, human health, food and agriculture, radioactive waste management, radiation safety, industry and earth sciences

  11. Accelerator mass spectrometry for quantitative in vivo tracing

    Vogel, J S

    2005-04-19

    Accelerator mass spectrometry (AMS) counts individual rare, usually radio-, isotopes such as radiocarbon at high efficiency and specificity in milligram-sized samples. AMS traces very low chemical doses ({micro}g) and radiative doses (100 Bq) of isotope labeled compounds in animal models and directly in humans for pharmaceutical, nutritional, or toxicological research. Absorption, metabolism, distribution, binding, and elimination are all quantifiable with high precision after appropriate sample definition.

  12. Electric and magnetic field optimization procedure for Penning trap mass spectrometers

    Beck, D; Bollen, G; Delahaye, P; George, S; Guénaut, C; Herfurth, F; Herlert, A; Lunney, D; Schweikhard, L; Yazidjian, C

    2009-01-01

    Significant systematic errors in high-precision Penning trap mass spectrometry can result from electric and magnetic field imperfections. An experimental procedure to minimize these uncertainties is presented for the on-line Penning trap mass spectrometer ISOLTRAP, located at ISOLDE/CERN. The deviations from the ideal magnetic and electric fields are probed by measuring the cyclotron frequency and the reduced cyclotron frequency, respectively, of stored ions as a function of the time between the ejection of ions from the preparation trap and their capture in the precision trap, which influences the energy of their axial motion. The correction parameters are adjusted to minimize the frequency shifts.

  13. Solid Phase Microextraction and Miniature Time-of-Flight Mass Spectrometer

    Hiller, j.m.

    1999-01-26

    A miniature mass spectrometer, based on the time-of-flight principle, has been developed for the detection of chemical warfare agent precursor molecules. The instrument, with minor modifications, could fulfill many of the needs for sensing organic molecules in various Defense Programs, including Enhanced Surveillance. The basic footprint of the instrument is about that of a lunch box. The instrument has a mass range to about 300, has parts-per-trillion detection limits, and can return spectra in less than a second. The instrument can also detect permanent gases and is especially sensitive to hydrogen. In volume, the device could be manufactured for under $5000.

  14. Acceleration and Deceleration of Coronal Mass Ejection (CME) Propagation

    Shen, F.; Wu, S.; Feng, X. S.; Wu, C.

    2011-12-01

    A major challenge to the space weather forecasting community is accurate prediction of coronal mass ejections (CME) induced Shock Arrival Time (SAT) at Earth's environment. In order to improve the current accuracy, it is necessary to understand the physical processes of the acceleration and deceleration of the CME propagation in the heliosphere. We present a three-dimensional (3D) magnetohydrodynamic (MHD) simulation of the evolution of two interacting CMEs in a realistic ambient solar wind for the March 28-31, 2001 event. The forces which caused the acceleration and deceleration are analyzed in detail. The force which caused the acceleration are Lorenz force and pressure gradient and the forces which caused the deceleration are aerodynamic drag and the Sun's gravity. In addition the momentum exchange between the solar wind and the moving CMEs can cause acceleration and deceleration of the CME which are now analyzed. In this specific CME event (March 28-31, 2001), we also investigate the interactions of two CMEs causing the acceleration and deceleration of the CMEs.

  15. Accelerator mass spectrometry of ultra-small samples with applications in the biosciences

    Salehpour, Mehran, E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, PO Box 516, SE-751 20 Uppsala (Sweden); Hakansson, Karl; Possnert, Goeran [Department of Physics and Astronomy, Ion Physics, PO Box 516, SE-751 20 Uppsala (Sweden)

    2013-01-15

    An overview is presented covering the biological accelerator mass spectrometry activities at Uppsala University. The research utilizes the Uppsala University Tandem laboratory facilities, including a 5 MV Pelletron tandem accelerator and two stable isotope ratio mass spectrometers. In addition, a dedicated sample preparation laboratory for biological samples with natural activity is in use, as well as another laboratory specifically for {sup 14}C-labeled samples. A variety of ongoing projects are described and presented. Examples are: (1) Ultra-small sample AMS. We routinely analyze samples with masses in the 5-10 {mu}g C range. Data is presented regarding the sample preparation method, (2) bomb peak biological dating of ultra-small samples. A long term project is presented where purified and cell-specific DNA from various part of the human body including the heart and the brain are analyzed with the aim of extracting regeneration rate of the various human cells, (3) biological dating of various human biopsies, including atherosclerosis related plaques is presented. The average built up time of the surgically removed human carotid plaques have been measured and correlated to various data including the level of insulin in the human blood, and (4) In addition to standard microdosing type measurements using small pharmaceutical drugs, pre-clinical pharmacokinetic data from a macromolecular drug candidate are discussed.

  16. Enhancing MALDI time-of-flight mass spectrometer performance through spectrum averaging.

    Morgan Mitchell

    Full Text Available Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrometers are simple and robust mass spectrometers used for analysis of biologically relevant molecules in diverse fields including pathogen identification, imaging mass spectrometry, and natural products chemistry. Despite high nominal resolution and accuracy, we have observed significant variability where 30-50% of individual replicate measurements have errors in excess of 5 parts-per-million, even when using 5-point internal calibration. Increasing the number of laser shots for each spectrum did not resolve this observed variability. What is responsible for our observed variation? Using a modern MALDI-TOF/TOF instrument, we evaluated contributions to variability. Our data suggest a major component of variability is binning of the raw flight time data by the electronics and clock speed of the analog-to-digital (AD detection system, which requires interpolation by automated peak fitting algorithms and impacts both calibration and the observed mass spectrum. Importantly, the variation observed is predominantly normal in distribution, which implies multiple components contribute to the observed variation and suggests a method to mitigate this variability through spectrum averaging. Restarting the acquisition impacts each spectrum within the electronic error of the AD detector system and defines a new calibration function. Therefore, averaging multiple independent spectra and not a larger number of laser shots leverages this inherent binning error to mitigate variability in accurate MALDI-TOF mass measurements.

  17. Onsets of nuclear deformation from measurements with the Isoltrap mass spectrometer

    Mass measurements provide important information concerning nuclear structure. This work presents results from the pioneering Penning trap spectrometer Isoltrap at CERN-Isolde. High-precision mass measurements of neutron-rich manganese (58-66Mn) and krypton isotopes (96,97Kr) are presented, of which the 66Mn and 96,97Kr masses are measured for the first time. In particular, the mass of 97Kr was measured using the preparation trap and required the definition of a new fit function. In the case of the manganese isotopes, the N=40 shell closure is addressed. The two-neutron-separation energies calculated from the new masses show no shell closure at N=40 but give an estimation of the proton-neutron interaction (around 0.5 MeV) responsible for the increase of collectivity and nuclear deformation in this mass region. The new krypton masses show behavior in sharp contrast with heavier neighbors where sudden and intense deformation is present, interpreted as the establishment of a nuclear quantum shape/phase transition critical-point boundary. The new masses confirm findings from nuclear mean-square charge-radius measurements up to N=60 but are at variance with conclusions from recent gamma-ray spectroscopy. Another part of this work was the design of new decay spectroscopy system behind the Isoltrap mass spectrometer. The beam purity achievable with Isoltrap will allow decay studies with and β detection coupled to a tape-station. This system has been mounted and commissioned with the radioactive beam 80Rb. (author)

  18. In Situ Geochemical Analysis and Age Dating of Rocks Using Laser Ablation-Miniature Mass Spectrometer

    Sinha, Mahadeva P.; Hecht, Michael H.; Hurowitz, Joel A.

    2012-01-01

    A miniaturized instrument for performing chemical and isotopic analysis of rocks has been developed. The rock sample is ablated by a laser and the neutral species produced are analyzed using the JPL-invented miniature mass spectrometer. The direct sampling of neutral ablated material and the simultaneous measurement of all the elemental and isotopic species are the novelties of this method. In this laser ablation-miniature mass spectrometer (LA-MMS) method, the ablated neutral atoms are led into the electron impact ionization source of the MMS, where they are ionized by a 70-eV electron beam. This results in a secondary ion pulse typically 10-100 microsecond wide, compared to the original 5-10-nanosecond laser pulse duration. Ions of different masses are then spatially dispersed along the focal plane of the magnetic sector of the miniature mass spectrometer and measured in parallel by a modified CCD (charge-coupled device) array detector capable of detecting ions directly. Compared to conventional scanning techniques, simultaneous measurement of the ion pulse along the focal plane effectively offers a 100% duty cycle over a wide mass range. LAMMS offers a more quantitative assessment of elemental composition than techniques that detect laser-ionized species produced directly in the ablation process because the latter can be strongly influenced by matrix effects that vary with the structure and geometry of the surface, the laser beam, and the ionization energies of the elements. The measurement of high-precision isotopic ratios and elemental composition of different rock minerals by LAMMS method has been demonstrated. The LA-MMS can be applied for the absolute age determination of rocks. There is no such instrument available presently in a miniaturized version that can be used for NASA space missions. Work is in progress in the laboratory for geochronology of rocks using LA-MMS that is based on K-Ar radiogenic dating technique.

  19. 36Chlorine accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator. RSP-12

    Accelerator mass spectrometry (AMS) is an ultra sensitive means of counting individual atoms having sufficiently long half life and available in small amount. The 14 UD Pelletron Accelerator is an ideal machine to carry out AMS studies with heavy isotopes like 36Cl and 129I. Cosmogenic radio isotope 36Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36Cl transport mechanism studies of Arctic Alpine ice core etc. As a part of the ongoing AMS programme at 14UD Pelletron Accelerator Facility, Mumbai, a segmented gas detector developed for identification of 36Cl was tested for performance. Recently a beam chopper required for this measurement has been developed. 36Cl measurements carried out to detect and measure the ratio of 36Cl to 35Cl in an irradiated sample and dated sample are reported in this paper

  20. 233U mass yield measurements around and within the symmetry region with the ILL Lohengrin spectrometer

    Chebboubi, A.; Kessedjian, G.; Sage, C.; Bernard, D.; Blanc, A.; Faust, H.; Köster, U.; Litaize, O.; Mutti, P.; Serot, O.

    2016-03-01

    The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. The LPSC in collaboration with ILL and CEA has developed a measurement program on fission fragment distributions at the Lohengrin spectrometer of the ILL, with a special focus on the masses constituting the heavy peak. We will present in this paper our measurement of the very low fission yields in the symmetry mass region and the heavy mass wing of the distribution for 233U thermal neutron induced fission. The difficulty due to the strong contamination by other masses with much higher yields will be addressed in the form of a new analysis method featuring the required contaminant correction. The apparition of structures in the kinetic energy distributions and possible interpretations will be discussed, such as a possible evidence of fission modes.

  1. Matrix-assisted laser desorption of biological molecules in the quadrupole ion trap mass spectrometer

    Chambers, D.M.; Goeringer, D.E.; McLuckey, S.A.; Glish, G.L. (Oak Ridge National Laboratory, TN (United States))

    1993-01-01

    Matrix-assisted laser desorption (MALD), which has been proven to be an effective ionization technique for biological molecules, has been implemented on a quadrupole ion trap mass spectrometer (ITMS). In the instrumental configuration used for this work both the sample probe and the laser beam are brought through holes in the ring electrode, thereby enabling MALD-generated ions to expand directly into the ion trap cavity. This approach for directly introducing MALD-generated ions compliments the capabilities of the ITMS to obtain low detection limits and to perform tandem mass spectrometric analysis. For example, detection limits in the single-unit femtomole regime have been achieved for small polypeptides such as leucine enkephalin, bradykinin, and neuromedin U-8. Furthermore, structural information has been acquired via multiple stages of mass spectrometry. One limitation that currently exists is an unanticipated drop in sensitivity and resolution as the mass/charge ratio for ions exceeds 3000. 42 refs., 11 figs., 1 tab.

  2. 233U mass yield measurements around and within the symmetry region with the ILL Lohengrin spectrometer

    Chebboubi A.

    2016-01-01

    Full Text Available The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. The LPSC in collaboration with ILL and CEA has developed a measurement program on fission fragment distributions at the Lohengrin spectrometer of the ILL, with a special focus on the masses constituting the heavy peak. We will present in this paper our measurement of the very low fission yields in the symmetry mass region and the heavy mass wing of the distribution for 233U thermal neutron induced fission. The difficulty due to the strong contamination by other masses with much higher yields will be addressed in the form of a new analysis method featuring the required contaminant correction. The apparition of structures in the kinetic energy distributions and possible interpretations will be discussed, such as a possible evidence of fission modes.

  3. Neutral Mass Spectrometer (NMS) for the Lunar Atmosphere and Dust Environment Explorer (LADEE) Mission

    Collier, Michael R.; Mahaffy, Paul R.; Benna, Mehdi; King, Todd T.; Hodges, Richard

    2011-01-01

    The Lunar Atmosphere and Dust Environment Explorer (LADEE) mission currently scheduled for launch in early 2013 aboard a Minotaur V will orbit the moon at a nominal periselene of 50 km to characterized the lunar atmosphere and dust environment. The science instrument payload includes a neutral mass spectrometer as well as an ultraviolet spectrometer and a dust detector. Although to date only He, Ar-40, K, Na and Rn-222 have been firmly identified in the lunar exosphere and arise from the solar wind (He), the lunar regolith (K and Na) and the lunar interior (Ar-40, Rn-222), upper limits have been set for a large number of other species, LADEE Neutral Mass Spectrometer (NMS) observations will determine the abundance of several species and substantially lower the present upper limits for many others. Additionally, LADEE NMS will observe the spatial distribution and temporal variability of species which condense at nighttime and show peak concentrations at the dawn terminator (e,g, Ar-40), possible episodic release from the lunar interior, and the results of sputtering or desorption processes from the regolith. In this presentation, we describe the LADEE NMS hardware and the anticipated science results.

  4. An application of Accelerator Mass Spectrometry to geology

    The radionuclide 10Be is produced in the atmosphere by fragmentation reactions induced by the impact of high energy cosmic protons on N2 and O2 molecules. It arrives to the oceans through wet precipitation and it is then accumulated in deep sea sediments. Therefore, the presence of 10Be in volcanic rocks provides clear evidence that the sediments are being incorporated beneath arcs during the subduction process of the tectonics plates, since the half life of 10Be is too short (1.39 My r,) to be present in the mantle. Accelerator Mass Spectrometry (A MS) is the most sensitive technique for the detection of long lived radioisotopes (or even stable nuclides), being capable of detecting one radioactive atom among 1015 of its stable isotope. The improvement of A MS over the conventional Mass Spectrometry (MS) relies on the use of the tandem accelerator, which ensures the destruction of isobar molecules at the stripper and provides high energy for the discrimination of isobar nuclides. With the purpose of estimate the amount of sediments involved in the subduction process a simply d model was used and the isotopic ratio 10Be/9Be have been measured by A MS in ash samples of three different volcanoes of South America. The measurements were performed in a 3 MV accelerator at VERA (Vienna Environ mental Research Accelerator) by using a 500 nm silicon nitride foil like passive absorber together with a switching magnet in order to reduce the isobaric interference of 10B. Besides, an ionization chamber with segmented anode at the end of the line allowed the discrimination of other interfering particles. The ratios found (10Be/9Be∼ 10-10) are one order of magnitude higher than the reported values in volcanic rocks. It could be due to atmospheric contamination of the samples with 10Be during the eruption. New measurements with samples leached with weak acids are planed to carried out using the TANDAR accelerator

  5. Penning trap mass spectrometry of neutron-rich Fe and Co isotopes around N=40 with the LEBIT mass spectrometer

    Penning trap mass spectrometry is presented as a complementary tool to nuclear spectroscopy experiments for the study of nuclear structure in the vicinity of N=40, Z=28. High-precision mass measurements of the 63-66Fe and 64-67Co isotopes have been carried out with the Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer. The newly obtained mass values for 66Fe and 67Co are presented, together with the previously reported LEBIT mass measurements in this region. In the case of 65Fe the existence of a new isomer is reported, and an isomer recently discovered by decay spectroscopy in 67Co is confirmed. Relative mass uncertainties as low as 4x10-8 are obtained. All mass values are found to be in good agreement with previous experimental results with the exception of 64Co, where a 5σ deviation is observed. Using these data the two neutron separation energies S2n are calculated. However, the large error bars in the mass values of the neighbor Fe and Co isotopes with N>40 complicate the validation of a weak subshell closure at N=40 for the Co isotopes or the possible reduction in the neutron shell gap in the case of the Fe isotopes, in accordance with the theoretical predictions of an onset of deformation in the region.

  6. Rapid Detection of Gas Hazards and Leaks with an Atmospheric Sampling, High Resolution, Mass Spectrometer with Low Pumping Requirements Project

    National Aeronautics and Space Administration — Miniaturization of mass spectrometers is restricted almost exclusively by the ability of small vacuum pumps to remove gas loads during operation of the instrument....

  7. Total evaporation measurements of plutonium with a Thermal Quadrupole Mass Spectrometer (THQ)

    On site verification of isotopic distributions of samples prepared at nuclear reprocessing or fuel fabrication plants requires a measurement procedure which is as independent as possible from varying sample preparation procedures or sample concentrations. With conventional peak jumping data collection, mass fractionation effects are dependent upon the total mass of sample taken and amount of that sample evaporated. This requires the sample concentrations to be maintained in a narrow range to allow accurate correction of the fractionation. This effect can be reduced or eliminated if the ion currents or relative ion ratios are summed while the sample is totally evaporated. Measurement of the ion currents for a total evaporation of the sample using a single collector requires a mass spectrometer capable of rapidly scanning or peak jumping the isotopes of interest. This is accomplished using a quadrupole mass spectrometer. A software package written to give a special peak jumping sequence combined with incremental increases of evaporation (sample) filament current makes it possible to evaporate about 98% of the sample. The amount of Pu on the filament is 100 nanograms. Reproducibility of the 240/239 of 0.3% and accuracies of 0.2% (coefficients of variation) have been measured. The measurement is described and results of measurement of standards and actual samples are presented. (author)

  8. Accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator. PD-1-2

    Accelerator mass spectrometry (AMS) is an ultra sensitive means of counting individual atoms having sufficiently long half-life and available in small amount. The 14 UD Pelletron Accelerator is an ideal machine to carry out AMS studies with heavy isotopes like 36Cl and 129I. Cosmogenic radioisotope 36Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36Cl transport mechanism studies of Arctic Alpine ice core etc . The AMS programme at the 14 UD Mumbai Pelletron Accelerator has taken off with the installation of the state of the art Terminal Potential Stabilizer setup and operation of the accelerator in Generating Volt Meter (GVM) mode. Feasibility studies have been carried out for detection/identification of 14C from a charcoal sample and 3He in natural Helium. As the primary interest of AMS programme at Mumbai Pelletron Accelerator is related to the cosmogenic nuclei, 36Cl and 129I, a segmented gas detector developed for identification of 36Cl was tested for performance. Recently a beam chopper required for this measurement has also been developed

  9. Influence of the coupling between an atmospheric pressure ion mobility spectrometer and the low pressure ion inlet of a mass spectrometer on the mobility measurement

    Gunzer Frank

    2016-01-01

    Full Text Available Ion mobility spectrometers (IMS are versatile gas analyzers. Due to their small size and robustness, combined with a very high sensitivity, they are often used in gas sensing applications such as environmental monitoring. In order to improve the selectivity, they are typically combined with a mass spectrometer (MS. Since IMS works at atmospheric pressure, and MS works at vacuum, a special interface reducing the pressure over normally two stages has to be used. In this paper the influence of this coupling of different pressure areas on the IMS signal will be analyzed with help of finite elements method simulations.

  10. Search for efficient laser resonance ionization schemes of tantalum using a newly developed time-of-flight mass-spectrometer in KISS

    Mukai, M.; Hirayama, Y.; Ishiyama, H.; Jung, H. S.; Miyatake, H.; Oyaizu, M.; Watanabe, Y. X.; Kimura, S.; Ozawa, A.; Jeong, S. C.; Sonoda, T.

    2016-06-01

    The technique of laser resonance ionization is employed for an element-selective ionization of multi-nucleon transfer reaction products which are stopped and neutralized in a gas cell filled with argon gas at 50 kPa. We have been searching for efficient laser ionization schemes for refractory elements of Z = 73-78 using a time-of-flight mass-spectrometer (TOF-MS) chamber. To evaluate the isotope shift and ionization efficiency for each candidate of the ionization scheme, isotope separation using the TOF-MS was devised. The TOF-MS was designed to separate the isotopes using two-stage linear acceleration with a mass resolving power M / ΔM of >350. A mass resolving power of 250 was experimentally confirmed by measuring the TOF of laser-ionized tantalum (Z = 73) ions with mass number 181. We searched for a laser resonance ionization scheme of tantalum using the TOF-MS.

  11. Identification of isomers and control of ionization and dissociation processes using dual-mass-spectrometer scheme and genetic algorithm optimization

    陈洲; 佟秋男; 张丛丛; 胡湛

    2015-01-01

    Identification of acetone and its two isomers, and the control of their ionization and dissociation processes are per-formed using a dual-mass-spectrometer scheme. The scheme employs two sets of time of flight mass spectrometers to simultaneously acquire the mass spectra of two different molecules under the irradiation of identically shaped femtosecond laser pulses. The optimal laser pulses are found using closed-loop learning method based on a genetic algorithm. Com-pared with the mass spectra of the two isomers that are obtained with the transform limited pulse, those obtained under the irradiation of the optimal laser pulse show large differences and the various reaction pathways of the two molecules are selectively controlled. The experimental results demonstrate that the scheme is quite effective and useful in studies of two molecules having common mass peaks, which makes a traditional single mass spectrometer unfeasible.

  12. Ultra-sensitive detection of plutonium by accelerator mass spectrometry

    Fifield, L.K.; Cresswell, R.G.; Ophel, T.R.; Ditada, M. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Day, J.P.; Clacher, A. [Manchester Univ. (United Kingdom). Dept. of Chemistry; Priest, N.D. [AEA Technology, Harwell (United Kingdom)

    1996-12-31

    On the bases of the measurements performed to date, a sensitivity of 10{sup 6} atoms is achievable with accelerator mass spectroscopy (AMS) for each of the plutonium isotopes. Not only does this open the way to the sort of study outlined, but it also makes possible other novel applications, of which two examples are given: (i)the ration of {sup 240}Pu to {sup 239}Pu as a sensitive indicator of the source of the plutonium; (ii) the biochemistry of plutonium in humans. The ultra-sensitive atom counting capability of AMS will make it possible to use the very long-lived {sup 244}Pu (8x10{sup 7}a) in human volunteer studies without any significant increase in radiation body burden. This paper will describe the AMS technique as applied to plutonium using the ANU`s 14UD accelerator, will present the results obtained to date, and will discuss the prospects for the future.

  13. Attomole quantitation of protein separations with accelerator mass spectrometry

    Vogel, J S; Grant, P G; Buccholz, B A; Dingley, K; Turteltaub, K W

    2000-12-15

    Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as 14C to sub-attomole sensitivity. We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5% . Micro-proton-induced-xray-emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phosphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome.

  14. 236U and its measurement with accelerator mass spectrometry

    236U is a long-lived radionuclide with half-life of 2.342(3) x 107 a. The ratio of 236U/238U is about 10-14 in the natural Uranium. The origin and production of 236U in globe are introduced and estimated in this paper, respectively. The major applications of 236U as a 100-million year neutron flux integrator, as a 'fingerprint' for monitoring nuclear environment and nuclear activity,and as a tracer in geological studies are briefly summarized. The accelerator mass spectrometry(AMS) measurement of 236U in the world and the research on HI-13 tandem accelerator at China Institute of Atomic Energy(CIAE) is also mentioned in this paper. (authors)

  15. High-Accuracy Mass Determination of Unstable Nuclei with a Penning Trap Mass Spectrometer.

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  16. Operational Parameters, Considerations, and Design Decisions for Resource-Constrained Ion Trap Mass Spectrometers

    Danell, Ryan M.; VanAmerom, Friso H. W.; Pinnick, Veronica; Cotter, Robert J.; Brickerhoff, William; Mahaffy, Paul

    2011-01-01

    Mass spectrometers are increasingly finding applications in new and unique areas, often in situations where key operational resources (i.e. power, weight and size) are limited. One such example is the Mars Organic Molecule Analyzer (MOMA). This instrument is a joint venture between NASA and the European Space Agency (ESA) to develop an ion trap mass spectrometer for chemical analysis on Mars. The constraints on such an instrument are significant as are the performance requirements. While the ideal operating parameters for an ion trap are generally well characterized, methods to maintain analytical performance with limited power and system weight need to be investigated and tested. Methods Experiments have been performed on two custom ion trap mass spectrometers developed as prototypes for the MOMA instrument. This hardware consists of quadrupole ion trap electrodes that are 70% the size of common commercial instrumentation. The trapping RF voltage is created with a custom tank circuit that can be tuned over a range of RF frequencies and is driven using laboratory supplies and amplifiers. The entire instrument is controlled with custom Lab VIEW software that allows a high degree of flexibility in the definition of the scan function defining the ion trap experiment. Ions are typically generated via an internal electron ionization source, however, a laser desorption source is also in development for analysis of larger intact molecules. Preliminary Data The main goals in this work have been to reduce the power required to generate the radio frequency trapping field used in an ion trap mass spectrometer. Generally minimizing the power will also reduce the volume and mass of the electronics to support the instrument. In order to achieve optimum performance, commercial instruments typically utilize RF frequencies in the 1 MHz range. Without much concern for power usage, they simply generate the voltage required to access the mass range of interest. In order to reduce the

  17. An indigenous cluster beam apparatus with a reflectron time-of-flight mass spectrometer

    G Raina; G U Kulkarni; R T Yadav; V S Ramamurthy; C N R Rao

    2000-04-01

    The design and fabrication of a Smalley-type cluster source in combination with a reflectron based time-of-flight (TOF) mass spectrometer are reported. The generation of clusters is based on supersonic jet expansion of the sampling plume. Sample cells for both liquid and solid targets developed for this purpose are described. Two pulsed Nd-YAG lasers are used in tandem, one (532 nm) for target vapourization and the other (355 nm) for cluster ionization. Methanol clusters of nuclearity up to 14 (mass 500 amu) were produced from liquid methanol as the test sample. The clusters were detected with a mass resolution of ~ 2500 in the R-TOF geometry. Carbon clusters up to a nuclearity of 28 were obtained using a polyimide target. The utility of the instrument is demonstrated by carrying out experiments to generate mixed clusters from alcohol mixtures.

  18. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-01-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spe...

  19. Implementation of Ultraviolet Photodissociation on a Benchtop Q Exactive Mass Spectrometer and Its Application to Phosphoproteomics.

    Fort, Kyle L; Dyachenko, Andrey; Potel, Clement M; Corradini, Eleonora; Marino, Fabio; Barendregt, Arjan; Makarov, Alexander A; Scheltema, Richard A; Heck, Albert J R

    2016-02-16

    Proteomics applications performed on the popular benchtop Q Exactive Orbitrap mass spectrometer have so far relied exclusively on higher collision-energy dissociation (HCD) fragmentation for peptide sequencing. While this fragmentation technique is applicable to a wide range of biological questions, it also has limitations, and all questions cannot be addressed equally well. Here, we demonstrate that the fragmentation capabilities of the Q Exactive mass spectrometer can be extended with ultraviolet photodissociation (UVPD) fragmentation, complete with synchronization triggering to make it compatible with liquid chromatography (LC)/tandem mass spectrometry (MS/MS) workflows. We show that UVPD not only is directly compatible with LC/MS workflows but also, when combined with these workflows, can result in higher database scores and increased identification rates for complex samples as compared to HCD methods. UVPD as a fragmentation technique offers prompt, high-energy fragmentation, which can potentially lead to improved analyses of labile post-translational modifications. Techniques like HCD result in substantial amounts of modification losses, competing with fragmentation pathways that provide information-rich ion fragments. We investigate here the utility of UVPD for identification of phosphorylated peptides and find that UVPD fragmentation reduces the extent of labile modification loss by up to ∼60%. Collectively, when integrated into a complete workflow on the Q Exactive Orbitrap, UVPD provides distinct advantages to the analysis of post-translational modifications and is a powerful and complementary addition to the proteomic toolbox. PMID:26760441

  20. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

    Jjunju, Fred P M

    2013-01-01

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

  1. GoAmazon 2014/15 Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) Field Campaign Report

    Smith, JN [Univ. of California, Irvine, CA (United States)

    2016-04-01

    The Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) deployment to the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility T3 site in Manacapuru, Brazil, was motivated by two main scientific objectives of the Green Ocean Amazon (GoAmazon) 2014/15 field campaign. 1) Study the interactions between anthropogenic and biogenic emissions by determining important molecular species in ambient nanoparticles. To address this, TDCIMS data will be combined with coincident measurements such as gas-phase sulfuric acid to determine the contribution of sulfuric acid condensation to nucleation and growth. We can then compare that result to TDCIMS-derived nanoparticle composition to determine the fraction of growth that can be attributed to the uptake of organic compounds. The molecular composition of sampled particles will also be used to attribute specific chemical species and mechanisms to growth, such as the condensation of low-volatility species or the oligomerization of α-dicarbonyl compounds. 2) Determine the source of new ambient nanoparticles in the Amazon. The hypothesis prior to measurements was that potassium salts formed from the evaporation of primary particles emitted by fungal spores can provide a unique and important pathway for new particle production in the Amazon basin. To explore this hypothesis, the TDCIMS recorded the mass spectra of sampled ambient particles using a protonated water cluster Chemical Ionization Mass Spectrometer (CIMS). Laboratory tests performed using potassium salts show that the TDCIMS can detect potassium with high sensitivity with this technique.

  2. Development of electrospray ionization of biomolecules on a magnetic sector mass spectrometer

    Zhang, Y

    2002-01-01

    The initial part of this study involves developments made on an electrospray ionization (ESI) source installed on a large-scale double-focusing reverse-geometry two-sector mass spectrometer. The practical considerations and some basic theory have been given in this thesis for each of the improvements made to the ESI source. The process of partial re-designing the ion optical system showed that the ion beam was affected by both gas dynamics and by the field penetration from the lenses of the ion optical system in the region immediately after second skimmer. More than one order magnitude stronger ion signal intensities at the mass spectrometer final detector and easier ESI source operation conditions and stable ion signals has been achieved. Mass-analyzed ion kinetic energy spectroscopy (MIKES) of different charge-states of relatively small peptides (substance P and bradykinin) for collision-induced dissociation (CID) and the metastable dissociation was carried out successfully. The translational energy losses ...

  3. A Rugged Miniature Mass-Spectrometer for Aqueous Geochemistry on Mars

    Stockstill, K.; Anderson, F.; Pilger, E.; McMurtry, G.; French, L.

    2005-12-01

    Introduction: We are attempting to miniaturize and shock-harden an electrospray ionization rotating field mass spectrometer (ESI-RFMS) for high precision measurements of aqueous geochemistry on Mars. The design is based on a mass spectrometer system currently being used in situ in deep ocean applications (McMurtry & Smith, 2001). It has the strengths of being small, low power, low mass, requires no precision machining, and is tolerant of moderate vacuum. A prototype RFMS instrument has been shock tested to 1200 without degrading performance. ESI-RFMS is a soft-ionization technique, allowing for the measurement of molecules with large masses, and thus is an attractive experimental methodology for aqueous geochemical analysis enabling in situ measurements of potential chemical, isotopic, and biologic signatures. For example, ESI-RFMS could determine the geochemistry and origin of near-surface deposits of ice, such as those in the northern lowlands of Mars. In addition, ESI-RFMS could examine the record of aqueous alteration contained in the compositions and mineralogy of surface materials and in the compositions of liquid water and ice on Mars. Furthermore, ESI-RFMS analyses of water could detect heavy organic compounds commonly associated with life. Results: Work to date has focused on the development of a vacuum ESI-RFMS to study heavy compounds in water directly. The ESI-RFMS design concept has now been tested under a wide variety of vacuum conditions and sample delivery pressures, as well as under a wide range of electrical conditions and sample chemistries. We have also tested the RFMS mass filter using an off-the-shelf electron impact (EI) ionizer, which has proved the new RFMS concepts of mass filtering and ion beam control, as well as significant advances in noise reduction. A critical issue that evolved from this work is the importance of a well-focused beam of ions for RFMS mass filters versus other similar but less capable spectrometers like the standard

  4. Onsets of nuclear deformation from measurements with the Isoltrap mass spectrometer

    Naimi, Sarah

    Mass measurements provide important information concerning nuclear structure. This work presents results from the pioneering Penning trap spectrometer ISOLTRAP at CERN-ISOLDE. High-precision mass measurements of neutron-rich manganese ($^{58−66}$Mn) and krypton isotopes ($^{96,97}$Kr) are presented, of which the $^{66}$Mn and $^{96,97}$Kr masses are measured for the first time. In particular, the mass of $^{97}$Kr was measured using the preparation trap and required the definition of a new fit function. In the case of the manganese isotopes, the N = 40 shell closure is addressed. The two-neutron-separation energies calculated from the new masses show no shell closure at N = 40 but give an estimation of the proton-neutron interaction (around 0.5 MeV) responsible for the increase of collectivity and nuclear deformation in this mass region. The new krypton masses show behavior in sharp contrast with heavier neighbors where sudden and intense deformation is present, interpreted as the establishment of a nuclea...

  5. Performance evaluation of a resonance ionization mass spectrometer developed for the FFDL system of fast reactors

    To prevent a fuel failure event from becoming a serious radiation accident, sodium-cooled fast reactors are equipped with a system for failed fuel detection and location (FFDL). The FFDL instrument employed in the prototype fast breeder reactor Monju is based on the gas tagging method, in which precise and accurate measurements of krypton and xenon isotope ratios (78Kr/80Kr, 82Kr/80Kr and 126Xe/129Xe) must be performed in a short time. Burnup measurements also contribute to accurate determination of 82Kr/80Kr. We have developed a highly sensitive resonance ionization mass spectrometer for the isotopic analyses, which uses resonance ionization of Kr and Xe atoms by a pulsed laser at wavelengths of 216.7 and 249.6 nm, respectively. In evaluating the performance of our spectrometer, we find that systematic errors caused by isotope shifts can be reduced to negligible levels, and that statistical errors of 3% at a nuclide concentration of 7 ppt can be achieved with a single measurement time of about 40 minutes for each Kr and Xe isotope ratio. This means that, within one hour, about 200 fuel assemblies can be individually identified with a probability of 99%, verifying the applicability of our spectrometer to the FFDL system of fast reactors. (author)

  6. Precision system of the magnetic field stabilization of mass-spectrometer

    Full text: In the report the development of the magnetic field stabilization system of the INP AS RUz mass - spectrometer, created on the basis of the device Sh-1-1, is presented [1]. The necessity for such development was caused by a moral and physical deterioration of the existing equipment. Existing system of the mass- spectrometer magnetic field stabilization already qualitatively did not correspond to the requirements of experiments directed on search not enough of intensive modes of heavy nuclei fission under action of reactor neutrons [2]. Such experiments require for the statistical accuracy of long expositions and, hence, of maintenance of the magnetic field stability in limits ± 0,001% - ± 0,002 % in a working range from 0,15 T up to 0,6 T and the necessity in the precision system of the mass - spectrometer magnetic field stabilization is obvious. For the decision of a task the variant of a compound power unit (PU) with three-step system of magnetic field stabilization on its basis was chosen, thus all three steps of the magnetic field stabilization system is worked on the basic winding of an electromagnet. The feed of PU is carried out from a network of 220 V with the entrance step of the crude stabilization on the basis of the electromechanical regulator, which the shaft is set in motion by the electric motor. Signals of the control of the electric motor are manufactured by the watch scheme. The first and second step of stabilization provide installation and maintenance of constant value of a feed current of a winding with accuracy not worse than 0,1 %. The function of stabilization with required accuracy of a magnetic field in a backlash of magnetic system is provided with the third step of stabilization. For maintenance of required accuracy of measurement of a magnetic field induction in a working backlash of a magnet by us was modified standard device Sh1-1, and the block of quartz stabilization of the frequency of generator (BQSGF) for given

  7. Isotope ratio analysis by a combination of element analyzer and mass spectrometer

    The use of stable isotope ratios of carbon, nitrogen and sulfur as analytical tool in many fields of research is of growing interest. A method has therefore been developed, consisting in essential of coupling an Elemental Analyzer with an Isotope Mass Spectrometer, which enables the gas preparation of carbon dioxide, nitrogen and sulfur dioxide from any solid or liquid sample in a fast and easy way. Results of carbon isotope measurements in food analysis are presented, whereat it is possible to check origin and treatment of sugar, oils, fats, mineral waters, spirituous liquors etc. and to detect adulterations as well. Also applications in the field of environmental research are given. (Author)

  8. A molecular beam/quadrupole mass spectrometer system with synchronized beam modulation and digital waveform analysis

    Pellett, G. L.; Adams, B. R.

    1983-01-01

    A performance evaluation is conducted for a molecular beam/mass spectrometer (MB/MS) system, as applied to a 1-30 torr microwave-discharge flow reactor (MWFR) used in the formation of the methylperoxy radical and a study of its subsequent destruction in the presence or absence of NO(x). The modulated MB/MS system is four-staged and differentially pumped. The results obtained by the MWFR study is illustrative of overall system performance, including digital waveform analysis; significant improvements over previous designs are noted in attainable S/N ratio, detection limit, and accuracy.

  9. A new tandem mass spectrometer for photofragment spectroscopy of cold, gas-phase molecular ions

    We present here the design of a new tandem mass spectrometer that combines an electrospray ion source with a cryogenically cooled ion trap for spectroscopic studies of cold, gas-phase ions. The ability to generate large ions in the gas phase without fragmentation, cool them to ∼10 K in an ion trap, and perform photofragment spectroscopy opens up new possibilities for spectroscopic characterization of large biomolecular ions. The incorporation of an ion funnel, together with a number of small enhancements, significantly improves the sensitivity, signal stability, and ease of use compared with the previous instrument built in our laboratory.

  10. Microsystem with integrated capillary leak to mass spectrometer for high sensitivity temperature programmed desorption

    Quaade, Ulrich; Jensen, Søren; Hansen, Ole

    2004-01-01

    Temperature programmed desorption (TPD) is a method for obtaining information about quantities and binding properties of adsorbed species on a surface. A microfabricated flow system for TPD with an integrated capillary leak to a mass spectrometer is presented. The use of an integrated capillary.......5 cm2 of platinum foil gives a clear desorption peak. By using the microfabricated flow system, TPD experiments can be performed in a carrier gas with a sensitivity approaching that of TPD experiments in vacuum. ©2004 American Institute of Physics...

  11. Accurate mass measurements of short-lived isotopes with the MISTRAL rf spectrometer

    Toader, C F; Borcea, C; Doubre, H; Duma, M; Jacotin, M; Henry, S; Képinski, J F; Lebée, G; Le Scornet, G; Lunney, M D; Monsanglant, C; De Saint-Simon, M; Thibault, C

    1999-01-01

    The MISTRAL experiment has measured its first masses at ISOLDE. Installed in May 1997, this radiofrequency transmission spectrometer is to concentrate on nuclides with particularly short half-lives. MISTRAL received its first stable beam in October and first radioactive beam in November 1997. These first tests, with a plasma ion source, resulted in excellent isobaric separation and reasonable transmission. Further testing and development enabled first data taking in July 1998 on neutron-rich Na isotopes having half-lives as short as 31 ms.

  12. Alternate technique for simultaneous measurement of photoionization cross-section of isotopes by TOF mass spectrometer

    New measurements of photoionization cross-sections of the lithium isotopes are reported employing a Time of Flight -TOF- mass spectrometer in conjunction with an atomic beam apparatus. Using a two-step selective photoionization and saturation technique, we have simultaneously measured the photoionization cross-section of the 2p excited state of both the isotopes Li6 and Li7 as 15 ± 2.5 Mb and 18 ± 2.5 Mb where the corresponding number densities have been determined as N0 ∼ 5.3*1010 atoms/cm3 and N0 ∼ 6.2*1011 atoms/cm3 respectively. (authors)

  13. Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2015-01-01

    Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides unparalleled mass accuracy and resolving power.[1],[2] With electrospray ionization (ESI), ions are typically transferred into the mass spectrometer through a skimmer, which serves as a conductance-limiting orifice. However, the skimmer allows only a small fraction of incoming ions to enter the mass spectrometer. An ion funnel, originally developed by Smith and coworkers at Pacific Northwest National Laboratory (PNNL)[3-5] provides much more efficient ion focusing and transfer. The large entrance aperture of the ion funnel allows almost all ions emanating from a heated capillary to be efficiently captured and transferred, resulting in nearly lossless transmission.

  14. Accelerator mass spectrometry as a tool in geology and archaeology

    Since its introduction more than twenty years ago, as a new method for 14 C-dating, accelerator mass spectrometry (AMS) has become an increasingly important tool for geologists and archaeologists. The possibility to use samples of a few mg or even smaller samples has opened for new applications in the field of 14 C-dating. Even more important is perhaps that AMS has made other, extremely rare cosmogenic isotopes like 10 Be, 26 Al and 36 Cl available for earth science. Some examples of new applications in geology and archaeology for 14 C and other cosmogenic isotopes will be given. (authors)

  15. 236U measurement with accelerator mass spectrometry at CIAE

    236U is a long-lived radioactive isotope which is produced principally by thermal neutron capture on 235U. 236U may be potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry is presently the most sensitive technique for the measurement of 236U and a measurement method for long-lived heavy ion 236U has been developed. The set-up uses a dedicated injector and the newly proposed 208Pb16O2- molecular ions for the simulation of 236U ion transport. A sensitivity of lower than 10-10 has been achieved for the isotopic ratio 236U/238U in present work.

  16. Application of accelerator mass spectrometry in aluminum metabolism studies

    The recent recognition that aluminum causes toxicity in uremic patients and may be associated with Alzheimer's disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope 26Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as humans. (Author) (24 refs., 3 figs.)

  17. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-07-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  18. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A. [High Temperature Gasdynamics Laboratory, Stanford University, Stanford, California 94305 (United States)

    2013-07-15

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  19. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions

  20. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode.

    Rieker, G B; Poehlmann, F R; Cappelli, M A

    2013-07-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions. PMID:23983449

  1. Extermination Of Uranium Isotopes Composition Using A Micro Computer With An IEEE-488 Interface For Mass Spectrometer Analysis

    A mass spectrometry method can be used to make qualitative or quantitative analysis. For qualitative analysis, identification of unknown materials by a Mass Spectrometer requires definite assignment of mass number to peak on chart. In quantitative analysis, a mass spectrometer is used to determine isotope composition material in the sample. Analysis system of a Mass Spectrometer possession of PPNY-BATAN based on comparison ion current intensity which enter the collector, and have been used to analyse isotope composition. Calculation of isotope composition have been manually done. To increase the performance and to avoid manual data processing, a micro computer and IEEE-488 interface have been installed, also software packaged has been made. So that the determination of the isotope composition of material in the sample will be faster and more efficient. Tile accuracy of analysis using this program on sample standard U3O8 NBS 010 is between 93,87% - 99,98%

  2. Workshop on CEBAF [Continuous Electron Beam Accelerator Facility] spectrometer magnet design and technology: Proceedings

    The planned experimental program at CEBAF includes high-resolution, large acceptance spectrometers and a large toroidal magnetic, detector. In order to take full advantage of the high quality beam characteristics, the performances required will make these devices quite unique instruments compared to existing facilities in the same energy range. Preliminary designs have shown that such performances can be reached, but key questions concerning design concepts and most appropriate and cost-effective technologies had to be answered before going further with the designs. It was the purpose of the Workshop on CEBAF Spectrometer Magnet Design and Technology, organized by the CEBAF Research and Engineering Divisions, to provide the most complete information about the state-of-the-art tools and techniques in magnet design and construction and to discuss the ones most appropriate to the CEBAF spectrometers. In addition, it is expected that this Workshop will be the staring point for further interactions and collaborations between international magnet experts and the CEBAF staff, during the whole process of designing and building the spectrometers

  3. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    In the present work, mass determinations of the eleven neutron-deficient nuclides 99-109Cd, of ten neutron-rich silver nuclides 112,114-121,123Ag, and seven neutron-rich cadmium nuclides 114,120,122-124,126,128Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of 99Cd and 123Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of 100Cd. In the case of a potential isomeric mixture as for 115,117,119Ag and 123Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for 115,117,119Ag and 123Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH+] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass 96Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of 100In were obtained. These mass measurements are an important step towards an understanding of the physics of the rp process that will enable a more reliable determination of the composition

  4. Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometer

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.

    1998-01-01

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.

  5. MOMA Gas Chromatograph-Mass Spectrometer onboard the 2018 ExoMars Mission: results and performance

    Buch, A.; Pinnick, V. T.; Szopa, C.; Grand, N.; Humeau, O.; van Amerom, F. H.; Danell, R.; Freissinet, C.; Brinckerhoff, W.; Gonnsen, Z.; Mahaffy, P. R.; Coll, P.; Raulin, F.; Goesmann, F.

    2015-10-01

    The Mars Organic Molecule Analyzer (MOMA) is a dual ion source linear ion trap mass spectrometer that was designed for the 2018 joint ESA-Roscosmos mission to Mars. The main scientific aim of the mission is to search for signs of extant or extinct life in the near subsurface of Mars by acquiring samples from as deep as 2 m below the surface. MOMA will be a key analytical tool in providing chemical (molecular and chiral) information from the solid samples, with particular focus on the characterization of organic content. The MOMA instrument, itself, is a joint venture for NASA and ESA to develop a mass spectrometer capable of analyzing samples from pyrolysis/chemical derivatization gas chromatography (GC) as well as ambient pressure laser desorption ionization (LDI). The combination of the two analytical techniques allows for the chemical characterization of a broad range of compounds, including volatile and non-volatile species. Generally, MOMA can provide information on elemental and molecular makeup, polarity, chirality and isotopic patterns of analyte species. Here we report on the current performance of the MOMA prototype instruments, specifically the demonstration of the gas chromatographymass spectrometry (GC-MS) mode of operation.

  6. Helium Mass Spectrometer Leak Detection: A Method to Quantify Total Measurement Uncertainty

    Mather, Janice L.; Taylor, Shawn C.

    2015-01-01

    In applications where leak rates of components or systems are evaluated against a leak rate requirement, the uncertainty of the measured leak rate must be included in the reported result. However, in the helium mass spectrometer leak detection method, the sensitivity, or resolution, of the instrument is often the only component of the total measurement uncertainty noted when reporting results. To address this shortfall, a measurement uncertainty analysis method was developed that includes the leak detector unit's resolution, repeatability, hysteresis, and drift, along with the uncertainty associated with the calibration standard. In a step-wise process, the method identifies the bias and precision components of the calibration standard, the measurement correction factor (K-factor), and the leak detector unit. Together these individual contributions to error are combined and the total measurement uncertainty is determined using the root-sum-square method. It was found that the precision component contributes more to the total uncertainty than the bias component, but the bias component is not insignificant. For helium mass spectrometer leak rate tests where unit sensitivity alone is not enough, a thorough evaluation of the measurement uncertainty such as the one presented herein should be performed and reported along with the leak rate value.

  7. Cold cathode field emitter array on a quadrupole mass spectrometer: Route to miniaturization

    We have improved the quadrupole mass spectrometer by substituting the conventional hot filament electron source by a field emitter array (FEA). Elimination of the hot filament avoids a number of common problems, including thermal cracking of delicate molecules, outgassing of the filament itself and nearby components, high power requirements for the filament, large size, stray light, stray magnetic fields, contamination by thoria and tungsten, and a long warm-up time. The advantages are clearest for portable applications where power requirements dominate. Here, the power savings are not just in eliminating the filament supply, but more important in reducing the largest component of the system, the vacuum pump. This comes about because the filament is the primary gas load and because chemical reactions taking place on it require fast pumping to keep the products from interfering with the spectra. Comparison between hot filament and cold cathode FEA ionization is made using a quadrupole mass spectrometer fitted with both electron sources, independently controlled. The FEA advantage is strongest when the ultrahigh vacuum system is throttled to a low pumping speed, mimicking a portable system with a small pump. FEAs also enable miniaturization and a corresponding decrease in pump size. Moreover, with miniaturization, shorter mean free paths and consequently higher working pressures can be tolerated further decreasing pump requirements. copyright 1999 American Vacuum Society

  8. Laser Ablation Mass Spectrometer (LAMS) as a Standoff Analyzer in Space Missions for Airless Bodies

    Li, X.; Brinckerhoff, W. B.; Managadze, G. G.; Pugel, D. E.; Corrigan, C. M.; Doty, J. H.

    2012-01-01

    A laser ablation mass spectrometer (LAMS) based on a time-of-flight (TOF) analyzer with adjustable drift length is proposed as a standoff elemental composition sensor for space missions to airless bodies. It is found that the use of a retarding potential analyzer in combination with a two-stage reflectron enables LAMS to be operated at variable drift length. For field-free drift lengths between 33 cm to 100 cm, at least unit mass resolution can be maintained solely by adjustment of internal voltages, and without resorting to drastic reductions in sensitivity. Therefore, LAMS should be able to be mounted on a robotic arm and analyze samples at standoff distances of up to several tens of cm, permitting high operational flexibility and wide area coverage of heterogeneous regolith on airless bodies.

  9. Expert systems technology applied to instrument operation and data acquisition of a triple quadrupole mass spectrometer (TQMS)

    This presentation covers the work done at Lawrence Livermore National Laboratory by some computer programmers and analytical chemists specializing in mass spectrometry to develop an expert system for real-time tuning and optimization of operations of a triple quadrupole mass spectrometer (TQMS). This capability is important to increase the sensitivity possible for selected compounds throughout the entire mass range of the instrument, rather than settling for the traditional normalized calibration which lowers sensitivity at both ends of the mass scale

  10. Highly miniaturized laser ablation time-of-flight mass spectrometer for a planetary rover

    We report the development and testing of a highly miniaturized mass spectrometer and ion source intended to be deployed on an airless planetary surface to measure the elemental and isotopic composition of solids, e.g., rocks and soils. Our design concentrates at this stage on the proposed BepiColombo mission to the planet Mercury. The mass analyzer is a novel combination of an electrostatic analyzer and a reflectron time-of-flight design. The ion source utilizes a laser induced plasma, which is directly coupled into the mass analyzer. Laser ablation gives high spatial resolution and avoids the need for sample preparation. Our prototype instrument has a demonstrated mass resolution m/Δm full width at half maximum in excess of 180 and a predicted dynamic range of better than five orders of magnitude. We estimate that a flight instrument would have a mass of 280 g (including laser and all electronics), a volume of 84 cm3, and could operate on 3 W power

  11. Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

    Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

    2016-01-01

    Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

  12. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    Breitenfeldt, Martin

    2009-07-03

    In the present work, mass determinations of the eleven neutron-deficient nuclides {sup 99-109}Cd, of ten neutron-rich silver nuclides {sup 112,114-121,123}Ag, and seven neutron-rich cadmium nuclides {sup 114,120,122-124,126,128}Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of {sup 99}Cd and {sup 123}Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of {sup 100}Cd. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH{sup +}] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass {sup 96}Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of {sup 100}In were obtained. These mass measurements are an important step towards an understanding of the physics of

  13. A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments

    Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accuracy are limited by the convolved transverse spot size and pointing jitter of the beam. In this paper we present an electron energy spectrometer consisting of two magnets designed specifically for laser wakefield experiments. In the primary magnet the field is produced by permanent magnets. A second optional electromagnet can be used to obtain better resolution for electron energies above 75 MeV. The spectrometer has an acceptance of 2.5-400 MeV (Emax/Emin>100) with a resolution of better than 1% rms for electron energies above 25 MeV. This high resolution is achieved by refocusing electrons in the energy plane and without any postprocessing image deconvolution. Finally, the spectrometer employs two complimentary detection mechanisms: (1) absolutely calibrated scintillation screens imaged by cameras outside the vacuum chamber and (2) an array of scintillating fibers coupled to a low-noise charge-coupled device.

  14. THE MECHANICAL AND SHIELDING DESIGN OF A PORTABLE SPECTROMETER AND BEAM DUMP ASSEMBLY AT BNLS ACCELERATOR TEST FACILITY

    A portable assembly containing a vertical-bend dipole magnet has been designed and installed immediately down-beam of the Compton electron-laser interaction chamber on beamline 1 of the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). The water-cooled magnet designed with field strength of up to 0.7 Tesla will be used as a spectrometer in the Thompson scattering and vacuum acceleration experiments, where field-dependent electron scattering, beam focusing and energy spread will be analyzed. This magnet will deflect the ATF's 60 MeV electron-beam 90o downward, as a vertical beam dump for the Compton scattering experiment. The dipole magnet assembly is portable, and can be relocated to other beamlines at the ATF or other accelerator facilities to be used as a spectrometer or a beam dump. The mechanical and shielding calculations are presented in this paper. The structural rigidity and stability of the assembly were studied. A square lead shield surrounding the assembly's Faraday Cup was designed to attenuate the radiation emerging from the 1 inch-copper beam stop. All photons produced were assumed to be sufficiently energetic to generate photoneutrons. A safety evaluation of groundwater tritium contamination due to the thermal neutron capturing by the deuterium in water was performed, using updated Monte Carlo neutron-photon coupled transport code (MCNP). High-energy neutron spallation, which is a potential source to directly generate radioactive tritium and sodium-22 in soil, was conservatively assessed in verifying personal and environmental safety

  15. The application of simple mass spectrometers to planetary sub-surface sampling using penetrators

    Sheridan, Simon; Morse, Andrew; Bardwell, Max; Barber, Simeon; Wright, Ian

    2010-05-01

    Ptolemy is an ion trap based gas-chromatograph isotope ratio mass spectrometer which is on-board the Rosetta Lander [Wright et al., 2006; Todd et al., 2007]. The instrument uses the principles of MODULUS (Methods of Determining and Understanding Light Elements From Unequivocal Stable Isotope Compositions [Pillinger and Wright, 1993], to enable results obtained in space to be interpreted directly in the context of terrestrial analyses of meteorites and returned samples. MODULUS typically involves use of a complex sample processing system to purify and separate individual species from a complex starting sample, allowing analysis by a relatively simple, low resolution, but stable and precise mass spectrometer instrumentation. A number of exciting future mission opportunities are arising where it is unlikely that it will be feasible to incorporate the full MODULUS-style sample processing system. Of particular interest are missions that offer the opportunity to gain access to surface and sub-surface material through the deployment of mass spectrometers from either high-speed penetrator platforms [Smith et al., 2009] or from sub-surface penetrating mole devices deployed by soft landers [Richter et al., 2003]. We will present work aimed at overcoming the resolution restrictions of ion trap mass spectrometers. It is anticipated that this will enable MODULUS style science return from relatively simple instrumentation which is compatible with the future miniaturised sampling platforms currently under consideration for Mars, asteroids, comets and planetary moons. References: Wright I. P., Barber S. J., Morgan G. H., Morse A. D., Sheridan S., Andrews D. J., Maynard J., Yau D., Evans S. T., Leese M. R., Zarnecki J. C., Kent B. J., Waltham N. R., Whalley M. S., Heys S., Drummond D. L., Edeson R. L., Sawyer E. C., Turner R. F., and Pillinger C. T. (2006). Ptolemy - an instrument to measure stable isotopic ratios of key volatiles on a cometary nucleus. Space Science Reviews, 128

  16. Proof-of-concept development of PXAMS (projectile x-ray accelerator mass spectrometry)

    Proctor, I.D.; Roberts, M.L.; McAninch, J.E.; Bench, G.S.

    1996-03-01

    Prior to the current work, accelerator mass spectrometry (AMS) was limited to a set of {approximately}8--10 isotopes. This limitation is caused primarily by the inability to discriminate against stable atomic isobars. An analysis scheme that combines the isotopic sensitivity of AMS with similar isobar selectivity would open a large new class of isotope applications. This project was undertaken to explore the use of characteristic x rays as a method for the detection and identification of ions,and to allow the post-spectrometer rejection of isobaric interferences for isotopes previously inaccessible to AMS. During the second half of FY94 (with Advanced Concepts funding from the Office of Non-Proliferation and National Security), we examined the feasability of this technique, which we are referring to as PXAMS (Projectile X ray AMS), to the detection of several isotopes at Lawrence Livermore National Laboratory (LLNL). In our first exploratory work, we measured the x ray yield vs energy for {sup 80}Se ions stopped in a thick Y target. These results, demonstrated that useful detection efficiencies could be obtained for Se ions at energies accessible with our accelerator, and that the count rate from target x rays is small compared to the Se K{alpha} rate. We followed these measurements with a survey of x ray yields for Z = 14-46.

  17. Design of Portable Mass Spectrometers with Handheld Probes: Aspects of the Sampling and Miniature Pumping Systems

    Chen, Chien-Hsun; Chen, Tsung-Chi; Zhou, Xiaoyu; Kline-Schoder, Robert; Sorensen, Paul; Cooks, R. Graham; Ouyang, Zheng

    2015-02-01

    Miniature mass spectrometry analytical systems of backpack configuration fitted with sampling probes could potentially be of significant interest for in-field, real-time chemical analysis. In this study, various configurations were explored in which a long narrow tube was used to connect the turbo and backing pumps used to create and maintain vacuum. Also, for the first time we introduced two new types of pumps for miniature mass spectrometers, the Creare 130 g drag pump and Creare 350 g scroll backing pump. These pumps, along with another Creare 550 turbo pump and the commercially available Pfeiffer HiPace 10 turbo and KnF diaphragm backing pumps, were tested with the backpack configurations. The system performance, especially the scan time, was characterized when used with a discontinuous atmospheric pressure interface (DAPI) for ion introduction. The pumping performance in the pressure region above 1 mtorr is critical for DAPI operation. The 550 g turbo pump was shown to have a relatively higher pumping speed above 1 mtorr and gave a scan time of 300 ms, almost half the value obtained with the larger, heavier HiPace 10 often used with miniature mass spectrometers. The 350 g scroll pump was also found to be an improvement over the diaphragm pumps generally used as backing pumps. With a coaxial low temperature plasma ion source, direct analysis of low volatility compounds glass slides was demonstrated, including 1 ng DNP (2,4-Dinitrophenol) and 10 ng TNT (2,4,6-trinitrotoluene) with Creare 550 g turbo pump as well as 10 ng cocaine and 20 ng DNP with Creare 130 g drag pump.

  18. Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions

    We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure (∼10-5 Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarily increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH+, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.

  19. Small-size mass spectrometer for determining gases and volatile compounds in air during breathing

    Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.

    2015-10-01

    We describe an automated mass spectrometer for diagnostics of deceases from the composition of exhaled air. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled air. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static mass analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the mass analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the mass resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.

  20. Role of accelerator mass spectrometry in nuclear physics

    Accelerator Mass Spectrometry (AMS) was developed in nuclear physics laboratories and up to now all experiments were performed at these places. However, AMS is being applied to a variety of fields which have very little to do with nuclear physics. The implications are for its original field can be divided in two domains. First, there are clearly instrumental implications. The overall demand of AMS for high efficiency ion sources, great stability, flexibility, and control of the entire accelerator system is certainly beneficial for the performance of any nuclear physics program. Second, AMS can be conveniently used to determine nuclear quantities of interest when the measurements involves very low radioisotope concentrations. Examples are the half-life measurement of 32Si and the cross section measurement of the 26Mg(p,n)26Al reaction. As the overall detection efficiency will improve there are some interesting problems in nuclear physics and elementary particle physics which are tempting to try. Although most of these experiments are beyond the present capability of AMS, some general aspects are discussed in section 5

  1. Dating of some fossil Romanian bones by accelerator mass spectrometry

    Some fossil bones from Romanian territories have been dated by accelerator mass spectrometry (AMS) using the pelletron system from Lund University. The preparation of samples has been the classical procedure to produce pure graphite from bones specimens, The Paleolithic site from Malu Rosu, near Giurgiu was thoroughly analyzed. Two human fossil skulls from Cioclovina and Baia de Fier of special archaeological importance have been estimated to be of around 30 000 years old, a conclusion with great implications for the history of ancient Romania. By this physical analysis, a long scientific dispute was settled. The two fossil human skulls are the only ones of this age from Romania. One could advance the hypothesis that the skulls belong to a certain type of a branch of Central European Cro-Magon, the classical western type, considering both the chronological and the anthropological features. They constitute eastern limit of the Cro-Magnon man type. (authors)

  2. Studies of Al metabolism in animal by accelerator mass spectrometry

    WangNa-Xiu; ZhuHan-Min; 等

    1997-01-01

    The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with 26Al,killed after 5,10,15,25,and 35d and 26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of 26Al,and the existed Al content and dementia was studied.

  3. 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer: A National Resource for Ultrahigh Resolution Mass Analysis

    Hendrickson, Christopher L.; Quinn, John P.; Kaiser, Nathan K.; Smith, Donald F.; Blakney, Greg T.; Chen, Tong; Marshall, Alan G.; Weisbrod, Chad R.; Beu, Steven C.

    2015-09-01

    We describe the design and initial performance of the first 21 tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The 21 tesla magnet is the highest field superconducting magnet ever used for FT-ICR and features high spatial homogeneity, high temporal stability, and negligible liquid helium consumption. The instrument includes a commercial dual linear quadrupole trap front end that features high sensitivity, precise control of trapped ion number, and collisional and electron transfer dissociation. A third linear quadrupole trap offers high ion capacity and ejection efficiency, and rf quadrupole ion injection optics deliver ions to a novel dynamically harmonized ICR cell. Mass resolving power of 150,000 ( m/Δm 50% ) is achieved for bovine serum albumin (66 kDa) for a 0.38 s detection period, and greater than 2,000,000 resolving power is achieved for a 12 s detection period. Externally calibrated broadband mass measurement accuracy is typically less than 150 ppb rms, with resolving power greater than 300,000 at m/z 400 for a 0.76 s detection period. Combined analysis of electron transfer and collisional dissociation spectra results in 68% sequence coverage for carbonic anhydrase. The instrument is part of the NSF High-Field FT-ICR User Facility and is available free of charge to qualified users.

  4. Development of a Linear Ion Trap Mass Spectrometer (LITMS) Investigation for Future Planetary Surface Missions

    Brinckerhoff, W.; Danell, R.; Van Ameron, F.; Pinnick, V.; Li, X.; Arevalo, R.; Glavin, D.; Getty, S.; Mahaffy, P.; Chu, P.; Zacny, K.; Rogacki, S.; Grubisic, A.; Cornish, T.

    2014-01-01

    Future surface missions to Mars and other planetary bodies will benefit from continued advances in miniature sensor and sample handling technologies that enable high-performance chemical analyses of natural samples. Fine-scale (approx.1 mm and below) analyses of rock surfaces and interiors, such as exposed on a drill core, will permit (1) the detection of habitability markers including complex organics in association with their original depositional environment, and (2) the characterization of successive layers and gradients that can reveal the time-evolution of those environments. In particular, if broad-based and highly-sensitive mass spectrometry techniques could be brought to such scales, the resulting planetary science capability would be truly powerful. The Linear Ion Trap Mass Spectrometer (LITMS) investigation is designed to conduct fine-scale organic and inorganic analyses of short (approx.5-10 cm) rock cores such as could be acquired by a planetary lander or rover arm-based drill. LITMS combines both pyrolysis/gas chromatograph mass spectrometry (GCMS) of sub-sampled core fines, and laser desorption mass spectrometry (LDMS) of the intact core surface, using a common mass analyzer, enhanced from the design used in the Mars Organic Molecule Analyzer (MOMA) instrument on the 2018 ExoMars rover. LITMS additionally features developments based on the Sample Analysis at Mars (SAM) investigation on MSL and recent NASA-funded prototype efforts in laser mass spectrometry, pyrolysis, and precision subsampling. LITMS brings these combined capabilities to achieve its four measurement objectives: (1) Organics: Broad Survey Detect organic molecules over a wide range of molecular weight, volatility, electronegativity, concentration, and host mineralogy. (2) Organic: Molecular Structure Characterize internal molecular structure to identify individual compounds, and reveal functionalization and processing. (3) Inorganic Host Environment Assess the local chemical

  5. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers

    Snyder, Dalton T.; Pulliam, Christopher J.; Wiley, Joshua S.; Duncan, Jason; Cooks, R. Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection.

  6. Multi-Beam Approach for Accelerating Alignment and Calibration of HyspIRI-Like Imaging Spectrometers

    Eastwood, Michael L.; Green, Robert O.; Mouroulis, Pantazis; Hochberg, Eric B.; Hein, Randall C.; Kroll, Linley A.; Geier, Sven; Coles, James B.; Meehan, Riley

    2012-01-01

    A paper describes an optical stimulus that produces more consistent results, and can be automated for unattended, routine generation of data analysis products needed by the integration and testing team assembling a high-fidelity imaging spectrometer system. One key attribute of the system is an arrangement of pick-off mirrors that provides multiple input beams (five in this implementation) to simultaneously provide stimulus light to several field angles along the field of view of the sensor under test, allowing one data set to contain all the information that previously required five data sets to be separately collected. This stimulus can also be fed by quickly reconfigured sources that ultimately provide three data set types that would previously be collected separately using three different setups: Spectral Response Function (SRF), Cross-track Response Function (CRF), and Along-track Response Function (ARF), respectively. This method also lends itself to expansion of the number of field points if less interpolation across the field of view is desirable. An absolute minimum of three is required at the beginning stages of imaging spectrometer alignment.

  7. Gibbs free energy of formation of lanthanum rhodate by quadrupole mass spectrometer

    The ternary oxide in the system La-Rh-O is of considerable importance because of its application in catalysis. Phase equilibria in the pseudo-binary system La2O3-Rh2O3 has been investigated by Shevyakov et. al. Gibbs free energy of LaRhO3(s) was determined by Jacob et. al. using a solid state Galvanic cell in the temperature range 890 to 1310 K. No other thermodynamic data were available in the literature. Hence it was decided to determine Gibbs free energy of formation of LaRhO3(s) by an independent technique, viz. quadrupole mass spectrometer (QMS) coupled with a Knudsen effusion cell and the results are presented

  8. The Neutral Mass Spectrometer on the Lunar Atmosphere and Dust Environment Explorer Mission

    Mahaffy, Paul R.; Richard Hodges, R.; Benna, Mehdi; King, Todd; Arvey, Robert; Barciniak, Michael; Bendt, Mirl; Carigan, Daniel; Errigo, Therese; Harpold, Daniel N.; Holmes, Vincent; Johnson, Christopher S.; Kellogg, James; Kimvilakani, Patrick; Lefavor, Matthew; Hengemihle, Jerome; Jaeger, Ferzan; Lyness, Eric; Maurer, John; Nguyen, Daniel; Nolan, Thomas J.; Noreiga, Felix; Noriega, Marvin; Patel, Kiran; Prats, Benito; Quinones, Omar; Raaen, Eric; Tan, Florence; Weidner, Edwin; Woronowicz, Michael; Gundersen, Cynthia; Battel, Steven; Block, Bruce P.; Arnett, Ken; Miller, Ryan; Cooper, Curt; Edmonson, Charles

    2014-12-01

    The Neutral Mass Spectrometer (NMS) of the Lunar Atmosphere and Dust Environment Explorer (LADEE) Mission is designed to measure the composition and variability of the tenuous lunar atmosphere. The NMS complements two other instruments on the LADEE spacecraft designed to secure spectroscopic measurements of lunar composition and in situ measurement of lunar dust over the course of a 100-day mission in order to sample multiple lunation periods. The NMS utilizes a dual ion source designed to measure both surface reactive and inert species and a quadrupole analyzer. The NMS is expected to secure time resolved measurements of helium and argon and determine abundance or upper limits for many other species either sputtered or thermally evolved from the lunar surface.

  9. Direct Measurement of Atmospheric Ammonia from an Airborne Miniature Chemical Ionization Mass Spectrometer (miniCIMS)

    Casados, K.; Schill, S.; Freeman, S.; Zoerb, M.; Bertram, T. H.; Lefer, B. L.

    2015-12-01

    Ammonia is emitted into the atmosphere from a variety of sources such as trees, ocean, diary fields, biomass burning, and fuel emissions. Previous studies have investigated the environmental impacts of atmospheric ammonia which can include chemical reactivity, nucleation of fine particulate matter 2.5 (PM 2.5 ), and implications for human health, but its chemical nature and relatively short lifetime make direct measurement of atmospheric ammonia difficult. During the 2015 NASA Student Airborne Research Program (SARP) an airborne miniature Chemical Ionization Mass Spectrometer (miniCIMS) was deployed on the NASA DC-8 flying laboratory in the Southern California region. The spatial and temporal variability of measured atmospheric ammonia concentrations will be discussed.

  10. Evaluation of a quadrupole mass spectrometer for the isotopic analysis of uranium hexafluoride

    A quadrupole mass spectrometer was examined for adaptation to the on-stream isotopic analysis of uranium hexafluoride (UF6) in gaseous diffusion cascades. Source modifications, in conjunction with a molecular beam type inlet system and a liquid nitrogen cold trap, made the quadrupole reasonably compatible with UF6 at analyzer pressures of not more than 10-8 torr. Uranium-235/uranium-238 ratios were measured using automatic peak-switching and integrating circuitry. These measurements indicated that the apparent high resolution of the quadrupole could not be realized with UF6, due to inadequate sensitivity and low signal-to-noise ratio. After extensive examination of the system, it was concluded that further efforts to adapt the quadrupole to isotopic analysis of UF6 would be impractical at this stage in quadrupole development. (U.S.)

  11. Interfacing of thermal ionization mass spectrometer with PC/XT and related software development

    A completely automated Thermal Ionization Mass Spectrometer (TIMS), is used in Power Reactor Fuel Reprocessing Plant (PREFRE) Tarapur for precise and accurate measurement of isotopic composition and concentration determination of special nuclear materials (Uranium and Plutonium) for the purpose of input accounting of the plant. It is provided with one Hewlett-Packard, H-9845B desktop computer to control various instrument parameters and perform automatic analysis of 13 samples in sequence. The computer gave fairly good service for six years with intermittent minor maintenance before it developed major problems. In view of the fact that its repair and maintenance cost is several times the cost of locally available computer, it was decided to replace the imported Hewlett-Packard 9845B desktop computer with PC/XT. This report describes the interfacing of TIMS with PC/XT and the related Software development. (author). 3 refs., 8 figs., 2 annexures

  12. Knudsen cell--mass spectrometer studies of cesium--urania interactions

    Limited Knudsen cell--mass spectrometer studies were made of the partial pressures of cesium-containing species [assumed to be primarily Cs(g)] over Cs2CO3 and over phase equilibria involving UO2 and probable Cs-U-O compounds formed from mixtures that initially contained either Cs2CO3-UO2 or CsOH-UO2. Although additional work is required to further define the equilibria involved, the data demonstrate unambiguously a significant reduction in cesium partial pressures due to probable Cs-U-O compound formation and indicate essentially identical behavior with either CsOH or Cs2CO3 as the starting material with UO2

  13. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride

    The continuous mass-spectrometric analysis of impurities in UF6 is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author)

  14. Automatic control of the ion-illumination angle in a spark-source mass spectrometer.

    Conzemius, R J; Svec, H J

    1973-05-01

    Automatic adjustment of only the spark-gap width in a spark-source mass spectrometer does not ensure that optimum conditions of electrode geometry are maintained with respect to the ion-optics system. A device has been developed which simultaneously maintains a constant gap width and also a more constant z-axis ion-illumination angle. This is the first development to utilize ion-optics parameters to adjust the sparking electrodes automatically. The system maintains the electrodes in an optimum configuration such that higher and more constant instrument sensitivity is maintained automatically. In addition, a significant improvement in the precision of instrumental response is demonstrated. It appears that relative isotopic abundances can be determined directly by the spark-source method which are comparable to those obtained in some cases by surface ionization or by electron bombardment. Results are given that support this contention. PMID:18961307

  15. The Neutral Mass Spectrometer on the Lunar Atmosphere and Dust Environment Explorer Mission

    Mahaffy, Paul R.; Hodges, R. Richard; Benna, Mehdi; King, Todd; Arvey, Robert; Barciniak, Michael; Bendt, Mirl; Carigan, Daniel; Errigo, Therese; Harpold, Daniel N.; Holmes, Vincent; Johnson, Christopher S.; Kellogg, James; Kimvilakani, Patrick; Lefavor, Matthew; Hengemihle, Jerome; Jaeger, Ferzan; Lyness, Eric; Maurer, John; Nguyen, Daniel; Nolan, Thomas; Noreiga, Felix; Noreiga, Marvin; Patel, Kiran; Prats, Benito; Quinones, Omar; Raaen, Eric; Tan, Florence; Weidner, Edwin; Woronowicz, Michael; Gundersen, Cynthia (Inventor); Battel, Steven; Block, Bruce P.; Arnett, Ken; Miller, Ryan

    2014-01-01

    The Neutral Mass Spectrometer (NMS) of the Lunar Atmosphere and Dust Environment Explorer (LADEE) Mission is designed to measure the composition and variability of the tenuous lunar atmosphere. The NMS complements two other instruments on the LADEE spacecraft designed to secure spectroscopic measurements of lunar composition and in situ measurement of lunar dust over the course of a 100-day mission in order to sample multiple lunation periods. The NMS utilizes a dual ion source designed to measure both surface reactive and inert species and a quadrupole analyzer. The NMS is expected to secure time resolved measurements of helium and argon and determine abundance or upper limits for many other species either sputtered or thermally evolved from the lunar surface.

  16. Calibration of the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite

    Mahaffy, P. R.; Trainer, M. G.; Eigenbrode, J. L.; Franz, H. B.; Stern, J. C.; Harpold, D.; Conrad, P. G.; Raaen, E.; Lyness, E.

    2011-01-01

    The SAM suite of instruments on the "Curiosity" Rover of the Mars Science Laboratory (MSL) is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The mission of the MSL investigations is to advance beyond the successful search for aqueous transformation in surface environments at Mars toward a quantitative assessment of habitability and preservation through a series of chemical and geological measurements. The SAM suite was delivered in December 2010 (Figure 1) to the Jet Propulsion Laboratory for integration into the Curiosity Rover. We previously outlined the range of SAM solid and gas calibrations implemented or planned and here we discuss a specific set of calibration experiments to establish the response of the SAM Quadrupole Mass Spectrometer (QMS) to the four most abundant gases in the Martian atmosphere CO2, N2, Ar, and O2, A full SAM instrument description and calibration report is presently in preparation.

  17. Electron-Induced Dissociation of Peptides in a Triple Quadrupole Mass Spectrometer Retrofitted with an Electromagnetostatic Cell

    Voinov, Valery G.; Bennett, Samuel E.; Barofsky, Douglas F.

    2015-05-01

    Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupole's resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in the product-ion spectra recorded in this study, as was the case for those recorded in earlier studies with FT ICR mass spectrometers, is currently at the margin of analytical utility. Given that this shortcoming can be remedied, EMS cells incorporated into QqQ or QqTOF mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and clinical samples.

  18. Accelerating and separating mixed beams of ions with similar charge to mass ratio in the CERN ps complex

    This paper reports that sulphur 32 ions were accelerated by the CERN machines to a world record energy of 6.4 TeV. An Electron Cyclotron Resonance source produces sulphur ions as a 5 per cent contamination of an oxygen ion beam. As their charge-to-mass ratios differ by only 5.4 E-4, the two species are not distinguishable by the downstream accelerators (RFQ, Linac 1, PSB), though measurable in a specially equipped spectrometer line. In this way, enough current is available for controlled acceleration at low beta in the PSB. However, at phase transition energy in the PS - about 6 GeV/nucleon (GeV/u) - this synchrotron becomes an extremely fine spectrometer, with sulphur 16+ ions being driven inwards, and oxygen 8+ outwards. This can be used for separating the beams by manipulating the low-level radio-frequency system at transition, so that either oxygen or sulphur is selected. Indeed, the SPS could be fed with a fairly intense oxygen beam for setting-up, and later with some 2E7 sulphur ions per PS cycle. The required RF manipulations, the present understanding on beam dynamics at transition, as well as diagnostic techniques for determining the amount of sulphur are presented

  19. Unmanned Aerial Mass Spectrometer Systems for In-Situ Volcanic Plume Analysis

    Diaz, Jorge Andres; Pieri, David; Wright, Kenneth; Sorensen, Paul; Kline-Shoder, Robert; Arkin, C. Richard; Fladeland, Matthew; Bland, Geoff; Buongiorno, Maria Fabrizia; Ramirez, Carlos; Corrales, Ernesto; Alan, Alfredo; Alegria, Oscar; Diaz, David; Linick, Justin

    2015-02-01

    Technology advances in the field of small, unmanned aerial vehicles and their integration with a variety of sensor packages and instruments, such as miniature mass spectrometers, have enhanced the possibilities and applications of what are now called unmanned aerial systems (UAS). With such technology, in situ and proximal remote sensing measurements of volcanic plumes are now possible without risking the lives of scientists and personnel in charge of close monitoring of volcanic activity. These methods provide unprecedented, and otherwise unobtainable, data very close in space and time to eruptions, to better understand the role of gas volatiles in magma and subsequent eruption products. Small mass spectrometers, together with the world's smallest turbo molecular pump, have being integrated into NASA and University of Costa Rica UAS platforms to be field-tested for in situ volcanic plume analysis, and in support of the calibration and validation of satellite-based remote sensing data. These new UAS-MS systems are combined with existing UAS flight-tested payloads and assets, such as temperature, pressure, relative humidity, SO2, H2S, CO2, GPS sensors, on-board data storage, and telemetry. Such payloads are capable of generating real time 3D concentration maps of the Turrialba volcano active plume in Costa Rica, while remote sensing data are simultaneously collected from the ASTER and OMI space-borne instruments for comparison. The primary goal is to improve the understanding of the chemical and physical properties of emissions for mitigation of local volcanic hazards, for the validation of species detection and abundance of retrievals based on remote sensing, and to validate transport models.

  20. Response of an aerosol mass spectrometer to organonitrates and organosulfates and implications for atmospheric chemistry.

    Farmer, D K; Matsunaga, A; Docherty, K S; Surratt, J D; Seinfeld, J H; Ziemann, P J; Jimenez, J L

    2010-04-13

    Organonitrates (ON) are important products of gas-phase oxidation of volatile organic compounds in the troposphere; some models predict, and laboratory studies show, the formation of large, multifunctional ON with vapor pressures low enough to partition to the particle phase. Organosulfates (OS) have also been recently detected in secondary organic aerosol. Despite their potential importance, ON and OS remain a nearly unexplored aspect of atmospheric chemistry because few studies have quantified particulate ON or OS in ambient air. We report the response of a high-resolution time-of-flight aerosol mass spectrometer (AMS) to aerosol ON and OS standards and mixtures. We quantify the potentially substantial underestimation of organic aerosol O/C, commonly used as a metric for aging, and N/C. Most of the ON-nitrogen appears as NO(x)+ ions in the AMS, which are typically dominated by inorganic nitrate. Minor organonitrogen ions are observed although their identity and intensity vary between standards. We evaluate the potential for using NO(x)+ fragment ratios, organonitrogen ions, HNO(3)+ ions, the ammonium balance of the nominally inorganic ions, and comparison to ion-chromatography instruments to constrain the concentrations of ON for ambient datasets, and apply these techniques to a field study in Riverside, CA. OS manifests as separate organic and sulfate components in the AMS with minimal organosulfur fragments and little difference in fragmentation from inorganic sulfate. The low thermal stability of ON and OS likely causes similar detection difficulties for other aerosol mass spectrometers using vaporization and/or ionization techniques with similar or larger energy, which has likely led to an underappreciation of these species. PMID:20194777

  1. Development of a GC/Quadrupole-Orbitrap mass spectrometer, part II: new approaches for discovery metabolomics.

    Peterson, Amelia C; Balloon, Allison J; Westphall, Michael S; Coon, Joshua J

    2014-10-21

    Identification of unknown peaks in gas chromatography/mass spectrometry (GC/MS)-based discovery metabolomics is challenging, and remains necessary to permit discovery of novel or unexpected metabolites that may elucidate disease processes and/or further our understanding of how genotypes relate to phenotypes. Here, we introduce two new technologies and an analytical workflow that can facilitate the identification of unknown peaks. First, we report on a GC/Quadrupole-Orbitrap mass spectrometer that provides high mass accuracy, high resolution, and high sensitivity analyte detection. Second, with an "intelligent" data-dependent algorithm, termed molecular-ion directed acquisition (MIDA), we maximize the information content generated from unsupervised tandem MS (MS/MS) and selected ion monitoring (SIM) by directing the MS to target the ions of greatest information content, that is, the most-intact ionic species. We combine these technologies with (13)C- and (15)N-metabolic labeling, multiple derivatization and ionization types, and heuristic filtering of candidate elemental compositions to achieve (1) MS/MS spectra of nearly all intact ion species for structural elucidation, (2) knowledge of carbon and nitrogen atom content for every ion in MS and MS/MS spectra, (3) relative quantification between alternatively labeled samples, and (4) unambiguous annotation of elemental composition. PMID:25166283

  2. A Thermal Desorption Chemical Ionization Mass Spectrometer for the In Situ Measurement of Aerosol Organic Compounds

    Thornberry, T.; Murphy, D. M.; Lovejoy, E. R.

    2005-12-01

    Organic material has been observed to comprise a significant fraction of organic aerosol mass in many regions of the troposphere. The organic compounds that comprise the organic fraction of atmospheric aerosol have the potential to affect the radiative and microphysical properties of the aerosol, with concomitant impacts on the role of the aerosol in climate forcing through direct and indirect effects. Knowledge of the organic compounds in atmospheric aerosols and their spatial distribution is needed to determine their effect on aerosol properties as well as to elucidate the role of aerosols in the chemistry of the atmosphere. The speciated measurement of aerosol organic compounds poses a significant experimental challenge due to the complexity and large number of organic species, and the low concentration at which individual species are present. A prototype instrument has been designed and built to make in situ speciated measurements of aerosol organic compounds. The instrument is composed of an aerosol collection/thermal desorption inlet coupled to a custom chemical ionization ion trap mass spectrometer. Aerosols are collected over a variable time by impaction on a target stage. The stage is then rapidly heated to volatilize the organic compounds into a small flow of helium carrier gas and conveyed to an ion-molecule reaction drift tube where proton transfer from H3O+ is used to softly ionize organic species. The ionized analyte molecules are then trapped and mass analyzed using a quadrupole ion trap. Results from preliminary experiments using laboratory-generated aerosol will be discussed

  3. Fluorescence Imaging for Visualization of the Ion Cloud in a Quadrupole Ion Trap Mass Spectrometer

    Talbot, Francis O.; Sciuto, Stephen V.; Jockusch, Rebecca A.

    2013-12-01

    Laser-induced fluorescence is used to visualize populations of gaseous ions stored in a quadrupole ion trap (QIT) mass spectrometer. Presented images include the first fluorescence image of molecular ions collected under conditions typically used in mass spectrometry experiments. Under these "normal" mass spectrometry conditions, the radial ( r) and axial ( z) full-width at half maxima (FWHM) of the detected ion cloud are 615 and 214 μm, respectively, corresponding to ~6 % of r 0 and ~3 % of z 0 for the QIT used. The effects on the shape and size of the ion cloud caused by varying the pressure of helium bath gas, the number of trapped ions, and the Mathieu parameter q z are visualized and discussed. When a "tickle voltage" is applied to the exit end-cap electrode, as is done in collisionally activated dissociation, a significant elongation in the axial, but not the radial, dimension of the ion cloud is apparent. Finally, using spectroscopically distinguishable fluorophores of two different m/ z values, images are presented that illustrate stratification of the ion cloud; ions of lower m/ z (higher q z ) are located in the center of the trapping region, effectively excluding higher m/ z (lower q z ) ions, which form a surrounding layer. Fluorescence images such as those presented here provide a useful reference for better understanding the collective behavior of ions in radio frequency (rf) trapping devices and how phenomena such as collisions and space-charge affect ion distribution.

  4. Aerosol quantification with the Aerodyne Aerosol Mass Spectrometer: detection limits and ionizer background effects

    F. Drewnick

    2008-10-01

    Full Text Available Systematic laboratory experiments were performed to investigate quantification of various species with two versions of the Aerodyne Aerosol Mass Spectrometer, a Q-AMS and a c-ToF-AMS. Here we present a new method to continuously determine the detection limits of the AMS analyzers during regular measurements, yielding DL information under various measurement conditions. Minimum detection limits range from 0.03 μg m−3 (nitrate, sulfate, and chloride up to 0.5 μg m−3 (organics for the Q-AMS. Those of the c-ToF-AMS are found between 0.003 μg m−3 (nitrate, sulfate and 0.03 μg m−3 (ammonium, organics. The DL values found for the c-ToF-AMS were ~10 times lower than those of the Q-AMS, mainly due to differences in ion duty cycle. Effects causing an increase of the detection limits include long-term instrument contamination, measurement of high aerosol mass concentrations and short-term instrument history. The self-cleaning processes which reduce the instrument background after measurement of large aerosol concentrations as well as the influences of increased instrument background on mass concentration measurements are discussed. Finally, improvement of detection limits by extension of averaging time intervals, selected or reduced ion monitoring, and variation of particle-to-background measurement ratio are investigated.

  5. A Hadamard transform electron ionization time-of-flight mass spectrometer

    Hudgens, Jeffrey W.; Bergeron, Denis E.

    2008-01-01

    We describe the first Hadamard transform time-of-flight mass spectrometer (HT-TOFMS) that incorporates an electron (impact) ionization source. This implementation was realized in an existent TOF instrument using commercially available components and simple modifications to the ion source. In the present apparatus, a Hadamard mask is expressed by modulating the ion generation process within the ion source; thus, the present approach differs from previous designs that use external electrostatic devices to modulate a continuous ion stream. The present implementation may be operated in conventional TOF mode at 12.5kHz and in HT-TOF mode at 20-40MHz. In Hadamard mode the design can operate using any circulant simplex code, allowing the operator much flexibility for optimizing resolution and mass range and for eliminating nonstochastic fluctuations, e.g., encoding errors and signal hum. We demonstrate typical performance of the HT-TOFMS in standard and reflectron geometries using sequences of three constructions and of varied length, generating HT-TOF mass spectra of molecules that match conventional reference spectra. The auxiliary material includes an electrical schematic for the floating high-speed encoding amplifier, which is also of use in other high-speed electrostatic optics applications, and a list of 537 validated vectors comprising the first row of each circulant simplex sequence (Sn=3-8219) derived using maximal shift register (n=2m-1), quadratic residue (n=4m-3), and twin prime constructions [n=p(p+2)].

  6. Single particle characterization using the soot particle aerosol mass spectrometer (SP-AMS

    A. K. Y. Lee

    2014-06-01

    Full Text Available Understanding the impact of atmospheric black carbon (BC containing particles on human health and radiative forcing requires knowledge of the mixing state of BC, including the characteristics of the materials with which it is internally mixed. In this study, we demonstrate for the first time the capabilities of the Aerodyne Soot-Particle Aerosol Mass Spectrometer equipped with a light scattering module (LS-SP-AMS to examine the mixing state of refractory BC (rBC and other aerosol components in an urban environment (downtown Toronto. K-means clustering analysis was used to classify single particle mass spectra into chemically distinct groups. One resultant cluster is dominated by rBC mass spectral signals (C1+ to C5+ while the organic signals fall into a few major clusters, identified as hydrocarbon-like organic aerosol (HOA, oxygenated organic aerosol (OOA, and cooking emission organic aerosol (COA. A nearly external mixing is observed with small BC particles only thinly coated by HOA (∼28% by mass on average, while over 90% of the HOA-rich particles did not contain detectable amounts of rBC. Most of the particles classified into other inorganic and organic clusters were not significantly associated with BC. The single particle results also suggest that HOA and COA emitted from anthropogenic sources were likely major contributors to organic-rich particles with low to mid-range aerodynamic diameter (dva. The similar temporal profiles and mass spectral features of the organic clusters and the factors from a positive matrix factorization (PMF analysis of the ensemble aerosol dataset validate the conventional interpretation of the PMF results.

  7. A high-resolution mass spectrometer to measure atmospheric ion composition

    H. Junninen

    2010-02-01

    Full Text Available In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG. Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm-3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (polyalkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.

  8. On Applicability of a Miniaturised Laser Ablation Time of Flight Mass Spectrometer for Trace Elements Measurements

    Marek Tulej

    2012-01-01

    Full Text Available We present results from mass spectrometric analysis of NIST standard materials and meteoritic samples conducted by a miniaturised laser ablation mass spectrometer designed for space research. The mass analyser supports investigation with a mass resolution (/Δ ≈ 500–600 and dynamic range within seven decades. Nevertheless, to maintain an optimal spectral quality laser irradiances lower than ~1 GW/cm2 are applied so far which results in a spread of RSC values. To achieve the quantitative performance of mass analyser, various effects influencing RSC factors have to be investigated. In this paper we investigate influence of laser irradiance, sampling procedure and plasma chemistry on the quantitative elemental and isotopic analysis. The studies indicate necessity for accurate control of laser characteristics and acquisition procedure. A relatively low irradiance applied causes a negligible sample damage and allows for accumulation of large number of waveforms from one sample location. The procedure yields statistically well averaged data and allows a sensitive in-depth analysis. The quantitative analyses of isotopic composition can be performed with accuracy and precision better as 1% and 2%, for isotopic patterns of elements and clusters, respectively. The numerical integration methods would be preferred to achieve more accurate results. The measurements of Allende sample yield detection of Pb isotopic pattern, nevertheless cluster species are readily observed in spectrum and make the elemental analysis of other trace elements difficult due to isobaric interferences. These detections are of a considerable interest because of possible application of the instrument for in situ elemental and isotopic analysis and radiometric dating of solids.

  9. Characterization of organic aerosols in Beijing using an aerodyne high-resolution aerosol mass spectrometer

    Zhang, Junke; Wang, Yuesi; Huang, Xiaojuan; Liu, Zirui; Ji, Dongsheng; Sun, Yang

    2015-06-01

    Fine particle of organic aerosol (OA), mostly arising from pollution, are abundant in Beijing. To achieve a better understanding of the difference in OA in summer and autumn, a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, Aerodyne Research Inc., USA) was deployed in urban Beijing in August and October 2012. The mean OA mass concentration in autumn was 30±30 μg m-3, which was higher than in summer (13±6.9 μg m-3). The elemental analysis found that OA was more aged in summer (oxygen-to-carbon (O/C) ratios were 0.41 and 0.32 for summer and autumn, respectively). Positive matrix factorization (PMF) analysis identified three and five components in summer and autumn, respectively. In summer, an oxygenated OA (OOA), a cooking-emission-related OA (COA), and a hydrocarbon-like OA (HOA) were indentified. Meanwhile, the OOA was separated into LV-OOA (low-volatility OOA) and SV-OOA (semi-volatile OOA); and in autumn, a nitrogen-containing OA (NOA) was also found. The SOA (secondary OA) was always the most important OA component, accounting for 55% of the OA in the two seasons. Back trajectory clustering analysis found that the origin of the air masses was more complex in summer. Southerly air masses in both seasons were associated with the highest OA loading, while northerly air masses were associated with the lowest OA loading. A preliminary study of OA components, especially the POA (primary OA), in different periods found that the HOA and COA all decreased during the National Day holiday period, and HOA decreased at weekends compared with weekdays.

  10. A high-resolution mass spectrometer to measure atmospheric ion composition

    H. Junninen

    2010-08-01

    Full Text Available In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG. Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm−3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (polyalkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.

  11. Fast ion mass spectrometry and charged particle spectrography investigations of transverse ion acceleration and beam-plasma interactions. Final report

    Ion acceleration transverse to the magnetic field in the topside ionosphere was investigated. Transverse acceleration is believed to be responsible for the upward-moving conical ion distributions commonly observed along auroral field lines at altitudes from several hundred to several thousand kilometers. Of primary concern in this investigation is the extent of these conic events in space and time. Theoretical predictions indicate very rapid initial heating rates, depending on the ion species. These same theories predict that the events will occur within a narrow vertical region of only a few hundred kilometers. Thus an instrument with very high spatial and temporal resolution was required; further, since different heating rates were predicted for different ions, it was necessary to obtain composition as well as velocity space distributions. The fast ion mass spectrometer (FIMS) was designed to meet these criteria. This instrument and its operation is discussed

  12. Fast ion mass spectrometry and charged particle spectrography investigations of transverse ion acceleration and beam-plasma interactions

    Gibson, W. C.; Tomlinson, W. M.; Marshall, J. A.

    1987-01-01

    Ion acceleration transverse to the magnetic field in the topside ionosphere was investigated. Transverse acceleration is believed to be responsible for the upward-moving conical ion distributions commonly observed along auroral field lines at altitudes from several hundred to several thousand kilometers. Of primary concern in this investigation is the extent of these conic events in space and time. Theoretical predictions indicate very rapid initial heating rates, depending on the ion species. These same theories predict that the events will occur within a narrow vertical region of only a few hundred kilometers. Thus an instrument with very high spatial and temporal resolution was required; further, since different heating rates were predicted for different ions, it was necessary to obtain composition as well as velocity space distributions. The fast ion mass spectrometer (FIMS) was designed to meet these criteria. This instrument and its operation is discussed.

  13. Accelerator mass spectrometry of the heaviest long-lived radionuclides with a 3-MV tandem accelerator

    Christof Vockenhuber; Robin Golser; Walter Kutschera; Alfred Priller; Peter Steier; Stephan Winkler; Vitaly Liechtenstein

    2002-12-01

    A 3-MV pelletron tandem accelerator is the heart of the Vienna environmental research accelerator (VERA). The original design of the beam transport components allows the transport of ions of all elements, from the lightest to the heaviest. For light ions the suppression of neighboring masses was sufficient to measure isotopic ratios of 14C/12C and 26Al/27Al as low as 10-15 and 10Be/9Be down to 10-13. To suppress neighboring masses for the heaviest radionuclides in the energy range of 10–20 MeV, the resolution of VERA was increased both by improving the ion optics of existing elements at the injection side and by installing a new high-resolution electrostatic separator at the high-energy side. Interfering ions which pass all beam filters are identified with a Bragg-type ionization detector and a high-resolution time-of-flight system. Two ultra-thin diamond-like carbon (DLC) foils are used in the start and stop detector, which substantially reduces losses due to beam straggling. This improved set up enables us to measure even the heaviest long-lived radionuclides, where stable isobaric interferences are absent (e.g. 236U and 244Pu), down to environmental levels. Moreover, the advantage of a ‘small’ and well manageable machine like VERA lies in its higher stability and reliability which allows to measure these heavy radionuclides more accurately, and also a large number of samples.

  14. High-temperature quadrupole mass spectrometer for studying vaporization from materials heated by a CO2 laser

    To evaluate the effectiveness of mass spectrometry techniques in studying vaporization from selected materials, we designed a mass spectrometer than can be used either with a continuous wave or pulsed laser heating system or with a conventional furnace heating system. Our experimental apparatus, the components of which are described in detail, consisted of a quadrupole mass spectrometer positioned in a crossed-beam configuration, controlling electronics, a data acquisition system, a vacuum system, a cryogenic collimation system, and a laser heating system. Results of mass spectral scans taken during laser pyrolysis of polymeric materials and laser vaporization of graphite were compatible with data reported in other studies. Results of mass spectral studies of laser-induced combustion in the Ti + C system are also presented

  15. Evolving mass spectra of the oxidized component of organic aerosol: results from aerosol mass spectrometer analyses of aged diesel emissions

    A. M. Sage

    2007-07-01

    Full Text Available The species and chemistry responsible for secondary organic aerosol (SOA formation remain highly uncertain. Laboratory studies of the oxidation of individual, high-flux SOA precursors do not lead to particles with mass spectra (MS matching those of ambient aged organic material. And, the complexity of real organic particles challenges efforts to identify their chemical origins. We have previously hypothesized that SOA can form from the atmospheric oxidation of a large suite of precursors with varying vapor pressures. Here, we support this hypothesis by using an aerosol mass spectrometer to track the chemical evolution of diesel exhaust as it is photochemically oxidized in an environmental chamber. With explicit knowledge of the condensed-phase MS of the primary emissions from our engine, we are able to decompose each recorded MS into contributing primary and secondary spectra throughout the experiment. We find that the SOA MS becomes increasingly oxidized as a function of time, eventually reaching a final MS that closely resembles that of ambient aged organic particulate matter. This observation is consistent with the idea that lower vapor pressure, semi-volatile organic emissions can form condensable products with fewer generations of oxidation, and therefore, they form relatively less oxidized SOA very quickly.

  16. Precision measurements with the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at ISOLDE/CERN

    Atanasov, Dinko; Ascher, Pauline; Borgmann, Christopher; Boehm, Christine; Eliseev, Sergey; Eronen, Tommi; George, Sebastian; Kisler, Dmitry; Naimi, Sarah [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Beck, Dietrich; Herfurth, Frank; Litvinov, Yuri; Minaya Ramirez, Enrique; Neidherr, Dennis [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Breitenfeldt, Martin [Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200d - bus 2418, 3001 Heverlee (Belgium); Cakirli, Burcu [University of Istanbul, Department of Physics, 34134 Istanbul (Turkey); Cocolios, Thomas Elias [University of Manchester, Manchester (United Kingdom); Herlert, Alexander Josef [FAIR GmbH, Planckstr. 1, D-64291 Darmstadt (Germany); Kowalska, Magdalena [CERN, Geneva 23, 1211 Geneva (Switzerland); Kreim, Susanne [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); CERN, Geneva 23, 1211 Geneva (Switzerland); Lunney, David; Manea, Vladimir [CSNSM-IN2P3-CNRS, 91405 Orsay Campus, Bat. 104, 108 (France); Rosenbusch, Marco; Schweikhard, Lutz; Wienholtz, Frank; Wolf, Robert [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, Felix-Hausdorff-Str. 6, 17487 Greifswald (Germany); Stanja, Juliane; Zuber, Kai [Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden, Zellescher Weg 19, 01069 Dresden (Germany)

    2014-07-01

    The masses of exotic nuclides are among the most important input parameters for modern nuclear theory and astrophysical models. At the high-precision Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN, a multi-reflection time-of-flight mass spectrometer (MR-ToF-MS) in combination with a Bradbury-Nielsen gate (BNG) can be used to achieve high-resolution isobar purification with mass-resolving powers of 105 in a few tens of milliseconds. Furthermore, the MR-ToF device can be used as a spectrometer to determine the masses of nuclides with very low yields and short half-lives, where a Penning-trap mass measurement becomes impractical due to the lower transport efficiency and decay losses during the purification and measurement cycles. Recent cross-check experiments show that the MR-ToF MS allows mass measurements with uncertainties in the sub-ppm range. In a first application the mass measurements of the nuclides 53,54Ca was performed, delivered with production rates as low as 10/s and half-lives of only 90(6) ms. The nuclides serve as important benchmarks for testing modern chiral effective theory with realistic 3-body forces. The contribution presents the on-line mass spectrometer ISOLTRAP focusing on the new applications, which became possible after the implementation of the MR-ToF MS into the current setup. In particular, the mass measurements of the neutron-rich calcium isotopes up to A=54 are discussed. In addition, measurements of the isotonic potassium isotopes are reported.

  17. Precision measurements with the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at ISOLDE/CERN

    The masses of exotic nuclides are among the most important input parameters for modern nuclear theory and astrophysical models. At the high-precision Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN, a multi-reflection time-of-flight mass spectrometer (MR-ToF-MS) in combination with a Bradbury-Nielsen gate (BNG) can be used to achieve high-resolution isobar purification with mass-resolving powers of 105 in a few tens of milliseconds. Furthermore, the MR-ToF device can be used as a spectrometer to determine the masses of nuclides with very low yields and short half-lives, where a Penning-trap mass measurement becomes impractical due to the lower transport efficiency and decay losses during the purification and measurement cycles. Recent cross-check experiments show that the MR-ToF MS allows mass measurements with uncertainties in the sub-ppm range. In a first application the mass measurements of the nuclides 53,54Ca was performed, delivered with production rates as low as 10/s and half-lives of only 90(6) ms. The nuclides serve as important benchmarks for testing modern chiral effective theory with realistic 3-body forces. The contribution presents the on-line mass spectrometer ISOLTRAP focusing on the new applications, which became possible after the implementation of the MR-ToF MS into the current setup. In particular, the mass measurements of the neutron-rich calcium isotopes up to A=54 are discussed. In addition, measurements of the isotonic potassium isotopes are reported.

  18. Sub-part-per-million Precursor and Product Mass Accuracy for High-throughput Proteomics on an Electron Transfer Dissociation-enabled Orbitrap Mass Spectrometer*

    Wenger, Craig D.; McAlister, Graeme C.; Xia, Qiangwei; Coon, Joshua J.

    2010-01-01

    We demonstrate a new approach for internal mass calibration on an electron transfer dissociation-enabled linear ion trap-orbitrap hybrid mass spectrometer. Fluoranthene cations, a byproduct of the reaction used for generation of electron transfer dissociation reagent anions, are co-injected with the analyte cations in all orbitrap mass analysis events. The fluoranthene cations serve as a robust internal calibrant with minimal impact on scan time (

  19. First performance results of a mobile high-resolution MR-ToF mass spectrometer for in-situ analytical mass spectrometry

    Lang, Johannes; Ebert, Jens [II. Physikalisches Institut, JLU Giessen (Germany); Dickel, Timo; Plass, Wolfgang; Geissel, Hans; Haettner, Emma; Scheidenberger, Christoph [II. Physikalisches Institut, JLU Giessen (Germany); GSI, Darmstadt (Germany); Yavor, Mikhail [RAS St. Petersburg (Russian Federation)

    2012-07-01

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been designed, built and commissioned. While other mobile mass spectrometers are restricted to low or medium mass resolving power, this MR-TOF-MS allows for the first time for a mass resolving power exceeding 100.000 and a sub ppm accuracy in a transportable format. It can thus resolve isobars and enables to accurately determine the composition and structure of biomolecules. An atmospheric pressure interface provides compatibility to various atmospheric ion sources. The mass spectrometer part comprises an RFQ mass filter, ion cooler, ion trap, time-of-flight analyzer and detector. Supply electronics, DAQ and control system are mounted together with the spectrometer into a single frame with a total volume of only 0.8 m{sup 3}. First results with the MR-TOF-MS are presented, and an overview of envisaged life science applications is given, such as realtime tissue recognition in electrosurgery, identification of mycotoxins and analysis of soil samples for environmental studies.

  20. First performance results of a mobile high-resolution MR-ToF mass spectrometer for in-situ analytical mass spectrometry

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been designed, built and commissioned. While other mobile mass spectrometers are restricted to low or medium mass resolving power, this MR-TOF-MS allows for the first time for a mass resolving power exceeding 100.000 and a sub ppm accuracy in a transportable format. It can thus resolve isobars and enables to accurately determine the composition and structure of biomolecules. An atmospheric pressure interface provides compatibility to various atmospheric ion sources. The mass spectrometer part comprises an RFQ mass filter, ion cooler, ion trap, time-of-flight analyzer and detector. Supply electronics, DAQ and control system are mounted together with the spectrometer into a single frame with a total volume of only 0.8 m3. First results with the MR-TOF-MS are presented, and an overview of envisaged life science applications is given, such as realtime tissue recognition in electrosurgery, identification of mycotoxins and analysis of soil samples for environmental studies.

  1. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  2. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed. PMID:27587105

  3. Development and characterization of a single particle laser ablation mass spectrometer (SPLAM for organic aerosol studies

    F. Gaie-Levrel

    2011-07-01

    Full Text Available A single particle instrument has been developed for real-time analysis of organic aerosols. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM, samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL, sodium chloride (NaCl and dioctylphtalate (DOP particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL and detection efficiency (DE were determined using size-selected DOP particles. The DE is ranging from 0.1 to 90 % for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. Scattered light is detected by two photomultipliers and the detected signals are used to trigger a UV excimer laser (λ = 248 nm used for laser desorption ionization (LDI of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 attograms. DOP particles were also used to test the overall functioning of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first scientific application of the instrument. Single particle mass spectra are obtained with a global hit rate of 10 %. They are found to be very different from one particle to another, reflecting chemical differences of the analyzed particles, and most of the detected mass peaks are attributed to oxidized products of indene.

  4. Advanced Ion Mass Spectrometer for Giant Planet Ionospheres, Magnetospheres and Moons

    Sittler, EC; Cooper, JF; Paschalidis, N.; Jones, SL; Rodriguez, M.; Ali, A.; Coplan, MA; Chornay, DJ; Sturner; Bateman, FB; Andre, N.; Fedorov, A.; Wurz, P.

    2015-10-01

    The Advanced Ion Composition Spectrometer (AIMS) has been under development from various NASA sources (NASA LWSID, NASA ASTID, NASA Goddard IRADs) to measure elemental, isotopic, and simple molecular composition abundances of 1 eV/e to 25 keV/e hot ions with wide field-of-view (FOV) in the 1 - 60 amu mass range at mass resolution M/ΔM ≤ 60 over a wide dynamic range of intensities and penetrating radiation background from the inner magnetospheres of Jupiter and Saturn to the outer magnetospheric boundary regions and the upstream solar wind. This instrument will work for both spinning spacecraft and 3-axis stabilized spacecraft with wide field-of-view capability in both cases. It will measure the ion velocity distribution functions (IVDF) for the individual ion species; ion velocity moments of the IVDF will give the fluid parameters (density, flow velocity and temperature) of the individual ion species. Outer planet mission applications are Io Observer, Jupiter Europa Orbiter/Europa Clipper, Enceladus Orbiter, and Uranus Orbiter as described in the decadal survey, but would also be valuable for inclusion on other missions to outer planet destinations such as Saturn- Titan and Neptune-Triton and for future missions to terrestrial planets, Venus and Mars, the Moon, asteroids, and comets, and of course for geospace applications to the Earth.

  5. Interlaboratory comparison for boron isotope ratio measurement with inductively coupled plasma-quadrupole mass spectrometer

    Boron isotope ratios were analyzed in seven domestic analytical labs for boric acid solutions with various compositions of boron isotope abundances, using an Inductively Coupled Plasma-Quadrupole Mass Spectrometer (ICP-QMS). Five sample solutions with different isotope abundances of 10B were prepared in the range of 10 to 20 % by mixing two boric acid solutions containing natural B and enriched 11B, respectively. Then, the 10B isotope abundances of each sample were certified by analyzing with thermal ionization mass spectrometry (TI-MS) according to ASTM-C791-04. Results obtained from each lab have indicated good coincidences with TI-MS results. Also, the relative standard deviations of results with ICP-QMS of seven analytical labs were 0.11 to 0.81 %. The measurement precision for ICP-QMS would be sufficient in terms of practical use, while taking into consideration a valid requirement required for verifying a depletion of the 10B isotope abundance in the PWR coolant, while this is greater than a nominal analytical error (relative value : 0.22 %) for TI-MS shown in ASTM-C791-04. (author)

  6. Triple quadrupole linear ion trap mass spectrometer for the analysis of small molecules and macromolecules.

    Hopfgartner, Gérard; Varesio, Emmanuel; Tschäppät, Viviane; Grivet, Chantal; Bourgogne, Emmanuel; Leuthold, Luc Alexis

    2004-08-01

    Recently, linear ion traps (LITs) have been combined with quadrupole (Q), time-of-flight (TOF) and Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). LITs can be used either as ion accumulation devices or as commercially available, stand-alone mass spectrometers with MSn capabilities. The combination of triple quadrupole MS with LIT technology in the form of an instrument of configuration QqLIT, using axial ejection, is particularly interesting, because this instrument retains the classical triple quadrupole scan functions such as selected reaction monitoring (SRM), product ion (PI), neutral loss (NL) and precursor ion (PC) while also providing access to sensitive ion trap experiments. For small molecules, quantitative and qualitative analysis can be performed using the same instrument. In addition, for peptide analysis, the enhanced multiply charged (EMC) scan allows an increase in selectivity, while the time-delayed fragmentation (TDF) scan provides additional structural information. Various methods of operating the hybrid instrument are described for the case of the commercial Q TRAP (AB/MDS Sciex) and applications to drug metabolism analysis, quantitative confirmatory analysis, peptides analysis and automated nanoelectrospray (ESI-chip-MS) analysis are discussed. PMID:15329837

  7. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Yunguang Huang

    2015-01-01

    Full Text Available A vacuum ultraviolet lamp based single photon ionization- (SPI- photoelectron ionization (PEI portable reflecting time-of-flight mass spectrometer (TOFMS was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX, SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1 with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

  8. First Signal on the Cryogenic Fourier-Transform Ion Cyclotron Resonance Mass Spectrometer

    Lin, Cheng; Mathur, Raman; Aizikov, Kostantin; O'Connor, Peter B.

    2009-01-01

    The construction and achievement of the first signal on a cryogenic Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR-MS) are reported here, demonstrating proof-of-concept of this new instrument design. Building the FTICR cell into the cold bore of a superconducting magnet provided advantages over conventional warm bore design. At 4.2 K, the vacuum system cryopumps itself, thus removing the requirement for a large bore to achieve the desired pumping speed for maintaining base pressure. Furthermore, because the bore diameter has been reduced, the amount of magnet wire needed to achieve high field and homogeneity was also reduced, greatly decreasing the cost/Tesla of the magnet. The current instrument implements an actively shielded 14-Tesla magnet of vertical design with an external matrix assisted laser desorption/ionization (MALDI) source. The first signal was obtained by detecting the laser desorbed/ionized (LDI) C60+• ions, with the magnet at 7 Tesla, unshimmed, and the preamplifier mounted outside of the vacuum chamber at room temperature. A subsequent experiment done with the magnet at 14 Tesla and properly shimmed produced a C60 spectrum showing ∼350,000 resolving power at m/z ∼720. Increased magnetic field strength improves many FTMS performance parameters simultaneously, particularly mass resolving power and accuracy. PMID:17931882

  9. Broadscale resolving power performance of a high precision uniform field ion mobility-mass spectrometer.

    May, Jody C; Dodds, James N; Kurulugama, Ruwan T; Stafford, George C; Fjeldsted, John C; McLean, John A

    2015-10-21

    An extensive study of two current ion mobility resolving power theories ("conditional" and "semi-empirical") was undertaken using a recently developed drift tube ion mobility-mass spectrometer. The current study investigates the quantitative agreement between experiment and theory at reduced pressure (4 Torr) for a wide range of initial ion gate widths (100 to 500 μs), and ion mobility values (K0 from 0.50 to 3.0 cm(2) V(-1) s(-1)) representing measurements obtained in helium, nitrogen, and carbon dioxide drift gas. Results suggest that the conditional resolving power theory deviates from experimental results for low mobility ions (e.g., high mass analytes) and for initial ion gate widths beyond 200 μs. A semi-empirical resolving power theory provided close-correlation of predicted resolving powers to experimental results across the full range of mobilities and gate widths investigated. Interpreting the results from the semi-empirical theory, the performance of the current instrumentation was found to be highly linear for a wide range of analytes, with optimal resolving powers being accessible for a narrow range of drift fields between 14 and 17 V cm(-1). While developed using singly-charged ion mobility data, preliminary results suggest that the semi-empirical theory has broader applicability to higher-charge state systems. PMID:26191544

  10. Functional residual capacity measurements in healthy infants: ultrasonic flow meter versus a mass spectrometer.

    Pillow, J J; Ljungberg, H; Hülskamp, G; Stocks, J

    2004-05-01

    Accurate, reproducible and portable bedside monitoring of lung volume could potentially facilitate the early recognition of both under and overinflation of the lungs in ventilated and nonventilated subjects. This study asked whether a prototype portable ultrasonic flow meter provided valid and reliable measurements of functional residual capacity (FRCUS) when compared to those obtained using a mass spectrometer (FRCMS) in nonventilated healthy infants. Paired, randomised measurements of FRCMS and FRCUS were obtained using the sulphur hexafluoride (SF6) multiple-breath washout technique in 23 healthy infants with a median (range) postnatal age of 34.6 (1.3-92.6) weeks and weight of 8.3 (3.9-11.7) kg. FRCUS was on average 5.7%, (95% CI: 1.0-10.4%) less than FRCMS equating to a difference of approximately 1 mL x kg(-1). The 95% limits of agreement (LA) between the two techniques were relatively wide (95% LA: -17.5% to 29%), although in keeping with previously reported within-patient variability for lung volume measurements. There was no significant difference between the within subject coefficient of variation for FRCMS (3.7%) and FRCUS (5.2%). The ultrasonic flow meter used in this study provides repeatable measurements of functional residual capacity in spontaneously breathing healthy infants that approximate those obtained during mass spectrometry. PMID:15176694

  11. Evaluating Mass Analyzers as Candidates for Small, Portable, Rugged Single Point Mass Spectrometers for Analysis of Permanent Gases

    Arkin, C. Richard; Ottens, Andrew K.; Diaz, Jorge A.; Griffin, Timothy P.; Follestein, Duke; Adams, Fredrick; Steinrock, T. (Technical Monitor)

    2001-01-01

    For Space Shuttle launch safety, there is a need to monitor the concentration of H2, He, O2 and Ar around the launch vehicle. Currently a large mass spectrometry system performs this task, using long transport lines to draw in samples. There is great interest in replacing this stationary system with several miniature, portable, rugged mass spectrometers which act as point sensors which can be placed at the sampling point. Five commercial and two non-commercial analyzers are evaluated. The five commercial systems include the Leybold Inficon XPR-2 linear quadrupole, the Stanford Research (SRS-100) linear quadrupole, the Ferran linear quadrupole array, the ThermoQuest Polaris-Q quadrupole ion trap, and the IonWerks Time-of-Flight (TOF). The non-commercial systems include a compact double focusing sector (CDFMS) developed at the University of Minnesota, and a quadrupole ion trap (UF-IT) developed at the University of Florida. The System Volume is determined by measuring the entire system volume including the mass analyzer, its associated electronics, the associated vacuum system, the high vacuum pump and rough pump. Also measured are any ion gauge controllers or other required equipment. Computers are not included. Scan Time is the time required for one scan to be acquired and the data to be transferred. It is determined by measuring the time required acquiring a known number of scans and dividing by said number of scans. Limit of Detection is determined first by performing a zero-span calibration (using a 10-point data set). Then the limit of detection (LOD) is defined as 3 times the standard deviation of the zero data set. (An LOD of 10 ppm or less is considered acceptable.)

  12. Human folate metabolism using 14C-accelerator mass spectrometry

    Clifford, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Arjomand, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Duecker, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, P. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zulim, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bucholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vogel, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-03-25

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkin's disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer.

  13. Human folate metabolism using 14C-accelerator mass spectrometry

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkins disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer

  14. Improving Tritium Exposure Reconstructions Using Accelerator Mass Spectrometry

    Love, A; Hunt, J; Knezovich, J

    2003-06-01

    Exposure reconstructions for radionuclides are inherently difficult. As a result, most reconstructions are based primarily on mathematical models of environmental fate and transport. These models can have large uncertainties, as important site-specific information is unknown, missing, or crudely estimated. Alternatively, surrogate environmental measurements of exposure can be used for site-specific reconstructions. In cases where environmental transport processes are complex, well-chosen environmental surrogates can have smaller exposure uncertainty than mathematical models. Because existing methodologies have significant limitations, the development or improvement of methodologies for reconstructing exposure from environmental measurements would provide important additional tools in assessing the health effects of chronic exposure. As an example, the direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples, which permit greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Tritium AMS was previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases.

  15. Biomass carbon-14 ratio measured by accelerator mass spectrometry

    Measurement methods of a biomass carbon ratio in biomass products based on 14C-radiocarbon concentration have been reviewed. Determination of the biomass carbon ratio in biomass products is important to secure the reliance in the commercial market, because the 'biomass products' could contain products from petroleum. The biomass carbon ratio can be determined from percent Modern Carbon (pMC) using ASTM D6866 methods. The pMC value is calculated from the comparison between the 14C in sample and 14C in reference material. The 14C concentration in chemical products can be measured by liquid scintillation counter (LSC) and accelerator mass spectrometry (AMS). LSC can be applicable to determine the biomass carbon ratio for liquid samples such as gasoline with bioethanol (E5 or E10). On the other hand, AMS can be used to determine the biomass carbon ratio for almost all kinds of organic and inorganic compounds such as starch, cellulose, ethanol, gasoline, or polymer composite with inorganic fillers. AMS can accept the gaseous and solid samples. The graphite derived from samples included in solid phase is measured by AMS. The biomass carbon of samples derived from wood were higher than 100% due to the effect of atomic bomb test in the atmosphere around 1950 which caused the artificial 14C injection. Exact calculation methods of the biomass carbon ratio from pMC will be required for the international standard (ISO standard). (author)

  16. Deep-sea astronomy with Accelerator Mass Spectrometry

    Accelerator Mass Spectrometry (AMS) is a highly sensitive method to measure extremely low isotopic ratios of long-lived radionuclides relative to its stable isotope. Inspired by findings of an excess of 60Fe in a ferromanganese crust approximately 2 Myr ago, which was interpreted to be of supernova-origin, we use this method to determine concentrations of a variety of radionuclides in deep-sea sediment samples covering a time range from 1.7 to 3.2 Myr. An international collaboration of different AMS facilities is utilized to search for signatures of 26Al, 53Mn, and 60Fe above terrestrial background production and extraterrestrial influx. In addition, the cosmogenic radionuclide 10Be is measured to confirm existing magnetostratigraphic dating of the samples and for comparison with atmospheric production ratios of 26Al/10Be. All 10Be and 26Al measurements are finished, 53Mn and 60Fe is in progress. Measurement results and the influence of different background sources on a potential supernova signature are presented and discussed.

  17. Some pitfalls in chemical sample preparation for accelerator mass spectrometry

    Sophisticated sample preparation including the determination of stable nuclides are an essential prerequisite for high-accuracy accelerator mass spectrometry (AMS) data. Improvements in the low-level regime already paid back, however, some pitfalls still exist or are (re-) appearing due to recent developments: 1.) As most samples prepared for 10Be-AMS need the addition of 9Be in the form of a liquid solution of known 9Be-concentration and commercial solutions contain too much 10Be, solutions from minerals originating from deep mines have been established. Special attention has recently been paid to the preparation of such a 9Be-carrier by the determination of the 9Be-value by an interlaboratory comparison. It could be shown that deviations between different labs exist, thus, it is strongly advised to have such solutions analysed at more than a single lab to prevent incorrect 10Be-results. 2.) In our approach to analyse as many radionuclides as possible in a single meteorite sample, small changes in the established chemical separation have been tested. Though, the secondary formation of partially insoluble compounds of Mg and Al by the pressure digestion is strongly influenced, thus, yielding to too low 27Al-results in the taken aliquot and overall incorrect 26Al-results.

  18. Ion source memory in 36Cl accelerator mass spectrometry

    Since the DREAMS (Dresden Accelerator Mass Spectrometry) facility went operational in 2011, constant effort was put into enabling routine measurements of long-lived radionuclides as 10Be, 26Al and 41Ca. For precise AMS-measurements of the volatile element Cl the key issue is the minimization of the long term memory effect. For this purpose one of the two original HVE sources was mechanically modified, allowing the usage of bigger cathodes with individual target apertures. Additionally a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, a small inter-laboratory comparison had been initiated. The long-term memory effect in the Cs sputter ion sources of the AMS facilities VERA, ASTER and DREAMS had been investigated by running samples of natural 35Cl/37Cl-ratio and samples containing highly enriched 35Cl(35Cl/37Cl > 500). Primary goals of the research are the time constants of the recovery from the contaminated sample ratio to the initial ratio of the sample and the level of the long-term memory effect in the sources.

  19. Aluminum-26 as a biological tracer using accelerator mass spectrometry

    Flarend, Richard Edward

    1997-06-01

    The development of accelerator mass spectrometry (AMS) has provided a practical method of detection for the only isotope of aluminum suitable as a tracer, 26Al. The use of 26Al as a tracer for aluminum has made possible the study of aluminum metabolism and the pharmacokinetics of aluminum-containing drugs at physiological levels. An overview of the various advantages of using 26Al as a tracer for aluminum and a general description of the AMS technique as applied to bio-medical applications is given. To illustrate the versatility of 26Al as a tracer for aluminum, 26Al studies of the past several years are discussed briefly. In addition, Two novel investigations dealing with 26Al-labeled drugs will be presented in more detail. In one of these studies, it was found that 26Al from aluminum hydroxide and aluminum phosphate vaccine adjuvants appeared in the blood just one hour after intramuscular injection. This is a surprising result since the currently held theory of how adjuvants work assumes that adjuvants remain insoluble and hold the antigen at the injection site for a long period of time. In another project, 26Al-labeled antiperspirants are being characterized by combining AMS with traditional analytical and chromatographic techniques. Future directions for this and other possible studies are discussed.

  20. Quadrapole mass spectrometer used as a tool to determine Gibbs free energy of formation of ThRh5(s)

    Gibbs free energy of formation of ThRh5(s) was determined by using Knudsen effusion-quadrupole mass spectrometer in the temperature range 1142≤T(K)≤1275. Gibbs free energy as a function of temperature can be given by: ΔfGo(ThRh5s) (Jmol-1) = -996.6 + 0.357 T(K). (author)

  1. Energy resolution methods efficiency depending on beam source position of potassium clusters in time-of-flight mass spectrometer

    Ş Şentürk; F Demiray; O Özsoy

    2007-09-01

    Energy resolution of the time-of-flight mass spectrometer was considered. The estimations indicate that the time-lag energy focusing method provides better resolution for the parallel case while the turnaround time is more convenient for the perpendicular position. Hence the applicability of the methods used for the energy resolution depends on beam source arrangement.

  2. A time of flight mass spectrometer with field free interaction region for low energy charged particle-molecule collision studies

    A new design of a linear time of flight mass spectrometer (ToFMS) is implemented that gives nearly field-free interaction region without compromising on the mass resolution. The design addresses problems that would arise in a conventional Wiley-McLaren type of ToFMS: (i) field leakages into the charged particle-molecule interaction region from various components of the mass spectrometer, including that through the high transparency mesh used to obtain evenly distributed electric fields; (ii) complete collection and transportation of the ions produced in the interaction region to the detector, which is essential for high sensitivity and cross section measurements. This ToFMS works over a wide range of masses from H+ to a few hundred Daltons and would be the most suitable for low energy charged particle-molecule interaction studies. Performance of the ToFMS has been tested by measuring the partial ionization cross sections for electron impact on CF4.

  3. Development and characterization of a single particle laser ablation mass spectrometer (SPLAM for organic aerosol studies

    F. Gaie-Levrel

    2012-01-01

    Full Text Available A single particle instrument was developed for real-time analysis of organic aerosol. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM, samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized by using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL, sodium chloride (NaCl and dioctylphtalate (DOP particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL and detection efficiency (DE were determined using size-selected DOP particles. The DE ranges from 0.1 to 90% for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. During optical detection, particle scattered light from the two diode lasers, is detected by two photomultipliers and the detected signals are used to trigger UV excimer laser (λ = 248 nm used for one-step laser desorption ionization (LDI of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 × 10−15 kg (∼4 × 103 molecules. DOP particles were also used to test the overall operation of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first application of the instrument. Single particle mass spectra were obtained with an effective hit rate of 8%. Some of these mass spectra were found to be very different from one particle to another possibly reflecting chemical differences within the investigated indene SOA particles. Our study shows that an exhaustive statistical analysis, over hundreds of particles

  4. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    Watrous, Matthew George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adamic, Mary Louise [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, John Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baeck, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fox, R. V. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hahn, P. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jenson, D. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lister, T. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world’s best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

  5. A Virtual Research Environment for a Secondary Ion Mass Spectrometer (SIMS)

    Wiedenbeck, M.; Schäfer, L.; Klump, J.; Galkin, A.

    2013-12-01

    Overview: This poster describes the development of a Virtual Research Environment for the Secondary Ion Mass Spectrometer (SIMS) at GFZ Potsdam. Background: Secondary Ion Mass Spectrometers (SIMS) are extremely sensitive instruments for analyzing the surfaces of solid and thin film samples. These instruments are rare, expensive and experienced operators are very highly sought after. As such, measurement time is a precious commodity, until now only accessible to small numbers of researchers. The challenge: The Virtual SIMS Project aims to set up a Virtual Research Environment for the operation of the CAMECA IMS 1280-HR instrument at the GFZ Potsdam. The objective of the VRE is to provide SIMS access not only to researchers locally present in Potsdam but also to scientists working with SIMS cooperation partners in e.g., South Africa, Brazil or India. The requirements: The system should address the complete spectrum of laboratory procedures - from online application for measurement time, to remote access for data acquisition to data archiving for the subsequent publication and for future reuse. The approach: The targeted Virtual SIMS Environment will consist of a: 1. Web Server running the Virtual SIMS website providing general information about the project, lab access proposal forms and calendar for the timing of project related tasks. 2. LIMS Server, responsible for scheduling procedures, data management and, if applicable, accounting and billing. 3. Remote SIMS Tool, devoted to the operation of the experiment within a remote control environment. 4. Publishing System, which supports the publication of results in cooperation with the GFZ Library services. 5. Training Simulator, which offers the opportunity to rehearse experiments and to prepare for possible events such as a power outages or interruptions to broadband services. First results: The SIMS Virtual Research Environment will be mainly based on open source software, the only exception being the CAMECA IMS

  6. Dust particle injector for hypervelocity accelerators provides high charge-to-mass ratio

    Berg, O. E.

    1966-01-01

    Injector imparts a high charge-to-mass ratio to microparticles and injects them into an electrostatic accelerator so that the particles are accelerated to meteoric speeds. It employs relatively large masses in the anode and cathode structures with a relatively wide separation, thus permitting a large increase in the allowable injection voltages.

  7. Development of a time-of-flight mass spectrometer for ion desorption studies at HiSOR

    Fujii, K; Nakashima, Y; Waki, S; Sardar, S A; Yasui, Y; Wada, S I; Sekitani, T; Tanaka, K

    2001-01-01

    We have developed a time-of-flight mass spectrometer which is now under operation at HiSOR storage ring for research of photon stimulated ion desorption (PSID). The employment of the pulsed high voltage method as a trigger allowed us to perform the investigations at a multi bunch operation of the storage ring. The performance of this spectrometer was evaluated by applying to the PSID measurements of PMMA (poly-methylmethacrylate) thin films. The results are compared with those obtained at Photon Factory by using pulsed synchrotron radiation in a single bunch operation. The capabilities of the apparatus for ion desorption studies are discussed.

  8. Applications of accelerator mass spectrometry to environmental and paleoclimate studies

    Full text: A wide range of climatic, geologic and archaeological records can be characterized by measuring their 14C and 10Be concentrations, using the accelerator mass spectrometry (AMS). These records are found not only in the traditional sampling sites such as lake sediments and ice cores, but also in diverse natural records such as: loess/paleosol deposits, corals, speleothems and forest-fire horizons. The in-situ production of cosmogenic radionuclides in terrestrial materials is a new methodology which provides several possibilities of determining their chronology. The purpose of this paper is to highlight selected applications of AMS, which have bearing to our understanding of both chronology of archival materials, and learning about climatic changes in the past. The development of a good chronology is very important to the understanding of past climatic changes and their relationship to other events. To correlate distinct climatic features requires that we are able to correlate phenomena, which can be dated independently. The improvement in the radiocarbon calibration curve over the last 26,000 yr has allowed us to cross-correlate fluctuations in the 14C curve directly with those in the ice-core record. This capability has improved attempts to cross-correlate different climatic events observed in one record with other proxy records. This extension of the calibration curve used tree rings to about 11,500 calibrated years and beyond that used corals and varved marine sediments. Other newer but perhaps less-reliable records can take us back to the limits of radiocarbon dating, using lake sediments and speleothem records. An important consideration in the geochronology of past climate change is that the same event might be manifest in different ways in different parts of the world. For example, the uniformly cold younger Dryas in northern Europe and eastern North America might not have the same expression elsewhere. To give one example, although the Younger

  9. The future of the accelerator mass spectrometry of rare long-lived radioactive isotopes

    Accelerators, originally designed for nuclear physics, can be added to mass spectrometric apparatus to increase the sensitivity so that isotope ratios in the range 10-12 to 10-15 can be measured routinely. This significant improvement of high-sensitivity mass spectrometry has been called Accelerator Mass Spectrometry. The present article addresses the basic principles of accelerator mass spectrometry and some recent applications which show its versatility. In particular, it is noted that accelerator mass spectrometry could play an increasing role in the measurement of the levels of long lived radioactivities in the environment, including the actinides, which result from human activities such as the use of nuclear power. To fulfill this promise, continued research and development is necessary to provide ion sources, various types of heavy ion accelerators and peripheral magnetic and electric analysers. (N.K.)

  10. Using accelerator mass spectrometry for radiocarbon dating of textiles

    Jull, A.J.T.

    1997-12-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, <1 mg for radiocarbon dating in contrast to earlier counting techniques. This has opened a vast array of applications of radiocarbon dating that was difficult to do before AMS because of sample size limitations of decay counting. Some of the many applications of AMS include paleoclimatic studies, archaeological research and the age of first settlement of North America by man, dating of art works and artifacts, fall times and terrestrial residence ages of meteorites, production of {sup 14}C in lunar samples by galactic and solar cosmic rays, studies of in situ {sup 14}C produced by cosmic ray spallation in rocks and ice, and studies of {sup 14}C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages.

  11. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    M. L. Adamic; J. E. Olson; D. D. Jenson; J. G. Eisenmenger; M. G. Watrous

    2012-09-01

    This NA 22 funded research project investigated the transition of iodine isotopic analyses from thermal ionization mass spectrometry (TIMS) to an accelerator mass spectrometry (AMS) system. Previous work (Fiscal Year 2010) had demonstrated comparable data from TIMS and AMS. With AMS providing comparable data with improved background levels and vastly superior sample throughput, improvement in the sample extraction from environmental sample matrices was needed to bring sample preparation throughput closer to the operation level of the instrument. Previous research used an extraction chemistry that was not optimized for yield or refined for reduced labor to prove the principle. This research was done to find an extraction with better yield using less labor per sample to produce a sample ready for the AMS instrument. An extraction method using tetramethyl ammonium hydroxide (TMAH) was developed for removal of iodine species from high volume air filters. The TMAH with gentle heating was superior to the following three extraction methods: ammonium hydroxide aided by sonication, acidic and basic extraction aided by microwave, and ethanol mixed with sodium hydroxide. Taking the iodine from the extraction solvent to being ready for AMS analysis was accomplished by a direct precipitation, as well as, using silver wool to harvest the iodine from the TMAH. Portions of the same filters processed in FY 2010 were processed again with the improved extraction scheme followed by successful analysis by AMS at the Swiss Federal Institute of Technology. The data favorably matched the data obtained in 2010. The time required for analysis has been reduced over the aqueous extraction/AMS approach developed in FY 2010. For a hypothetical batch of 30 samples, the AMS methodology is about 10 times faster than the traditional gas phase chemistry and TIMS analysis. As an additional benefit, background levels for the AMS method are about 1000 times lower than TIMS. This results from the

  12. Inductively coupled plasma mass spectrometer with laser ablation metal ions release detection in the human mouth

    Kueerova, Hana; Dostalova, Tatjana; Prochazkova, J.

    2002-06-01

    Presence of more dental alloys in oral cavity often causes pathological symptoms. Due to various and multi-faced symptomatology, they tend to be a source of significant problems not only for the patient but also for the dentist. Metal ions released from alloys can cause subjective and objective symptoms in mouth. The aim of this study was detection of metal elements presence in saliva. There were 4 groups of examined persons: with intact teeth (15 individuals) with metallic restorations, pathological currents 5-30 (mu) A, multi-faced subjective symptomatology and uncharacteristic objective diagnosis (32 patients), with metallic restorations and no subjective symptoms (14 persons) and with metallic restorations, without pathological currents and with problems related to galvanism (13 patients). Presence of 14 metal elements was checked by inductively coupled plasma mass spectrometer with laser ablation. Nd:YAG laser detector was used. There were significant differences in content of silver, gold and mercury between persons with intact teeth and other three groups. There were no differences found between subjects with and without galvanic currents, and presence of subjective and objective symptoms.

  13. Elastic and inelastic polarization effects observed with the Argonne effective mass spectrometer

    The Argonne polarized proton beam was used together with the effective mass spectrometer to study several different aspects of pp and pn interactions. The polarized asymmetry for pn elastic scattering was measured for the first time above cyclotron energies. The results show that both I = 0 and I = 1 exchanges have important contributions to the t-channel single-flip amplitudes. While the I = 1 amplitude has the energy dependence expected, the I = 0 contribution falls much faster with energy. For pp → Δ++n using a polarized proton beam a left-right production asymmetry of about 40% for -t greater than or equal to 0.5 GeV2, independent of energy is found. Absorbed one-pion-exchange together with quark-model calculations give a qualitative explanation of the Δ++ decay distributions and their dependence on the beam polarization. In the diffractive process pp → Δ++π-p using a polarized proton beam asymmetries are observed in the low mean Δπ system that can be described by interference between an S-wave Deck background and a P-wave N*1470 resonance contribution. 16 references

  14. Atmospheric pressure flow reactor / aerosol mass spectrometer studies of tropospheric aerosol nucleat and growth kinetics. Final report, June, 2001

    Worsnop, Douglas R.

    2001-06-01

    The objective of this program was to determine the mechanisms and rates of growth and transformation and growth processes that control secondary aerosol particles in both the clear and polluted troposphere. The experimental plan coupled an aerosol mass spectrometer (AMS) with a chemical ionization mass spectrometer to provide simultaneous measurement of condensed and particle phases. The first task investigated the kinetics of tropospheric particle growth and transformation by measuring vapor accretion to particles (uptake coefficients, including mass accommodation coefficients and heterogeneous reaction rate coefficients). Other work initiated investigation of aerosol nucleation processes by monitoring the appearance of submicron particles with the AMS as a function of precursor gas concentrations. Three projects were investigated during the program: (1) Ozonolysis of oleic acid aerosols as model of chemical reactivity of secondary organic aerosol; (2) Activation of soot particles by measurement deliquescence in the presence of sulfuric acid and water vapor; (3) Controlled nucleation and growth of sulfuric acid aerosols.

  15. A field-deployable, chemical ionization time-of-flight mass spectrometer

    T. H. Bertram

    2011-07-01

    Full Text Available We constructed a new chemical ionization time-of-flight mass spectrometer (CI-TOFMS that measures atmospheric trace gases in real time with high sensitivity. We apply the technique to the measurement of formic acid via negative-ion proton transfer, using acetate as the reagent ion. A novel high pressure interface, incorporating two RF-only quadrupoles is used to efficiently focus ions through four stages of differential pumping before analysis with a compact TOFMS. The high ion-duty cycle (>20 % of the TOFMS combined with the efficient production and transmission of ions in the high pressure interface results in a highly sensitive (>300 ions s−1 pptv−1 formic acid instrument capable of measuring and saving complete mass spectra at rates faster than 10 Hz. We demonstrate the efficient transfer and detection of both bare ions and ion-molecule clusters, and characterize the instrument during field measurements aboard the R/V Atlantis as part of the CalNex campaign during the spring of 2010. The in-field short-term precision is better than 5 % at 1 pptv (pL/L, for 1-s averages. The detection limit (3 σ, 1-s averages of the current version of the CI-TOFMS, as applied to the in situ detection of formic acid, is limited by the magnitude and variability in the background determination and was determined to be 4 pptv. Application of the CI-TOFMS to the detection of other inorganic and organic acids, as well as the use of different reagent ion molecules (e.g. I, CF3O, CO3 is promising, as we have demonstrated efficient transmission and detection of both bare ions and their associated ion-molecule clusters.

  16. Multiplexed parallel reaction monitoring targeting histone modifications on the QExactive mass spectrometer.

    Tang, Hui; Fang, Huasheng; Yin, Eric; Brasier, Allan R; Sowers, Lawrence C; Zhang, Kangling

    2014-06-01

    Histone acetylation and methylation play an important role in the regulation of gene expression. Irregular patterns of histone global acetylation and methylation have frequently been seen in various diseases. Quantitative analysis of these patterns is of high value for the evaluation of disease development and of outcomes from therapeutic treatment. Targeting histone acetylation and methylation by selected reaction monitoring (SRM) is one of the current quantitative methods. Here, we reported the use of the multiplexed parallel reaction monitoring (PRM) method on the QExactive mass spectrometer to target previously known lysine acetylation and methylation sites of histone H3 and H4 for the purpose of establishing precursor-product pairs for SRM. 55 modified peptides among which 29 were H3 K27/K36 modified peptides were detected from 24 targeted precursor ions included in the inclusion list. The identification was carried out directly from the trypsin digests of core histones that were separated without derivatization on a homemade capillary column packed with Waters YMC ODS-AQ reversed phase materials. Besides documenting the higher-energy c-trap dissociation (HCD) MS(2) spectra of previously known histone H3/H4 acetylated and methylated tryptic peptides, we identified novel H3 K18 methylation, H3 K27 monomethyl/acetyl duel modifications, H2B K23 acetylation, and H4 K20 acetylation in mammalian histones. The information gained from these experiments sets the foundation for quantification of histone modifications by targeted mass spectrometry methods directly from core histone samples. PMID:24823915

  17. Acceleration of the GrIS mass loss as observed by GRACE

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2012-01-01

    The mass loss of the Greenland Ice Sheet (GrIS) has previously been analysed in a variety of ways, including altimetry, gravimetry and mass budget calculations, establishing a continuing decrease in the ice mass, with a number of studies finding acceleration in the mass loss. Here, we examine this...... acceleration and its statistical significance, using different sets of processed gravimetric data from the GRACE mission. Using an OLS model that takes annual and subannual variation into account, we compare three different GRACE solutions, determining the spatial variability of the acceleration and confidence...

  18. Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer TRIGA-TRAP

    The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard 12C. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3-4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are discussed in the context of valence proton-neutron interactions using double differences of binding energies, δVpn(Z,N).

  19. Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer TRIGA-TRAP

    Ketelaer, J.; Audi, G.; Beyer, T.; Blaum, K.; Block, M.; Cakirli, R. B.; Casten, R. F.; Droese, C.; Dworschak, M.; Eberhardt, K.; Eibach, M.; Herfurth, F.; Minaya Ramirez, E.; Nagy, Sz.; Neidherr, D.; Nörtershäuser, W.; Smorra, C.; Wang, M.

    2011-07-01

    The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard C12. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3-4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are discussed in the context of valence proton-neutron interactions using double differences of binding energies, δVpn(Z,N).

  20. Measurement of Uranium Isotopes in Particles of U3O8 by Secondary Ion Mass Spectrometry-Single-Stage Accelerator Mass Spectrometry (SIMS-SSAMS).

    Fahey, Albert J; Groopman, Evan E; Grabowski, Kenneth S; Fazel, Kamron C

    2016-07-19

    A commercial secondary ion mass spectrometer (SIMS) was coupled to a ± 300 kV single-stage accelerator mass spectrometer (SSAMS). Positive secondary ions generated with the SIMS were injected into the SSAMS for analysis. This combined instrument was used to measure the uranium isotopic ratios in particles of three certified reference materials (CRM) of uranium, CRM U030a, CRM U500, and CRM U850. The ability to inject positive ions into the SSAMS is unique for AMS systems and allows for simple analysis of nearly the entire periodic table because most elements will readily produce positive ions. Isotopic ratios were measured on samples of a few picograms to nanograms of total U. Destruction of UH(+) ions in the stripper tube of the SSAMS reduced hydride levels by a factor of ∼3 × 10(4) giving the UH(+)/U(+) ratio at the SSAMS detector of ∼1.4 × 10(-8). These hydride ion levels would allow the measurement of (239)Pu at the 10 ppb level in the presence of U and the equivalent of ∼10(-10 236)U concentration in natural uranium. SIMS-SSAMS analysis of solid nuclear materials, such as these, with signals nearly free of molecular interferences, could have a significant future impact on the way some measurements are made for nuclear nonproliferation. PMID:27321905

  1. Towards the hand-held mass spectrometer: design considerations, simulation, and fabrication of micrometer-scaled cylindrical ion traps

    Blain, Matthew G.; Riter, Leah S.; Cruz, Dolores; Austin, Daniel E.; Wu, Guangxiang; Plass, Wolfgang R.; Cooks, R. Graham

    2004-08-01

    Breakthrough improvements in simplicity and reductions in the size of mass spectrometers are needed for high-consequence fieldable applications, including error-free detection of chemical/biological warfare agents, medical diagnoses, and explosives and contraband discovery. These improvements are most likely to be realized with the reconceptualization of the mass spectrometer, rather than by incremental steps towards miniaturization. Microfabricated arrays of mass analyzers represent such a conceptual advance. A massively parallel array of micrometer-scaled mass analyzers on a chip has the potential to set the performance standard for hand-held sensors due to the inherit selectivity, sensitivity, and universal applicability of mass spectrometry as an analytical method. While the effort to develop a complete micro-MS system must include innovations in ultra-small-scale sample introduction, ion sources, mass analyzers, detectors, and vacuum and power subsystems, the first step towards radical miniaturization lies in the design, fabrication, and characterization of the mass analyzer itself. In this paper we discuss design considerations and results from simulations of ion trapping behavior for a micrometer scale cylindrical ion trap (CIT) mass analyzer (internal radius r0 = 1 [mu]m). We also present a description of the design and microfabrication of a 0.25 cm2 array of 106 one-micrometer CITs, including integrated ion detectors, constructed in tungsten on a silicon substrate.

  2. Improved Ion Optics for Introduction of Ions into a 9.4 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2014-01-01

    Enhancements to the ion source and transfer optics of our 9.4 T FT-ICR mass spectrometer have resulted in improved ion transmission efficiency for more sensitive mass measurement of complex mixtures at the MS and MS/MS levels. The tube lens/skimmer has been replaced by a dual ion funnel and the following octopole by a quadrupole for reduced ion cloud radial expansion before transmission into a mass-selective quadrupole. The number of ions that reach the ICR cell is increased by an order of magnitude for the funnel/quadrupole relative to the tube lens/skimmer/octopole. PMID:25601704

  3. Coupling of fully automated chip-based electrospray ionization to high-capacity ion trap mass spectrometer for ganglioside analysis.

    Almeida, Reinaldo; Mosoarca, Cristina; Chirita, Marius; Udrescu, Valentina; Dinca, Nicolae; Vukelić, Zeljka; Allen, Mark; Zamfir, Alina D

    2008-07-01

    NanoMate robot was coupled to a high-capacity ion trap (HCT) mass spectrometer to create a system merging automatic chip-based electrospray ionization (ESI) infusion, ultrafast ion detection, and multistage sequencing at superior sensitivity. The interface between the NanoMate and HCT mass spectrometer consists of an in-laboratory constructed mounting device that allows adjustment of the robot position with respect to the mass spectrometer inlet. The coupling was optimized for ganglioside (GG) high-throughput analysis in the negative ion mode and was implemented in clinical glycolipidomics for identification and structural characterization of anencephaly-associated species. By NanoMate HCT mass spectrometry (MS), data corroborating significant differences in GG expression in anencephalic versus age-matched normal brain tissue were collected. The feasibility of chip-based nanoESI HCT multistage collision-induced dissociation (CID MS(n)) for polysialylated GG fragmentation and isomer discrimination was tested on a GT1 (d18:1/18:0) anencephaly-associated structure. MS(2)-MS(4) obtained by accumulating scans at variable fragmentation amplitudes gave rise to the first fragmentation patterns from which the presence of GT1b structural isomer could be determined unequivocally without the need for supplementary investigation by any other analytical or biochemical methods. PMID:18406832

  4. Toward a Fieldable Atomic Mass Spectrometer for Safeguards Applications: Sample Preparation and Ionization

    Barinaga, Charles J.; Hager, George J.; Hart, Garret L.; Koppenaal, David W.; Marcus, R. Kenneth; Jones, Sarah MH; Manard, Benjamin T.

    2014-10-31

    The International Atomic Energy Agency’s (IAEA’s) long-term research and development plan calls for the development of new methods to detect misuse at nuclear fuel cycle facilities such as reprocessing and enrichment plants. At enrichment plants, for example, the IAEA’s contemporary safeguards approaches are based on a combination of routine and random inspections that include collection of UF6 samples from in-process material and selected cylinders for subsequent analyses. These analyses include destructive analysis (DA) in a laboratory (typically by mass spectrometry [MS]) for isotopic characterization, and environmental sampling (ES) for subsequent laboratory elemental and isotopic analysis (also both typically by MS). One area of new method development includes moving this kind of isotope ratio analytical capability for DA and ES activities into the field. Some of the reasons for these developments include timeliness of results, avoidance of hazardous material shipments, and guidance for additional sample collecting. However, this capability does not already exist for several reasons, such as that most lab-based chemical and instrumental methods rely on laboratory infrastructure (highly trained staff, power, space, hazardous material handling, etc.) and require significant amounts of consumables (power, compressed gases, etc.). In addition, there are no currently available, fieldable instruments for atomic or isotope ratio analysis. To address these issues, Pacific Northwest National Laboratory (PNNL) and collaborator, Clemson University, are studying key areas that limit the fieldability of isotope ratio mass spectrometry for atomic ions: sample preparation and ionization, and reducing the physical size of a fieldable mass spectrometer. PNNL is seeking simple and robust techniques that could be effectively used by inspectors who may have no expertise in analytical MS. In this report, we present and describe the preliminary findings for three candidate

  5. Inside Enceladus’ plumes: the view from Cassini’s mass spectrometer

    Perry, Mark E.; Hurley, Dana M.; Teolis, Ben D.; Waite, J. Hunter; Magee, Brian A.; Smith, H. Todd; Tenishev, Valeriy; Westlake, Joe H.; McNutt, Ralph L.

    2015-11-01

    Between early 2008 and late 2012, the Ion and Neutral Mass Spectrometer (INMS) on Cassini measured particles deep inside the plumes of Enceladus seven times from varying altitudes and locations. From these measurements and the models that use them, we have extracted information that can be used to constrain the physical processes that create the plumes and govern their source.Neutral densities are high only when INMS is within view of the tiger stripes. Inside the plumes, INMS measures spatial variations that are consistent with Mach-4 jets superimposed on more-diffuse vapor. INMS measured vapor velocity directly during a portion of one encounter, finding a Mach-4 distribution centered on 1.2 km/s. Modeling of vapor sources distributed along the tiger stripes show they contribute 20% to 75% of the total density, depending on the encounter and assumptions on the discrete sources. Model-fitted velocities range from 500 to 1300 m/s. The INMS data also show 3x variations in total density that are consistent with the orbit-phase variations detected in visual and IR remote observations of dust plumes. Only H3O+ ions are observed clearly inside the plumes.An ice grain entering INMS increases the counts for one measurement. These spikes are the largest source of uncertainty (40%) in vapor measurements, but also provide independent measurements of ice grains. The frequency of these ice grains matches the Cosmic Dust Analyzer counts for grains larger than 0.2 μm. Their orbit-phase variability as seen by INMS is also consistent with VIMS data.Water vapor comprises at least 90% of the plumes, with CO2, NH3, and CH4 positively identified and less than 1%, each. H2 is likely 5-10%, but its abundance is uncertain due to fractionation of H2O in the instrument. A species (CO or N2) with a mass of 28 u is as abundant as CO2. The C2 group totals 100 u. During individual encounters, CO2 and the 28-u species show differences that are due at least in part to mass-dependent thermal

  6. The composition of the Jovian atmosphere as determined by the Galileo probe mass spectrometer.

    Niemann, H B; Atreya, S K; Carignan, G R; Donahue, T M; Haberman, J A; Harpold, D N; Hartle, R E; Hunten, D M; Kasprzak, W T; Mahaffy, P R; Owen, T C; Way, S H

    1998-09-25

    The Galileo probe mass spectrometer determined the composition of the Jovian atmosphere for species with masses between 2 and 150 amu from 0.5 to 21.1 bars. This paper presents the results of analysis of some of the constituents detected: H2, He, Ne, Ar, Kr, Xe, CH4, NH3, H2O, H2S, C2 and C3 nonmethane hydrocarbons, and possibly PH3 and Cl. 4He/H2 in the Jovian atmosphere was measured to be 0.157 +/- 0.030. 13C/C12 was found to be 0.0108 +/- 0.0005, and D/H and 3He/4He were measured. Ne was depleted, < or = 0.13 times solar, Ar < or = 1.7 solar, Kr < or = 5 solar, and Xe < or = 5 solar. CH4 has a constant mixing ratio of (2.1 +/- 0.4) x 10(-3) (12C, 2.9 solar), where the mixing ratio is relative to H2. Upper limits to the H2O mixing ratio rose from 8 x 10(-7) at pressures <3.8 bars to (5.6 +/- 2.5) x 10(-5) (16O, 0.033 +/- 0.015 solar) at 11.7 bars and, provisionally, about an order of magnitude larger at 18.7 bars. The mixing ratio of H2S was <10(-6) at pressures less than 3.8 bars but rose from about 0.7 x 10(-5) at 8.7 bars to about 7.7 x 10(-5) (32S, 2.5 solar) above 15 bars. Only very large upper limits to the NH3 mixing ratio have been set at present. If PH3 and Cl were present, their mixing ratios also increased with pressure. Species were detected at mass peaks appropriate for C2 and C3 hydrocarbons. It is not yet clear which of these were atmospheric constituents and which were instrumentally generated. These measurements imply (1) fractionation of 4He, (2) a local, altitude-dependent depletion of condensables, probably because the probe entered the descending arm of a circulation cell, (3) that icy planetesimals made significant contributions to the volatile inventory, and (4) a moderate decrease in D/H but no detectable change in (D + 3He)/H in this part of the galaxy during the past 4.6 Gyr. PMID:11543372

  7. Precision mass measurements of exotic calcium isotopes using ISOLTRAP's multi-reflection time-of-flight (MR-ToF) mass spectrometer

    Wienholtz, Frank; George, Sebastian; Rosenbusch, Marco; Schweikhard, Lutz; Wolf, Robert [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, Greifswald (Germany); Beck, Dietrich; Herfurth, Frank; Neidherr, Denis [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Blaum, Klaus; Borgmann, Christopher [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Breitenfeldt, Martin [Katholieke Universiteit, Leuven (Belgium); Cakirli, R. Burcu [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); University of Istanbul, Istanbul (Turkey); Holt, Jason D.; Simonis, Johannes [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Kowalska, Magdalena [CERN, Geneva (Switzerland); Kreim, Susanne [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); CERN, Geneva (Switzerland); Lunney, David; Manea, Vladimir [CSNSM-IN2P3-CNRS, Universite Paris-Sud, Orsay (France); Menendez, Javier; Schwenk, Achim [ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Stanja, Juliane; Zuber, Kai [Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden (Germany)

    2013-07-01

    State-of-the-art precision measurements on radioactive ions have been performed with the Penning-trap mass spectrometer ISOLTRAP at CERN. Minute production rates often accompanied by huge isobaric background and millisecond half-lives pose enormous challenges on the experimental setup and often require new experimental techniques. The ISOLTRAP setup has recently been enhanced with an electrostatic mirror ion trap acting as a multi-reflection time-of-flight mass separator (MR-ToF MS) for beam purification. It can likewise be used as a spectrometer in combination with a suitable detector increasing the mass-measurement capability of ISOLTRAP considerably. The measurements on the calcium isotopic chain will be presented together with the nuclear structure they reveal. The measurements up to {sup 54}Ca are compared with predictions from models that utilize three-body nuclear forces.

  8. Construction of γπ0 spectrometer and photon tagging facility at Bates Linear Accelerator. Final report, July 31, 1979-July 31, 1980

    The funds provided under Contract No. DE-AC02-79ER10486 were totally expended for hardware and supplies required by two related devices at the Bates Linear Accelerator. These were a photon tagging facility and a γπ0 spectrometer in Beam Line C of the new South Experimental Hall. Construction was begun in November of 1979 and both systems became fully operational in the summer of 1981. Preliminary data was taken in 1980 with a prototype γπ0 spectrometer will be carried out in the fall of 1981 and spring of 1982. The photon tagging system has been used successfully to calibrate the γπ0 spectrometer for the BU - MIT collaboration and to test a lead glass detector system for Brandeis University

  9. On-line monitoring of control rod integrity in BWRs using a mass spectrometer

    Larsson, I.; Loner, H.; Ammon, K.; Sihver, L.; Ledergerber, G.

    2013-01-01

    Surveillance of fuel and control rod integrity in the core of a boiling water reactor is essential for maintaining a safe and reliable operation. Control rods of a boiling water reactor are mainly filled with boron carbide as a neutron absorber. Due to the irradiation of boron with neutrons, a continuous production of lithium and helium will occur inside a control rod. Most of the created helium will be retained in the boron carbide lattice; however a small part will escape into the void volume of the control blade. Therefore the integrity of control rods during operation can efficiently be followed by on-line measurements of helium concentration in the reactor off-gas system using a mass spectrometer. Since helium is a fill gas in fuel rods, the same method is a useful early warning system for primary fuel failures. In this paper, we introduce an on-line helium detector system which is installed at the nuclear power plant in Leibstadt. Furthermore the measuring experiences of control rod failure detection at the plant are presented. Different causes of increased helium levels in the off-gas system have been distinguished. There are spontaneous helium releases as well as helium releases caused by changed conditions in the reactor (power reduction, control rod movement, etc.). Helium peaks can also be characterized according to the released amount of helium, the peak shape and the duration of the release, which leads to different interpretations of the release mechanisms. In addition, the measured amount of released helium from a 50 days period (280 l) is also compared to the calculated amount of produced helium from the washed out boron during the same time period (190 l).

  10. Development of Soft Ionization for Particulate Organic Detection with the Aerodyne Aerosol Mass Spectrometer

    Trimborn, A; Williams, L R; Jayne, J T; Worsnop, D R

    2008-06-19

    During this DOE SBIR Phase II project, we have successfully developed several soft ionization techniques, i.e., ionization schemes which involve less fragmentation of the ions, for use with the Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS). Vacuum ultraviolet single photon ionization was demonstrated in the laboratory and deployed in field campaigns. Vacuum ultraviolet single photon ionization allows better identification of organic species in aerosol particles as shown in laboratory experiments on single component particles, and in field measurements on complex multi-component particles. Dissociative electron attachment with lower energy electrons (less than 30 eV) was demonstrated in the measurement of particulate organics in chamber experiments in Switzerland, and is now a routine approach with AMS systems configured for bipolar, negative ion detection. This technique is particularly powerful for detection of acidic and other highly oxygenated secondary organic aerosol (SOA) chemical functionality. Low energy electron ionization (10 to 12 eV) is also a softer ionization approach routinely available to AMS users. Finally, Lithium ion attachment has been shown to be sensitive to more alkyl-like chemical functionality in SOA. Results from Mexico City are particularly exciting in observing changes in SOA molecular composition under different photochemical/meteorological conditions. More recent results detecting biomass burns at the Montana fire lab have demonstrated quantitative and selective detection of levoglucosan. These soft ionization techniques provide the ToF-AMS with better capability for identifying organic species in ambient atmospheric aerosol particles. This, in turn, will allow more detailed study of the sources, transformations and fate of organic-containing aerosol.

  11. Developments of remote-controlled Electron Probe Micro Analyzer and Secondary Ion Mass Spectrometer

    The remote controlled Electron Probe Micro Analyzer (EPMA) and Secondary Ion Mass Spectrometer (SIMS) which were shielded by each lead box have been developed to study and research the characteristics of highly irradiated fuel pellets and cladding tubes. EPMA and SIMS are utilized to investigate the distribution or composition of fission products (FP) and intermetallic compounds, etc. in detail. This paper describes the summary of these instruments and the example of applications. As a sample is automatically transferred by rack-and-pinion, which was specially designed in each instrument, from the sample handling cell to the analytical chambers, the outer surface of instruments has no radioactive contamination. It means the maintenance of instruments is easy and speedy. EPMA was installed in 1991, and had been applied to examinations of irradiated fuel pellets and cladding tubes. SIMS is under a mock-up-test using unirradiated samples. This instrument has several features as shown below. (1) Cs+ ion gun and 02+ ion gun were attached to the analytical chamber. The minimum diameter of CS+ ion beam is ≤ 0.2 μm and that of 02+ ion beam is ≤ 2 μm. Ion guns will be suitably selected according to the analytical elements or the size of analytical area, etc. (2) Auger electron spectroscopy (AES) other than SIMS was attached. This makes possible speedy quantitative analysis to supplement the results of SIMS. (3) The compact machine which fractures a specimen by tensile tension was attached to AES chamber. The clean surface fractured under ultrahigh vacuum condition can be analyzed. (author). 9 refs, 9 figs, 1 tab

  12. Determining Solubility and Diffusivity by Using a Flow Cell Coupled to a Mass Spectrometer.

    Khodayari, Mehdi; Reinsberg, Philip; Abd-El-Latif, Abd-El-Aziz A; Merdon, Christian; Fuhrmann, Juergen; Baltruschat, Helmut

    2016-06-01

    One of the main challenges in metal-air batteries is the selection of a suitable electrolyte that is characterized by high oxygen solubility, low viscosity, a liquid state and low vapor pressure across a wide temperature range, and stability across a wide potential window. Herein, a new method based on a thin layer flow through cell coupled to a mass spectrometer through a porous Teflon membrane is described that allows the determination of the solubility of volatile species and their diffusion coefficients in aqueous and nonaqueous solutions. The method makes use of the fact that at low flow rates the rate of species entering the vacuum system, and thus the ion current, is proportional to the concentration times the flow rate (c⋅u) and independent of the diffusion coefficient. The limit at high flow rates is proportional to D2/3·c·u1/3 . Oxygen concentrations and diffusion coefficients in aqueous electrolytes that contain Li(+) and K(+) and organic solvents that contain Li(+) , K(+) , and Mg(2+) , such as propylene carbonate, dimethyl sulfoxide tetraglyme, and N-methyl-2-pyrrolidone, have been determined by using different flow rates in the range of 0.1 to 80 μL s(-1) . This method appears to be quite reliable, as can be seen by a comparison of the results obtained herein with available literature data. The solubility and diffusion coefficient values of O2 decrease as the concentration of salt in the electrolyte was increased due to a "salting out" effect. PMID:27017297

  13. Atmospheric amines and ammonia measured with a Chemical Ionization Mass Spectrometer (CIMS

    Y. You

    2014-06-01

    Full Text Available We report ambient measurements of amines and ammonia with a~fast response chemical ionization mass spectrometer (CIMS in a southeastern US forest in Alabama and a~moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv and ammonia (up to 2 ppbv were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1–C6 at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast US. At the moderately polluted Kent site, higher concentrations of amines (C1–C6, from pptv to tens of pptv and ammonia (up to 6 ppbv were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

  14. Atmospheric Amines and Ammonia Measured with a Chemical Ionization Mass Spectrometer (CIMS)

    You, Y.; Kanawade, V. P.; de Gouw, J. A.; Guenther, Alex B.; Madronich, Sasha; Sierra-Hernandez, M. R.; Lawler, M.; Smith, James N.; Takahama, S.; Ruggeri, G.; Koss, A.; Olson, K.; Baumann, K.; Weber, R. J.; Nenes, A.; Guo, H.; Edgerton, Eric S.; Porcelli, L.; Brune, W. H.; Goldstein, Allen H.; Lee, S.-H

    2014-11-19

    We report ambient measurements of amines and ammonia with a fast response chemical ionization mass spectrometer (CIMS) in a Southeastern U.S. forest in Alabama and a moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1-C6) at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast U.S. At the moderately polluted Kent site, higher concentrations of amines (C1-C6, from pptv to tens of pptv) and ammonia (up to 6 ppbv) were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

  15. Analysis of the fatty acid composition of taraxicuum officinale flowers oil by gas chromatography mass spectrometer

    Taraxicum officinale, is a highly valuable medicinal plant. The roots is an important herbal drug, having long been used on the continent as a remedy for liver complaints. Keeping in view the importance and wide applications in the pharmaceutical industries, the present study was therefore aimed to analyze the chemical constituents of the flowers of T. officinale. The T. officinale flowers oil constituents of methyl ester derivatives of fatty acids were analyzed applying gas chromatography coupled to mass spectrometer. The results obtained showed the presence of both containing the saturated as well as unsaturated fatty acids in T. officinale flower oils. A total of 19 different components were identified and quantified. The concentration level of Methyl ester of Lenolenic acid was found very effective in concentration 3.33%, among the identified analytes of interest. In addition, the level of other chemical constituents of methyl ester of palmitic acid 3.11%, myristic acid 1.87, linolenic acids 1.67%, stearic acid 0.97 were found. The concentration level of the rest of identified fatty acids analytes were below 1%. Thus the results obtained from the current initiative is very promising due to the presence of high percentage of valuable analytes concentrations recorded in the fatty acid of T. officinale flower oil. Thus due to the presence of highly important analytes which have increased their importance for consumption in the pharmaceuticals as well as its applications in the new formulations for different skin, cosmetics and health purposes and for use by local practioners. The study will also provide a scientific database line. (author)

  16. Establishing and Monitoring an Aseptic Workspace for Building the MOMA Mass Spectrometer

    Lalime, Erin

    2016-01-01

    Mars Organic Molecule Analyzer (MOMA) is an instrument suite on the ESA ExoMars 2018 Rover, and the Mass Spectrometer (MOMA-MS) is being built at Goddard Space Flight Center (GSFC). As MOMA-MS is a life-detection instrument and it thus falls in the most stringent category of Planetary Protection (PP) biological cleanliness requirements. Less than 0.03 sporem2 is allowed in the instrument sample path. In order to meet these PP requirements, MOMA-MS must be built and maintained in a low bioburden environment. The MOMA-MS project at GSFC maintains three cleanrooms with varying levels of bioburden control. The Aseptic Assembly Cleanroom has the highest level of control, applying three different bioburden reducing methods: 70 IPA, 7.5 Hydrogen Peroxide, and Ultra-Violet C light. The three methods are used in rotation and each kills microbes by a different mechanism, reducing the likelihood of microorganisms developing resistance to all three. The Integration and Mars Chamber Cleanrooms use less biocidal cleaning, with the option to deploy extra techniques as necessary. To support the monitoring of cleanrooms and verification that MOMA-MS hardware meets PP requirements, a new Planetary Protection lab was established that currently has the capabilities of standard growth assays for spore or vegetative bacteria, rapid bioburden analysis that detects Adenosine Triphosphate (ATP), plus autoclave and DHMR verification. The cleanrooms are monitored both for vegetative microorganisms and by rapid ATP assay, and a clear difference in bioburden is observed between the aseptic the other cleanroom.

  17. Airborne observations of formic acid using a chemical ionization mass spectrometer

    M. Le Breton

    2012-12-01

    Full Text Available The first airborne measurements of formic acid mixing ratios over the United Kingdom were measured on the FAAM BAe-146 research aircraft on 16 March 2010 with a chemical ionization mass spectrometer using I reagent ions. The I ionization scheme was able to measure formic acid mixing ratios at 1 Hz in the boundary layer.

    In-flight standard addition calibrations from a formic acid source were used to determine the instrument sensitivity of 35 ± 6 ion counts pptv−1 s−1 and a limit of detection of 25 pptv. Routine measurements were made through a scrubbed inlet to determine the instrumental background. Three plumes of formic acid were observed over the UK, originating from London, Humberside and Tyneside. The London plume had the highest formic acid mixing ratio throughout the flight, peaking at 358 pptv. No significant correlations of formic acid with NOx and ozone were found, but a positive correlation was observed between CO and HCOOH within the two plumes where coincident data were recorded.

    A trajectory model was employed to determine the sources of the plumes and compare modelled mixing ratios with measured values. The model underestimated formic acid concentrations by up to a factor of 2. This is explained by missing sources in the model, which were considered to be both primary emissions of formic acid of mainly anthropogenic origin and a lack of precursor emissions, such as isoprene, from biogenic sources, whose oxidation in situ would lead to formic acid formation.

  18. Modification of a tandem mass-spectrometer for infrared multi-photon dissociation (IRMPD) of gas-phase ions

    Gillis, Julie M.; Osburn, Sandra M.; van Stipdonk, Michael J.; Corcovilos, Theodore A.

    2015-05-01

    Infrared multi-photon dissociation (IRMPD) is a method of fragmenting molecular ions for structural analysis of the parent molecule. The target ions absorb many photons, increasing the vibrational state of the excited bonds until the dissociation occurs. We have modified a commercial linear quadrupole trap tandem mass spectrometer (Thermo-Fisher LTQ) by installing a removable high-vacuum window in the rear accessory plate of the mass spectrometer. The window allows us to inject laser light into the ion trap. The shape of the injected laser beam is optimized to match the volume of the ion cloud within the ion trap, improving IRMPD efficiency. We present preliminary data of the IRMPD of weakly bound uranyl-acetone and uranyl-dimethyl sulfoxide clusters using a 20-W pulsed CO2 laser (wavelength 10 . 6 μm), showing previously undetected fragmentation products.

  19. A global thermospheric model based on mass spectrometer and incoherent scatter data MSIS. I - N2 density and temperature

    Hedin, A. E.; Reber, C. A.; Newton, G. P.; Spencer, N. W.; Salah, J. E.; Evans, J. V.; Kayser, D. C.; Alcayde, D.; Bauer, P.; Cogger, L.

    1977-01-01

    Measurements of neutral nitrogen density from mass spectrometers on five satellites (AE-B, Ogo 6, San Marco 3, Aeros A, and AE-C) and neutral temperatures inferred from incoherent scatter measurements at four ground stations are combined to produce a model of thermospheric neutral temperatures and nitrogen densities similar to the Ogo 6 empirical model (Hedin et al., 1974). This global model is designated MSIS (mass spectrometer and incoherent scatter). The global average temperature, the annual temperature variation, lower bound density, and lower bound temperature are discussed. The data set covers the time period from the end of 1965 to mid-1975 and also a wide range of solar activities. Diurnal and semidiurnal variations in lower bound density and temperature are considered, as is magnetic activity.

  20. Direct Chemical Analysis of Solids by Laser Ablation in an Ion-Storage Time-of-Flight Mass Spectrometer

    Klunder, G L; Grant, P M; Andresen, B D; Russo, R E

    2003-09-29

    A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows direct viewing and selected analysis of the sample. Measurements identified trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Resolution (m/{micro}m) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

  1. Compensation of large ion energy spreads by multigap grid reflectors in time-of-flight mass spectrometers

    Pilyugin, I. I.

    2016-03-01

    The problem of compensation of the initial ion energy spread by a multigap grid reflector of the time-of-flight mass spectrometer is considered. It is shown mathematically that the problem can be reduced to analysis of properties of catastrophes A n under additional conditions of positive geometrical gaps of the reflector. Examples of design of reflectors corresponding to catastrophes A 2 and A 3 are analyzed. The advantage of a three-gap reflector over a two-gap reflector in the compensation of a large energy spread of ions for the same value of the resolution of the device is demonstrated. The application of the three-gap reflector improves the sensitivity of the time-of-flight mass spectrometer. The results of calculations are confirmed experimentally.

  2. Charging characteristics of Dynamic Explorer I Retarding Ion Mass Spectrometer and the consequence for core plasma measurements

    Olsen, Richard Christopher

    1989-01-01

    Approved for public release; distribution is unlimited. The Retarding Ion Mass Spectrometer (RIMS) on the Dynamics Explorer I (DE I) satellite has provided a new range of data, and challenges for studies of the core plasma of the magnetosphere. Analysis of the RIMS data provides a measure of the satellite potential in the inner magnetosphere. As the satellite leaves the inner plasmasphere, it begins to charge positively, crossing the 0 V mark at about 1000/cc. The potential rises slowly in...

  3. Characterization of particulate matter emissions from on-road gasoline and diesel vehicles using a soot particle aerosol mass spectrometer

    Dallmann, T. R; Onasch, T. B.; Kirchstetter, T. W.; D. R. Worton; Fortner, E. C.; S. C. Herndon; Wood, E C; J. P. Franklin; Worsnop, D.R.; Goldstein, A. H.; R. A. Harley

    2014-01-01

    Particulate matter (PM) emissions were measured in July 2010 from on-road motor vehicles driving through a highway tunnel in the San Francisco Bay area. A soot particle aerosol mass spectrometer (SP-AMS) was used to measure the chemical composition of PM emitted by gasoline and diesel vehicles at high time resolution. Organic aerosol (OA) and black carbon (BC) concentrations were measured during various time periods that had different levels of diesel influence, as well as d...

  4. Characterization of particulate matter emissions from on-road gasoline and diesel vehicles using a soot particle aerosol mass spectrometer

    Dallmann, T. R; Onasch, T. B.; Kirchstetter, T. W.; D. R. Worton; Fortner, E. C.; S. C. Herndon; Wood, E C; J. P. Franklin; Worsnop, D.R.; Goldstein, A. H.; R. A. Harley

    2014-01-01

    Particulate matter (PM) emissions were measured in July 2010 from on-road motor vehicles driving through a highway tunnel in the San Francisco Bay area. A soot particle aerosol mass spectrometer (SP-AMS) was used to measure the chemical composition of PM emitted by gasoline and diesel vehicles at high time resolution. Organic aerosol (OA) and black carbon (BC) concentrations were measured during various time periods that had different levels of diesel influence, as well a...

  5. A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

    E. S. Saltzman; W. J. De Bruyn; Lawler, M J; Marandino, C. A.; McCormick, C. A.

    2009-01-01

    A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS") has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS) in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer ...

  6. The applications of a commercial gas/liquid separator coupled with an inductively coupled plasma mass spectrometer

    Hitchen, Peter; Hutton, Robert; Tye, Christopher

    1992-01-01

    A commercially available hydride generator, with a novel membrane gas-liquid separator, has been coupled to a new ICPMS instrument which itself features many unique design considerations. Little or no optimization of the mass spectrometer or ionization source was required to obtain excellent analytical data; and a variety of matrices have been analysed. The elements As and Se are usually used to demonstrate the effectiveness of a hydride generation system, and these are of particular importan...

  7. A Dual Source Ion Mobility-Mass Spectrometer for Direct Comparison of ESI and MALDI Collision Cross Section Measurements

    Sundarapandian, Sevugarajan; May, Jody C.; McLean, John A.

    2010-01-01

    In this report, we describe a dual ionization source ion mobility-mass spectrometer (IM-MS) instrument platform for investigations that critically compare ion mobility collision cross section (CCS) measurements obtained from different ionization methods. The instrument incorporates both matrix-assisted laser desorption ionization (MALDI) and nano-electrospray ionization (nESI) sources. The nESI source incorporates a keyhole geometry ion funnel design which facilitates axial ion focusing, accu...

  8. Quantification of diesel exhaust gas phase organics by a thermal desorption proton transfer reaction mass spectrometer

    M. H. Erickson

    2012-02-01

    Full Text Available A new approach was developed to measure the total abundance of long chain alkanes (C12 and above in urban air using thermal desorption with a proton transfer reaction mass spectrometer (PTR-MS. These species are emitted in diesel exhaust and may be important precursors to secondary organic aerosol production in urban areas. Long chain alkanes undergo dissociative proton transfer reactions forming a series of fragment ions with formula CnH2n+1. The yield of the fragment ions is a function of drift conditions. At a drift field strength of 80 Townsends, the most abundant ion fragments from C10 to C16 n-alkanes were m/z 57, 71 and 85. The PTR-MS is insensitive to n-alkanes less than C8 but displays an increasing sensitivity for larger alkanes. Higher drift field strengths yield greater normalized sensitivity implying that the proton affinity of the long chain n-alkanes is less than H2O. Analysis of diesel fuel shows the mass spectrum was dominated by alkanes (CnH2n+1, monocyclic aromatics, and an ion group with formula CnH2n−1 (m/z 97, 111, 125, 139. The PTR-MS was deployed in Sacramento, CA during the Carbonaceous Aerosols and Radiative Effects Study field experiment in June 2010. The ratio of the m/z 97 to 85 ion intensities in ambient air matched that found in diesel fuel. Total diesel exhaust alkane concentrations calculated from the measured abundance of m/z 85 ranged from the method detection limit of ~1 μg m−3 to 100 μg m−3 in several air pollution episodes. The total diesel exhaust alkane concentration determined by this method was on average a factor of 10 greater than the sum of alkylbenzenes associated with spark ignition vehicle exhaust.

  9. Characterization of aerosol composition, concentrations, and sources at Baengnyeong Island, Korea using an aerosol mass spectrometer

    Lee, Taehyoung; Choi, Jinsoo; Lee, Gangwoong; Ahn, Junyoung; Park, Jin Soo; Atwood, Samuel A.; Schurman, Misha; Choi, Yongjoo; Chung, Yoomi; Collett, Jeffrey L.

    2015-11-01

    To improve understanding of the sources and chemical properties of particulate pollutants on the western side of the Korean Peninsula, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine (PM1) particles from May to November, 2011 at Baengnyeong Island, South Korea. Organic matter and sulfate were generally the most abundant species and exhibited maximum concentrations of 36 μg/m3 and 39 μg/m3, respectively. Nitrate concentrations peaked at 32 μg/m3 but were typically much lower than sulfate and organic matter concentrations. May, September, October, and November featured the highest monthly average concentrations, with lower concentrations typically observed from June through August. Potential source contribution function (PSCF) analysis and individual case studies revealed that transport from eastern China, an area with high SO2 emissions, was associated with high particulate sulfate concentrations at the measurement site. Observed sulfate aerosol sometimes was fully neutralized by ammonium but often was acidic; the average ammonium to sulfate molar ratio was 1.49. Measured species size distributions revealed a range of sulfate particle size distributions with modes between 100 and 600 nm. Organic aerosol source regions were widespread, including contributions from eastern China and South Korea. Positive matrix factorization (PMF) analysis indicated three "factors," or types of organic aerosol, comprising one primary, hydrocarbon-like organic aerosol (HOA) and two oxidized organic aerosol (OOA) components, including a more oxidized (MO-OOA) and a less oxidized (LO-OOA) oxidized organic aerosol. On average, HOA and OOA contributed 21% and 79% of the organic mass (OM), respectively, with the MO-OOA fraction nearly three times as abundant as the LO-OOA fraction. Biomass burning contributions to observed OM were low during the late spring/early summer agricultural burning season in eastern China, since

  10. Spurious barometric pressure acceleration in Antarctica and propagation into GRACE Antarctic mass change estimates

    Kim, Byeong-Hoon; Eom, Jooyoung; Seo, Ki-Weon; Wilson, Clark R.

    2016-06-01

    Apparent acceleration in GRACE Antarctic ice mass time series may reflect both ice discharge and surface mass balance contributions. However, a recent study suggests there is also contamination from errors in atmospheric pressure de-aliasing fields (ECMWF operational products) used during GRACE data processing. To further examine this question, we compare GRACE atmospheric pressure de-aliasing (GAA) fields with in-situ surface pressure data from coastal and inland stations. Differences between the two are likely due to GAA errors, and provide a measure of error in GRACE solutions. Time series of differences at individual weather stations are fit to four presumed error components: annual sinusoids, a linear trend, an acceleration term, and jumps at times of known ECMWF model changes. Using data from inland stations, we estimate that atmospheric pressure error causes an acceleration error of about +7.0 Gt/yr2, which is large relative to prior GRACE estimates of Antarctic ice mass acceleration in the range of -12 to -14 Gt/yr2. We also estimate apparent acceleration rates from other barometric pressure (reanalysis) fields, including ERA-Interim, MERRA and NCEP/DOE. When integrated over East Antarctica, the four mass acceleration estimates (from GAA and the three reanalysis fields) vary considerably (by ˜2-16 Gt/yr2). This shows the need for further effort to improve atmospheric mass estimates in this region of sparse in situ observations, in order to use GRACE observations to measure ice mass acceleration and related sea level change.

  11. Investigations of paleoclimate variations using accelerator mass spectrometry

    Southon, J R; Kashgarian, M; Brown, T A

    2000-08-24

    This project has used Accelerator Mass Spectrometry (AMS) {sup 14}C measurements to study climate and carbon cycle variations on time scales from decades to millennia over the past 30,000 years, primarily in the western US and the North Pacific. {sup 14}C dates provide a temporal framework for records of climate change, and natural radiocarbon acts as a carbon cycle tracer in independently dated records. The overall basis for the study is the observation that attempts to model future climate and carbon cycle changes cannot be taken seriously if the models have not been adequately tested. Paleoclimate studies are unique because they provide realistic test data under climate conditions significantly different from those of the present, whereas instrumental results can only sample the system as it is today. The aim of this project has been to better establish the extent, timing, and causes of past climate perturbations, and the carbon cycle changes with which they are linked. This provides real-world data for model testing, both for the development of individual models and also for inter-model diagnosis and comparison activities such as those of LLNL's PCMDI program; it helps us achieve a better basic understanding of how the climate system works so that models can be improved; and it gives an indication of the natural variability in the climate system underlying any anthropogenically-driven changes. The research has involved four projects which test hypotheses concerning the overall behavior of the North Pacific climate system. All are aspects of an overall theme that climate linkages are strong and direct, so that regional climate records are correlated, details of fine structure are important, and accurate and precise dating is critical for establishing correlations and even causality. An important requirement for such studies is the requirement for an accurate and precise radiocarbon calibration, to allow better correlation of radiocarbon-dated records with

  12. An Automated High Performance Capillary Liquid Chromatography Fourier Transform Ion Cyclotron Resonance Mass Spectrometer for High-Throughput Proteomics

    We report on a fully automated 9.4 tesla Fourier transform ion resonance cyclotron (FTICR) mass spectrometer coupled to reverse-phase chromatography for high-throughput proteomic studies. Modifications made to the front-end of a commercial FTICR instrument--a dual-ESI-emitter ion source; dual-channel electrodynamic ion funnel; and collisional-cooling, selection and accumulation quadrupoles--significantly improved the sensitivity, dynamic range and mass measurement accuracy of the mass spectrometer. A high-pressure capillary liquid chromatography (LC) system was incorporated with an autosampler that enabled 24 h/day operation. A novel method for accumulating ions in the ICR cell was also developed. Unattended operation of the instrument revealed the exceptional reproducibility (1-5% deviation in elution times for peptides from a bacterial proteome), repeatability (10-20% deviation in detected abundances for peptides from the same aliquot analyzed a few weeks apart) and robustness (high-throughput operation for 5 months without downtime) of the LC/FTICR system. When combined with modulated-ion-energy gated trapping, the internal calibration of FTICR mass spectra decreased dispersion of mass measurement errors for peptide identifications in conjunction with high resolution capillary LC separations to < 5 ppm over a dynamic range for each spectrum of 10 3

  13. Ambient Aerosol in Southeast Asia: High Resolution Aerosol Mass Spectrometer Measurements Over Oil Palm (Elaeis guineensis)

    Phillips, G.; Dimarco, C.; Misztal, P.; Nemitz, E.; Farmer, D.; Kimmel, J.; Jimenez, J.

    2008-12-01

    The emission of organic compounds in the troposphere is important factor in the formation of secondary organic aerosol (SOA). A very large proportion of organic material emitted globally is estimated to arise from biogenic sources, with almost half coming from tropical and sub-tropical forests. Preliminary analyses of leave cuvette emission studies suggest that oil palm (Elaeis guineensis) is a significantly larger source of isoprene than tropical forest. Much larger sources of isoprene over oil palm allied with a larger anthropogenic component of local emissions contrast greatly with the remote tropical forest environment and therefore the character of SOA formed may differ significantly. These issues, allied with the high price of palm oil on international markets leading to increased use of land for oil palm production, could give rise to rapidly changing chemical and aerosol regimes in the tropics. It is therefore important to understand the current emissions and composition of organic aerosol over all important land-uses in the tropical environment. This in turn will lead to a greater understanding of the present, and to an improvement in predictive capacity for the future system. To help address these issues, a high resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) was deployed in the Sabahmas (PPB OIL) oil palm plantation near Lahad Datu, in Eastern Sabah, as part of the field component of the Aerosol Coupling in the Earth System (ACES) project, part of the UK NERC APPRAISE program. This project was allied closely with measurements made of similar chemical species and aerosol components at a forest site in the Danum Valley as part of the UK Oxidant and Particle Photochemical Processes above a Southeast Asian tropical rainforest (OP3) project. Measurements of submicron non- refractory aerosol composition are presented along with some preliminary analysis of chemically resolved aerosol fluxes made with a new eddy covariance system, based on the

  14. Investigating ion-surface collisions with a niobium superconducting tunnel junction detector in a time-of-flight mass spectrometer

    Westmacott; Zhong; Frank; Friedrich; Labov; Benner

    2000-01-01

    The performance of an energy sensitive, niobium superconducting tunnel junction (STJ) detector is investigated by measuring the pulse height produced by impacting molecular and atomic ions at different kinetic energies. Ions are produced by laser desorption and matrix-assisted laser desorption in a time-of-flight mass spectrometer. Our results show that the STJ detector pulse height decreases for increasing molecular ion mass, passes through a minimum at around 2000 Da, and then increases with increasing mass of molecular ions above 2000 Da. The detector does not show a decline in sensitivity for high mass ions as is observed with microchannel plate ion detectors. These detector plus height measurements are discussed in terms of several physical mechanisms involved in an ion-surface collision. PMID:10775095

  15. Study on the atmospheric photochemical reaction of CF3 radicals using ultraviolet photoelectron and photoionization mass spectrometer

    2008-01-01

    A study of the atmospheric photochemical reaction of CF3 radical with CO and O2 was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3OC(O)OOC(O)- OCF3 were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3OC(O)OOC(O)OCF3 are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3 group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.21 and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3OCO+ and CF3+. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

  16. Determination of trace quantity of uranium in end product plutonium oxide samples by isotopic dilution mass spectrometry using an indigenous thermal ionization mass spectrometer

    Characterization of special nuclear materials is an important step for efficient nuclear material management (NMM) in a fuel reprocessing plant. Determination of trace quantity of impurities present in the end product plutonium oxide is very important in categorizing the product for end-user specifications. An accurate knowledge of uranium quantity helps in many ways to characterize the material. Objective of this present work is to optimize the indigenous thermal ionization mass spectrometer for this work and develop a better and effective separation procedure prior to mass spectrometric analysis for determination of trace quantity of uranium in plutonium product stream oxide samples

  17. A Micro-Cylindrical Ion Trap (5-CIT) Micro-Mass Spectrometer Instrument System (5-MSIS) for NASA Planetary Exploration Project

    National Aeronautics and Space Administration — This activity will significantly increase the fidelity of the miniaturized component packaging of the µ-CIT mass spectrometer assembly. Our design approach...

  18. A Micro-Cylindrical Ion Trap (B5-CIT) Micro-Mass Spectrometer Instrument System (B5-MSIS) for NASA Planetary Exploration Project

    National Aeronautics and Space Administration — This activity will significantly increase the fidelity of the miniaturized component packaging of the μ-CIT mass spectrometer assembly. Our design approach...

  19. Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

    Povinec, Pavel P.; Masarik, Jozef; Ješkovský, Miroslav; Kaizer, Jakub; Šivo, Alexander; Breier, Robert; Pánik, Ján; Staníček, Jaroslav; Richtáriková, Marta; Zahoran, Miroslav; Zeman, Jakub

    2015-10-01

    An Accelerator Mass Spectrometry (AMS) laboratory has been established at the Centre for Nuclear and Accelerator Technologies (CENTA) at the Comenius University in Bratislava comprising of a MC-SNICS ion source, 3 MV Pelletron tandem accelerator, and an analyzer of accelerated ions. The preparation of targets for 14C and 129I AMS measurements is described in detail. The development of AMS techniques for potassium, uranium and thorium analysis in radiopure materials required for ultra-low background underground experiments is briefly mentioned.

  20. A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

    E. S. Saltzman

    2009-11-01

    Full Text Available A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS" has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems, which has been modified for use as a chemical ionization mass spectrometer. The mini-CIMS has a gas phase detection limit of 220 ppt DMS for a 1 min averaging time, which is roughly equivalent to a seawater DMS concentration of 0.1 nM DMS at 20°C. The mini-CIMS has the sensitivity, selectivity, and time response required for underway measurements of surface ocean DMS over the full range of oceanographic conditions. The simple, robust design and relatively low cost of the instrument are intended to facilitate use in process studies and surveys, with potential for long-term deployment on research vessels, ships of opportunity, and large buoys.

  1. A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

    E. S. Saltzman

    2009-07-01

    Full Text Available A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS" has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems, which has been modified for use as a chemical ionization mass spectrometer. The mini-CIMS has a gas phase detection limit of 170 ppt DMS for a 1 min averaging time, which is roughly equivalent to a seawater DMS concentration of 0.1 nM DMS at 20°C. The mini-CIMS has the sensitivity, selectivity, and time response required for underway measurements of surface ocean DMS over the full range of oceanographic conditions. The simple, robust design and relatively low cost of the instrument are intended to facilitate use in process studies and surveys, with potential for long-term deployment on research vessels, ships of opportunity, and large buoys.

  2. Search for high mass resonances in the dimuon channel using the muon spectrometer of the atlas experiment at CERN

    This thesis covers the search of new neutral gauge bosons decaying into a pair of muons in the ATLAS detector. The Large Hadron Collider (LHC) at CERN will produce parton collisions with very high center of mass energy and may produce Z' predicted by many theories beyond the standard model. Such a resonance should be detected by the ATLAS experiment. For the direct search of Z' decaying into two muons, a small number of events is enough for its discovery, which is possible with the first data. We shall study in particular the effects of the muon spectrometer alignment on high pT tracks and on the Z' discovery potential in the ATLAS experiment. The discovery potentials computed with this method have been officially approved by the ATLAS collaboration and published. At the start of the LHC operation, the muon spectrometer alignment will not have reached the nominal performances. This analysis aims at optimizing the discovery potential of ATLAS for a Z' boson in this degraded initial conditions. The impact on track reconstruction of a degraded alignment is estimated with simulated high pT tracks. Results are given in terms of reconstruction efficiency, momentum and invariant mass resolutions, charge identification and sensitivity to discovery or exclusion. With the first data, an analysis using only the muon spectrometer in stand alone mode will be very useful. Finally, a study on how to determine the initial geometry of the spectrometer (needed for its absolute alignment) is performed. This study uses straight tracks without a magnetic field and also calculates the beam time necessary for reaching a given accuracy of the alignment system. (author)

  3. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Congedo, Giuseppe

    2014-01-01

    The basic constituent of interferometric gravitational wave detectors -- the test mass to test mass interferometric link -- behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as non-gravitational spurious forces. This last contribution is going to be characterised by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system free evolution dominating the slow displacement dynamics of low-...

  4. Thermally Accelerated Oxidative Degradation of Quercetin Using Continuous Flow Kinetic Electrospray-Ion Trap-Time of Flight Mass Spectrometry

    Barnes, Jeremy S.; Foss, Frank W.; Schug, Kevin A.

    2013-10-01

    Thermally accelerated oxidative degradation of aqueous quercetin at pH 5.9 and 7.4 was kinetically measured using an in-house built online continuous flow device made of concentric capillary tubes, modified to fit to the inlet of an electrospray ionization-ion trap-time-of-flight-mass spectrometer (ESI-IT-TOF-MS). Time-resolved mass spectral measurements ranging from 2 to 21 min were performed in the negative mode to track intermediate degradation products and to evaluate the degradation rate of the deprotonated quercetin ion, [Q-H]-. Upon heating solutions in the presence of dissolved oxygen, degradation of [Q-H]- was observed and was accelerated by an increase in pH and temperature. Regardless of the condition, the same degradation pathways were observed. Degradation mechanisms and structures were determined using higher order tandem mass spectrometry (up to MS3) and high mass accuracy. The observed degradation mechanisms included oxidation, hydroxylation, and ring-cleavage by nucleophilic attack. A chalcan-trione structure formed by C-ring opening after hydroxylation at C2 was believed to be a precursor for other degradation products, formed by hydroxylation at the C2, C3, and C4 carbons from attack by nucleophilic species. This resulted in A-type and B-type ions after cross-ring cleavage of the C-ring. Based on time of appearance and signal intensity, nucleophilic attack at C3 was the preferred degradation pathway, which generated 2,4,6-trihydroxymandelate and 2,4,6-trihydroxyphenylglyoxylate ions. Overall, 23 quercetin-related ions were observed.

  5. Operation and application of a new time-of-flight e-gas secondary neutral mass spectrometer (ToF-SNMS).

    Kopnarski, M; Lösch, J; Simeonov, L

    2009-04-01

    The low-pressure rf plasma of a secondary neutral mass spectrometer (e-gas SNMS) was connected with a time-of-flight (ToF) mass spectrometer for the first time. As opposed to ToF-SIMS in e-gas SNMS, the primary ion pulse cannot be used for triggering the flight time measurement. Therefore, an extraction pulse is used which at a defined time loads an ion package from the beam of the post-ionised particles into the ToF spectrometer. The newly developed ToF-SNMS system is described, and first experimental results are presented. PMID:19130045

  6. Application of a Bonner sphere spectrometer for the determination of the angular neutron energy spectrum of an accelerator-based BNCT facility

    Experimental activities are underway at INFN Legnaro National Laboratories (LNL) (Padua, Italy) and Pisa University aimed at angular-dependent neutron energy spectra measurements produced by the 9Be(p,xn) reaction, under a 5 MeV proton beam. This work has been performed in the framework of INFN TRASCO-BNCT project. Bonner Sphere Spectrometer (BSS), based on 6LiI (Eu) scintillator, was used with the shadow-cone technique. Proper unfolding codes, coupled to BSS response function calculated by Monte Carlo code, were finally used. The main results are reported here. - Highlights: • Bonner sphere spectrometer is used to determine the angular neutron energy spectrum of an accelerator-based BNCT facility. • The shadow-cone technique is a method used with Bonner sphere spectrometer to remove the neutron scattered contribution. • The response function matrix for the set of Bonner sphere spectrometer is calculated by Monte Carlo code. • Unfolding codes are used to obtain neutron spectra at different neutron emission angles (0°, 40°, 80° and 120°)

  7. Measurement of 59Ni and 63Ni by accelerator mass spectrometry at CIAE

    Wang, Xiaoming; He, Ming; Ruan, Xiangdong; Xu, Yongning; Shen, Hongtao; Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran; Lan, Xiaoxi; Wu, Shaoyong; Zhao, Qingzhang; Cai, Li; Pang, Fangfang

    2015-10-01

    The long lived isotopes 59Ni and 63Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for 59Ni and 63Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of 59Ni and 63Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of 59Ni and 63Ni measurements are determined as 59Ni/Ni = 1 × 10-13 and 63Ni/Ni = 2 × 10-12, respectively.

  8. Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

    Kelstrup, Christian D; Jersie-Christensen, Rosa R; Batth, Tanveer Singh;

    2014-01-01

    Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is...... evaluated by four different acquisition methods and benchmarked across three generations of Q Exactive instruments (ProteomeXchange dataset PXD001305). We find the ultra-high-field Orbitrap mass analyzer capable of attaining a sequencing speed above 20 Hz and it routinely exceeds 10 peptide spectrum matches......-shot phosphoproteomics, where we identify 7600 unique HeLa phospho-peptides in one gradient hour and find the quality of fragmentation spectra to be more important than quantity for accurate site assignment....

  9. A time-of-flight mass spectrometer with laser ionization for sensitive product molecule detection for heterogeneous model reactions

    Investigations of model catalysts are very often performed in ultra-high vacuum for ensuring very well-defined systems. Usually, product molecule detection is performed by electron impact (EI) ionization in a quadrupole mass spectrometer. While this method offers the possibilities of continuous measurements and high sensitivity, it features the drawback that a mass scan has to be performed to detect the masses of all reaction products. In addition, the discrimination between isobars is difficult to achieve because of the unselective properties of EI ionization. In this work we present a time-of-flight MS in combination with laser ionization. Due to the setup, this system allows for a very sensitive detection of isobaric species. In this poster the detection principle is illustrated and first proof-of-principle measurements are shown.

  10. Reduction and scientific analysis of data from the charge-energy-mass (CHEM) spectrometer on the AMPTE/CCE spacecraft

    Gloeckler, G.; Hamilton, D. C.; Ipavich, F. M.

    1987-01-01

    The Charge-Energy-Mass (CHEM) spectrometer instrument on the AMPTE/Charge Composition Explorer (CCE) spacecraft is designed to measure the mass and charge-state abundance of magnetospheric and magnetosheath ions between 0.3 and 315 keV/e, an energy range that includes the bulk of the ring current and the dynamically important portion of the plasma sheet population. Continuing research is being conducted using the AMPTE mission data set, and in particular, that of the CHEM spectrometer which has operated flawlessly since launch and still provides excellent quality data. The requirted routine data processing and reduction, and software develpment continues to be performed. Scientific analysis of composition data in a number of magnetospheric regions including the ring current region, near-earth plasma sheet and subsolar magnetosheath continues to be undertaken. Correlative studies using data from the sister instrument SULEICA, which determines the mass and charge states of ions in the energy range of approximately 10 to 250 keV/e on the IRM, as well as other data from the CCE and IRM spacecraft, particularly in the upstream region and plasma sheet have also been undertaken.

  11. Finnigan ion trap mass spectrometer detection limits and thermal energy analyzer interface status report and present capabilities

    Alcaraz, A.; Andresen, B.; Martin, W.

    1990-10-18

    A new Finnigan ion trap mass spectrometer was purchased and installed at LLNL. Over a period of several months the instrument was tested under a variety of conditions utilizing a capillary gas chromatography interface which allowed separated organic compounds to be carried directly into the ion source of the mass spectrometer. This direct interface allowed maximum analytical sensitivity. A variety of critical tests were performed in order to optimize the sensitivity of the system under a variety of analysis conditions. These tests altered the critical time cycles of the ionization, ion trapping, and detection. Various carrier gas pressures were also employed in order to ascertain the overall sensitivity of the instrument. In addition we have also interfaced a thermal energy analyzer (TEA) to the gas chromatograph in order to simultaneously detect volatile nitrogen containing compounds while mass spectral data is being acquired. This is the first application at this laboratory of simultaneous ultra-trace detections while utilizing two orthogonal analytical techniques. In particular, explosive-related compound and/or residues are of interest to the general community in water, soil and gas sampler. In this paper are highlighted a few examples of the analytical power of this new GC-TEA-ITMS technology.

  12. Real-time monitoring of trace-level VOCs by an ultrasensitive compact lamp-based VUV photoionization mass spectrometer

    W. Q. Sun

    2015-06-01

    Full Text Available In this study, we report on the development of a compact lamp-based vacuum ultraviolet (VUV photoionization mass spectrometer (PIMS; hereafter referred to as VUV-PIMS in our laboratory; it is composed of a radio frequency-powered VUV lamp, a VUV photoionizer, an ion-immigration region, and a reflection time-of-flight mass spectrometer. By utilizing the novel photoionizer consisting of a photoionization cavity and a VUV light baffle, extremely low background noise was obtained. An ultrasensitive detection limit (2σ of 3 pptv was achieved for benzene after an acquisition time of 10 s. To examine its potential for application in real-time sample monitoring, the developed VUV-PIMS was employed for the continuous measurement of urban air for six days in Beijing, China. Strong signals of trace-level volatile organic compounds such as benzene and its alkylated derivatives were observed in the mass spectra. These initial experimental results reveal that the instrument can be used for the online monitoring of trace-level species in the atmosphere.

  13. The application of Guided Ion Beam Tandem Mass Spectrometer; Bond dissociation energies of bare and ligated copper group cluster anions

    Threshold energies, fragmentation patterns, and integral cross sections for the reactions of collision induced dissociations of bare and ligated copper group cluster anions are determined using a Guided Ion Beam Tandem Mass Spectrometer (GIB-MS). The bond breaking patterns for the copper cluster anions show dramatic even/odd tendencies, e.g., all copper group anions generate as the predominant reaction product, Carbon monoxide is weakly bound to copper group cluster anions. Cohesive energies of the bare copper and silver cluster anions are determined and exhibit a good correspondence with estimate cohesive energies by the model of Miedema.

  14. Analysis of benomyl by liquid chromatography/time-of-flight mass spectrometer and its occurrence in the environment

    Seo, Yong Chan; Kim, Kee D. [Sangji Univ., Wonju (Korea, Republic of); Kim, Nack Joo [Seoul National Univ., Seoul (Korea, Republic of)

    2002-03-01

    Benomyl, one of the known endocrine disrupting chemicals, was analyzed to understand the fate in the nature. Water, sediment and biota samples are acidified to hydrolyze benomyl into carbendazim then followed by extraction and concentration. The concentrations of carbendazim in the samples were determined by liquid chromatography/time-of-flight mass spectrometer. Analysis data showed that certain amount of carbendazim was accumulated in sediment. On the contrary, no sign of accumulation in biota was observed probably due to the increased degradation rate in vivo. It is , however, that no one can claim carbendazim is not harmful to biota, since carbendazim may give a negative effect against organisms at the point of intaking.

  15. Transmission Mode Ion/Ion Reactions in the RF-only Ion Guide of Hybrid Tandem Mass Spectrometers

    Emory, Joshua F; Hassell, Kerry H.; Londry, Frank A.; McLuckey, Scott A.

    2009-01-01

    Transmission mode ion/ion reactions have been performed within the first quadrupole, the Q0 RF-only quadrupole, of two types of hybrid tandem mass spectrometers (viz., triple quadrupole/linear ion trap and QqTOF instruments). These transmission mode reactions involved the storage of either the reagent species and the transmission of the analyte species through the Q0 quadrupole for charge inversion reactions or the storage of the analyte ions and transmission of the reagent ions as in charge ...

  16. Use of the Isomass 54E thermal ionisation mass spectrometer at AEE Winfrith. Part II: plutonium analysis

    This report describes the application of the Isomass 54E Thermal ionisation mass spectrometer for the isotopic analysis of plutonium, and gives details of the development of a method for quantitative determination of plutonium in sample solutions using isotopic dilution. A computer program for the control of the 54E is also described. Isotope dilution was used to compare results of plutonium content of twelve zebra reactor fuel pellets with results obtained by titrimetry. The Isomass 54E is shown to be capable of high precision analysis of plutonium sample solutions for both isotopic content and total plutonium concentration using an isotope dilution technique. (U.K.)

  17. Spurious barometric pressure acceleration in Antarctica and propagation into GRACE Antarctic mass change estimates

    Kim, Byeong-Hoon; Eom, Jooyoung; Seo, Ki-Weon; Wilson, Clark R.

    2016-08-01

    Apparent acceleration in Gravity Recovery and Climate Experiment (GRACE) Antarctic ice mass time-series may reflect both ice discharge and surface mass balance contributions. However, a recent study suggests there is also contamination from errors in atmospheric pressure de-aliasing fields [European Center for Medium-Range Weather Forecast (ECMWF) operational products] used during GRACE data processing. To further examine this question, we compare GRACE atmospheric pressure de-aliasing (GAA) fields with in situ surface pressure data from coastal and inland stations. Differences between the two are likely due to GAA errors, and provide a measure of error in GRACE solutions. Time-series of differences at individual weather stations are fit to four presumed error components: annual sinusoids, a linear trend, an acceleration term and jumps at times of known ECMWF model changes. Using data from inland stations, we estimate that atmospheric pressure error causes an acceleration error of about +7.0 Gt yr-2, which is large relative to prior GRACE estimates of Antarctic ice mass acceleration in the range of -12 to -14 Gt yr-2. We also estimate apparent acceleration rates from other barometric pressure (reanalysis) fields, including ERA-Interim, MERRA and NCEP/DOE. When integrated over East Antarctica, the four mass acceleration estimates (from GAA and the three reanalysis fields) vary considerably (by ˜2-16 Gt yr-2). This shows the need for further effort to improve atmospheric mass estimates in this region of sparse in situ observations, in order to use GRACE observations to measure ice mass acceleration and related sea level change.

  18. Accelerator mass spectrometry at the University of Washington

    Our program is directed toward measurement of 10Be and 14C using the FN Tandem accelerator of the Nuclear Physics Laboratory. We began work in June 1977. Our progress and results up to August, 1979, were reported at the Tenth International Radiocarbon Conference. The present report covers chiefly our work since then. For 14C, we are in the final stages of testing a new sample changer and alternator and are comparing three systems of normalizing the rare and abundant ion beams to give isotope ratios. We have successfully prepared graphitized carbon source samples from contemporary and other material; while the graphitized sources have given the largest carbon beams, we are exploring other possibilities, among which the use of C/Ag combinations appears very promising. For 10Be, we have begun testing and measuring samples prepared from Antarctic and Peruvian snow and ice. In both the carbon and the beryllium programs various technical developments are in progress in addition to those reported here

  19. A satellite-borne ion mass spectrometer for the energy range 0 to 16 keV

    The Ion Composition Experiment (ICE) on GEOS represents the first comprehensive attempt to measure the positive ion composition at high altitudes in the magnetosphere. Due to the heterogeneous nature of the magnetospheric plasma a novel mass spectrometer has been developed to cover the mass per charge range from 1H+ to beyond 138Ba+ and the energy per charge range from 0 to 16 keV/e. The ICE consists primarily of a cylindrical electrostatic analyzer followed by a curved analyzer incorporating crossed magnetic and electric fields. This combination has limited angular and energy focussing properties, but it maintains a mass resolution of about 4 over a wide range in energy and mass, sufficient for the objectives of measuring plasmas of both solar and terrestrial origin. High sensitivity and low background should allow measurements of rarer ion constituents, such as 3He2+ and 16O6+, down to flux levels of 10-2 ions (cm2 sec ster eV)-1. The unusually large mass range offers the possibility of identifying Li+ or Ba+ tracer ions which may be injected into the magnetosphere by active experiments. A sophisticated electronics combined with powerful ground computer and telecommand systems allow for very efficient scanning of the mass-energy space. Based on survey measurements a variety of special modes can be commanded, either manually or automatically by means of the ground station computer. (Auth.)

  20. Measurements of hydrogen, oxygen and carbon isotope ratios by SIRA 10 mass spectrometer and some problems of their quality assurance

    Full text: Hydrogen and oxygen are two chemical elements that combined between them forms the water molecules. Hydrogen has two stable isotopes 1H and 2H, with abundance, respectively, 99.985 % and 0.015 %, while the oxygen has three stable isotopes 16O, 17O, 18O with the abundance, respectively, 99.756 %, 0.039 %, 0.205 %. Hydrogen and oxygen stable isotopes, in our laboratory, are used in the hydrology and hydrogeology studies. The 'δ' values of hydrogen and oxygen of water samples are expressed in per mille with respect to SMOW, while, for carbon is expressed in per mille with respect to PDB. The isotopic compositions of these elements are measured using the SIRA 10 mass spectrometer, which is similar with the Nier mass spectrometer. SIRA 10 mass spectrometer, destined for the measurements of the isotopic ratios of the light elements, is equipped with double inlet system and with three collectors system (for the oxygen, carbon, nitrogen etc. isotopes) and double collector system for the hydrogen isotopes. The vacuum 10-9 torr is realized by the two oil diffusion pumps. The gas samples (H2, CO2, etc.) are admitted to the ion source of the mass spectrometer, where are transformed into positive ions by the electron impact. The magnetic field is normal to the path of the ions and is realized by a permanent magnet. The quality assurance of the 'δ' determination dependent from the preparation of the gas samples and from the measurements of the isotopic ratios. Stable isotopes hydrogen of the water samples are measured through the hydrogen gas which is gained from the water by the reduction reaction with metallic Zinc in a separate line, in vacuum conditions and high temperature. The reduction process of the water was occurred not normally because in the inside of the glass balloons seems water droplets. The different experiments of the changes the water quantity, Zinc quantity, dimensions of the metallic Zinc and the temperature of the reduction reaction didn

  1. Accelerator mass spectrometry with fully stripped 26Al, 36Cl, 41Ca and 59Ni ions

    The detection system of accelerator mass spectrometry (AMS) with completely stripped ions of 26Al, 36Cl, 41Ca and 59Ni at the Munich accelerator laboratory and measurements with these ions are presented. Detection limits are given. The presented applications are: dating of groundwater of the Milk River aquifer and deduction of the neutron fluence and spectrum of the Hiroshima A-bomb. (orig.)

  2. Accelerating Twisted Mass LQCD with QPhiX

    Schröck, Mario; Strelchenko, Alexei

    2015-01-01

    We present the implementation of twisted mass fermion operators for the QPhiX library. We analyze the performance on the Intel Xeon Phi (Knights Corner) coprocessor as well as on Intel Xeon Haswell CPUs. In particular, we demonstrate that on the Xeon Phi 7120P the Dslash kernel is able to reach 80\\% of the theoretical peak bandwidth, while on a Xeon Haswell E5-2630 CPU our generated code for the Dslash operator with AVX2 instructions outperforms the corresponding implementation in the tmLQCD library by a factor of $\\sim 5\\times$ in single precision. We strong scale the code up to 6.8 (14.1) Tflops in single (half) precision on 64 Xeon Haswell CPUs.

  3. Direct and Sensitive Detection of CWA Simulants by Active Capillary Plasma Ionization Coupled to a Handheld Ion Trap Mass Spectrometer

    Wolf, Jan-Christoph; Etter, Raphael; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2016-07-01

    An active capillary plasma ionization (ACI) source was coupled to a handheld mass spectrometer (Mini 10.5; Aston Labs, West Lafayette, IN, USA) and applied to the direct gas-phase detection and quantification of chemical warfare agent (CWA) related chemicals. Complementing the discontinuous atmospheric pressure interface (DAPI) of the Mini 10.5 mass spectrometer with an additional membrane pump, a quasi-continuous sample introduction through the ACI source was achieved. Nerve agent simulants (three dialkyl alkylphosphonates, a dialkyl phosporamidate, and the pesticide dichlorvos) were detected at low gas-phase concentrations with limits of detection ranging from 1.0 μg/m3 to 6.3 μg/m3. Our results demonstrate a sensitivity enhancement for portable MS-instrumentation by using an ACI source, enabling direct, quantitative measurements of volatile organic compounds. Due to its high sensitivity, selectivity, low power consumption (<80 W) and weight (<13 kg), this instrumentation has the potential for direct on-site CWA detection as required by military or civil protection.

  4. Direct and Sensitive Detection of CWA Simulants by Active Capillary Plasma Ionization Coupled to a Handheld Ion Trap Mass Spectrometer.

    Wolf, Jan-Christoph; Etter, Raphael; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2016-07-01

    An active capillary plasma ionization (ACI) source was coupled to a handheld mass spectrometer (Mini 10.5; Aston Labs, West Lafayette, IN, USA) and applied to the direct gas-phase detection and quantification of chemical warfare agent (CWA) related chemicals. Complementing the discontinuous atmospheric pressure interface (DAPI) of the Mini 10.5 mass spectrometer with an additional membrane pump, a quasi-continuous sample introduction through the ACI source was achieved. Nerve agent simulants (three dialkyl alkylphosphonates, a dialkyl phosporamidate, and the pesticide dichlorvos) were detected at low gas-phase concentrations with limits of detection ranging from 1.0 μg/m(3) to 6.3 μg/m(3). Our results demonstrate a sensitivity enhancement for portable MS-instrumentation by using an ACI source, enabling direct, quantitative measurements of volatile organic compounds. Due to its high sensitivity, selectivity, low power consumption (<80 W) and weight (<13 kg), this instrumentation has the potential for direct on-site CWA detection as required by military or civil protection. Graphical Abstract ᅟ. PMID:27020924

  5. Extending the application area of a time-of-flight mass spectrometer to detect fragments resulting from multicharged ion collisions

    The detection of the fragments resulting from collisions of high energy multicharged ions is connected with the extraction of the analysed charged particles from a large volume. This implies some specific conditions concerning the time-focusing. Therefore, some modifications of the design of the time-of-flight mass spectrometer for fullerene ion detection were carried out. The ion source was adapted to accommodate the high energy ion beam. The structure of the ion extracting electrode system was redesigned with this purpose. Appropriate diameter openings were provided to obtain the desired reacting gas throughput. The reflectron was adapted to the deeper analysed ion forming region. With this purpose the system was recalculated for second order focusing conditions. A solution was found accounting for the insertion of an additional grid in the former reflectron design. To obtain the best configuration with a minimal modification of the field free spaces and to locate the detector closely to its initial position a detailed ion optical study of the time focusing conditions was worked out. Based on the estimations concerning the interaction region sizes and knowing the new instrumental parameters, the resolution of the time-of-flight mass spectrometer for multicharged ion collisions has been evaluated. Other possible improvements are outlined. (authors)

  6. LAVA Subsystem Integration and Testing for the RESOLVE Payload of the Resource Prospector Mission: Mass Spectrometers and Gas Chromatography

    Coan, Mary R.; Stewart, Elaine M.

    2015-01-01

    The Regolith and Environment Science & Oxygen and Lunar Volatile Extraction (RESOLVE) payload is part of Resource Prospector (RP) along with a rover and a lander that are expected to launch in 2020. RP will identify volatile elements that may be combined and collected to be used for fuel, air, and water in order to enable deeper space exploration. The Resource Prospector mission is a key part of In-Situ Resource Utilization (ISRU). The demand for this method of utilizing resources at the site of exploration is increasing due to the cost of resupply missions and deep space exploration goals. The RESOLVE payload includes the Lunar Advanced Volatile Analysis (LAVA) subsystem. The main instrument used to identify the volatiles evolved from the lunar regolith is the Gas Chromatograph-Mass Spectrometer (GC-MS). LAVA analyzes the volatiles emitted from the Oxygen and Volatile Extraction Node (OVEN) Subsystem. The objective of OVEN is to obtain, weigh, heat and transfer evolved gases to LAVA through the connection between the two subsystems called the LOVEN line. This paper highlights the work completed during a ten week internship that involved the integration, testing, data analysis, and procedure documentation of two candidate mass spectrometers for the LAVA subsystem in order to aid in determining which model to use for flight. Additionally, the examination of data from the integrated Resource Prospector '15 (RP' 15) field test will be presented in order to characterize the amount of water detected from water doped regolith samples.

  7. An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS for fast PAN and PPN measurements

    H. Schlager

    2011-02-01

    Full Text Available An airborne chemical ionization ion trap mass spectrometer instrument (CI-ITMS has been developed for tropospheric and stratospheric fast in-situ measurements of PAN (peroxyacetyl nitrate and PPN (peroxypropionyl nitrate. The first scientific deployment of the FASTPEX instrument (FASTPEX = Fast Measurement of Peroxyacyl nitrates took place in the Arctic during 18 missions aboard the DLR research aircraft Falcon, within the framework of the POLARCAT-GRACE campaign in the summer of 2008. The FASTPEX instrument is described and characteristic properties of the employed ion trap mass spectrometer are discussed. Atmospheric data obtained at altitudes of up to ~12 km are presented, from the boundary layer to the lowermost stratosphere. Data were sampled with a time resolution of 2 s and a 2σ detection limit of 25 pmol mol−1. An isotopically labelled standard was used for a permanent on-line calibration. For this reason the accuracy of the PAN measurements is better than ±10% for mixing ratios greater than 200 pmol mol−1. PAN mixing ratios in the summer Arctic troposphere were in the order of a few hundred pmol mol−1 and generally correlated well with CO. In the Arctic boundary layer and lowermost stratosphere smaller PAN mixing ratios were observed due to a combination of missing local sources of PAN precursor gases and efficient removal processes (thermolysis/photolysis. PPN, the second most abundant PAN homologue, was measured simultaneously. Observed PPN/PAN ratios range between ~0.03 and 0.3.

  8. Laserspray ionization on a commercial atmospheric pressure-MALDI mass spectrometer ion source: selecting singly or multiply charged ions.

    McEwen, Charles N; Larsen, Barbara S; Trimpin, Sarah

    2010-06-15

    Multiply charged ions, similar to those obtained with electrospray ionization, are produced at atmospheric pressure (AP) using standard MALDI conditions of laser fluence and reflective geometry. Further, the charge state can be switched to singly charged ions nearly instantaneously by changing the voltage applied to the MALDI target plate. Under normal AP-MALDI operating conditions in which a voltage is applied to the target plate, primarily singly charged ions are observed, but at or near zero volts, highly charged ions are observed for peptides and proteins. Thus, switching between singly and multiply charged ions requires only manipulation of a single voltage. As in ESI, multiple charging, produced using the AP-MALDI source, allows compounds with molecular weights beyond the mass-to-charge limit of the mass spectrometer to be observed and improves the fragmentation relative to singly charged ions. PMID:20469839

  9. Hyphenation of two simultaneously employed soft photo ionization mass spectrometers with thermal analysis of biomass and biochar

    Highlights: ► First simultaneous hyphenation of two time-of-flight mass spectrometers with different soft photo ionization techniques (SPI and REMPI) to Thermal Analysis using a newly developed prototype for EGA is presented. ► Resonance enhanced multi-photon ionization (REMPI) enables sensitive and selective analysis of aromatic species. ► Single photon ionization (SPI) using VUV light supplied by an innovative electron-beam pumped excimer light source (EBEL) comprehensively ionizes (nearly) all organic molecules. ► The resulting mass spectra show distinct patterns for the evolved gases of the miscellaneous biomasses and chars thereof. ► The potential for detailed kinetic studies is apparent on account of the complex pyrolysis gas compositions. - Abstract: Evolved gas analysis (EGA) is a powerful and complementary tool for Thermal Analysis. In this context, two time-of-flight mass spectrometers with different soft photo-ionization techniques are simultaneously hyphenated to a thermo balance and applied in form of a newly developed prototype for EGA of pyrolysis gases from biomass and biochar. Resonance enhanced multi-photon ionization (REMPI) is applied for selective analysis of aromatic species. Furthermore, single photon ionization (SPI) using VUV light supplied by an electron-beam pumped excimer light source (EBEL) was used to comprehensively ionize (nearly) all organic molecules. The soft ionization capability of photo-ionization techniques allows direct and on-line analysis of the evolved pyrolysis gases. Characteristic mass spectra with specific patterns could be obtained for the miscellaneous biomass feeds used. Temperature profiles of the biochars reveal a desorption step, followed by pyrolysis as observed for the biomasses. Furthermore, the potential for kinetic studies is apparent for this instrumental setup.

  10. Measurement of mass yields from the 241Am(2nth,f reaction at the Lohengrin Spectrometer

    Köster U.

    2013-03-01

    Full Text Available The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. While the yields are known for the major actinides (235U, 239Pu in the thermal neutron-induced fission, only few measurements have been performed on 242Am. The interest of 242Am concerns the reduction of radiotoxicity of 241Am in nuclear wastes using transmutation reactions. This paper presents the measurement of the fission mass yields from the reaction 241Am(2nth,f performed at the Lohengrin mass spectrometer (ILL, France for both the light and the heavy peaks: a total of 41 mass yields have been measured. The experiment was also meant to determine whether there is a difference in mass yields between the isomeric state and the ground state as it exists in fission and capture cross sections. The method used to address this question is based on a repeated measurement of a set of fission mass yields as a function of the ratio between the 242gAm and the 242mAm fission rates. The presented experiment is also a first step towards the measurement of the isotopic fission yields of 242Am.

  11. IonCCD Detector for Miniature Sector-Field Mass Spectrometer : Investigation of Peak Shape and Detector Surface Artifacts Induced by keV Ion Detection

    Hadjar, Omar; Schlatholter, Thomas; Davila, Stephen; Catledge, Shane A.; Kuhn, Ken; Kassan, Scott; Kibelka, Gottfried; Cameron, Chad; Verbeck, Guido F.

    2011-01-01

    A recently described ion charge coupled device detector IonCCD (Sinha and Wadsworth, Rev. Sci. Instrum. 76(2), 2005; Hadjar, J. Am. Soc. Mass Spectrom. 22(4), 612-624, 2011) is implemented in a miniature mass spectrometer of sector-field instrument type and Mattauch-Herzog (MH)-geometry (Rev. Sci. I

  12. Acceleration of the Greenland ice sheet mass loss as observed by GRACE: Confidence and sensitivity

    Svendsen, P. L.; Andersen, O. B.; Nielsen, A. A.

    2013-02-01

    We examine the scale and spatial distribution of the mass change acceleration in Greenland and its statistical significance, using processed gravimetric data from the GRACE mission for the period 2002-2011. Three different data products - the CNES/GRGS, DMT-1b and GGFC GRACE solutions - have been used, all revealing an accelerating mass loss in Greenland, though with significant local differences between the three datasets. Compensating for leakage effects, we obtain acceleration values of -18.6 Gt/yr2 for CNES/GRGS, -8.8 Gt/yr2 for DMT-1b, and -14.8 Gt/yr2 for GGFC. We find considerable mass loss acceleration in the Canadian Arctic Archipelago, some of which will leak into the values for Greenland, depending on the approach used, and for our computations the leakage has been estimated at up to -4.7 Gt/yr2. The length of the time series of the GRACE data makes a huge difference in establishing an acceleration of the data. For both 10-day and monthly GRACE solutions, an observed acceleration on the order of 10-20 Gt/yr2 is shown to require more than 5 yrs of data to establish with statistical significance. In order to provide an independent evaluation, ICESat laser altimetry data have been smoothed to match the resolution of the GRACE solutions. This gives us an estimated upper bound for the acceleration of about -29.7 Gt/yr2 for the period 2003-2009, consistent with the acceleration values and corresponding confidence intervals found with GRACE data.

  13. Determination of the presence or absence of sulfur materials in drywall using direct analysis in real time in conjunction with an accurate-mass time-of-flight mass spectrometer.

    Curtis, Matthew E; Jones, Patrick R; Sparkman, O David; Cody, Robert B

    2009-11-01

    Based on the concern about the presence of sulfur materials being in drywall (wallboard), a quick and reliable test to confirm the presence or absence of these materials using direct analysis in real time (DART) mass spectrometry in conjunction with an accurate-mass time-of-flight (TOF) mass spectrometer has been developed and is described here. PMID:19700343

  14. Mass Spectrometry-based Proteomics Using Q Exactive, a High-performance Benchtop Quadrupole Orbitrap Mass Spectrometer

    Michalski, A.; Damoc, E.; Hauschild, J.-P.; O. Lange; Wieghaus, A.; Makarov, A.; Nagaraj, N.; Cox, J; Mann, M; Horning, S.

    2011-01-01

    Mass spectrometry-based proteomics has greatly benefitted from enormous advances in high resolution instrumentation in recent years. In particular, the combination of a linear ion trap with the Orbitrap analyzer has proven to be a popular instrument configuration. Complementing this hybrid trap-trap instrument, as well as the standalone Orbitrap analyzer termed Exactive, we here present coupling of a quadrupole mass filter to an Orbitrap analyzer. This “Q Exactive” instrument features high io...

  15. Chemical ionization tandem mass spectrometer for the in situ measurement of methyl hydrogen peroxide

    A new approach for measuring gas-phase methyl hydrogen peroxide [(MHP) CH3OOH] utilizing chemical ionization mass spectrometry is presented. Tandem mass spectrometry is used to avoid mass interferences that hindered previous attempts to measure atmospheric CH3OOH with CF3O- clustering chemistry. CH3OOH has been successfully measured in situ using this technique during both airborne and ground-based campaigns. The accuracy and precision for the MHP measurement are a function of water vapor mixing ratio. Typical precision at 500 pptv MHP and 100 ppmv H2O is ±80 pptv (2 sigma) for a 1 s integration period. The accuracy at 100 ppmv H2O is estimated to be better than ±40%. Chemical ionization tandem mass spectrometry shows considerable promise for the determination of in situ atmospheric trace gas mixing ratios where isobaric compounds or mass interferences impede accurate measurements.

  16. Evaluation of an Omegatron mass spectrometer for use in the plasma exhaust processing of a fusion reactor

    The plasma exhaust processing plant of fusion reactors require on-line analysis of gas streams to monitor various gas compositions. The resolution of an Omegatron increases with decreasing mass and it can easily discriminate between all the 20+ species of ions between masses 1 and 9, except between T+ and He3+ ions. The Omegatron is a candidate device for gas analysis, it is small, simple to operate and relatively inexpensive. The disadvantages are the upper pressure limit of about 1.0E-6 mbar and low output currents, typically less than 1.0E-11 A, which give slow response times. The Omegatron at the Tritium Laboratory Karlsruhe is well established and has been used successfully for qualitative analyses of tritiated gas mixtures. Quantitative measurements on known gas mixtures up to mass 28 have revealed several anomalies, particularly when helium is present. Work to explain this effect is reported. The gas in the mass spectrometer has to be a representative sample and be introduced in a reasonable timescale. A potential pumping and expansion arrangement is described. The Omegatron is highly suited to computer control as the cyclotron frequencies of the various ions are precisely known and techniques to control the Omegatron and evaluate the results are proposed

  17. Experimental setup of a time-of-flight mass spectrometer for reaction product detection in heterogeneous catalysis

    Mass spectrometry is a very powerful analytical tool for the study of heterogeneous catalysis. It is often used to study reaction processes by analyzing the reaction products, both in a qualitative and in a quantitative way. Typically, mass spectrometers work by using electron impact ionization, where discrimination between isomers is difficult to achieve. Fragmentation patterns of the isomers must differ to a large extent to be distinguishable. A powerful and soft method for selective ionization is REMPI (Resonant Enhanced Multiphoton Ionization). In this technique a laser of specific wavelength is employed to ionize a single isomer through resonant intermediate states. Other isomers are not ionized as they are non resonant at the energy used. A new experimental setup was built for the study of catalytic reactions on metal clusters supported on single crystal surfaces under UHV conditions. Custom ion optics were designed to incorporate the crystal support and enable future desorption-ionization studies and enantioselective laser mass spectrometry. In this work we present our experimental setup, in which we combine time of flight mass spectrometry and resonance enhanced multiphoton ionization for investigation of products formed via surface reactions. It will thus be possible to examine the selectivity of catalytic reactions on size selected clusters.

  18. Non-thermal internal energy distribution of ions observed in an electrospray source interfaced with a sector mass spectrometer.

    Rondeau, David; Galland, Nicolas; Zins, Emilie-Laure; Pepe, Claude; Drahos, László; Vékey, Károly

    2011-02-01

    The internal energy distribution P(E(int)) of ions emitted in an electrospray (ESI) source interfaced with a sector mass spectrometer is evaluated by using the experimental survival yield (SY) method including the kinetic shift. This method is based on the relationship between the degree of fragmentation of an ion and its amount of internal energy and uses benzylpyridinium cations due to their simple fragmentation scheme. Quantum chemical calculations are performed, namely at G3(MP2)//B3LYP and QCISD/MP2 levels of theory. The results show that the internal energy distribution of the ions emitted in the ESI source interfaced with a sector analyzer is very narrow. The MassKinetics software is used to confirm these observations. The P(E(int)) is the parameter that allows to fit the experimental SY of each substituted benzylpyridinium cation with theoretical mass spectra generated by the MassKinetics software. The resulting internal energy distributions are similar to the ones obtained with the experimental SY method. This indicates that in the present experimental conditions, P(E(int)) cannot be compared with a 'thermal-like' Boltzmann distribution. In addition, it appears that with the sector analyzer, increasing the collision energy in the first pumping stage of the ESI source does not correspond to a warm-up of the produced ions. PMID:21254312

  19. Laboratory investigation of photochemical oxidation of organic aerosol from wood fires Part 2: Analysis of aerosol mass spectrometer data

    Grieshop, A. P.; Donahue, N. M.; Robinson, A. L.

    2008-09-01

    Experiments were conducted to investigate the effects of photo-oxidation on organic aerosol (OA) in dilute wood smoke by exposing emissions from soft- and hard-wood fires to UV light in a smog chamber. This paper focuses on changes in OA composition measured using a unit mass resolution quadrupole Aerosol Mass Spectrometer (AMS). The results highlight how photochemical processing can lead to considerable evolution of the mass, the volatility and the level of oxygenation of biomass-burning OA. Photochemical oxidation produced substantial new OA, more than doubling the primary contribution after a few hours of aging under typical summertime conditions. Aging decreased the OA volatility of the total OA as measured with a thermodenuder; it also made the OA progressively more oxygenated in every experiment. With explicit knowledge of the condensed-phase mass spectrum (MS) of the primary emissions from each fire, each MS can be decomposed into primary and residual spectra throughout the experiment. The residual spectra provide an estimate of the composition of the photochemically produced OA. These spectra are also very similar to those of the oxygenated OA that dominates ambient AMS datasets. In addition, aged wood smoke spectra are shown to be similar to those from OA created by photo-oxidized dilute diesel exhaust and aged biomass-burning OA measured in urban and remote locations. This demonstrates that the oxygenated OA observed in the atmosphere can be produced by photochemical aging of dilute emissions from combustion of fuels containing both modern and fossil carbon.

  20. Combined distance-of-flight and time-of-flight mass spectrometer

    Enke, Christie G; Ray, Steven J; Graham, Alexander W; Hieftje, Gary M; Barinaga, Charles J; Koppenaal, David W

    2014-02-11

    A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

  1. A first attempt to measure 92Nb/93Nb ratios with Accelerator Mass Spectrometry

    Guozhu, He; Ming, He; Zuying, Zhou; Zhenyu, Li; Kejun, Dong; Shaoyong, Wu; Shilong, Liu; Xiongjun, Chen; Qiwen, Fan; Chaoli, Li; Xianwen, He; Heng, Li; Shan, Jiang

    2013-01-01

    An Accelerator Mass Spectrometry (AMS) method for the measurement of the long-lived radionuclide 92Nb has been established at the HI-13 Tandem Accelerator of the China Institute of Atomic Energy (CIAE). Niobium powder mixed with PbF2 by a ratio of 1:2 (in mass) was used as the cathode material. Atomic anions of Nb- were extracted from a Cs-beam sputter source. The terminal voltage of the tandem accelerator was 8.5 MV. Nb13+ ions were selected after terminal foil stripping. A multi-anode gas ionization chamber was used for the particle detection. The total suppression factor of the two major interfering isobars, 92Zr and 92Mo, was about 103. A detection limit of about 10-11 was achieved for 92Nb/93Nb ratio measurements on a blank sample.

  2. Acceleration of the Greenland ice sheet mass loss as observed by GRACE: Confidence and sensitivity

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2013-01-01

    used, all revealing an accelerating mass loss in Greenland, though with significant local differences between the three datasets. Compensating for leakage effects, we obtain acceleration values of -18.6 Gt / yr2 for CNES/GRGS, -8.8 Gt / yr2 for DMT-1b, and -14.8 Gt / yr2 for GGFC.We find considerable...... mass loss acceleration in the Canadian Arctic Archipelago, some of which will leak into the values for Greenland, depending on the approach used, and for our computations the leakage has been estimated at up to -4.7 Gt / yr2.The length of the time series of the GRACE data makes a huge difference in...

  3. Some interesting and exotic applications of carbon-14 dating by accelerator mass spectrometry

    There are many applications of 14C dating and other measurements using accelerator mass spectrometry (AMS). In particular, applications to dating of archaeological samples and interesting artifacts are discussed. Other applications, such as to extraterrestrial materials such as lunar samples and meteorites show the broad range of topics that can be addressed with 14C studies.

  4. Modeling the Impact and Costs of Semiannual Mass Drug Administration for Accelerated Elimination of Lymphatic Filariasis

    W.A. Stolk (Wilma); Q.A. ten Bosch (Quirine); S.J. de Vlas (Sake); P.U. Fischer (Peter); G.J. Weil (Gary); A.S. Goldman (Ann)

    2013-01-01

    textabstractThe Global Program to Eliminate Lymphatic Filariasis (LF) has a target date of 2020. This program is progressing well in many countries. However, progress has been slow in some countries, and others have not yet started their mass drug administration (MDA) programs. Acceleration is neede

  5. Accelerator mass spectrometry of 36Cl produced by neutrons from the Hiroshima bomb

    Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine 36Cl/Cl ratios of samples from a tombstone exposed to neutrons from the Hiroshima bomb. The ratios were determined from the surface to deeper positions. The depth profile of 36Cl/Cl can be used for estimating the neutron energy distribution and intensity near the hypocentre in Hiroshima. (author)

  6. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range

    Duijn, E. van; Sandman, H.; Grossouw, D.; Mocking, J.A.J.; Coulier, L.; Vaes, W.H.J.

    2014-01-01

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. H

  7. Accelerator mass spectrometry in the study of vitamin and mineral metabolism in humans

    Accelerator mass spectrometry is an isotopic ratio method that can estimate the concentrations of long-lived radioisotopes such as carbon-14 and calcium-41, making it useful in biochemical and physiological research. It is capable of measuring radio-labeled nutrients and their metabolites in attomol...

  8. Mass measurements on neutron-deficient nuclides at SHIPTRAP and commissioning of a cryogenic narrow-band FT-ICR mass spectrometer

    Ferrer Garcia, R.

    2007-07-01

    The dissertation presented here deals with high-precision Penning trap mass spectrometry on short-lived radionuclides. Owed to the ability of revealing all nucleonic interactions, mass measurements far off the line of {beta}-stability are expected to bring new insight to the current knowledge of nuclear properties and serve to test the predictive power of mass models and formulas. In nuclear astrophysics, atomic masses are fundamental parameters for the understanding of the synthesis of nuclei in the stellar environments. This thesis presents ten mass values of radionuclides around A=90 interspersed in the predicted rp-process pathway. Six of them have been experimentally determined for the first time. The measurements have been carried out at the Penning-trap mass spectrometer SHIPTRAP using the destructive time-of-flight ion-cyclotron-resonance (TOF-ICR) detection technique. Given the limited performance of the TOF-ICR detection when trying to investigate heavy/superheavy species with small production cross sections ({sigma} <1 {mu}b), a new detection system is found to be necessary. Thus, the second part of this thesis deals with the commissioning of a cryogenic double-Penning trap system for the application of a highly-sensitive, narrow-band Fourier-transform ion-cyclotron-resonance (FT-ICR) detection technique. With the non-destructive FT-ICR detection method a single singly-charged trapped ion will provide the required information to determine its mass. First off-line tests of a new detector system based on a channeltron with an attached conversion dynode, of a cryogenic pumping barrier, to guarantee ultra-high vacuum conditions during mass determination, and of the detection electronics for the required single-ion sensitivity are reported. (orig.)

  9. Mass measurements on neutron-deficient nuclides at SHIPTRAP and commissioning of a cryogenic narrow-band FT-ICR mass spectrometer

    The dissertation presented here deals with high-precision Penning trap mass spectrometry on short-lived radionuclides. Owed to the ability of revealing all nucleonic interactions, mass measurements far off the line of β-stability are expected to bring new insight to the current knowledge of nuclear properties and serve to test the predictive power of mass models and formulas. In nuclear astrophysics, atomic masses are fundamental parameters for the understanding of the synthesis of nuclei in the stellar environments. This thesis presents ten mass values of radionuclides around A=90 interspersed in the predicted rp-process pathway. Six of them have been experimentally determined for the first time. The measurements have been carried out at the Penning-trap mass spectrometer SHIPTRAP using the destructive time-of-flight ion-cyclotron-resonance (TOF-ICR) detection technique. Given the limited performance of the TOF-ICR detection when trying to investigate heavy/superheavy species with small production cross sections (σ <1 μb), a new detection system is found to be necessary. Thus, the second part of this thesis deals with the commissioning of a cryogenic double-Penning trap system for the application of a highly-sensitive, narrow-band Fourier-transform ion-cyclotron-resonance (FT-ICR) detection technique. With the non-destructive FT-ICR detection method a single singly-charged trapped ion will provide the required information to determine its mass. First off-line tests of a new detector system based on a channeltron with an attached conversion dynode, of a cryogenic pumping barrier, to guarantee ultra-high vacuum conditions during mass determination, and of the detection electronics for the required single-ion sensitivity are reported. (orig.)

  10. Cluster analysis of the organic peaks in bulk mass spectra obtained during the 2002 New England Air Quality Study with an Aerodyne aerosol mass spectrometer

    C. Marcolli

    2006-06-01

    Full Text Available We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS bulk mass spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol mass – 17% of the total organic mass – that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

  11. Acceleration and deceleration of coronal mass ejections during propagation and interaction

    Shen, Fang; Wu, S. T.; Feng, Xueshang; Wu, Chin-Chun

    2012-11-01

    A major challenge to the space weather forecasting community is accurate prediction of Coronal Mass Ejections (CMEs) induced Shock Arrival Time (SAT) at Earth's environment. In order to improve the current accuracy, one of the steps is to understand the physical processes of the acceleration and deceleration of a CME's propagation in the heliosphere. We employ our previous study of a three-dimensional (3D) magnetohydrodynamic (MHD) simulation for the evolution of two interacting CMEs in a realistic ambient solar wind during the period 28-31 March 2001 event to illustrate these acceleration and deceleration processes. The forces which caused the acceleration and deceleration are analyzed in detail. The forces which caused the acceleration are the magnetic pressure term of Lorentz force and pressure gradient. On the other hand, the forces which caused the deceleration are aerodynamic drag, the Sun's gravity and the tension of magnetic field. In addition the momentum exchange between the solar wind and the moving CMEs can cause acceleration and deceleration of the CME which are now analyzed. In this specific CME event 28-31 March 2001 we have analyzed those forces which cause acceleration and deceleration of CME with and without interaction with another CME. It shows that there are significant momentum changes between these two interacting CMEs to cause the acceleration and deceleration.

  12. Accuracy studies with carbon clusters at the Penning trap mass spectrometer TRIGA-TRAP

    Ketelaer, J.; Beyer, T.; Blaum, K.; Block, M.; Eberhardt, K.; Eibach, M.; Herfurth, F.; Smorra, C.; Nagy, Sz.

    2010-05-01

    Extensive cross-reference measurements of well-known frequency ratios using various sizes of carbon cluster ions 12Cn + (10≤n≤23) were performed to determine the effects limiting the accuracy of mass measurements at the Penning-trap facility TRIGA-TRAP. Two major contributions to the uncertainty of a mass measurement have been identified. Fluctuations of the magnetic field cause an uncertainty in the frequency ratio due to the required calibration by a reference ion of uf(νref)/νref = 6(2) × 10-11/min × Δt. A mass-dependent systematic shift of the frequency ratio of epsilonm(r)/r = -2.2(2) × 10-9 × (m-mref)/u has been found as well. Finally, the nuclide 197Au was used as a cross-check since its mass is already known with an uncertainty of 0.6 keV.

  13. Laboratory investigation of photochemical oxidation of organic aerosol from wood fires 2: analysis of aerosol mass spectrometer data

    Grieshop, A. P.; Donahue, N. M.; Robinson, A. L.

    2009-03-01

    Experiments were conducted to investigate the effects of photo-oxidation on organic aerosol (OA) in dilute wood smoke by exposing emissions from soft- and hard-wood fires to UV light in a smog chamber. This paper focuses on changes in OA composition measured using a unit-mass-resolution quadrupole Aerosol Mass Spectrometer (AMS). The results highlight how photochemical processing can lead to considerable evolution of the mass, volatility and level of oxygenation of biomass-burning OA. Photochemical oxidation produced substantial new OA, more than doubling the OA mass after a few hours of aging under typical summertime conditions. Aging also decreased the volatility of the OA and made it progressively more oxygenated. The results also illustrate strengths of, and challenges with, using AMS data for source apportionment analysis. For example, the mass spectra of fresh and aged BBOA are distinct from fresh motor-vehicle emissions. The mass spectra of the secondary OA produced from aging wood smoke are very similar to those of the oxygenated OA (OOA) that dominates ambient AMS datasets, further reinforcing the connection between OOA and OA formed from photo-chemistry. In addition, aged wood smoke spectra are similar to those from OA created by photo-oxidizing dilute diesel exhaust. This demonstrates that the OOA observed in the atmosphere can be produced by photochemical aging of dilute emissions from different types of combustion systems operating on fuels with modern or fossil carbon. Since OOA is frequently the dominant component of ambient OA, the similarity of spectra of aged emissions from different sources represents an important challenge for AMS-based source apportionment studies.

  14. Comprehensive lipidome analysis by shotgun lipidomics on a hybrid quadrupole-orbitrap-linear ion trap mass spectrometer

    Almeida, Reinaldo; Pauling, Josch Konstantin; Sokol, Elena; Hannibal-Bach, Hans Kristian; Ejsing, Christer S.

    2015-01-01

    Here we report on the application of a novel shotgun lipidomics platform featuring an Orbitrap Fusion mass spectrometer equipped with an automated nanoelectrospray ion source. To assess the performance of the platform for in-depth lipidome analysis, we evaluated various instrument parameters...... fragmentation analysis demonstrated that combined use of HCD and CID yields complementary fragment ions of molecular lipid species. To support global lipidome analysis, we designed a method, termed MS(ALL), featuring high resolution FTMS analysis for lipid quantification, and FTMS(2) analysis using both HCD and......-based resonant-excitation collision-induced dissociation (CID). This evaluation demonstrated that FTMS analysis with a resolution setting of 450,000 allows distinguishing isotopes from different lipid species and features a linear dynamic quantification range of at least four orders of magnitude. Evaluation of...

  15. Portable mass spectrometer with one or more mechanically adjustable electrostatic sectors and a mechanically adjustable magnetic sector all mounted in

    This patent describes a portable mass spectrometer. It comprises: a vacuum chamber; a source of material to be analyzed; an ionization chamber coupled to the vacuum chamber and adapted to receive material to be analyzed from the source and to form an ion beam comprising ions of the material; an adjustable electrostatic sector in the vacuum chamber generally aligned with the ion beam emerging from the ionization chamber; mechanical means for adjusting the electrostatic sector to focus the ion beam; an adjustable magnetic sector in the vacuum chamber generally aligned with the path of the ion beam emerging from the electrostatic sector; mechanical means for adjusting the magnetic sector to focus the ion beam; and detection means for detecting the ion beam focused by the electrostatic sector and the magnetic sector

  16. Evaluation of the MAT-thermal ionization quadrupole mass spectrometer for potential use for on-situ safeguards verifications

    The Thermoquad THQ of Finnigan MAT is a quadrupole mass spectrometer with a Faraday cup and a secondary electron multiplier. The multiplier is placed at an angle of 90 degrees to the axis of the quadrupole rods. The sample size was for solution loadings 1/μg of uranium. Resin bead loadings carry about 2 ng of sample material. Both types of loadings have been used to test the instrument. The accuracy as well as the internal and external precision have been studied on standards and real samples. The possibilities as well as the limitations of the instrument are discussed with regard to its potential use for on-site safeguards verification measurements

  17. The charge-energy-mass spectrometer for 0.3-300 keV/e ions on the AMPTE CCE

    Gloeckler, G.; Ipavich, F. M.; Hamilton, D. C.; Lundgren, R. A.; Studemann, W.; Wilken, B.; Kremser, G.; Hovestadt, D.; Gliem, F.; Rieck, W.

    1985-01-01

    The charge-energy-mass (CHEM) spectrometer on the Charge Composition Explorer (CCE) has the function to measure the energy spectra, pitch-angle distributions, and ionization states of ions in the earth's magnetosphere and magnetosheath in the energy range from 0.3 to 300 keV/charge with a time resolution of less than 1 min. The obtained data will provide essential information on outstanding problems related to ion sources and dynamical processes of space plasmas and of suprathermal ions. A description of the CHEM experiment is given, taking into account the principle of operation, the sensor, the electronics, instrument characteristics, specifications, and requirements. Questions of postlaunch performance are also discussed.

  18. First data on helium isotope composition obtained with the use of single-cascade static mass-spectrometer MI-1201

    Kalinskij, I.L.; Tolstikhin, I.N.; Sharkov, I.V.; Pushkarev, Yu.D. (AN SSSR, Apatity. Geologicheskij Inst. Kol' skogo Filiala)

    1984-01-01

    Determination of isotope ratio and helium content in samples of the most ancient rocks of basic composition and in rocks of carbonatite complex of a relatively young alkali massif, and also in samples of the most ancient lithium-containing minerals( Kola Peninsula) has been carried out. For isotope analysis of helium the MI-1201 single-cascade static mass-spectrometer is used. The /sup 3/He//sup 4/He ratio in gabbro-anorthosite is shown to reach high values( up to 1.26x10/sup -6/). Isotope analysis of helium in the Khibiny alkal massif rock samples has shown these rocks, characterized by higher contents of radioactive elements to preserve a /sup 3/He excess. The content and isotope composition of helium in larga spodumene crystal samples show the excess of helium light isotope to be related to high contents of radioactive elements in enclosing rocks.

  19. Empirical model of global thermospheric temperature and composition based on data from the OGO-6 quadrupole mass spectrometer

    Hedin, A. E.; Mayr, H. G.; Reber, C. A.; Spencer, N. W.; Carignan, G. R.

    1972-01-01

    An empirical global model for magnetically quiet conditions has been derived from longitudinally averaged N2, O, and He densities by means of an expansion in spherical harmonics. The data were obtained by the OGO-6 neutral mass spectrometer and cover the altitude range 400 to 600 km for the period 27 June 1969 to 13 May 1971. The accuracy of the analytical description is of the order of the experimental error for He and O and about three times experimental error for N2, thus providing a reasonable overall representation of the satellite observations. Two model schemes are used: one representing densities extrapolated to 450 km and one representing densities extrapolated to 120 km with exospheric temperatures inferred from N2 densities. Using the best fit model parameters the global thermospheric structure is presented in the form of a number of contour plots.

  20. Construction and simulation of a multi-reflection time-of-flight mass spectrometer at the University of Notre Dame

    Schultz, B. E.; Kelly, J. M.; Nicoloff, C.; Long, J.; Ryan, S.; Brodeur, M.

    2016-06-01

    One of the most significant problems in the production of rare isotopes is the simultaneous production of contaminants, often time isobaric. Thus, a high-resolution beam purification method is required which needs to be compatible with both the low yield and short half-life of the desired radionuclide. A multi-reflection time-of-flight mass spectrometer meets all these criteria, in addition to boasting a smaller footprint relative to traditional separator dipole magnets. Such a device is currently under construction at the University of Notre Dame and is intended to be coupled to the IG-ISOL source of the planned cyclotron facility. The motivation and conceptual design are presented, as well as the status of simulations to determine the feasibility of using a Bradbury-Nielsen gate for bunching ion beams during initial system testing.