Surface Mass Balance Contributions to Acceleration of Antarctic Ice Mass Loss during 2003- 2013

Science.gov (United States)

Seo, K. W.; Wilson, C. R.; Scambos, T. A.; Kim, B. M.; Waliser, D. E.; Tian, B.; Kim, B.; Eom, J.

2015-12-01

Recent observations from satellite gravimetry (the GRACE mission) suggest an acceleration of ice mass loss from the Antarctic Ice Sheet (AIS). The contribution of surface mass balance changes (due to variable precipitation) is compared with GRACE-derived mass loss acceleration by assessing the estimated contribution of snow mass from meteorological reanalysis data. We find that over much of the continent, the acceleration can be explained by precipitation anomalies. However, on the Antarctic Peninsula and other parts of West Antarctica mass changes are not explained by precipitation and are likely associated with ice discharge rate increases. The total apparent GRACE acceleration over all of the AIS between 2003 and 2013 is -13.6±7.2 GTon/yr2. Of this total, we find that the surface mass balance component is -8.2±2.0 GTon/yr2. However, the GRACE estimate appears to contain errors arising from the atmospheric pressure fields used to remove air mass effects. The estimated acceleration error from this effect is about 9.8±5.8 GTon/yr2. Correcting for this yields an ice discharge acceleration of -15.1±6.5 GTon/yr2.

Surface mass balance contributions to acceleration of Antarctic ice mass loss during 2003-2013

OpenAIRE

Seo, Ki-Weon; Wilson, Clark R.; Scambos, Ted; Kim, Baek-Min; Waliser, Duane E.; Tian, Baijun; Kim, Byeong-Hoon; Eom, Jooyoung

2015-01-01

Abstract Recent observations from satellite gravimetry (the Gravity Recovery and Climate Experiment (GRACE) mission) suggest an acceleration of ice mass loss from the Antarctic Ice Sheet (AIS). The contribution of surface mass balance changes (due to variable precipitation) is compared with GRACE?derived mass loss acceleration by assessing the estimated contribution of snow mass from meteorological reanalysis data. We find that over much of the continent, the acceleration can be explained by ...

Accelerator mass spectrometry-current status in techniques and applications

International Nuclear Information System (INIS)

Imamura, Mineo; Nagai, Hisao; Kobayashi, Koichi.

1991-01-01

Accelerator mass spectrometry (AMS) is the mass spectrometry by incorporating an accelerator. After samples are ionized, they are accelerated to a certain energy, and mass, energy, nuclear charge (atomic number) are distinguished, and ion counting is made one by one with a heavy ion detector. For the measurement of long half-life radioisotopes, mass spectrometry has been used because of the high sensitivity, but in low energy mass spectrometry, there are the difficulties due to the mixing of the molecular ions having nearly same mass and the existence of isobars. One of the methods solving these difficulties is an accelerator which enables background-free measurement. The progress of AMS is briefly described, and at present, it is carried out in about 30 facilities in the world. In AMS, the analysis is carried out in the order of the ionization of samples, the acceleration of beam, the electron stripping with a thin film, the sorting of the momentum and energy of beam and the identification of particles. The efficiency, sensitivity and accuracy of detection and the application are reported. (K.I.)

Accelerator mass spectrometry and associated facilities at Inter-University Accelerator Centre, New Delhi, India

International Nuclear Information System (INIS)

Kumar, Pankaj; Bohra, Archna; Ojha, S.; Gargari, S.; Joshi, R.; Roonwal, G.S.; Chopra, S.; Pattanaik, J.K.; Balakrishnan, S.

2011-01-01

Accelerator Mass Spectrometry (AMS) facility at Inter-University Accelerator Centre (IUAC) is developed by upgrading its existing 15UD Pelletron accelerator. Since last two decades Pelletron is mainly used for nuclear physics, materials science, atomic physics, radiation biology and accelerator mass spectrometry is recent development. In addition, a chemistry laboratory in clean room for the chemical processing of samples for AMS studies has also been established. At present the AMS facility is used for 10 Be, 26 Al measurements and soon other long lived radio-isotopes will also be used

Development of accelerator-based γ-ray-induced positron annihilation spectroscopy technique

International Nuclear Information System (INIS)

Selim, F.A.; Wells, D.P.; Harmon, J. F.; Williams, J.

2005-01-01

Accelerator-based γ-ray-induced positron annihilation spectroscopy performs positron annihilation spectroscopy by utilizing MeV bremsstrahlung radiation generated from an accelerator (We have named the technique 'accelerator-based γ-ray-induced PAS', even though 'bremsstrahlung' is more correct here than 'γ rays'. The reason for that is to make the name of the technique more general, since PAS may be performed by utilizing MeV γ rays emitted from nuclei through the use of accelerators as described later in this article and as in the case of positron lifetime spectroscopy [F.A. Selim, D.P. Wells, and J.F. Harmon, Rev. Sci. Instrum. 76, 033905 (2005)].) instead of using positrons from radioactive sources or positron beams. MeV γ rays create positrons inside the materials by pair production. The induced positrons annihilate with the material electrons emitting a 511-keV annihilation radiation. Doppler broadening spectroscopy of the 511-keV radiation provides information about open-volume defects and plastic deformation in solids. The high penetration of MeV γ rays allows probing of defects at high depths in thick materials up to several centimeters, which is not possible with most of the current nondestructive techniques. In this article, a detailed description of the technique will be presented, including its benefits and limitations relative to the other nondestructive methods. Its application on the investigation of plastic deformation in thick steel alloys will be shown

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 1995-1997

International Nuclear Information System (INIS)

2003-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 1995-1997 years: 1 - Nuclear structure: structure of first well states, superdeformation, high-spin state populations of stable or neutron-rich nuclei, high-k isomers physics, theoretical works, technical developments; 2 - Nuclear astrophysics; 3 - Basic symmetries; 4 - Accelerator-based mass spectroscopy; 5 - Solid State Astrophysics; 6 - Physics and Chemistry of Irradiation; 7 - Solid State Physics; 8 - SEMIRAMIS (ion source and ion beam handling); 9 - Computer Department; 10 - Electronics Group; 11 - Mechanics Department; 12 - Permanent training; 13 - Health and safety; 14 - Seminars and communications; 15 - Dissertations; 16 - Publications; 17 - Staff

Design of a ram accelerator mass launch system

Science.gov (United States)

Aarnio, Michael; Armerding, Calvin; Berschauer, Andrew; Christofferson, Erik; Clement, Paul; Gohd, Robin; Neely, Bret; Reed, David; Rodriguez, Carlos; Swanstrom, Fredrick

1988-01-01

The ram accelerator mass launch system has been proposed to greatly reduce the costs of placing acceleration-insensitive payloads into low earth orbit. The ram accelerator is a chemically propelled, impulsive mass launch system capable of efficiently accelerating relatively large masses from velocities of 0.7 km/sec to 10 km/sec. The principles of propulsion are based on those of a conventional supersonic air-breathing ramjet; however the device operates in a somewhat different manner. The payload carrying vehicle resembles the center-body of the ramjet and accelerates through a stationary tube which acts as the outer cowling. The tube is filled with premixed gaseous fuel and oxidizer mixtures that burn in the vicinity of the vehicle's base, producing a thrust which accelerates the vehicle through the tube. This study examines the requirement for placing a 2000 kg vehicle into a 500 km circular orbit with a minimum amount of on-board rocket propellant for orbital maneuvers. The goal is to achieve a 50 pct payload mass fraction. The proposed design requirements have several self-imposed constraints that define the vehicle and tube configurations. Structural considerations on the vehicle and tube wall dictate an upper acceleration limit of 1000 g's and a tube inside diameter of 1.0 m. In-tube propulsive requirements and vehicle structural constraints result in a vehicle diameter of 0.76 m, a total length of 7.5 m and a nose-cone half angle of 7 degrees. An ablating nose-cone constructed from carbon-carbon composite serves as the thermal protection mechanism for atmospheric transit.

Accelerator mass spectrometry at IFIN-HH in Bucharest

International Nuclear Information System (INIS)

Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.

1999-01-01

An AMS (Accelerator Mass Spectrometry) facility was constructed at the FN - 8 MV Tandem Accelerator of the National Institute for Physics and Nuclear Engineering in Bucharest. It represents the first experimental setup of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarised at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses), a double focussing, 90 angle analysing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight stack magazine attached to the ion source. On the exit side of the Tandem Accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high energy side, is optically achromatic and contains two 90 angle analysing magnets of 150 MEP. For particle detection a Bragg-curve Spectroscopy Detector (ionisation chamber) is used and a multi-anode gas detector with TOF discrimination is under construction. The research programme at this new facility is focused on using 26 Al for medical applications. In future it will be use for 129 I - AMS measurements as a nuclear safeguard. This long lived isotope will be used to monitor and investigate the transport of 129 I in vicinity of three nuclear power plants in Eastern Europe: Kozloduy (Bulgaria), Cernavoda (Romania) and Chernobyl (Ukraine). Measurements will concern soil, precipitation and air samples. Water samples will be collected along the flow of rivers Danube and Dnieper, from the Danube Delta and from coastal areas of the Black Sea. (authors)

Plan for mass accelerator spectrometry at Gif-sur-Yvette and Saclay

International Nuclear Information System (INIS)

Berthier, B.; Bianchi, L.; Delibrias, G.; Koechlin, Y.

1981-05-01

From early 50', a carbon 14 dating laboratory was created at the Centre des Faibles Radioactivites de Gif-sur-Yvette (C.F.R.). From this time, more than 5,000 archaeological and geological samples were measured with the Libby method by this laboratory. C.F.R. is in the way to actualize its dating activities with the new accelerator method. A 3 MV General Ionex Tandetron is planed to be located at Gif-sur-Yvette next year and shared with Orsay University for 14 C. 10 Be and 36 Cl mass spectroscopy measurement. During the same time attempts have been made to adapt the Super FN Tandem of the Centre d'Etudes Nucleaires de Saclay for 14 C dating

Mass spectrometry with particle accelerator

International Nuclear Information System (INIS)

Anon.

1983-01-01

The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

Accelerator mass spectrometry: state of the art

Energy Technology Data Exchange (ETDEWEB)

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.

Accelerator mass spectrometry: state of the art

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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.

Mass spectrometry by means of tandem accelerators

International Nuclear Information System (INIS)

Tuniz, C.

1985-01-01

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

Accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator

International Nuclear Information System (INIS)

Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Gore, J.A.; Sparrow, H.; Bhagwat, P.V.; Kailas, S.

2006-01-01

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 36 Cl and 129 I. Cosmogenic radio isotope 36 Cl is widely being detected using ABMs as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl 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 36 Cl 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)

Gamma-induced Positron Spectroscopy (GiPS) at a superconducting electron linear accelerator

International Nuclear Information System (INIS)

Butterling, Maik; Anwand, Wolfgang; Cowan, Thomas E.; Hartmann, Andreas; Jungmann, Marco; Krause-Rehberg, Reinhard; Krille, Arnold; Wagner, Andreas

2011-01-01

A new and unique setup for Positron Annihilation Spectroscopy has been established and optimized at the superconducting linear electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (Germany). The intense, pulsed (26 MHz) photon source (bremsstrahlung with energies up to 16 MeV) is used to generate positrons by means of pair production throughout the entire sample volume. Due to the very short gamma bunches (< 5 ps temporal length), the facility for Gamma-induced Positron Spectroscopy (GiPS) is suitable for positron lifetime spectroscopy using the accelerator's radiofrequency as time reference. Positron lifetime and Doppler broadening Spectroscopy are employed by a coincident measurement (Age-Momentum Correlation) of the time-of-arrival and energy of the annihilation photons which in turn significantly reduces the background of scattered photons resulting in spectra with high signal to background ratios. Simulations of the setup using the GEANT4 framework have been performed to yield optimum positron generation rates for various sample materials and improved background conditions.

Gamma-induced Positron Spectroscopy (GiPS) at a superconducting electron linear accelerator

Energy Technology Data Exchange (ETDEWEB)

Butterling, Maik, E-mail: maik.butterling@googlemail.com [Martin-Luther University, Dept. of Physics, 06099 Halle (Germany); Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Anwand, Wolfgang; Cowan, Thomas E.; Hartmann, Andreas [Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Jungmann, Marco; Krause-Rehberg, Reinhard [Martin-Luther University, Dept. of Physics, 06099 Halle (Germany); Krille, Arnold; Wagner, Andreas [Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany)

2011-11-15

A new and unique setup for Positron Annihilation Spectroscopy has been established and optimized at the superconducting linear electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (Germany). The intense, pulsed (26 MHz) photon source (bremsstrahlung with energies up to 16 MeV) is used to generate positrons by means of pair production throughout the entire sample volume. Due to the very short gamma bunches (< 5 ps temporal length), the facility for Gamma-induced Positron Spectroscopy (GiPS) is suitable for positron lifetime spectroscopy using the accelerator's radiofrequency as time reference. Positron lifetime and Doppler broadening Spectroscopy are employed by a coincident measurement (Age-Momentum Correlation) of the time-of-arrival and energy of the annihilation photons which in turn significantly reduces the background of scattered photons resulting in spectra with high signal to background ratios. Simulations of the setup using the GEANT4 framework have been performed to yield optimum positron generation rates for various sample materials and improved background conditions.

Accelerator mass spectrometry.

Science.gov (United States)

Hellborg, Ragnar; Skog, Göran

2008-01-01

In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples. Copyright 2008 Wiley Periodicals, Inc.

The use of vapour phase ultra-violet spectroscopy for the analysis of arson accelerants in fire scene debris.

Science.gov (United States)

McCurdy, R J; Atwell, T; Cole, M D

2001-12-01

A method has been developed for the analysis of arson accelerants in fire scene debris by vapour phase ultra-violet (UV) spectroscopy. The method is rapid, inexpensive, simple to use and is sufficiently sensitive and discriminating to be of use for the analysis of crime scene samples. Application to casework samples is described. On occasion, the method offers additional information to that which can be obtained by gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) and represents a useful adjunct to these techniques. In addition, the method offers advantages where the use of GC-MS analysis of arson accelerants in fire scene debris is not a practical proposition.

Applications of accelerator mass spectrometry to nuclear physics and astrophysics

International Nuclear Information System (INIS)

Guo Zhiyu; Zhang Chuan

2002-01-01

As an ultra high sensitive analyzing method, accelerator mass spectrometry is playing an important role in the studies of nuclear physics and astrophysics. The accelerator mass spectrometry (AMS) applications in searching for violation of Pauli exclusion principle and study on supernovae are discussed as examples

Electrostatic accelerators fundamentals and applications

CERN Document Server

2005-01-01

Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

Principle of accelerator mass spectrometry

International Nuclear Information System (INIS)

Matsuzaki, Hiroyuki

2007-01-01

The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

Observations of the Coronal Mass Ejection with a Complex Acceleration Profile

Science.gov (United States)

Reva, A. A.; Kirichenko, A. S.; Ulyanov, A. S.; Kuzin, S. V.

2017-12-01

We study the coronal mass ejection (CME) with a complex acceleration profile. The event occurred on 2009 April 23. It had an impulsive acceleration phase, an impulsive deceleration phase, and a second impulsive acceleration phase. During its evolution, the CME showed signatures of different acceleration mechanisms: kink instability, prominence drainage, flare reconnection, and a CME–CME collision. The special feature of the observations is the usage of the TESIS EUV telescope. The instrument could image the solar corona in the Fe 171 Å line up to a distance of 2 {R}ȯ from the center of the Sun. This allows us to trace the CME up to the LASCO/C2 field of view without losing the CME from sight. The onset of the CME was caused by kink instability. The mass drainage occurred after the kink instability. The mass drainage played only an auxiliary role: it decreased the CME mass, which helped to accelerate the CME. The first impulsive acceleration phase was caused by the flare reconnection. We observed the two-ribbon flare and an increase of the soft X-ray flux during the first impulsive acceleration phase. The impulsive deceleration and the second impulsive acceleration phases were caused by the CME–CME collision. The studied event shows that CMEs are complex phenomena that cannot be explained with only one acceleration mechanism. We should seek a combination of different mechanisms that accelerate CMEs at different stages of their evolution.

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

International Nuclear Information System (INIS)

Gaal, Andrew

2004-01-01

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)

Mass spectroscopy of recoiled ions, secondary ion mass spectroscopy, and Auger electron spectroscopy investigation of Y2O3-stabilized ZrO2(100) and (110)

International Nuclear Information System (INIS)

Herman, G.S.; Henderson, M.A.; Starkweather, K.A.; McDaniel, E.P.

1999-01-01

We have studied the (100) and (110) surfaces of yttria-stabilized cubic ZrO 2 using Auger electron spectroscopy, low energy electron diffraction (LEED), direct recoil spectroscopy, mass spectroscopy of recoiled ions (MSRI), and secondary ion mass spectroscopy (SIMS). The concentration of yttrium at the surface was weakly influenced by the surface structure under the experimental conditions investigated. Both MSRI and SIMS indicated a more enhanced yttrium signal than zirconium signal at the surface compared to the respective bulk concentrations. The surfaces were not very well ordered as indicated by LEED. The yttria-stabilized cubic ZrO 2 single crystal surfaces may not be a suitable model material for pure phase ZrO 2 surfaces due to significant yttria concentrations at the surface. copyright 1999 American Vacuum Society

A GPU Accelerated Spring Mass System for Surgical Simulation

DEFF Research Database (Denmark)

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...... to 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)....

A statistical investigation of the mass discrepancy-acceleration relation

Science.gov (United States)

Desmond, Harry

2017-02-01

We use the mass discrepancy-acceleration relation (the correlation between the ratio of total-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 16 statistics that quantify its four most important features: shape, 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 LCDM to generate predictions for these statistics, starting with conventional correlations (halo abundance matching; AM) and introducing more where required. Comparing to the SPARC data, we find that: (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 relation and its normalization at low acceleration, and furthermore positions dark matter too close to galaxies' centres on average; (3) the MDAR affords 2σ evidence for an anticorrelation of galaxy size and Hubble type with halo mass or concentration at fixed stellar mass. Our analysis lays the groundwork for a bottom-up determination of the galaxy-halo connection from relations such as the MDAR, provides concrete statistical tests for specific galaxy formation models, and brings into sharper focus the relative evidence accorded by galaxy kinematics to LCDM and modified gravity alternatives.

Accelerator mass spectrometry for measurement of long-lived radioisotopes.

Science.gov (United States)

Elmore, D; Phillips, F M

1987-05-01

Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

Accelerator mass spectrometry in NIPNE

International Nuclear Information System (INIS)

Ivascu, M; Marinescu, L.; Dima, R.; Cata-Danil, D.; Petrascu, M.; Popescu, I.; Stan-Sion, C.; Radulescu, M.; Plostinaru, D.

1997-01-01

The Accelerator Mass Spectrometry (AMS) is today the method capable to measure the lowest concentration of a particular nuclide in sample materials. The method has applications in environmental physics, medicine, measurements of cosmic-ray or nuclear power plant produced radionuclides in the earth's atmosphere. All over the world, more than 40 charged particles and heavy ion accelerators are performing such analyses concerning the research interest of a huge number of laboratories. The Romanian Institute of Nuclear Physics and Engineering in Bucharest has initiated a construction project for the AMS facility at the FN - Van de Graaff Tandem accelerator. This program benefits of technical and financial assistance provided by IAEA in the frame of the IAEA-TC Project ROM 8014-265C. A general lay-out of the AMS project is presented. The construction work has begun and first tests of the AMS injector will take place between July - September this year. (authors)

Negative-Ion source for mass selective photodetachment photoelectron spectroscopy

International Nuclear Information System (INIS)

Kaesmaier, R.; Baemann, C.; Drechsler, G.; Boesl, U.

1995-01-01

We have designed and constructed a negative ion source for mass spectrometry and mass selective photodetachement photoelectron spectroscopy. The characteristics of the source are high anion densities and a large variety of accessible systems. Thus, mass spectra and photoelectron spectra of large unvolatile moelcules (biomolecules), of metal-organic compounds and of molecule water clusters, especially mentioned in this article, have been measured. Combining mass spectrometry, photoelectron spectroscopy (PES) and high resolution ZEKE (zero kinetic energy)-PES (1) should make the apparatus to an ideal diagnostic tool for structural assignment

A New Accelerator-Based Mass Spectrometry.

Science.gov (United States)

Gove, H. E.

1983-01-01

Tandem electrostatic accelerators produce beams of positive ions which are used to penetrate atomic nuclei in a target, inducing nuclear reactions whose study elucidates varied properties of the nucleus. Uses of the system, which acts like a mass spectrometer, are discussed. These include radiocarbon dating measurements. (JN)

The future of the accelerator mass spectrometry of rare long-lived radioactive isotopes

International Nuclear Information System (INIS)

Litherland, A.E.

1990-01-01

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.)

Design of a superconducting accelerator for positron annihilation spectroscopy

International Nuclear Information System (INIS)

Oshima, Nagayasu; Kuroda, Ryunosuke; Suzuki, Ryoichi; Kinomura, Atsushi; Ohdaira, Toshiyuki; Hayashizaki, Noriyosu; Hattori, Toshiyuki

2008-01-01

A design of a superconducting accelerator for a positron beam with energy of ∼1 MeV for positron annihilation spectroscopy is proposed. The total system can be extremely small with an application of superconducting technology. Both a miniaturization and easy maintenance of the accelerator can be achieved by usage of a small liquidless refrigerator for cooling of a superconducting RF cavity. Moreover, operation duty cycle of the superconducting cavity is ∼100%. The required RF power to drive the system is only ∼10 W, therefore a large-size klystron is not necessary. The designed system including a slow positron source is small (∼2 m 3 ) enough to be used in a general laboratory. (author)

Radiocarbon accelerator mass spectrometry: background and contamination

International Nuclear Information System (INIS)

Beukens, R.P.

1993-01-01

Since the advent of radiocarbon accelerator mass spectrometry (AMS) many studies have been conducted to understand the background from mass spectrometric processes and the origins of contamination associated with the ion source and sample preparation. By studying the individual contributions a better understanding of these processes has been obtained and it has been demonstrated that it is possible to date samples reliably up to 60 000 BP. (orig.)

Tritium depth profiling in carbon by accelerator mass spectrometry

International Nuclear Information System (INIS)

Friedrich, M.; Pilz, W.; Sun, G.; Behrisch, R.; Garcia-Rosales, C.; Bekris, N.; Penzhorn, R.-D.

2000-01-01

Tritium depth profiling measurements by accelerator mass spectrometry have been performed at the facility installed at the Rossendorf 3 MV Tandetron. In order to achieve a uniform erosion at the target surface inside a commercial Cs ion sputtering source and to avoid edge effects, the samples were mechanically scanned and the signals were recorded only during sputtering at the centre of the sputtered area. The sputtered negative ions were mass analysed by the injection magnet of the Tandetron. Hydrogen and deuterium profiles were measured with the Faraday cup between the injection magnet and the accelerator, while the tritium was counted after the accelerator with semiconductor detectors. Depth profiles have been measured for carbon samples which had been exposed to the plasma at the first wall of the Garching fusion experiment ASDEX-Upgrade and from the European fusion experiment JET, Culham, UK

Determination of {sup 135}Cs by accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

MacDonald, C.M.; Charles, C.R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L.; Kieser, W.E. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Cornett, R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [IsoTrace Laboratory, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada)

2015-10-15

The ratio of anthropogenic {sup 135}Cs and {sup 137}Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying {sup 135}Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn{sub 2}, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10{sup −3} and 1.7 × 10{sup −7} respectively. This quantification of {sup 135}Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

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

International Nuclear Information System (INIS)

Bhagwat, P.V.

2007-01-01

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 36 Cl and 129 I. Cosmogenic radioisotope 36 Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl 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 14 C from a charcoal sample and 3 He in natural Helium. As the primary interest of AMS programme at Mumbai Pelletron Accelerator is related to the cosmogenic nuclei, 36 Cl and 129 I, a segmented gas detector developed for identification of 36 Cl was tested for performance. Recently a beam chopper required for this measurement has also been developed

Continuous-flow accelerator mass spectrometry for radiocarbon analysis

International Nuclear Information System (INIS)

Wills, J.S.C.; Han, B.X.; Von Reden, K.F.; Schneider, R.J.; Roberts, M.L.

2006-01-01

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 14 C 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)

Continuous-flow accelerator mass spectrometry for radiocarbon analysis

International Nuclear Information System (INIS)

Wills, J.S.C.; Han, B.X.; Von Reden, K.F.; Schneider, R.J.; Roberts, M.L.

2006-05-01

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 14 C 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)

Accelerator Mass Spectrometry at the National Institute of Nuclear Physics and Engineering in Bucharest

International Nuclear Information System (INIS)

Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.; Ivascu, M.; Marinescu, L.; Dima, R.

2000-01-01

The Accelerator Mass Spectrometry (AMS) is today the experimental physical method capable to measure the lowest concentration of a particular nuclide in a sample material. Ratios of radionuclides in the range 10 -13 - 10 -15 are normally measured with this technique, corresponding to a sensitivity which makes possible the detection of only 1 Atom in a surrounding material of about 1 Million of Billions of other Atoms. Thus, the AMS has advanced the art of Classical Mass Spectrometry (sensitivity 10 -11 ) to a sensitivity which allows for the first time the performance of special applications in environmental physics, medicine, pharmacology, geology, archaeology, measurements of radio nuclides in the Earth's atmosphere produced by cosmic-rays or by nuclear power plants, applications in astrophysics and in nuclear physics.An Accelerator Mass Spectrometry facility was constructed at the FN - 8 MV tandem accelerator of the National Institute of Physics and Nuclear Engineering . The construction was possible in the frame of a co-operation with the Technical University Munich and with financial support from IAEA-Vienna. It represents the first experimental set-up of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarized at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses) a double focussing, 90 angle analyzing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight-stack magazine attached to the ion source. On the exit side of the tandem accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high-energy side, is optically achromatic and contains two 90 angle analyzing magnets of

Issues and opportunities in accelerator mass spectrometry for stable isotopes.

Science.gov (United States)

Matteson, Sam

2008-01-01

Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. Copyright 2008 Wiley Periodicals, Inc.

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

Science.gov (United States)

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.

Acceleration of the GrIS mass loss as observed by GRACE

DEFF Research Database (Denmark)

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...

Method of N-15 analysis by mass-spectroscopy on ion implanter MPB-200

International Nuclear Information System (INIS)

Vo Van Thuan; Dang Duc Nhan; Nguyen Phuc; Nguyen Tien Dung; Nguyen Van Dach

1993-01-01

The industrial implanter MPB-200 has been modified to a light-isotope mass spectrometer. Mass-resolution has been improved by combination of quadrupole focusing system and a collimator with additional scattering shielding. Single beam method has been set up, in which mass-spectrum are obtained by scanning magnetic field of the separator. A start-stop control system has been added to operate automatically the magnet and registration system, from which signals are transferred to a XT/AT computer for saving and analysis. The mass-resolution is satisfactory for analysis of light isotopes with mass number A less than 40. A testing measurement has been done with standard samples of natural and enriched N-15 isotope, at acceleration energy of 50 keV, beam current less than 100 nA, vacuum of 4x10E-6 and collimator's shell of 1 mm. Obtained resolution and background condition allowed to achieve a good linear dependence of relative isotope ratio data vs real abundance in the range from natural 0.365% to 5.0% with a 3% error (96% of reliability). Routine N-15 may achieve (5-10)% accuracy by a 7-10 minutes measurement for every sample. Sensitivity of the mass-spectrometer is better almost by one order in comparing with one of emission spectrometers. The new mass-spectroscopy system is applied to research in agriculture, biology and environmental study. (author). 4 refs, 4 figs

Accelerator Laboratory of the University and the Technical University of Munich. Annual report 1992

International Nuclear Information System (INIS)

Korschinek, G.; Lutter, R.; Riess, F.

1993-01-01

This report contains extended abstracts about the work performed at the named laboratory together with a list of publications and reports. The abstracts concern experiments on nuclear reactions, nuclear spectroscopy, atomic physics, accelerator mass spectroscopy with heavy ions, and applications of nuclear techniques, theoretical work on nuclear reactions, nuclear structure, atomic physics, and astrophysics, developments of accelerators and radiation instrumentation, as well as data processing. (HSI)

Computer automation of an accelerator mass spectrometry system

International Nuclear Information System (INIS)

Gressett, J.D.; Maxson, D.L.; Matteson, S.; McDaniel, F.D.; Duggan, J.L.; Mackey, H.J.; North Texas State Univ., Denton, TX; Anthony, J.M.

1989-01-01

The determination of trace impurities in electronic materials using accelerator mass spectrometry (AMS) requires efficient automation of the beam transport and mass discrimination hardware. The ability to choose between a variety of charge states, isotopes and injected molecules is necessary to provide survey capabilities similar to that available on conventional mass spectrometers. This paper will discuss automation hardware and software for flexible, high-sensitivity trace analysis of electronic materials, e.g. Si, GaAs and HgCdTe. Details regarding settling times will be presented, along with proof-of-principle experimental data. Potential and present applications will also be discussed. (orig.)

New applications of accelerator mass spectrometry

International Nuclear Information System (INIS)

Davis, J.C.

1991-01-01

Since its invention in the late 70's, and reduction to near-routine practice by the mid-80's, accelerator mass spectrometry (AMS) has become a powerful tool for archaeological and geochemical measurements in which cosmogenic isotopes such as 10 Be, 14 C, 26 Al, 36 Cl and 129 I are used as either tracers or chronometers. The utility of such measurements is demonstrated by the fact that most accelerators having AMS capabilities have significant backlogs of samples awaiting measurement. In designing and justifying a new accelerator facility in which AMS was to be a major feature, we sought to advance the field and increase the resources available for it by two steps: (1) development of new research applications in which intentionally added isotopic labels were used rather than just naturally present ones; and (2) enhancement of spectrometer throughout, making new classes of experiments possible by greatly increasing the number of samples that could be measured in individual experiments. Results of the effort to date suggest that development of a family of very small spectrometers optimized for just tritium and/or radiocarbon will be attractive in the near future

Determination of "1"3"5Cs by accelerator mass spectrometry

International Nuclear Information System (INIS)

MacDonald, C.M.; Charles, C.R.J.; Zhao, X.-L.; Kieser, W.E.; Cornett, R.J.; Litherland, A.E.

2015-01-01

The ratio of anthropogenic "1"3"5Cs and "1"3"7Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying "1"3"5Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn_2, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10"−"3 and 1.7 × 10"−"7 respectively. This quantification of "1"3"5Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

Present and future prospects of accelerator mass spectrometry

International Nuclear Information System (INIS)

Kutschera, W.

1987-04-01

Accelerator Mass Spectrometry (AMS) has become a powerful technique for measuring extremely low abundances (10 -10 to 10 -15 relative to stable isotopes) of long-lived radioisotopes with half-lives in the range from 10 2 to 10 8 years. With a few exceptions, tandem accelerators turned out to be the most useful instruments for AMS measurements. Both natural (mostly cosmogenic) and man-made (anthropogenic) radioisotopes are studied with this technique. In some cases very low concentrations of stable isotope are also measured. Applications of AMS cover a large variety of fields including anthropology, archaeology, oceanography, hydrology, climatology, volcanology, minerals exploration, cosmochemistry, meteoritics, glaciology, sedimentary processes, geochronology, environmental physics, astrophysics, nuclear and particle physics. Present and future prospects of AMS are discussed as an interplay between the continuous development of new techniques and the investigation of problems in the above mentioned fields. Typical factors to be considered are energy range and type of accelerator, and the possibilities of dedicated versus partial use of new or existing accelerators

Applications of accelerator mass spectrometry: advances and innovation

International Nuclear Information System (INIS)

Fifield, L.K.

2004-01-01

Emerging trends in the applications of accelerator mass spectrometry (AMS) are identified and illustrated with specific examples. Areas of application covered include rapid landscape evolution, calibration of the radiocarbon time scale, compound-specific radiocarbon studies, tracing of nuclear discharges, and searches for extraterrestrial isotopes

Mass, charge, and energy separation by selective acceleration with a traveling potential hill

Science.gov (United States)

Tung, L. Schwager; Barr, W. L.; Lowder, R. S.; Post, R. F.

1996-10-01

A traveling electric potential hill has been used to generate an ion beam with an energy distribution that is mass dependent from a monoenergetic ion beam of mixed masses. This effect can be utilized as a novel method for mass separation applied to identification or enrichment of ions (e.g., of elements, isotopes, or molecules). This theory for mass-selective acceleration is presented here and is shown to be confirmed by experiment and by a time-dependent particle-in-cell computer simulation. Results show that monoenergetic ions with the particular mass of choice are accelerated by controlling the hill potential and the hill velocity. The hill velocity is typically 20%-30% faster than the ions to be accelerated. The ability of the hill to pickup a particular mass uses the fact that small kinetic energy differences in the lab frame appear much larger in the moving hill frame. Ions will gain energy from the approaching hill if their relative energy in the moving hill frame is less than the peak potential of the hill. The final energy of these accelerated ions can be several times the source energy, which facilitates energy filtering for mass purification or identification. If the hill potential is chosen to accelerate multiple masses, the heaviest mass will have the greatest final energy. Hence, choosing the appropriate hill potential and collector retarding voltage will isolate ions with the lightest, heaviest, or intermediate mass. In the experimental device, called a Solitron, purified 20Ne and 22Ne are extracted from a ribbon beam of neon that is originally composed of 20Ne:22Ne in the natural ratio of 91:9. The isotopic content of the processed beam is determined by measuring the energy distribution of the detected current. These results agree with the theory. In addition to mass selectivity, our theory can also be applied to the filtration of an ion beam according to charge state or energy. Because of this variety of properties, the Solitron is envisioned to

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

International Nuclear Information System (INIS)

Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Gore, J.A.; Sparrow, H.; Bhagwat, P.V.; Kailas, S.; Kale, R.M.; Hemalatha, M.

2007-01-01

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 36 Cl and 129 I. Cosmogenic radio isotope 36 Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl 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 36 Cl was tested for performance. Recently a beam chopper required for this measurement has been developed. 36 Cl measurements carried out to detect and measure the ratio of 36 Cl to 35 Cl in an irradiated sample and dated sample are reported in this paper

Accelerator mass spectrometry of 41Ca with a positive-ion source and the UNILAC accelerator

International Nuclear Information System (INIS)

Steinhof, A.; Henning, W.; Mueller, M.; Roeckl, E.; Schuell, D.; Korschinek, G.; Nolte, E.; Paul, M.

1987-06-01

We have made first tests investigating the performance characteristics of the UNILAC accelerator system at GSI, in order to explore the sensitivity achievable in accelerator mass spectrometry (AMS) of 41 Ca with high-current positive-ion sources. Positively charged Ca 3+ ions of up to about 100 micro-amperes electrical current were injected from a penning-sputter source and, after further stripping to Ca 9+ , accelerated to 14.3 MeV/nucleon. The combination of velocity-focussing accelerator and magnetic ion-beam transport system completely eliminated background from the other calcium isotopes. Full-stripping and detection of 41 Ca 20+ ions with a magnetic spectrograph provides separation from isobaric 41 K and, at present, a level of sensitivity of 41 Ca/Ca ≅ 2x10 -15 . Future improvements and implications for dating of Pleistoscene samples will be discussed. (orig.)

Heavy-ion accelerator mass spectrometry with a 'small' accelerator

International Nuclear Information System (INIS)

Steier, P.; Golser, R.; Priller, A.; Vockenhuber, C.; Irlweck, K.; Kutschera, W.; Lichtenstein, V.

2001-01-01

Full text: VERA, the Vienna environmental research accelerator, is based on a 3-MV pelletron tandem accelerator and is designed to allow the transport of ions of all elements, from the lightest to the heaviest. The VERA heavy ion program tries to establish measurement methods which work for the long-lived radionuclides where suppression of isobars is not required. Among these are 129 I, 210 Pb, 236 U and all heavier ions where no stable isobars exist. To suppress neighboring masses, the resolution of VERA was increased, both by improving the ion optics of existing elements and by installing a new electrostatic separator after the analyzing magnet. Interfering ions which pass all beam filters are identified with a high-resolution time-of-flight system, using a 0.5 μg/cm 2 DLC (diamond-like carbon) foil in the start detector, which substantially reduces beam straggling. Compared to heavy ion AMS at large tandem accelerators (TV ≥ 8 MV) and for cases where stable isobar interference is absent, it is possible to offset the disadvantage of lower ion energy. Moreover, the more compact facilities like VERA achieve higher stability and reliability and provide advanced computer control. This promises even higher precision and sensitivity for a larger number of samples, which is a prerequisite for research on natural-occurring heavy radioisotopes at environmental levels. First results on the measurement of 210 Pb (half-life 22 a) and 236 U (23 Ma) encourages us to push towards even heavier radionuclides (e.g. 224 Pu, 81 Ma). (author)

Application of the mass-spectrometer MASHA for mass-spectrometry and laser-spectroscopy

Science.gov (United States)

Rodin, A. M.; Belozerov, A. V.; Dmitriev, S. N.; Oganessian, Yu. Ts.; Sagaidak, R. N.; Salamatin, V. S.; Stepantsov, S. V.; Vanin, D. V.

2010-02-01

We report the present status of the mass-spectrometer MASHA (Mass-Analyzer of Supper Heavy Atoms) designed for determination of the masses of superheavy elements. The mass-spectrometer is connected to the U-400M cyclotron of the Flerov Laboratory for Nuclear Reactions (FLNR) JINR, Dubna. The first experiments on mass-measurements for 112 and 114 elements will be performed in the upcoming 2010. For this purpose a hot catcher, based on a graphite stopper, is constructed. The α-decay of the superheavy nuclides or spontaneous fission products will be detected with a silicon 192 strips detector. The experimental program of future investigations using the technique of a gas catcher is discussed. It should be regarded as an alternative of the classical ISOL technique. The possibilities are considered for using this mass-spectrometer for laser spectroscopy of nuclei far off-stability.

Application of the mass-spectrometer MASHA for mass-spectrometry and laser-spectroscopy

International Nuclear Information System (INIS)

Rodin, A. M.; Belozerov, A. V.; Dmitriev, S. N.; Oganessian, Yu. Ts.; Sagaidak, R. N.; Salamatin, V. S.; Stepantsov, S. V.; Vanin, D. V.

2010-01-01

We report the present status of the mass-spectrometer MASHA (Mass-Analyzer of Supper Heavy Atoms) designed for determination of the masses of superheavy elements. The mass-spectrometer is connected to the U-400M cyclotron of the Flerov Laboratory for Nuclear Reactions (FLNR) JINR, Dubna. The first experiments on mass-measurements for 112 and 114 elements will be performed in the upcoming 2010. For this purpose a hot catcher, based on a graphite stopper, is constructed. The α-decay of the superheavy nuclides or spontaneous fission products will be detected with a silicon 192 strips detector. The experimental program of future investigations using the technique of a gas catcher is discussed. It should be regarded as an alternative of the classical ISOL technique. The possibilities are considered for using this mass-spectrometer for laser spectroscopy of nuclei far off-stability.

Application of the mass-spectrometer MASHA for mass-spectrometry and laser-spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Rodin, A. M., E-mail: rodin@nrmail.jinr.ru; Belozerov, A. V.; Dmitriev, S. N.; Oganessian, Yu. Ts.; Sagaidak, R. N.; Salamatin, V. S.; Stepantsov, S. V.; Vanin, D. V. [JINR, Flerov Laboratory of Nuclear Reactions (Russian Federation)

2010-02-15

We report the present status of the mass-spectrometer MASHA (Mass-Analyzer of Supper Heavy Atoms) designed for determination of the masses of superheavy elements. The mass-spectrometer is connected to the U-400M cyclotron of the Flerov Laboratory for Nuclear Reactions (FLNR) JINR, Dubna. The first experiments on mass-measurements for 112 and 114 elements will be performed in the upcoming 2010. For this purpose a hot catcher, based on a graphite stopper, is constructed. The {alpha}-decay of the superheavy nuclides or spontaneous fission products will be detected with a silicon 192 strips detector. The experimental program of future investigations using the technique of a gas catcher is discussed. It should be regarded as an alternative of the classical ISOL technique. The possibilities are considered for using this mass-spectrometer for laser spectroscopy of nuclei far off-stability.

Chlorococcalean microalgae Ankistrodesmus convolutes biodiesel characterization with Fourier transform-infrared spectroscopy and gas chromatography mass spectroscopy techniques

Directory of Open Access Journals (Sweden)

Swati SONAWANE

2015-12-01

Full Text Available The Chlorococcalean microalgae Ankistrodesmus convolutes was found in fresh water Godawari reservoir, Ahmednagar district of Maharashtra State, India. Microalgae are modern biomass for the production of liquid biofuel due to its high solar cultivation efficiency. The collection, harvesting and drying processes were play vital role in converting algal biomass into energy liquid fuel. The oil extraction was the important step for the biodiesel synthesis. The fatty acid methyl ester (FAME synthesis was carried through base catalyzed transesterification method. The product was analyzed by using the hyphened techniques like Fourier Transform-Infrared spectroscopy (FT-IR and Gas Chromatography Mass Spectroscopy (GCMS. FT-IR Spectroscopy was results the ester as functional group of obtained product while the Gas Chromatography Mass Spectroscopy was results the six type of fatty acid methyl ester with different concentration. Ankistrodesmus convolutes biodiesel consist of 46.5% saturated and 49.14% unsaturated FAME.

Subattomole sensitivity in biological accelerator mass spectrometry.

Science.gov (United States)

Salehpour, Mehran; Possnert, Göran; Bryhni, Helge

2008-05-15

The Uppsala University 5 MV Pelletron tandem accelerator has been used to study (14)C-labeled biological samples utilizing accelerator mass spectrometry (AMS) technology. We have adapted a sample preparation method for small biological samples down to a few tens of micrograms of carbon, involving among others, miniaturizing of the graphitization reactor. Standard AMS requires about 1 mg of carbon with a limit of quantitation of about 10 amol. Results are presented for a range of small sample sizes with concentrations down to below 1 pM of a pharmaceutical substance in human blood. It is shown that (14)C-labeled molecular markers can be routinely measured from the femtomole range down to a few hundred zeptomole (10 (-21) mol), without the use of any additional separation methods.

Neutrino mass and mixing, and non-accelerator experiments

International Nuclear Information System (INIS)

Robertson, R.G.H.

1992-01-01

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

Acceleration Signal Characteristics for Intuitional Mass Analysis of Metallic Loose Parts

International Nuclear Information System (INIS)

Lee, Kwang-Hyun; Jung, Chang-Gyu

2016-01-01

Nuclear power plants (NPPs) have operated LPMS (Loose Parts Monitoring System) for early detection of the possible presence of metallic parts in the reactor coolant system (RCS); however, analysis of the metallic impact wave characteristics in the LPMS is an important issue because information, such as the mass of the metallic part and the impact location, is not provided. Most studies have concentrated on fieldwork using the frequency characteristics for the analysis of the metallic part mass. Thus, the field engineers cannot analyze signals without special software and access to the system. This paper is intended to introduce a process of intuitional mass analysis using the attenuation rate of the acceleration signal and the intervals between peak signals. Most studies related to mass analysis of a metallic part impact signal in LPMS have used the frequency spectrum. This paper presents a method of using the acceleration signal characteristics for intuitional mass analysis of loose metallic parts. With the method proposed in this paper, because the mass of a metallic part can be understood intuitionally without any special analysis program, intuitional analysis used in parallel with frequency spectrum analysis will be in effect

Acceleration Signal Characteristics for Intuitional Mass Analysis of Metallic Loose Parts

Energy Technology Data Exchange (ETDEWEB)

Lee, Kwang-Hyun; Jung, Chang-Gyu [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

Nuclear power plants (NPPs) have operated LPMS (Loose Parts Monitoring System) for early detection of the possible presence of metallic parts in the reactor coolant system (RCS); however, analysis of the metallic impact wave characteristics in the LPMS is an important issue because information, such as the mass of the metallic part and the impact location, is not provided. Most studies have concentrated on fieldwork using the frequency characteristics for the analysis of the metallic part mass. Thus, the field engineers cannot analyze signals without special software and access to the system. This paper is intended to introduce a process of intuitional mass analysis using the attenuation rate of the acceleration signal and the intervals between peak signals. Most studies related to mass analysis of a metallic part impact signal in LPMS have used the frequency spectrum. This paper presents a method of using the acceleration signal characteristics for intuitional mass analysis of loose metallic parts. With the method proposed in this paper, because the mass of a metallic part can be understood intuitionally without any special analysis program, intuitional analysis used in parallel with frequency spectrum analysis will be in effect.

Present and future prospects of accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Kutschera, W

1988-05-20

Accelerator mass spectrometry (AMS) has become a powerful technique for measuring extremely low abundances (10/sup -10/ to 10/sup -15/ relative to stable isotopes) of long-lived radioisotopes with half-lives in the range from 10/sup 2/ to 10/sup 8/ years. With a few exceptions, tandem accelerators turned out to be the most useful instruments for AMS measurements. Both natural (mostly cosmogenic) and manmade (anthropogenic) radioisotopes are studied with this technique. In some cases very low concentrations of stable isotopes are also measured. Applications of AMS cover a large variety of fields including anthropology, archaeology, oceanography, hydrology, climatology, volcanology, mineral exploration, cosmochemistry, meteoritics, glaciology, sedimentary processes, geochronology, environmental physics, astrophysics, nuclear and particle physics. Present and future prospects of AMS will be discussed as an interplay between the continuous development of new techniques and the investigation of problems in the above mentioned field. Depending on the specific problem to be investigated, different aspects of an AMS system are of importance. Typical factors to be considered are energy range and type of accelerator, and the possibilities of dedicated versus partial use of new or existing accelerators.

The origin of mass and experiments on high-energy particle accelerators

International Nuclear Information System (INIS)

Ioffe, B.L.

2006-01-01

The visible world is one consisting of nucleons and electrons. The mass of nucleon arises from chiral symmetry breaking in quantum chromodynamics, so high energy accelerator experiments cannot give a clue to the nature of mass of matter in the visible world. The origin of the mass of the matter will be clarified when the mechanism of chiral symmetry breaking in quantum chromodynamics is established [ru

14C Accelerator mass spectrometry in Brazil

International Nuclear Information System (INIS)

Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L.; Carvalho, C.R.A.

2011-01-01

Radiocarbon Accelerator Mass Spectrometry is an ultra-sensitive technique that enables the direct measurement of carbon isotopes in samples as small as a few milligrams. The possibility of dating or tracing rare or even compound specific carbon samples has application in many fields of science such as Archaeology, Geosciences and Biomedicine. Several kinds of material such as wood, charcoal, carbonate and bone can be chemically treated and converted to graphite to be measured in the accelerator system. The Physics Institute of Universidade Federal Fluminense (UFF), in Brazil will soon be able to perform the complete 14 C-AMS measurement of samples. At the Nuclear Chronology Laboratory (LACRON) samples are prepared and converted to carbon dioxide. A stainless steel vacuum system was constructed for carbon dioxide purification and graphitization is performed in sealed tubes in a muffle oven. Graphite samples will be analyzed in a 250 kV Single Stage Accelerator produced by National Electrostatic Corporation which will be installed in the beginning of 2012. With the sample preparation laboratory at LACRON and the SSAMS system, the Physics Institute of UFF will be the first 14 C-AMS facility in Latin America. (author)

New method for laser driven ion acceleration with isolated, mass-limited targets

International Nuclear Information System (INIS)

Paasch-Colberg, T.; Sokollik, T.; Gorling, K.; Eichmann, U.; Steinke, S.; Schnuerer, M.; Nickles, P.V.; Andreev, A.; Sandner, W.

2011-01-01

A new technique to investigate laser driven ion acceleration with fully isolated, mass-limited glass spheres with a diameter down to 8μm is presented. A Paul trap was used to prepare a levitating glass sphere for the interaction with a laser pulse of relativistic intensity. Narrow-bandwidth energy spectra of protons and oxygen ions have been observed and were attributed to specific acceleration field dynamics in case of the spherical target geometry. A general limiting mechanism has been found that explains the experimentally observed ion energies for the mass-limited target.

On-line high-resolution mass spectroscopy. Progress report, January 1, 1975--July 1, 1975

International Nuclear Information System (INIS)

Macfarlane, R.D.

1975-01-01

The report begins with a brief introduction, summary of activities, and lists of personnel, facilities used, publications, and presentations. Work on xanthine--tyrosine and sulfuric acid esters was completed in the project on 252 Cf-plasma desorption mass spectroscopy of involatile molecules. Work is continuing in the following areas: beta--gamma directional correlations and second-class currents in nuclear beta decay (mass-20 system), beta--neutrino directional correlations in mass 8, atomic mass measurements, and 252 Cf-plasma desorption mass spectroscopy of large biomolecules. (3 figures) (RWR)

Accelerator mass spectrometry - From DNA to astrophysics

International Nuclear Information System (INIS)

Kutschera, W.

2013-01-01

A brief review of accelerator mass spectrometry (AMS) is presented. The present work touches on a few technical aspects and recent developments of AMS, and describes two specific applications of AMS, the dating of human DNA with the 14 C bomb peak and the search for superheavy elements in nature. Since two extended general reviews on technical developments in AMS [1] and applications of AMS [2] will appear in 2013, frequent reference to these reviews is made. (authors)

Injection system of the minicyclotron accelerator mass spectrometer

International Nuclear Information System (INIS)

Liu Yonghao; Li Deming; Chen Maobai; Lu Xiangshun

1999-01-01

The existing injection system of the SMCAMS (super-sensitive mini-cyclotron accelerator mass spectrometer) is described together with the discussion of its disadvantages exposed after having been operating for five years, which provides a basis for consideration of improvements to the injection system. An optimized injection system with an analytical magnet added prior to the minicyclotron has been proposed and calculated

Accelerator mass spectrometry for radiocarbon dating

International Nuclear Information System (INIS)

Bronk, C.R.

1987-01-01

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)

Importance of the virtual mass force in accelerating steam/water mixtures

International Nuclear Information System (INIS)

Khalil, Y.F.; Kazimi, M.S.

1987-01-01

Virtual mass force is one of the forces that must be considered against accelerating a dispersed fluid flowing in the bulk of a continuous fluid. This force depends on the geometry of the interface and the flow pattern of the two fluids. For dilute two-phase flow mixtures where the bubbles are singly dispersed, the value of the virtual mass force coefficient is dependent on the geometry of the bubble. However, for high void fraction cases, such as depressurization initiated by a pipe break in light water reactors, more intense interaction is expected between the two phase and, therefore, the value of the virtual mass force must be well defined. The effects of implementing the virtual mass force term in the momentum equations of a two-fluid model may be significant for improving the stability of the solution of the conservation equations, the accuracy of the numerical results, and the computation time. In the current work, a new stability criterion is derived after implementing Hancox's model for the virtual mass force in the momentum equations of the six-equation two-phase flow model of TERMIT. A one-dimensional blow-down in a horizontal pipe is considered to investigate the importance of incorporating the virtual mass force in accelerating mixtures flows

Resonance Ionization Mass Spectrometry (RIMS): applications in spectroscopy and chemical dynamics

International Nuclear Information System (INIS)

Naik, P.D.; Kumar, Awadhesh; Upadhyaya, Hari; Bajaj, P.N.

2009-01-01

Resonance ionization is a photophysical process wherein electromagnetic radiation is used to ionize atoms, molecules, transient species, etc., by exciting them through their quantum states. The number of photons required to ionize depends on the species being investigated and energy of the photon. Once a charged particle is produced, it is easy to detect it with high efficiency. With the advent of narrow band high power pulsed and cw tunable dye lasers, it has blossomed into a powerful spectroscopic and analytical technique, commonly known as resonance ionization spectroscopy (RIS)/resonance enhanced multiphoton ionization (REMPI). The alliance of resonance ionization with mass spectrometry has grown into a still more powerful technique, known as resonance ionization mass spectrometry (RIMS), which has made significant contributions in a variety of frontier areas of research and development, such as spectroscopy, chemical dynamics, analytical chemistry, cluster science, surface science, radiochemistry, nuclear physics, biology, environmental science, material science, etc. In this article, we shall describe the application of resonance ionization mass spectrometry to spectroscopy of uranium and chemical dynamics of polyatomic molecules

Measuring test mass acceleration noise in space-based gravitational wave astronomy

Science.gov (United States)

Congedo, Giuseppe

2015-03-01

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 nongravitational spurious forces. This last contribution is going to be characterized 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's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners

Directory of Open Access Journals (Sweden)

Lin Shun-Ping

2014-12-01

Full Text Available Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional centerof- mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5 and a sub-elite group (SG; n = 5. The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML acceleration (r = −0.83 to −0.93, p < 0.05, and between anterior-posterior (AP acceleration and running distance (r = −0.8953 to −0.9653, p < 0.05, but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated.

Mass measurement of 80Y by β-γ coincidence spectroscopy

International Nuclear Information System (INIS)

Barton, C.J.; Caprio, M.A.; Beausang, C.W.; Casten, R.F.; Cooper, J.R.; Kruecken, R.; Novak, J.R.; Pietralla, N.; Brenner, D.S.; Zamfir, N.V.; Aprahamian, A.; Wiescher, M.C.; Shawcross, M.; Teymurazyan, A.; Berant, Z.; Wolf, A.; Gill, R.L.

2003-01-01

The Q EC value of 80 Y has been measured by β-γ coincidence spectroscopy to be ≥8929(83) keV. Combining this result with the adopted mass excess of the daughter 80 Sr gives a mass excess for 80 Y of ≥-61 376(83) keV. Results are compared with other measurements, with Audi-Wapstra systematics, and with predictions of mass formulas. Implications of this measurement are considered for the rp process

Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

Science.gov (United States)

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.

Mass-selective Neutron Spectroscopy Beyond the Proton

International Nuclear Information System (INIS)

Krzystyniak, M; Seel, A G; Richards, S E; Gutmann, M J; Fernandez-Alonso, F

2014-01-01

We discuss ongoing methodological developments underpinning the determination of nuclear-momentum distributions from mass-resolved neutron Compton data of lightweight materials. To this end, two systems are considered in detail, namely, lithium hydride (including its deuterated counterpart) and squaric acid, an organic antiferroelectric material containing hydrogen, carbon, and oxygen. Beyond the usual case of the proton, our approach enables direct access to detailed line shape information associated with the underlying nuclear-momentum distributions of both deuterium and lithium. For oxygen and carbon, mean kinetic energies can also be obtained directly from the neutron data, as demonstrated by a detailed analysis of mass- resolved data from squaric acid. From an instrumentation point of view, this work provides a suitable platform for a detailed assessment of existing capabilities and future developments in mass-selective neutron spectroscopy on the VESUVIO spectrometer at ISIS

Optical spectroscopy versus mass spectrometry: The race for fieldable isotopic analysis

International Nuclear Information System (INIS)

Barshick, C.M.; Young, J.P.; Shaw, R.W.

1995-01-01

Several techniques have been developed to provide on-site isotopic analyses, including decay-counting and mass spectrometry, as well as methods that rely on the accessibility of optical transitions for isotopic selectivity (e.g., laser-induced fluorescence and optogalvanic spectroscopy). The authors have been investigating both mass spectrometry and optogalvanic spectroscopy for several years. Although others have considered these techniques for isotopic analysis, the authors have focussed on the use of a dc glow discharge for atomization and ionization, and a demountable discharge cell for rapid sample exchange. The authors' goal is a fieldable instrument that provides useful uranium isotope ratio information

Hyperfine structure of 147,149Sm measured using saturated absorption spectroscopy in combination with resonance-ionization mass spectroscopy

International Nuclear Information System (INIS)

Park, Hyunmin; Lee, Miran; Rhee, Yongjoo

2003-01-01

The hyperfine structures of four levels of the Sm isotopes have been measured by means of diode-laser-based Doppler-free saturated absorption spectroscopy in combination with a diode-laser-initiated resonance-ionization mass spectroscopy. It was demonstrated that combining the two spectroscopic methods was very effective for the identification and accurate measurement of the spectral lines of atoms with several isotopes, such as the rare-earth elements. From the obtained spectra, the hyperfine constants A and B for the odd-mass isotopes 147 Sm and 149 Sm were determined for four upper levels of the studied transitions.

Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

Energy Technology Data Exchange (ETDEWEB)

Povinec, Pavel P., E-mail: povinec@fmph.uniba.sk; Masarik, Jozef; Ješkovský, Miroslav; Kaizer, Jakub; Šivo, Alexander; Breier, Robert; Pánik, Ján; Staníček, Jaroslav; Richtáriková, Marta; Zahoran, Miroslav; Zeman, Jakub

2015-10-15

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 {sup 14}C and {sup 129}I 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.

Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

Science.gov (United States)

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.

CologneAMS, a dedicated center for accelerator mass spectrometry in Germany

Energy Technology Data Exchange (ETDEWEB)

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.

Accelerator mass spectrometry - Indian scenario. PD-1-1

International Nuclear Information System (INIS)

Kailas, S.

2007-01-01

Accelerator based ultra sensitive Mass Spectrometry (AMS) programmes are being vigorously pursued world over for the past three decades. There are more than 50 accelerator facilities devoted to this multidisciplinary activity. Realizing the importance of this programme, the work related to AMS has commenced at three major accelerator facilities in India: Institute of Physics, Bhubaneswar; Interuniversity Accelerator Centre, Delhi; BARC - TIFR Pelletron accelerator facility, Mumbai. At Bhubaneswar, facilities have been set up to carry our high precision 14 C based AMS programmes using the 3 MV Pelletron. A magnetic bouncer, an electrostatic analyzer and a chemistry lab for making samples in graphite form are some of the important features of this AMS facility. A number of users have already got their samples analysed using this AMS facility. The AMS programme has used upto 20 % of beam time available from the 3 MV Pelletron at Bhubaneswar. At Delhi efforts are underway and initial success has been achieved for carrying out 10 Be based AMS programme. Novel method based on simultaneously injecting oxide of Be - ( 9 Be and 17 O) and ( 10 Be and 16 O) has been tried to obtain the ratio of 9 Be / 10 Be. A velocity filter is also available for this programme. Both at Bhubaneswar and Delhi, provision exists in the form of a multi cathode target wheel for carrying out measurements for a number of samples. At Mumbai the emphasis has been in precision measurement of 36 Cl in samples. Segmented anode detector has been developed for the separation of interfering 36 S and 36 Cl isobars

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

Energy Technology Data Exchange (ETDEWEB)

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)

Accelerator mass spectrometry-enabled studies: current status and future prospects.

Science.gov (United States)

Arjomand, Ali

2010-03-01

Accelerator mass spectrometry is a detection platform with exceptional sensitivity compared with other bioanalytical platforms. Accelerator mass spectrometry (AMS) is widely used in archeology for radiocarbon dating applications. Early exploration of the biological and pharmaceutical applications of AMS began in the early 1990s. AMS has since demonstrated unique problem-solving ability in nutrition science, toxicology and pharmacology. AMS has also enabled the development of new applications, such as Phase 0 microdosing. Recent development of AMS-enabled applications has transformed this novelty research instrument to a valuable tool within the pharmaceutical industry. Although there is now greater awareness of AMS technology, recognition and appreciation of the range of AMS-enabled applications is still lacking, including study-design strategies. This review aims to provide further insight into the wide range of AMS-enabled applications. Examples of studies conducted over the past two decades will be presented, as well as prospects for the future of AMS.

Radionuclides in man and his environment measured by accelerator mass spectrometry

International Nuclear Information System (INIS)

Hellborg, Ragnar; Erlandsson, Bengt; Kiisk, Madis; Persson, Per; Skog, Goeran; Stenstroem, Kristina; Mattsson, Soeren; Leide-Svegborn, Sigrid; Olofsson, Mikael

1999-01-01

Accelerator mass spectrometry (AMS) is a highly sensitive analytical method for measuring very low concentrations of both radionuclides and stable nuclides. For radioanalytical purposes, the main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg size) and shorter measuring times (less than one hour). In this report some current applications of the AMS technique at the Lund Pelletron accelerator are presented, in particular studies of 14 C-labeled pharmaceuticals used in clinical nuclear medicine and biomedical research

The convective noise floor for the spectroscopic detection of low mass companions to solar type stars

Science.gov (United States)

Deming, D.; Espenak, F.; Jennings, D. E.; Brault, J. W.

1986-01-01

The threshold mass for the unambiguous spectroscopic detection of low mass companions to solar type stars is defined here as the time when the maximum acceleration in the stellar radial velocity due to the Doppler reflex of the companion exceeds the apparent acceleration produced by changes in convection. An apparent acceleration of 11 m/s/yr in integrated sunlight was measured using near infrared Fourier transform spectroscopy. This drift in the apparent solar velocity is attributed to a lessening in the magnetic inhibition of granular convection as solar minimum approaches. The threshold mass for spectroscopic detection of companions to a one solar mass star is estimated at below one Jupiter mass.

Thorium molecular negative ion production in a cesium sputter source at BARC-TIFR pelletron accelerator ion source test set up

International Nuclear Information System (INIS)

Gupta, A.K.; Mehrotra, N.; Kale, R.M.; Alamelu, D.; Aggarwal, S.K.

2005-01-01

Ion source test set up at Pelletron Accelerator facility has been utilized extensively for the production and characterization of negative ions, with particular emphasis being place at the species of experimental users interest. The attention have been focussed towards the formation of rare earth negative ions, due to their importance in the ongoing accelerator mass spectroscopy program and isotopic abundance measurements using secondary negative ion mass spectrometry

Accelerator mass spectrometry of small biological samples.

Science.gov (United States)

Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

2008-12-01

Accelerator mass spectrometry (AMS) is an ultra-sensitive technique for isotopic ratio measurements. In the biomedical field, AMS can be used to measure femtomolar concentrations of labeled drugs in body fluids, with direct applications in early drug development such as Microdosing. Likewise, the regenerative properties of cells which are of fundamental significance in stem-cell research can be determined with an accuracy of a few years by AMS analysis of human DNA. However, AMS nominally requires about 1 mg of carbon per sample which is not always available when dealing with specific body substances such as localized, organ-specific DNA samples. Consequently, it is of analytical interest to develop methods for the routine analysis of small samples in the range of a few tens of microg. We have used a 5 MV Pelletron tandem accelerator to study small biological samples using AMS. Different methods are presented and compared. A (12)C-carrier sample preparation method is described which is potentially more sensitive and less susceptible to contamination than the standard procedures.

Compact toroid formation, compression, and acceleration

International Nuclear Information System (INIS)

Degnan, J.H.; Peterkin, R.E. Jr.; Baca, G.P.; Beason, J.D.; Bell, D.E.; Dearborn, M.E.; Dietz, D.; Douglas, M.R.; Englert, S.E.; Englert, T.J.; Hackett, K.E.; Holmes, J.H.; Hussey, T.W.; Kiuttu, G.F.; Lehr, F.M.; Marklin, G.J.; Mullins, B.W.; Price, D.W.; Roderick, N.F.; Ruden, E.L.; Sovinec, C.R.; Turchi, P.J.; Bird, G.; Coffey, S.K.; Seiler, S.W.; Chen, Y.G.; Gale, D.; Graham, J.D.; Scott, M.; Sommars, W.

1993-01-01

Research on forming, compressing, and accelerating milligram-range compact toroids using a meter diameter, two-stage, puffed gas, magnetic field embedded coaxial plasma gun is described. The compact toroids that are studied are similar to spheromaks, but they are threaded by an inner conductor. This research effort, named MARAUDER (Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation), is not a magnetic confinement fusion program like most spheromak efforts. Rather, the ultimate goal of the present program is to compress toroids to high mass density and magnetic field intensity, and to accelerate the toroids to high speed. There are a variety of applications for compressed, accelerated toroids including fast opening switches, x-radiation production, radio frequency (rf) compression, as well as charge-neutral ion beam and inertial confinement fusion studies. Experiments performed to date to form and accelerate toroids have been diagnosed with magnetic probe arrays, laser interferometry, time and space resolved optical spectroscopy, and fast photography. Parts of the experiment have been designed by, and experimental results are interpreted with, the help of two-dimensional (2-D), time-dependent magnetohydrodynamic (MHD) numerical simulations. When not driven by a second discharge, the toroids relax to a Woltjer--Taylor equilibrium state that compares favorably to the results of 2-D equilibrium calculations and to 2-D time-dependent MHD simulations. Current, voltage, and magnetic probe data from toroids that are driven by an acceleration discharge are compared to 2-D MHD and to circuit solver/slug model predictions. Results suggest that compact toroids are formed in 7--15 μsec, and can be accelerated intact with material species the same as injected gas species and entrained mass ≥1/2 the injected mass

Annual report 1991 of Munich University and Technical University Accelerator Laboratory

International Nuclear Information System (INIS)

1992-01-01

The experimental work in the Accelerator Laboratory contains investigations of nuclear reactions and nuclear structure, studies of atom physics and the application of nuclear physics methods in physics and in interdisciplinary research. These applications are acceleration mass spectrometry to detect traces of radio-isotopes and material analysis with particle beams. The development of apparatus in the fields of accelereator construction, ion sources and targets are at the heart of the laboratory and help to establish its reputation. They are of the greatest importance for the education of students. The development stage for the superconducting post-accelerator TRITRON is complete and prototypes of the magnets and resonators were successfully tested and operated. The mass-production of all the components is under way or already finished. The standard injector for the tandem axxelerator and an injector for accelerator mass spectroscopy with stable isotopes are being newly designed. The experimental work is supplemented by the calculations of our theoretical collagues of core reaction mechanisms, core de-excitation and the Cerenkov radiation of core structures and transition strengths, by relativistic Hartree-Fock calculations and by star model calculations. (orig.) [de

Report of the consultants' meeting on accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

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.

Report of the consultants' meeting on accelerator mass spectrometry

International Nuclear Information System (INIS)

1995-01-01

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

Radiocarbon dating with accelerator mass spectrometry

International Nuclear Information System (INIS)

Blake, W. Jr.

1985-01-01

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

Designing double-gap linear accelerators for a wide mass range

International Nuclear Information System (INIS)

Lysenko, W.P.; Wadlinger, E.A.; Rusnak, B.; Krawczyk, F.; Saadatmand, K.; Wan, Z.

1998-01-01

For applications like ion implantation, rf linacs using double-gap structures with external resonators can be used because they are practical at low frequencies. However, since the two gaps associated with a given resonator cannot be individually phased, it is not obvious how to build a linac that can efficiently accelerate particles having different mass/charge ratios. This paper describes the beam dynamics of double-gap rf linacs and shows how to maximize the range of mass/charge ratios. The theory also tells one how to rescale a linac tune (i.e., reset the voltages and phases) so that a new particle, having a different mass or charge, will behave similarly to the original particle

Study of electron beam effects on surfaces using x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS)

International Nuclear Information System (INIS)

Gettings, M.; Coad, J.P.

1976-02-01

Discrepancies in the surface analyses of oxidised or heavily contaminated materials have been observed between X-ray Photoelectron Spectroscopy (XPS) and techniques using electron beams (primarily Auger Electron Spectroscopy (AES)). These discrepancies can be ascribed to the influence of the primary electron beam and to illustrate the various types of electron effects different materials were analysed using XPS and Secondary Ion Mass Spectroscopy (SIMS) before and after large area electron bombardment. The materials used included chrome and stainless steels, nickel, platinum, glass and brass. (author)

Accelerator mass spectrometry with the Grenoble and Orsay cyclotrons

International Nuclear Information System (INIS)

Raisbeck, G.M.; Yiou, F.

1981-01-01

Three and one half years ago, at the Rochester meeting, we presented our first accelerator mass spectrometry measurements of 10 Be using the external ion source of the Grenoble cyclotron. Since that time the technique has been used to measure 10 Be in more than 100 geophysical samples. We have also used the ALICE accelerator facility (linear accelerator plus cyclotron) at Orsay to detect 26 Al (half-life 730,000 years) and 41 Ca (100,000 years). While the latter measurements have so far been carried out only with enriched samples, they did demonstrate the feasibility of eliminating interference from lower atomic number isobars by analyzing fully stripped ions of the species being sought. We describe here the present experimental status of these two techniques, following closely two papers presented recently at another conference. We would like to stress that these techniques have not been developed arbitrarily, or as goals in themselves, but rather with certain applications in mind. It is therefore perhaps useful to first briefly outline these applications, which can be divided into three areas

14 C dating by using mass spectrometry with particle accelerator

International Nuclear Information System (INIS)

Santos, G.M.; Gomes, P.R.S.; Yokoyama, Y.; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K.

1999-01-01

The different aspects concerning the 14 C dating are described, including the cosmogenic origin of 14 C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

Science.gov (United States)

LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

2010-01-01

Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

Accelerator Mass Spectrometry at the Nuclear Science Laboratory: Applications to Nuclear Astrophysics

Science.gov (United States)

Collon, P.; Bauder, W.; Bowers, M.; Lu, W.; Ostdiek, K.; Robertson, D.

The Accelerator Mass Spectrometry (AMS) program at the Nuclear Science Laboratory of the University of Notre Dame is focused on measurements related to galactic radioactivity and to nucleosynthesis of main stellar burning as well as the production of so called Short-Lived Radionuclides (SLRs) in the Early Solar System (ESS). The research program is based around the 11MV FN tandem accelerator and the use of the gas-filled magnet technique for isobar separation. Using a technique that evolved from radiocarbon dating, this paper presents a number of research programs that rely on the use of an 11MV tandem accelerator at the center of the AMS program.

Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

International Nuclear Information System (INIS)

Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

1988-01-01

Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

Method and apparatus for accelerating a solid mass

International Nuclear Information System (INIS)

Tidman, D.A.; Goldstein, Y.A.

1984-01-01

An axi-symmetrical projectile, having a mass ranging from fractions of a gram to kilograms, is accelerated to velocities in the range of 10 5 to 10 7 centimeters per second by a propelling force produced by a plasma resulting from electric discharge. The discharge is imploded against the projectile surface so lines of the magnetic fields are approximately azimuthal around the projectile axis. The projectile is tapered so it experiences a net, stable axial accelerating force along the accelerator axis by the combined action of the magnetic field producing radially directed momentum and pressure on the plasma, the interaction of the magnetic field and ions induced by the plasma on the surface, as well as material the plasma ablates from the surface. The plasma discharge is initiated either in low density background gas between anode and cathode of a discharge module, or along an insulator surface between the electrodes in low density background gas. Alternatively, in either of these situations the discharge can be initiated in a gas which is produced by ablation of the projectile surface. In an alternative situation, the projectile acts as a switch for triggering discharges. Eddy current heating of the projectile is minimized by shaping the discharge current pulse so the plasma has a relatively weak magnetic field when it arrives at the surface, or by making the projectile electrically non-conducting. To provide a long acceleration path, a series of modules is aligned. In one embodiment, the projectile position, as it advances between modules, is sensed and discharges are switched on sequentially in the modules

Ion desorption induced by charged particle beams: mechanisms and mass spectroscopy

International Nuclear Information System (INIS)

Silveira, E.F. da; Schweikert, E.A.

1988-01-01

Surface analysis, through desorption, induced by fast particles, is presented and discussed. The stopping of projectils is essentially made by collisions with the target electrons. The desorbed particles are generally emmited with kinetic energy from 0.1 to 20 eV. Mass, charge, velocity and emission angle give information about the surface components, its structure as well as beam-solid interaction processes. Time-of-flight mass spectroscopy of desorbed ions, determine the mass of organic macromolecules and biomolecules. (A.C.A.S.) [pt

Radioecological studies at the National Accelerator Centre based on the determination of 129I by accelerator mass spectrometry (AMS)

International Nuclear Information System (INIS)

Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Chamizo, E.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

2013-01-01

Since 2006 a compact system of mass spectrometry with Accelerator (AMS) is installed at the National Center of Accelerators, Seville. After an initial set-up and study have been opening many lines of research in fields such as archeology, geology, paleontology, oceanography, oceanography, internal dosimetry and characterization of radioactive waste, among others. In particular, based on the measurement of 1 29I have made contributions to the field of radioecology and radiation protection. In this work they are summarized and presented some of these investigations. (Author)

Hertzian spectroscopy application to excited states in accelerated ion beams

Energy Technology Data Exchange (ETDEWEB)

Gaillard, M L

1974-01-01

Accelerated ion beams enables the application of optical hertzian spectrometry methods to be extended to research on the excited states of free ionic systems. The photon beat method has proved especially simple to apply in beam foil geometry because of the unidirectional beam velocity while the beam gas device is suitable for experiments of the energy level crossing type. Only the resonance technique involving direct application of high-frequency magnetic fields poses serious problems because of the high HF powers necessary. So far structure intervals have been measured in ions carrying up to three charges (seven in the special case of Lamb shift measurements) with a precision of a few percent. Study of hydrogen-like or helium-like ions of high Z allows the fundamental calculations of quantum electrodynamics to be checked with regard to the Lamb shift or the spontaneous emission theory. In more complex electronic systems, optical spectroscopy of accelerated ion beams gives wavelengths with a resolution reaching 10/sup -5/, lifetimes with an accuracy better than 10% when the cascade effects are properly studied, and Lande factors with a precision of several % under present technical conditions. The photon beat method concerns hyperfine nuclear effects in light atoms of Z < = 20. (FR)

Calibration samples for accelerator mass spectrometry

International Nuclear Information System (INIS)

Hershberger, R.L.; Flynn, D.S.; Gabbard, F.

1981-01-01

Radioactive samples with precisely known numbers of atoms are useful as calibration sources for lifetime measurements using accelerator mass spectrometry. Such samples can be obtained in two ways: either by measuring the production rate as the sample is created or by measuring the decay rate after the sample has been obtained. The latter method requires that a large sample be produced and that the decay constant be accurately known. The former method is a useful and independent alternative, especially when the decay constant is not well known. The facilities at the University of Kentucky for precision measurements of total neutron production cross sections offer a source of such calibration samples. The possibilities, while quite extensive, would be limited to the proton rich side of the line of stability because of the use of (p,n) and (α,n) reactions for sample production

Infrared spectroscopy of mass-selected carbocations

Energy Technology Data Exchange (ETDEWEB)

Duncan, Michael A. [Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States)

2015-01-22

Small carbocations are of longstanding interest in astrophysics, but there are few measurements of their infrared spectroscopy in the gas phase at low temperature. There are fewer-still measurements of spectra across the full range of IR frequencies useful to obtain an IR signature of these ions to detect them in space. We have developed a pulsed-discharge supersonic nozzle ion source producing high densities of small carbocations at low temperatures (50–70K). We employ mass-selected photodissociation spectroscopy and the method of rare gas “tagging”, together with new broadly tunable infrared OPO lasers, to obtain IR spectra for a variety of small carbocations including C{sub 2}H{sub 3}{sup +}, C{sub 3}H{sub 3}{sup +}, C{sub 3}H{sub 5}{sup +}, protonated benzene and protonated naphthalene. Spectra in the frequency range of 600–4500 cm{sup −1} provide new IR data for these ions and evidence for the presence of co-existing isomeric structures (e.g., C{sub 3}H{sub 3}{sup +} is present as both cyclopropenyl and propargyl). Protonated naphthalene has sharp bands at 6.2, 7.7 and 8.6 microns matching prominent features in the UIR spectra.

Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

Science.gov (United States)

Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

2014-01-01

Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions. Copyright © 2014 John Wiley & Sons, Ltd.

Accelerator mass spectrometry of heavy elements: /sup 36/Cl to /sup 205/Pb

Energy Technology Data Exchange (ETDEWEB)

Henning, W

1987-08-25

Measurements are discussed in which the technique of accelerator mass spectrometry was applied to problems involving heavy radioisotopes. These measurements, which depend on the ion energies that can be reached with the new heavy-ion accelerator facilities, were performed at the Argonne tandem linac accelerator system (ATLAS) and at the UNILAC accelerator at GSI. The topics include a discussion of measurements of long nuclear lifetimes, of radioisotope detection of interest to solar neutrino experiments, and of a determination of the /sup 41/Ca concentration in natural samples of terrestrial origin by making use of isotopic pre-enrichment in an isotope separator. A long-known method of isobar separation, employing a gas-filled magnetic field region, has been revived for some of these measurements and its characteristics and advantages are briefly reviewed.

Accelerator mass spectrometry with a coupled tandem-linac system

International Nuclear Information System (INIS)

Kutschera, W.

1984-01-01

A coupled system provides higher energies, which allows one to extend AMS to hitherto untouched mass regions. Another important argument is that the complexity, although bothersome for the operation, increases the selectivity of detecting a particular isotope. The higher-energy argument holds for any heavy-ion accelerator which is capable of delivering higher energy than a tandem. The present use of tandem-linac combinations for AMS, rather than cyclotrons, linacs or combinations of these machines, has mainly to do with the fact that this technique was almost exclusively developed around tandem accelerators. Therefore the tandem-linac combination is a natural extension to higher energies. The use of negative ions has some particular advantages in suppressing background from unwanted elements that do not form stable negative ions (e.g., N, Mg, Ar). On the other hand, this limits the detection of isotopes to elements which do form negative ions. For particular problems it may therefore be advantageous to use a positive-ion machine. What really matters most for choosing one or the other machine is to what extent the entire accelerator system can be operated in a truly quantiative way from the ion source to the detection system. 20 references, 4 figures

Study of Polymer Material Aging by Laser Mass Spectrometry, UV-Visible Spectroscopy, and Environmental Scanning Electron Microscopy

Directory of Open Access Journals (Sweden)

Junien Exposito

2007-01-01

Full Text Available Dyed natural rubber (NR and styrene butadiene rubber (SBR, designed for outdoor applications, were exposed to an accelerated artificial aging in xenon light. The aging results in the deterioration of the exposed surface material properties. The ability of dyed polymers to withstand prolonged sunlight exposure without fading or undergoing any physical deterioration is largely determined not only by the photochemical characteristics of the absorbing dyestuff itself but also by the polymer structure and fillers. Results obtained by laser mass spectrometry, UV-visible spectroscopy, and environmental scanning electron microscopy indicate that dyed filled NR and SBR samples behave differently during the photo-oxidation. The fading of the dyed polymers was found to be promoted in the NR sample. This can be correlated with LDI-FTICRMS results, which show the absence of [M-H]− orange pigment pseudomolecular ion and also its fragment ions after aging. This is confirmed by both EDX and UV/Vis spectroscopy. EDX analysis indicates a concentration of chlorine atoms, which can be considered as a marker of orange pigment or its degradation products, only at the surface of SBR flooring after aging. Reactivity of radicals formed during flooring aging has been studied and seems to greatly affect the behavior of such organic pigments.

Applying radiochemical methods and accelerator mass spectrometry for determination of the depth-dependent, long-lived spallation fragments 10Be, 26Al, 36Cl and 53Mn in stone meteorites. Some suggestions concerning the still unknown origin of the Shergottites

International Nuclear Information System (INIS)

Sarafin, R.

1985-01-01

Stone meteorites from the Antarctica are examined for their cosmogenic nuclides. These arise from galactic and solar cosmic radiation. Concentration and activity of these nuclides permit to obtain information on the irradiation and the terrestrial age. By means of the neutron activation analysis and accelerator mass spectroscopy a very small number of samples can be analyzed. (PW) [de

Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health

Energy Technology Data Exchange (ETDEWEB)

Tumey, S J; Brown, T A; Hamilton, T F; Hillegonds, D J

2008-03-03

Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of {sup 90}Sr by accelerator mass spectrometry. Despite a pervasive interference from {sup 90}Zr, our initial development has yielded an instrumental background of {approx} 10{sup 8} atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10{sup 6} atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health.

Time dependent thermal treatment of oxidized MWCNTs studied by the electron and mass spectroscopy methods

Czech Academy of Sciences Publication Activity Database

Stobinski, L.; Lesiak, B.; Zemek, Josef; Jiříček, Petr

2012-01-01

Roč. 258, č. 20 (2012), s. 7912-7917 ISSN 0169-4332 Institutional research plan: CEZ:AV0Z10100521 Keywords : MWCNTs * ox-MWCNTs * functional materials * electron spectroscopy * mass spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.112, year: 2012

Radiocarbon accelerator mass spectrometry (AMS) sample preparation laboratory in Brazil

International Nuclear Information System (INIS)

Macario, Kita D.; Gomes, Paulo R. S.; Anjos, Roberto M. dos; Linares, Roberto; Queiroz, Eduardo; Oliveira, Fabiana M. de; Cardozo, Laio; Carvalho, Carla R.A.

2011-01-01

Full text: For decades Accelerator Mass Spectrometry has been widely used for radiocarbon measurements all over the world with application in several fields of science from archaeology to geosciences. This technique provides ultrasensitive analysis of reduced size samples or even specific compounds since sample atoms are accelerated to high energies and measured using nuclear particle detectors. Sample preparation is extremely important for accurate radiocarbon measurement and includes chemical pre-treatment to remove all possible contaminants. For beam extraction in the accelerator ion source, samples are usually converted to graphite. In this work we report a new radiocarbon sample preparation facility installed at the Physics Institute of Universidade Federal Fluminense (UFF), in Brazil. At the Nuclear Chronology Laboratory (LACRON) samples are chemically treated and converted to carbon dioxide by hydrolysis or combustion. A stainless steel based vacuum line was constructed for carbon dioxide separation and graphitization is performed in sealed quartz tubes in a muffle oven. Successful graphite production is important to provide stable beam currents and to minimize isotopic fractionation. Performance tests for graphite production are currently under way and isotopic analysis will soon be possible with the acquisition of a Single Stage AMS System by our group. The Single Stage Accelerator produced by National Electrostatic Corporation is a 250 kV air insulated accelerator especially constructed to measure the amount of 14 C in small modern graphite samples to a precision of 0.3 % or better. With the installation of such equipment in the first half of 2012, UFF will be ready to perform the 14C -AMS technique. (author)

Accelerator mass spectrometry of 59Ni and Fe isotopes at the Argonne superconducting linac

International Nuclear Information System (INIS)

Henning, W.; Kutschera, W.; Myslek-Laurikainen, B.; Pardo, R.C.; Smither, R.K.; Yntema, J.L.

1981-01-01

We have obtained initial results in an attempt to use the Argonne tandem-linac system for accelerator mass spectrometry of medium-heavy nuclei. Nuclei of the radioisotope 59 Ni (T/sub 1/2 = 7.5 x 10 5 y) and of the stable isotope 58 Fe at low concentrations have been accelerated and clearly identified. The latter experiment is in preparation of a measurement of the half-life of 60 Fe

Accelerator mass analysis at tandem accelerator in Kyoto University

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Masanobu; Tazawa, Yuji; Matsumoto, Hiroshi; Hirose, Masanori [Kyoto Univ. (Japan). Faculty of Science; Ogino, Koya; Kohno, Masuchika; Funaba, Hiroyuki

1996-12-01

Tandem accelerator in Science Faculty, Kyoto University was renewed from 5 MV in the highest terminal voltage of Van de Graaff to 8 MV of Peletron in 1992. And, AMS effective for cosmic ray, dating, environment measurement and so forth is determined to a column of collaborative studies by universities and institutes in Japan. On this renewal, because of using high energy beam transportation of the present tandem accelerator, super high sensitivity measurement of long half-life radioactive isotopes of heavy elements such as {sup 36}Cl, {sup 41}Ca, {sup 129}I and so forth is aimed, although having some limitations due to small magnet. The accelerator is active in characteristics of the middle size tandem accelerator, and developing {sup 14}C measurement for its standard technology, as aiming at {sup 36}Cl measurement, at first. As a result, in this tandem accelerator stable and high beam transmittance could be obtained by adding a slit at negative ion source to make emittance of incident beam smaller. {sup 14}C/{sup 12}C ratio of Modan`s sample obtained by graphitizing NBS oxalic acid and Ded`s sample consisting of mineral graphite produced in Sri Lanka are measured to confirm better reproductivity of this system. Future development of successive incident method is planned to test actual carbon samples. (G.K.)

Accelerated mass loss from Greenland ice sheet : Links to atmospheric circulation in the North Atlantic

NARCIS (Netherlands)

Seo, Ki-Weon; Waliser, Duane E.; Lee, Choon-Ki; Tian, Baijun; Scambos, Ted; Kim, Baek-Min; van Angelen, Jan H.; van den Broeke, Michiel R.

Understanding the mechanisms that drive the mass imbalance of the Greenland ice sheet (GrIS) is critical to the accurate projection of its contribution to future sea level rise. Greenland's ice mass loss has been accelerating recently. Using satellite Earth-gravity and regional climate model data,

Improved single ion cyclotron resonance mass spectroscopy

International Nuclear Information System (INIS)

Boyce, K.R.

1993-01-01

The author has improved the state of the art for precision mass spectroscopy of a mass doublet to below one part in 10 10 . By alternately loading single ions into a Penning trap, the author has determined the mass ratio M(CO + )/M(N + 2 ) = 0.999 598 887 74(11), an accuracy of 1 x 10 -10 . This is a factor of 4 improvement over previous measurements, and a factor of 10 better than the 1985 atomic mass table adjustment [WAA85a]. Much of the author's apparatus has been rebuilt, increasing the signal-to-noise ratio and improving the reliability of the machine. The typical time needed to make and cool a single ion has been reduced from about half an hour to under 5 minutes. This was done by a combination of faster ion-making and a much faster procedure for driving out ions of the wrong species. The improved S/N, in combination with a much better signal processing algorithm to extract the ion phase and frequency from the author's data, has substantially reduced the time required for the actual measurements. This is important now that the measurement time is a substantial fraction of the cycle time (the time to make a new ion and measure it). The improvements allow over 30 comparisons in one night, compared to 2 per night previously. This not only improves the statistics, but eliminates the possibility of large non-Gaussian errors due to sudden magnetic field shifts

Accelerator mass spectrometry at Peking University: experiments and progress

International Nuclear Information System (INIS)

Chen Jiaer; Guo Zhiyu; Yan Shengqing; Li Renxing; Xiao Min; Li Kun; Liu Hongtao; Liu Kexin; Wang Jianjun; Li Bin; Lu Xiangyang; Yuan Sixun; Chen Tiemei; Gao Shijun; Zheng Shuhui; Chen Chengye; Liu Yan

1997-01-01

The Peking University Accelerator Mass Spectrometer (PKUAMS) has been put into routine operation. 14 C measurements of archaeological samples with fast cycling injection have shown good results. The new multi-target high-intensity sputtering ion source has been tested and 10 Be measurements were carried out with a new detector in which both the stopping of the intense flux of 10 B ions and the identification of 10 Be ions are performed. 26 Al samples were also measured. While various applications show good prospects for PKUAMS, further upgrade is desirable

Development of accelerator mass spectrometry in China Institute of Atomic Energy

International Nuclear Information System (INIS)

He Ming; Jiang Shan; Dong Kejun; Qiu Jiuzi; Peng Bo; Guan Yongjing; Yin Xinyi; Wu Shaoyong; Li Shihong; Zhou Duo

2005-01-01

The measurement method for some radio isotope such as 99 Tc, 182 Hf, 151 Sm is developing in China Institute of Atomic Energy (CIAE) accelerator mass spectrometry (AMS) system, and applications in the fields of nuclear physics, geosciences, life science and materials science is carried out. The brief introduction of these methods and applications are described in this paper. (authors)

What can we learn from the self-attraction and loading fingerprints about pre-GRACE mass-loss acceleration from Greenland and Antarctica?

Science.gov (United States)

Davis, J. L.; Vinogradova, N. T.

2017-12-01

Tide-gauge records from the North Atlantic reveal significant acceleration in sea level starting in the late 20th century. We have analyzed the tide-gauge data using a model in which the accelerations are assumed to be zero prior to 1990. The estimated accelerations range from -1 to +3 m cy-2 and exhibit a systematic spatial variability. Davis and Vinogradova [2017] demonstrated that to model this variability in sea-level acceleration requires contributions from several distinct physical processes: accelerated mass loss from the Greenland and Antarctic Ice Sheets and acceleration associated with ocean circulation and heat uptake. Atmospheric pressure also contributes to the observed changes in sea level, at a much smaller amplitude. Because we are focusing on sea-level accelerations (i.e., sea-level rate changes), the contribution from Glacial Isostatic Adjustment (GIA) is negligible. Modeling of observed sea-level acceleration is achieved using external constraints for the important physical processes. Using GRACE results, we can calculate the sea-level "fingerprints" for Greenland and Antarctica associated with mass loading and gravitational perturbations. For the North Atlantic, Greenland induces a significant spatial variation in sea-level change—dominated by the solid-Earth response to the mass loss—whereas Antarctica contributes a spatially constant acceleration. The observations prefer a scaling of the solid-Earth/gravitational response, and we present the implications of this result for ice-mass changes prior to the onset of GRACE observations (2002-3).

Dissociation mechanism of HNIW ions investigated by chemical ionization and electron impact mass spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Yang, Rongjie; Xiao, Hemiao [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

2006-04-15

Chemical Ionization (CI) with Collision-Induced Dissociation (CID) spectroscopy and Electron Impacting (EI) with metastable Mass analyzed Ion Kinetic Energy (MIKE) spectroscopy have been applied to study ionic dissociations of Hexanitrohexaazaisowurtzitane (HNIW). Similarities and differences between EI/MIKE and CI/CID mass spectra of HNIW were analyzed. In EI mass spectra, the ions [HNIW-n NO{sub 2}]{sup +} (n=2-5), such as the ion at m/z 347, were less frequent (1-2% relative abundance), but in CI mass spectra, these ions were very abundant. For some ions of large molar mass from HNIW, their dissociations pathways from parent ions to daughter ions were built according to CID and MIKE spectra. Molecular ions of HNIW with a protonated nitro group at five-member ring seem more stable than at six-member ring. The HNIW ions losing five of six nitro groups are very stable based on CID spectra, which agrees with some research results for thermal decomposition of HNIW in literature. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

On-line high-resolution mass spectroscopy. Progress report, July 1, 1975--July 1, 1976

International Nuclear Information System (INIS)

Macfarlane, R.D.; Torgerson, D.F.

1976-08-01

The search for second-class currents in nuclear beta decay continued with measurements of beta--gamma correlations for the mirror decays 20 F(β - ) 20 Ne*(1.63) and 20 Na(β + ) 20 Ne*(1.63). The 20 F beta--gamma correlation was measured in beam, and the results are being compared with values obtained using the He-jet method. A careful analysis of ion velocity distributions emitted from fission fragment tracks in solids yielded new information on the nature of the process. The temperature of the microplasma formed by a fission fragment was determined to be of the order 10 4 K, and the temperature is dependent on the fission fragment's energy. A mass reflectron is being developed for high mass resolution using time-of-flight mass spectroscopy. The application of 252 Cf-PDMS (plasma desorption mass spectroscopy) to new classes of involatile compounds continued. Techniques are being studied for the routine analysis of involatile species of mass greater than 2000. The report is basically descriptive in nature. 5 figures, 1 table

FRAGMENTATION STUDIES OF D6,7-ANHIDROERITROMISIN-A BY LIQUID CHROMATOGRAPHY-MASS SPECTROSCOPY (LC-MS

Directory of Open Access Journals (Sweden)

Khairan Khairan

2010-06-01

Full Text Available Semisynthesis of D6,7-Anhydroerythromycin-A was done by biomodification technique by addition of 0.2% INH into a culture fermentation of Saccharopolyspora erythraea ATCC 11635 in medium Hutchinson. The aim of this research is to studies of fragmentation pattern from new matabolite of D6,7-Anhydroerythromycin-A by Liquid Chromatography-Mass Spectroscopy (LC-MS and the ionization of mass spectroscopy is use by ESI (Electrospray Ionization pattern. The FT-IR spectrometric analyzes showed a stretching vibration of C=C conjugated group at wave number 1602.7 cm-1. This C=C conjugated vibration indicated the existence of double bond between C6 and C7 (D6,7, this confirmed that isolate contained D6,7-Anhydroerythromycin-A (the possibility of D6,7 was positive. For complementation, a LC-MS (Liquid Chromatography-Mass Spectroscopy analyzes using ESI-MS (Electrospray Ionization-Mass Spectroscopy ionization pattern was conducted to the isolate which resulted Quassimolecular ions [M+H]+ of D7,8- and D6,7-Anhydroerythromycin-A. LC-MS spectrogram of the isolate, which gave two peaks of m/z 732.2460 and m/z 716.2522, confirmed that the m/z 732.2460 possibly was D7,8-Anhydroerythromycin-A, while the m/z 716.2502 and m/z 715.2522 possibly were D6,7-Anhydroerythromycin-A.   Keywords: isoniazid, enoyl reduction, D6,7-Anhidroeritromisin-A, fragmentation, LC-MS.

Analysis of trace elements by means of accelerator secondary ion mass spectrometry

International Nuclear Information System (INIS)

Ender, R.M.

1997-01-01

The analysis of material composition and trace element concentration is of increasing interest primarily in semiconductor technology but also in metallurgy, geology, biology and medicine. At present, Secondary Ion Mass Spectrometry (SIMS) is in many respects the best technique to provide 3-dimensional information on the distribution of trace elements with concentrations below 1 ppm. However, due to the presence of molecular ions the detectability of many trace elements it restricted because of molecular mass interferences. In addition, detectors used in SIMS have a background counting rate of 0.1-1 Hz, which further limits trace element analysis. In Accelerator Mass Spectrometry (AMS) long-lived radionuclides are detected free of molecular interferences and detector background at isotopic ratios as low as 10 -15 . Moreover, isobaric interferences can be reduced as well. In order to benefit from these advantages a combination of SIMS and AMS (Accelerator SIMS) has been proposed almost 20 years ago, but no facility has ever been fully developed. It has been the aim of this work to add a new sputtering chamber for AMS measurements of ultrapure semiconductor material to the existing PSI/ETH AMS facility. To fulfill the requirements of material analysis, an UHV chamber with special precautions against contamination has been built and adapted to the existing AMS setup. For sputtering, a commercial Cs gun with an ExB filter and a 1 o beam bend for neutral particle suppression is used to obtain a pure Cs ion beam. The gun is equipped with different apertures for varying the diameter of the beam spot. With the integrated scanning unit the 10 keV Cs beam can be rastered over approximately 1 mm 2 . This allows different applications such as bulk analysis, depth profiling and imaging. The secondary ion extraction is matched to the ion optical and geometrical requirements of the existing accelerator mass spectrometer. (author) figs., tabs., 67 refs

X-ray photoelectron spectroscopy and secondary electron yield analysis of Al and Cu samples exposed to an accelerator environment

Science.gov (United States)

Rosenberg, R. A.; McDowell, M. W.; Ma, Q.; Harkay, K. C.

2003-09-01

It is well known that exposure to an accelerator environment can cause ``conditioning'' of the vacuum chamber surfaces. In order to understand the manner in which the surface structure might influence the production of gases and electrons in the accelerator, such surfaces should be studied both before and after exposure to accelerator conditions. Numerous studies have been performed on representative materials prior to being inserted into an accelerator, but very little has been done on materials that have ``lived'' in the accelerator for extended periods. In the present work, we mounted Al and Cu coupons at different positions in a section of the Advanced Photon Source storage ring and removed them following exposures ranging from 6 to 18 months. X-ray photoelectron spectroscopy (XPS) of the surface was performed before and after exposure. Changes were observed that depended on the location and whether the coupon was facing the chamber interior or chamber wall. These results will be presented and compared to XPS and secondary electron yield data obtained from laboratory measurements meant to simulate the accelerator conditions.

The AMS [Accelerator Mass Spectrometer] program at LLNL

International Nuclear Information System (INIS)

Proctor, I.D.

1988-09-01

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 SF 6 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

Laser-based secondary neutral mass spectroscopy: Useful yield and sensitivity

International Nuclear Information System (INIS)

Young, C.E.; Pellin, M.J.; Calaway, W.F.; Joergensen, B.; Schweitzer, E.L.; Gruen, D.M.

1986-01-01

A variety of problems exist in order to optimally apply resonance ionization spectroscopy (RIS) to the detection of sputtered neutral atoms, however. Several of these problems and their solutions are examined in this paper. First, the possible useful yields obtainable and the dependence of useful yield on various laser parameters for this type of sputtered neutral mass spectrometer (SNMS) are considered. Second, the choice of a mass spectrometer and its effect on the instrumental useful yield is explored in light of the unique ionization region for laser based SNMS. Finally a brief description of noise sources and their effect on the instrumental sensitivity is discussed. 33 refs., 12 figs

Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

Energy Technology Data Exchange (ETDEWEB)

Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

2013-01-15

A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

Pushing the accelerator - speeding up drug research with accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Garner, R.C. E-mail: colin.garner@cbams.co.uk; Leong, D

2000-10-01

Accelerator mass spectrometry (AMS) is the most sensitive analytical method yet developed for elemental isotope analysis and has a broad range of applications. The measurement of {sup 14}C is of most interest to biomedical researchers but few studies have been reported using AMS in drug discovery and development. For biomedical use, {sup 14}C is incorporated into organic molecules by either radiosynthesis or biosynthetically and the isotope is used as a surrogate for the distribution of the radiolabelled molecule either in animal or human studies. The majority of users of {sup 14}C quantitate the radioactivity using decay counting usually with a liquid scintillation counter (LSC). Our Centre over the past 12 months has been evaluating and validating the use of AMS as an alternative detection method. In vitro spiking studies of human plasma with {sup 14}C-Fluconazole, a prescription antifungal drug has demonstrated an excellent correlation between AMS and LSC (correlation coefficient 0.999). Human Phase I clinical studies have been conducted with radioactive doses ranging from 120 Bq (7000 dpm) to 11 kBq (300 nCi) to provide mass balance, plasma concentration and radioactive metabolite profiling data. Limits of detection of 0.00022 Bq {sup 14}C-labelled drug/ml plasma have been accurately quantitated in a plasma background of 0.0078 Bq/ml (0.013 dpm/ml in a plasma background of 0.47 dpm/ml or 2.72 pMC in a background of 90.19 pMC)

14 MV pelletron accelerator and superconducting ECR ion source

International Nuclear Information System (INIS)

Gupta, A.K.

2015-01-01

The BARC-TIFR 14UD Pelletron Accelerator at Mumbai has completed more than two and a half decade of successful operation. The accelerator is primarily used for basic research in the fields of nuclear, atomic and molecular, condensed matter physics and material science. The application areas include accelerator mass spectrometry, production of track-etch membranes, radioisotopes production, radiation damage studies and secondary neutron production for cross section measurement etc. Over the years, numerous developmental activities have been carried out in-house that have resulted in improving the overall performance and uptime of the accelerator and has also made possible to initiate variety of application oriented programmes. Since the SF 6 pressure vessels have been in operation for about 29 years, a comprehensive refurbishment and retrofitting work is carried out to comply with the safety recommendations. Recently, the beam trials were conducted with 18 GHz superconducting ECR (Electron Cyclotron Resonance) Ion Source system at Van-de-Graaff as per BARC Safety Council permission. Various ion beams with different charge states were extracted and mass analyzed and the beam quality was measured by recording their transverse emittance in situ. Experimental measurements pertaining to projectile X-rays Spectroscopy were carried out using variety of ion beams at variable energies. The superconducting Linac booster provides additional acceleration to the ions from Pelletron injector up to A ∼60 region with E∼5 MeV/A. In order to cover the entire mass range of the elements across the periodic table, an ECR based heavy ion accelerator was initiated under plan project. This heavy ion accelerator essentially comprises of a superconducting ECR ion source, room temperature RFQ (Radio Frequency Quadrupole) followed by superconducting Niobium resonators as accelerating elements. This talk will provide an overview of the developmental activities and the safety features

Application of accelerator mass spectrometry in aluminum metabolism studies

International Nuclear Information System (INIS)

Meirav, O.; Vetterli, D.; Johnson, R.R.; Sutton, R.A.L.; Walker, V.R.; Halabe, A.; Fink, D.; Middleton, R.; Klein, J.

1990-06-01

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 26 Al. 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.)

Characterization of Nuclear Materials Using Complex of Non-Destructive and Mass-Spectroscopy Methods of Measurements

International Nuclear Information System (INIS)

Gorbunova, A.; Kramchaninov, A.

2015-01-01

Information and Analytical Centre for nuclear materials investigations was established in Russian Federation in the February 2 of 2009 by ROSATOM State Atomic Energy Corporation (the order #80). Its purpose is in preventing unauthorized access to nuclear materials and excluding their illicit traffic. Information and Analytical Centre includes analytical laboratory to provide composition and properties of nuclear materials of unknown origin for their identification. According to Regulation the Centre deals with: · identification of nuclear materials of unknown origin to provide information about their composition and properties; · arbitration analyzes of nuclear materials; · comprehensive research of nuclear and radioactive materials for developing techniques characterization of materials; · interlaboratory measurements; · measurements for control and accounting; · confirmatory measurements. Complex of non-destructive and mass-spectroscopy techniques was developed for the measurements. The complex consists of: · gamma-ray techniques on the base of MGAU, MGA and FRAM codes for uranium and plutonium isotopic composition; · gravimetrical technique with gamma-spectroscopy in addition for uranium content; · calorimetric technique for plutonium mass; · neutron multiplicity technique for plutonium mass; · measurement technique on the base of mass-spectroscopy for uranium isotopic composition; · measurement technique on the base of mass-spectroscopy for metallic impurities. Complex satisfies the state regulation requirements of ensuring the uniformity of measurements including the Russian Federation Federal Law on Ensuring the Uniformity of Measurements #102-FZ, Interstate Standard GOST R ISO/IEC 17025-2006, National Standards of Russian Federation GOST R 8.563-2009, GOST R 8.703-2010, Federal Regulations NRB-99/2009, OSPORB 99/2010. Created complex is provided in reference materials, equipment end certificated techniques. The complex is included in accredited

Sample preparation for accelerator mass spectrometry at the University of Washington

International Nuclear Information System (INIS)

Grootes, P.M.; Stuiver, M.; Farwell, G.W.; Schmidt, F.H.

1981-01-01

The adaptation of the University of Washington FN tandem Van de Graaff to accelerator mass spectrometry (AMS), as well as some of the results obtained, are described in another paper in this volume (Farwell et al., 1981). Here we discuss our experiences in preparing carbon and beryllium samples that give large and stable ion beams when used in our Extrion cesium sputter source with an inverted cesium beam geometry

Mass transfer effects in feeder flow-accelerated corrosion wall thinning

International Nuclear Information System (INIS)

Pietralik, J.

2008-01-01

Flow conditions play a dominant role in Flow-Accelerated Corrosion (FAC) under certain conditions, e.g., in CANDU feeders. While chemistry and materials set the overall potential for FAC, flow conditions determine the local distribution of wall thinning. Recent plant data of feeders and laboratory tests confirms that there is a close relationship between local flow conditions, expressed by mass transfer coefficient, and FAC rate in CANDU feeder bends. The knowledge of local effects can be useful for minimizing the number of inspected components, predicting the location of the highest FAC rate for a given piping component, and determining what components or feeders should be replaced. A similar evaluation applies also to FAC in heat transfer equipment such as heat exchangers and steam generators. The objective of this paper is to examine the relationship between FAC rate and local mass transfer parameters. For FAC where the flow is dominant, the FAC rate is proportional to mass flux of ferrous ions. The mass flux is the product of the mass transfer coefficient and the concentration difference, or degree of saturation. The mass transfer coefficient describes the intensity of the transport of corrosion products (ferrous ions) from the oxide-water interface into the bulk water. Therefore, this parameter can be used for predicting the local distribution of FAC rate in the mass-transfer controlled FAC. The degree of saturation reduces the mass flux, thus reducing the FAC rate. This effect can be significant in long piping, e.g., in outlet feeders. The paper presents plant and laboratory evidence for the relationship between local mass transfer conditions and the FAC rate. It shows correlations for mass transfer coefficient in components that are highly susceptible to FAC and most important flow parameters that affect mass transfer coefficient. The role of surface roughness, wall shear stress, and local turbulence is also discussed. (author)

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

International Nuclear Information System (INIS)

Salehpour, Mehran; Håkansson, Karl; Possnert, Göran

2013-01-01

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 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 μg 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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Phantom dark energy with varying-mass dark matter particles: Acceleration and cosmic coincidence problem

International Nuclear Information System (INIS)

Leon, Genly; Saridakis, Emmanuel N.

2010-01-01

We investigate several varying-mass dark matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. Imposing exponential or power-law potentials and exponential or power-law mass dependence, we conclude that the coincidence problem cannot be solved or even alleviated. Thus, if dark energy is attributed to the phantom paradigm, varying-mass dark matter models cannot fulfill the basic requirement that led to their construction.

Application of accelerator mass spectrometry in nuclear science

International Nuclear Information System (INIS)

Wang Xiaobo; Hu Jinjun; Wang Huijuan; Guan Yongjing; Wang Wei

2013-01-01

Accelerator mass spectrometry (AMS) is a promising method to provide extreme sensitivity measurements of the production yields of long-lived radioisotopes, which cannot be detected by other methods. AMS technique plays an important role in the research of nuclear physics, as well as the application field of AMS covered nuclear science and technology, life science, earth science, environmental science, archaeology etc. The newest AMS field is that of actinide, particularly U and Pu, isotopic assay with expanding applications in nuclear safeguards and monitoring, and as a modern bomb-fallout tracer for atmospheric transport and surface sediment movement. This paper reviews the applications of AMS in the research of nuclear energy and nuclear security including the research of half life of radionuclides, cross section of nuclear reaction. (authors)

Accelerator Mass Spectrometry with 15 UD pelletron at the Nuclear Science Centre, New Delhi

International Nuclear Information System (INIS)

Datta, S.K.

1997-01-01

The 15 UD Pelletron machine is widely used to carry on investigations in a variety of disciplines like nuclear physics, materials science, radiobiology etc. Accelerator Mass Spectrometry studies with 15 UD pelletron machine at Nuclear Science Centre are elaborated

Early stages of methanol radiolysis from data of photoelectron spectroscopy and mass spectrometry

International Nuclear Information System (INIS)

Kalyazin, E.P.; Kovalev, G.V.

1982-01-01

Comparison of data on photoelectron spectroscopy and mass spectrometry permits to conclude that 4 types of molecular ions CH 3 O + H, H + CH 2 OH, H 3 C + OH and CH 3 O + H are initial products of methanol radiolysis. They start four parallel lines of methanol transformations. Mass spectrum of methanol can be evaluated according to the structural formula of methanol molecule. Composition of radiolysis products of gaseous methanol correlate satisfactorily with its mass spectrum. Reasons for the difference in compositions of radiolysis products of liquid and gaseous methanol are discussed

Application of accelerator mass spectrometry in aluminum metabolism studies

Energy Technology Data Exchange (ETDEWEB)

Meirav, O; Vetterli, D; Johnson, R R [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Sutton, R A.L.; Walker, V R; Halabe, A [British Columbia U.iv., Vancouver, BC (Canada). Dept. of Medicine; Fink, D; Middleton, R; Klein, J [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Physics

1990-06-01

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 {sup 26}Al. 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.).

36Cl accelerator mass spectrometry with a bespoke instrument

International Nuclear Information System (INIS)

Wilcken, K.M.; Freeman, S.P.H.T.; Schnabel, C.; Binnie, S.A.; Xu, S.; Phillips, R.J.

2013-01-01

Cosmogenic 36 Cl analysis by accelerator mass spectrometry (AMS) is a valuable environmental and geological sciences research tool. Overcoming the stable nuclide 36 S isobar interfering with measurement is challenging, however. Traditionally this has required large accelerators, but following recent technical advances it is now possible with ∼30 MeV ion energies. Consequently 5 MV or even smaller modern bespoke spectrometers are now 36 Cl-capable, increasing accessibility and promoting wider and more varied 36 Cl use. However, the technical ability to identify 36 Cl ions is quite distinct from demonstrated high-performance AMS. Such is the theme of this paper. We present a systematic analysis of the accurate measurement of sample radioisotope relative to the stable chlorine, the normalisation of the measured ratio and correction for remaining 36 S interference, all combined with the use of stable-isotope dilution to determine sample Cl concentration to begin with. We conclude by showing that repeated analyses support our claims for routine 3% 36 Cl-AMS data. Accordingly, the modest SUERC spectrometer well competes with the performance of larger longer-established instruments, and the results may be quite generic for modern bespoke instruments.

Laser photodissociation and spectroscopy of mass-separated biomolecular ions

CERN Document Server

Polfer, Nicolas C

2014-01-01

This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book ""Laser photodissociation and spectroscopy of mass-separated biomolecular ions"" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. Th

Accelerator mass spectrometry radiocarbon ages of amino acid extracts from Californian palaeoindian skeletons

International Nuclear Information System (INIS)

Bada, J.L.; Gillespie, R.; Gowlett, J.A.J.; Hedges, R.E.M.

1984-01-01

The authors have used accelerator mass spectrometry to determine the radiocarbon ages of the amino acid extracts used in the original racemization studies of skeletal remains found in California. The studies indicate that some of the controversial Californian skeletons, which had been assigned to the Upper Pleistocene, are in fact Holocene. (author)

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

International Nuclear Information System (INIS)

Shao Yuhe

2001-01-01

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

Detection of sputtered molecular doubly charged anions: a comparison of secondary-ion mass spectrometry (SIMS) and accelerator mass spectrometry (AMS)

International Nuclear Information System (INIS)

Gnaser, Hubert; Golser, Robin; Kutschera, Walter; Priller, Alfred; Steier, Peter; Vockenhuber, Christof

2004-01-01

The detection of small molecular dianions by secondary-ion mass spectrometry (SIMS) and by accelerator mass spectrometry (AMS) is compared. In SIMS, the existence of these dianions can be identified safely if the total mass number of the molecule is odd and the dianion is hence detected at a half-integral mass number. The occurrence of fragmentation processes which may interfere with this scheme, is illustrated by means of the energy spectra of singly and doubly charged negative cluster ions. As compared to SIMS, AMS can rely, in addition, on the break-up of molecular species in the stripping process: this allows to monitor the simultaneous arrival of several atomic constituents with a clear energetic pattern in coincidence at the detector. This feature is exemplified for the C 10 2- dianion

Optical emission and mass spectroscopy of plasma processes in reactive DC pulsed magnetron sputtering of aluminium oxide

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Pokorný, Petr; Bočan, Jiří; Fitl, Přemysl; Lančok, Ján; Musil, Jindřich

2010-01-01

Roč. 12, č. 3 (2010), 697-700 ISSN 1454-4164 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : reactive magnetron sputtering * alumina * plasma spectroscopy * mass spectroscopy * optical emission spectroscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

Precise isotope analysis. Application of accelerator mass spectrometry to human sample

International Nuclear Information System (INIS)

Tokanai, Fuyuki

2016-01-01

Isotope 14 C is a radioisotope with a half-life of 5,730 years, and the measurement of its concentration makes it possible to calculate 'carbon 14 age.' This paper introduces up-to-date accelerator mass spectrometry (AMS), which is used in 14 C concentration measurement, and outlines its applied researches in pharmaceutical and medical fields. AMS technique has been applied in Europe and the United States to microdose clinical tests. In Japan, implementation foundation has been ready through the guidelines of the Ministry of Health, Labour and Welfare, five years behind Europe and the United States. Although conventional AMS measurement of 14 C required an acceleration voltage of 3 million volts or more, technological development has enabled a high accuracy of 14 C concentration measurement with the low acceleration voltage of about 400,000 volts. A sample for AMS method is graphitized, transformed to carbon ions ( 12 C-, 13 C-, and 14 C-) through negative ionization with cesium irradiation, accelerated under 450 kV, bombarded with argon gas, charge-converted to 12 C+, 13 C+, and 14 C+, and measured. Biological samples for microdose study are plasma, urine, feces, and biological tissue. Model tests showed a very good linearity between the concentrations of 14 C-containing compounds and 14 C concentrations. Applied research on microdose clinical tests is expected to increase its usability in the future, as an effective means of drug development. (A.O.)

Self-compensation in ZnO thin films: An insight from X-ray photoelectron spectroscopy, Raman spectroscopy and time-of-flight secondary ion mass spectroscopy analyses

International Nuclear Information System (INIS)

Saw, K.G.; Ibrahim, K.; Lim, Y.T.; Chai, M.K.

2007-01-01

As-grown ZnO typically exhibits n-type conductivity and the difficulty of synthesizing p-type ZnO for the realization of ZnO-based optoelectronic devices is mainly due to the compensation effect of a large background n-type carrier concentration. The cause of this self-compensation effect has not been conclusively identified although oxygen vacancies, zinc interstitials and hydrogen have been suggested. In this work, typical n-type ZnO thin films were prepared by sputtering and investigated using X-ray photoelectron spectroscopy, Raman spectroscopy and time-of-flight secondary ion mass spectroscopy to gain an insight on the possible cause of the self-compensation effect. The analyses found that the native defect that most likely behaved as the donor was zinc interstitial but some contribution of n-type conductivity could also come from the electronegative carbonates or hydrogen carbonates incorporated in the ZnO thin films

An improved method for statistical analysis of raw accelerator mass spectrometry data

International Nuclear Information System (INIS)

Gutjahr, A.; Phillips, F.; Kubik, P.W.; Elmore, D.

1987-01-01

Hierarchical statistical analysis is an appropriate method for statistical treatment of raw accelerator mass spectrometry (AMS) data. Using Monte Carlo simulations we show that this method yields more accurate estimates of isotope ratios and analytical uncertainty than the generally used propagation of errors approach. The hierarchical analysis is also useful in design of experiments because it can be used to identify sources of variability. 8 refs., 2 figs

Verification of the sputter-generated 32SFn- (n = 1-6) anions by accelerator mass spectrometry

Science.gov (United States)

Mane, R. G.; Surendran, P.; Kumar, Sanjay; Nair, J. P.; Yadav, M. L.; Hemalatha, M.; Thomas, R. G.; Mahata, K.; Kailas, S.; Gupta, A. K.

2016-01-01

Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase 32SFn- (n = 1-6) anions for all size 'n' can be readily generated from a variety of surfaces undergoing Cs+ ion sputtering in the presence of high purity SF6 gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio 34SFn-/32SFn- (n = 1-6) was found to be close to its natural abundance but not for all size 'n'. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant 32SFn- (n = 1-6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

LEAD SLOWING DOWN SPECTROSCOPY FOR DIRECT Pu MASS MEASUREMENTS

International Nuclear Information System (INIS)

Ressler, Jennifer J.; Smith, Leon E.; Anderson, Kevin K.

2008-01-01

The direct measurement of Pu in previously irradiated fuel assemblies is a recognized need in the international safeguards community. A suitable technology could support more timely and independent material control and accounting (MC and A) measurements at nuclear fuel storage areas, the head-end of reprocessing facilities, and at the product-end of recycled fuel fabrication. Lead slowing down spectroscopy (LSDS) may be a viable solution for directly measuring not only the mass of 239Pu in fuel assemblies, but also the masses of other fissile isotopes such as 235U and 241Pu. To assess the potential viability of LSDS, an LSDS spectrometer was modeled in MCNP5 and 'virtual assays' of nominal PWR assemblies ranging from 0 to 60 GWd/MTU burnup were completed. Signal extraction methods, including the incorporation of nonlinear fitting to account for self-shielding effects in strong resonance regions, are described. Quantitative estimates of Pu uncertainty are given for simplistic and more realistic fuel isotopic inventories calculated using ORIGEN. A discussion of additional signal-perturbing effects that will be addressed in future work, and potential signal extraction approaches that could improve Pu mass uncertainties, are also discussed

Two-photon laser spectroscopy of antiprotonic helium and the antiproton-to-electron mass ratio

CERN Document Server

Hori, Masaki; Barna, Daniel; Andreas Dax,; Hayano, Ryugo; Friedreich, Susanne; Juhász, Bertalan; Pask, Thomas; Widmann, Eberhard; Horváth, Dezső; Venturelli, Luca; Zurlo, Nicola; 10.1038/nature10260

2013-01-01

Physical laws are believed to be invariant under the combined transformations of charge, parity and time reversal (CPT symmetry). This implies that an antimatter particle has exactly the same mass and absolute value of charge as its particle counterpart. Metastable antiprotonic helium ($\\bar{p}He^+$) is a three-body atom2 consisting of a normal helium nucleus, an electron in its ground state and an antiproton ($\\bar{p}$) occupying a Rydberg state with high principal and angular momentum quantum numbers, respectively n and l, such that n ≈ l + 1 ≈ 38. These atoms are amenable to precision laser spectroscopy, the results of which can in principle be used to determine the antiproton-to-electron mass ratio and to constrain the equality between the antiproton and proton charges and masses. Here we report two-photon spectroscopy of antiprotonic helium, in which $\\bar{p}^{3}He^{+}$ and $\\bar{p}^{4}He^{+}$ isotopes are irradiated by two counter-propagating laser beams. This excites nonlinear, two-phot...

Microdroplet fusion mass spectrometry: accelerated kinetics of acid-induced chlorophyll demetallation.

Science.gov (United States)

Lee, Jae Kyoo; Nam, Hong Gil; Zare, Richard N

2017-01-01

Kinetics of acid-induced chlorophyll demetallation was recorded in microdroplets by fusing a stream of microdroplets containing 40 µM chlorophyll a or b dissolved in methanol with a stream of aqueous microdroplets containing 35 mM hydrochloric acid (pH = 1·46). The kinetics of the demetallation of chlorophyll in the fused microdroplets (14 ± 6 µm diameter; 84 ± 18 m s-1 velocity) was recorded by controlling the traveling distance of the fused microdroplets between the fusion region and the inlet of a mass spectrometer. The rate of acid-induced chlorophyll demetallation was about 960 ± 120 times faster in the charged microdroplets compared with that reported in bulk solution. If no voltage was applied to the sprayed microdroplets, then the acceleration factor was about 580 ± 90, suggesting that the applied voltage is not a major factor determining the acceleration. Chlorophyll a was more rapidly demetallated than chlorophyll b by a factor of ~26 in bulk solution and ~5 in charged microdroplets. The demetallation kinetics was second order in the H+ concentration, but the acceleration factor of microdroplets compared with bulk solution appeared to be unchanged in going from pH = 1·3 to 7·0. The water:methanol ratio of the fused microdroplets was varied from 7:3 to 3:7 causing an increase in the reaction rate of chlorophyll a demetallation by 20%. This observation demonstrates that the solvent composition, which has different evaporation rates, does not significantly affect the acceleration. We believe that a major portion of the acceleration can be attributed to confinement effects involving surface reactions rather than either to evaporation of solvents or to the introduction of charges to the microdroplets.

Development of positron annihilation spectroscopy to test accelerated weathering of protective polymer coatings

CERN Document Server

Zhang, R; Chen, H M; Mallon, P; Sandreczki, T C; Richardson, J R; Jean, Y C; Nielsen, B; Suzuki, R; Ohdaira, T

2000-01-01

A variable mono-energetic positron beam with a computer-controlled system has recently been constructed at the University of Missouri-Kansas City for weathering studies of polymeric coatings. The beam is designed to measure the S-parameter from Doppler-broadening energy spectra and the sub-nanometer defect properties from positron annihilation lifetimes (PAL). Significant variations of S-parameter and ortho-positronium intensity in coatings, as obtained from the newly built beam and from the Electrotechnical Laboratory's beam, respectively, are observed as a function of depth and exposure time due to the Xe-light irradiation. A high sensitivity of positron annihilation signal response to the early stage of degradation is observed. Development of positron annihilation spectroscopy to test accelerated weathering of polymeric coatings is discussed.

Accelerating two-dimensional nuclear magnetic resonance correlation spectroscopy via selective coherence transfer

Science.gov (United States)

Ye, Qimiao; Chen, Lin; Qiu, Wenqi; Lin, Liangjie; Sun, Huijun; Cai, Shuhui; Wei, Zhiliang; Chen, Zhong

2017-01-01

Nuclear magnetic resonance (NMR) spectroscopy serves as an important tool for both qualitative and quantitative analyses of various systems in chemistry, biology, and medicine. However, applications of one-dimensional 1H NMR are often restrained by the presence of severe overlap among different resonances. The advent of two-dimensional (2D) 1H NMR constitutes a promising alternative by extending the crowded resonances into a plane and thereby alleviating the spectral congestions. However, the enhanced ability in discriminating resonances is achieved at the cost of extended experimental duration due to necessity of various scans with progressive delays to construct the indirect dimension. Therefore, in this study, we propose a selective coherence transfer (SECOT) method to accelerate acquisitions of 2D correlation spectroscopy by converting chemical shifts into spatial positions within the effective sample length and then performing an echo planar spectroscopic imaging module to record the spatial and spectral information, which generates 2D correlation spectrum after 2D Fourier transformation. The feasibility and effectiveness of SECOT have been verified by a set of experiments under both homogeneous and inhomogeneous magnetic fields. Moreover, evaluations of SECOT for quantitative analyses are carried out on samples with a series of different concentrations. Based on these experimental results, the SECOT may open important perspectives for fast, accurate, and stable investigations of various chemical systems both qualitatively and quantitatively.

Trace analysis of plutonium in environmental samples by resonance ionization mass spectroscopy (RIMS)

International Nuclear Information System (INIS)

Erdmann, N.; Herrmann, G.; Huber, G.; Koehler, S.; Kratz, J.V.; Mansel, A.; Nunnemann, M.; Passler, G.; Trautmann, N.; Waldek, A.

1997-01-01

Trace amounts of plutonium in the environment can be detected by resonance ionization mass spectroscopy (RIMS). An atomic beam of plutonium is produced after its chemical separation and deposition on a filament. The atoms are ionized by a three-step excitation using pulsed dye-lasers. The ions are mass-selectively detected in a time-of-flight (TOF) mass spectrometer. With this setup a detection limit of 1·10 6 atoms of plutonium has been achieved. Furthermore, the isotopic composition can be determined. Different samples, including soil from the Chernobyl area, IAEA-certified sediments from the Mururoa Atoll and urine, have been investigated. copyright 1997 American Institute of Physics

A theoretical investigation of the collective acceleration of cluster ions with accelerated potential waves

International Nuclear Information System (INIS)

Suzuki, Hiroshi; Enjoji, Hiroshi; Kawaguchi, Motoichi; Noritake, Toshiya

1984-01-01

A theoretical treatment of the acceleration of cluster ions for additional heating of fusion plasma using the trapping effect in an accelerated potential wave is described. The conceptual design of the accelerator is the same as that by Enjoji, and the potential wave used is sinusoidal. For simplicity, collisions among cluster ions and the resulting breakups are neglected. The masses of the cluster ions are specified to range from 100 m sub(D) to 1000 m sub(D) (m sub(D): mass of a deuterium atom). Theoretical treatment is carried out only for the injection velocity which coincides with the phase velocity of the applied wave at the entrance of the accelerator. An equation describing the rate for successful acceleration of ions with a certain mass is deduced for the continuous injection of cluster ions. Computation for a typical mass distribution shows that more than 70% of the injected particles are effectively accelerated. (author)

IMPULSIVE ACCELERATION OF CORONAL MASS EJECTIONS. II. RELATION TO SOFT X-RAY FLARES AND FILAMENT ERUPTIONS

Energy Technology Data Exchange (ETDEWEB)

Bein, B. M.; Berkebile-Stoiser, S.; Veronig, A. M.; Temmer, M. [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Vrsnak, B. [Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kaciceva 26, HR-10000 Zagreb (Croatia)

2012-08-10

Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak accelerations and lower acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME acceleration duration and negatively correlated with the CME peak acceleration. For the majority of the events the CME acceleration starts before the flare onset (for 75% of the events) and the CME acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In {approx}60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME acceleration is smaller than {+-}5 minutes, which hints at a feedback relationship between the CME acceleration and the energy release in the associated flare due to magnetic reconnection.

Calorimetric low-temperature detectors for low-energy (E≤1 MeV/amu) heavy ions and their first application in the accelerator mass spectroscopy for trace analysis of 236U

International Nuclear Information System (INIS)

Kraft-Bermuth, S.

2004-01-01

In the thesis presented here, calorimetric low temperature detectors were for the first time applied in accelerator mass spectrometry (AMS) to determine the isotope ratio of 236 U to 238 U in several samples of natural uranium. The detectors consist of a superconducting aluminium film deposited onto a sapphire absorber which is used as thermistor. An energetic heavy ion deposits its kinetic energy as heat in the absorber. The temperature rise is detected by the resistance change of the superconductor. The AMS experiments were performed at the tandem accelerator VERA of the ''Institut fuer Isotopenforschung und Kernphysik'' of the University of Vienna. In an energy range of 10-60 MeV, a relative energy resolution of ΔE/E=7.10 -3 could be achieved, one order of magnitude better than with conventional ionization detectors. Improving thermal and electronic noise yielded in a second experiment for uranium ions with E=17 MeV a relative energy resolution of ΔE/E=4.6.10 -3 . The energy response of the detectors was linear over the whole energy range and independent of the ion mass. Down to a level of 0.1%, no pulse height defect was observed. With the energy resolution obtained it is possible to determine the isotope ratio of 236 U/ 238 U for several samples of natural uranium. With the resolution achieved it is possible furthermore to apply the detectors in several test experiments for direct mass identification of heavy ions using a combined energy/time of flight measurement. In these first tests, a mass resolution of ΔM/M=(8.5-11.0).10 -3 was achieved. In a first test to apply the detectors for detection of so called ''super heavy elements (Z>=112)'', the large dynamic range allowed to identify the reaction products and their alpha decays simultaneously and time dependent. (orig.)

Flow and mass transfer downstream of an orifice under flow accelerated corrosion conditions

International Nuclear Information System (INIS)

Ahmed, Wael H.; Bello, Mufatiu M.; El Nakla, Meamer; Al Sarkhi, Abdelsalam

2012-01-01

Highlights: ► Mass transfer downstream of orifices was numerically and experimentally investigated. ► The surface wear pattern is measured and used to validate the present numerical results. ► The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. ► The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. ► The current study offered very useful information for FAC engineers for better preparation of nuclear plant inspection scope. - Abstract: Local flow parameters play an important role in characterizing flow accelerated corrosion (FAC) downstream of sudden area change in power plant piping systems. Accurate prediction of the highest FAC wear rate locations enables the mitigation of sudden and catastrophic failures, and the improvement of the plant capacity factor. The objective of the present study is to evaluate the effect of the local flow and mass transfer parameters on flow accelerated corrosion downstream of an orifice. In the present study, orifice to pipe diameter ratios of 0.25, 0.5 and 0.74 were investigated numerically by solving the continuity and momentum equations at Reynolds number of Re = 20,000. Laboratory experiments, using test sections made of hydrocal (CaSO 4 ·½H 2 O) were carried out in order to determine the surface wear pattern and validate the present numerical results. The numerical results were compared to the plants data as well as to the present experiments. The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. This location was also found to correspond to the location of elevated turbulent kinetic energy generated within the flow separation vortices downstream of the orifice. The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. The current study found to offer very

Radiocarbon dating of lake sediments and peats by accelerator mass spectrometry

International Nuclear Information System (INIS)

Fowler, A.J.

1985-01-01

The small sample size requirement of accelerator mass spectrometry has allowed the measurement of the 14C/12C ratio for components of various lake sediment and peat samples, with a view to gaining greater understanding of sedimentary processes and to overcome some of the problems associated with conventional radiocarbon dating of sediments, where the 14C/12C ratio of the whole sample, less carbonate, is measured. Some of the fractions of sedimentary organic matter are amenable to analysis. Different molecules are specific to higher plants, algae and bacteria, so estimates of the major sources of input to the sediment can be made. The lipid fraction, though a small component (1%) of the total organic matter, yields most source information. Analyses of n-fatty acids and n-alkanes by capillary gas chromatography are used to interpret the radiocarbon result for the total crude lipid samples in the light of the environmental information so gained. Comparison of the various radiocarbon results for different components of the sediment has provided evidence for the importance of the amount of organic carbon in the samples, microbial attack during storage, the presence of mineral carbon, mixing, hard-water effects and the influence of terrestrial material on lake sediments. A regime has been proposed for the routine preparation of samples at an accelerator mass spectrometry facility in order to provide maximum useful information on a sediment sample. (author)

Techniques of tandem accelerator mass spectrometry and their applications to 14C measurements

International Nuclear Information System (INIS)

Nakamura, Toshio; Nakai, Nobuyuki; Furukawa, Michiaki

1990-01-01

A tandem accelerator mass spectrometer, named Tandetron was installed at Nagoya University in 1982 for 14 C measurement. The Tandetron spectrometer consists of a Cs sputter ion source to produce negative carbon ions, a Schenkel-type 2.2 MV tandem accelerator, an ion-beam analyzing apparatus with a charge-energy selector and mass spectrometer, and a heavy ion detector to identify and count 14 C 3+ ions from various background ions. The 14 C concentrations in pine needles, sampled at the Higashiyama Campus of Nagoya University, have been measured since 1984. The present article describes some of the measurements of 14 C in pine needles, focusing on the annual changes in the Δ 14 C value of atmospheric CO 2 , and on the effect upon 14 C concentrations for pine needles of a local 14 CO 2 emission from incineration of radioactive organic solvent wastes containing 14 C, at the Radioisotope Center in the Higashiyama Campus. The pine needles at some locations seemed to be influenced by local artificial CO 2 emission. The Δ 14 C values increased noticeably from 1956 to 1964 as a result of artificial 14 C produced in nuclear weapon tests. (N.K.)

Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Hellman, Hal

1968-01-01

This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

Analysis of accelerator based neutron spectra for BNCT using proton recoil spectroscopy

International Nuclear Information System (INIS)

Wielopolski, L.; Ludewig, H.; Powell, J.R.; Raparia, D.; Alessi, J.G.; Lowenstein, D.I.

1998-01-01

using a proton recoil spectroscopy detection system. Comparison was also made between in phantom 10 BF 3 readings made at the BMRR and those made at the RARAF accelerator facility

A post-accelerator for the US rare isotope accelerator facility

CERN Document Server

Ostroumov, P N; Kolomiets, A A; Nolen, J A; Portillo, M; Shepard, K W; Vinogradov, N E

2003-01-01

The proposed rare isotope accelerator (RIA) facility includes a post-accelerator for rare isotopes (RIB linac) which must produce high-quality beams of radioactive ions over the full mass range, including uranium, at energies above the Coulomb barrier, and have high transmission and efficiency. The latter requires the RIB linac to accept at injection ions in the 1+ charge state. A concept for such a post accelerator suitable for ions up to mass 132 has been previously described . This paper presents a modified concept which extends the mass range to uranium. A high resolution separator for purifying beams at the isobaric level precedes the RIB linac. The mass filtering process will provide high purity beams while preserving transmission. For most cases a resolution of about m/DELTA m=20 000 is adequate at mass A=100 to obtain a separation between isobars of mass excess difference of 5 MeV. The design for a device capable of purifying beams at the isobaric level includes calculations up to fifth order. The RIB...

Correlation analysis of measurement result between accelerator mass spectrometry and gamma counter

International Nuclear Information System (INIS)

Minamimoto, Ryogo; Cheng, C.; Oka, Takashi; Inoue, Tomio; Hamabe, Yoshimi; Shimoda, Marika

2010-01-01

The guidelines for microdosing in clinical trials were published in Japan in 2008 following the guidelines of the European Medicines Agency and the Food and Drug Administration. They recommend utilizing accelerator mass spectrometry (AMS) and positron emission tomography as candidates for monitoring drug metabolites in preclinical studies. We correlate the two methods by measuring appropriately labeled tissue samples from various mouse organs using both AMS and gamma counter. First, we measured the 14 C background levels in mouse organs using the AMS system. We then clarified the relationship between AMS and gamma counter by simultaneously administering 14 C-2-fluoro-2-deoxyglucose ( 14 C-FDG) and 18 F-2-fluoro-2-deoxyglucose ( 18 F-FDG). Tissue distribution was examined after 30 min, 1 h, 2 h and 4 h using the AMS system for 14 C-FDG and gamma counter for 18 F-FDG. Background 14 C levels were subtracted from the data obtained with radiotracer administration. The background 14 C concentration differed with tissue type measured. Background 14 C concentration in mouse liver was higher than in other organs, and was approximately 1.5-fold that in blood. The correlation coefficient (r) of the measurements between AMS ( 14 C-FDG) and gamma counter ( 18 F-FDG) was high in both normal (0.99 in blood, 0.91 in brain, 0.61 in liver and 0.78 in kidney) and tumor-bearing mice (0.95 in blood and 0.99 in tumor). The clearance profile of 18 F-FDG was nearly identical to that of 14 C-FDG measured with AMS. Accelerator mass spectrometry analysis has an excellent correlation with biodistribution measurements using gamma counter. Our results suggest that the combination of AMS and positron emission tomography (PET) can act as a complementary approach to accelerate drug development. (author)

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

Science.gov (United States)

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.

VEDs for charged particle accelerators: Indian scenario

International Nuclear Information System (INIS)

Bhandari, R.K.

2012-01-01

In the initial times after their invention, the charged particle accelerators have, primarily, been used for fundamental studies on nuclei and atoms. From the first modern accelerator, the cathode ray tube, used by J.J. Thomson for the discovery of electron, very recently the gigantic 27 km circumference Large Hadron Collider (LHC) is operational in the search of Higg's boson and related physics issues. Particle accelerators have emerged as powerful microscopes for investigating the finest details of cells, genes, molecules, atoms, protons, neutrons, muons, electrons, quarks and, possibly, still undiscovered even more fundamental constituents of the universe, such as dark matter and dark energy. Several noble prize winning discoveries have been made using accelerators. Accelerators are now being used in a wide area of industrial and medical applications. They are used for the production of radioisotopes for medical imaging, cancer therapy, food sterilization, treatment of waste water, sterilization of medical equipment, material modification, mass spectroscopy, cargo scanning, fabrication of semiconductors etc. Ongoing effort towards the development of accelerators with megawatt beam power is showing hope for a cleaner source of nuclear energy and treatment of nuclear waste. Several tens of thousands of accelerators are presently operational in the world for basic research and applications. Development of new accelerators has several times been driven by new technologies and materials and sometimes they have driven the technological developments towards cutting edge. Some examples are ultra-high vacuum in large volumes, superfluid helium in cryogenics, cryocoolers, superconducting magnets and RF cavities, high power vacuum electronic devices, global control systems, superfast computing and communication networks, giant data storage/processing systems etc. India has been pursuing a fairly robust programme of accelerator development at various institutions. It

Analysis of uranium and thorium thin targets irradiated at the PSI accelerator

International Nuclear Information System (INIS)

Wenger, H.U.; Botta, F.; Chawla, R.; Daum, M.; Gavillet, D.; Hegedues, F.; Ingold, F.; Kopajtic, Z.; Ledergerber, G.; Linder, H.P.; Roellin, S.; Wichser, J.; Wyss, F.

1997-01-01

The aim of the ATHENA programme at PSI is to provide experimental data for the validation of theoretical models in nucleon-meson transport codes used for accelerator-based transmutation studies. Emphasis is placed on the mass yield distribution of spallation and fission products for irradiated thin actinide targets. This paper presents results of an irradiation experiment carried out with 238 UO 2 and 232 ThO 2 . Isobaric production cross-sections of fission and spallation products based on mass spectrometric measurements and γ-spectroscopy are compared with calculations carried out using the HETC code and the RAL high-energy fission model. (author) 6 figs., 8 refs

Accelerator mass spectrometry of the heaviest long-lived ...

Indian Academy of Sciences (India)

A 3-MV pelletron tandem accelerator is the heart of the Vienna environmental research accelerator (VERA). ... Vienna Environmental Research Accelerator, Institute for Isotopic Research and Nuclear Physics, University of Vienna, A-1090 Vienna, Austria; Russian Research Center, “Kurchatov Institute”, Institute of Nuclear ...

Accurate determination of 41Ca concentrations in spent resins from the nuclear industry by Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Nottoli, Emmanuelle; Bourlès, Didier; Bienvenu, Philippe; Labet, Alexandre; Arnold, Maurice; Bertaux, Maité

2013-01-01

The radiological characterisation of nuclear waste is essential for managing storage sites. Determining the concentration of Long‐Lived RadioNuclides (LLRN) is fundamental for their long-term management. This paper focuses on the measurement of low 41 Ca concentrations in ions exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). 41 Ca concentrations were successfully measured by Accelerator Mass Spectrometry (AMS) after the acid digestion of resin samples, followed by radioactive decontamination and isobaric suppression through successive hydroxide, carbonate, nitrate and final CaF 2 precipitations. Measured 41 Ca concentrations ranged from 0.02 to 0.03 ng/g, i.e. from 0.06 to 0.09 Bq/g. The 41 Ca/ 60 Co activity ratios obtained were remarkably reproducible and in good agreement with the current ratio used for resins management. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 41 Ca in spent resins using Accelerator Mass Spectrometry. • A chemical treatment procedure was developed to quantitatively recover calcium in solution and selectively extract it. • Developed firstly on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • Accelerator mass spectrometry allowed measuring concentrations of 41 Ca in spent resins as low as 0.02 ng/g of dry resin. • Final results are in agreement with current data used for spent resins management

Design Study of a Mini Cyclotron for the Application of Biomedical Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Kim, Jong-Won; Yun, Chong-Chul; Youn, Min-Yong; Wang, Sonjong

2009-01-01

A small cyclotron has been considered for the use of biomedical accelerator mass spectrometer (BAMS). Over a decade ago a few cyclotrons had been constructed and tested for AMS, but technical problems of instability and poor transmission efficiency caused to discontinue further developments. The major reason of the demise of cyclotron AMS was the dominance of commercial Tandem-based AMS facilities. Now BAMS may ask for more compact system, and perhaps using positive ions to accelerate isotope tracers is a favorable feature. The design of a cyclotron to meet the requirements of BAMS has been performed by adopting a compact magnet with high stability and a flat-topping rf system to increase transmission efficiency.

Prospects for detection of intermediate-mass black holes in globular clusters using integrated-light spectroscopy

Science.gov (United States)

de Vita, R.; Trenti, M.; Bianchini, P.; Askar, A.; Giersz, M.; van de Ven, G.

2017-06-01

The detection of intermediate-mass black holes (IMBHs) in Galactic globular clusters (GCs) has so far been controversial. In order to characterize the effectiveness of integrated-light spectroscopy through integral field units, we analyse realistic mock data generated from state-of-the-art Monte Carlo simulations of GCs with a central IMBH, considering different setups and conditions varying IMBH mass, cluster distance and accuracy in determination of the centre. The mock observations are modelled with isotropic Jeans models to assess the success rate in identifying the IMBH presence, which we find to be primarily dependent on IMBH mass. However, even for an IMBH of considerable mass (3 per cent of the total GC mass), the analysis does not yield conclusive results in one out of five cases, because of shot noise due to bright stars close to the IMBH line of sight. This stochastic variability in the modelling outcome grows with decreasing BH mass, with approximately three failures out of four for IMBHs with 0.1 per cent of total GC mass. Finally, we find that our analysis is generally unable to exclude at 68 per cent confidence an IMBH with mass of 103 M⊙ in snapshots without a central BH. Interestingly, our results are not sensitive to GC distance within 5-20 kpc, nor to misidentification of the GC centre by less than 2 arcsec (<20 per cent of the core radius). These findings highlight the value of ground-based integral field spectroscopy for large GC surveys, where systematic failures can be accounted for, but stress the importance of discrete kinematic measurements that are less affected by stochasticity induced by bright stars.

Accelerator mass spectrometry: ultrasensitive analysis of global science

International Nuclear Information System (INIS)

Tuniz, C.; Bird, J.B.; Fink, D.; Herzog, G.F.

1998-01-01

Accelerator mass spectrometry (AMS), an innovative analytical technique, measures rare atoms at unprecedented levels of sensitivity, revolutionizing the science of radiocarbon dating and accessing new environmental tracers and chronometers. AMS can study extraterrestrial materials, the earth sciences, the future of the global environment, and the history of mankind. The Shroud of Turin, meteorites from Mars, the crown of Charlemagne, and ancient air trapped in Antarctic ice indicate some of the samples on which AMS has been applied. This book has compiled the diverse set of scientific literature into a single volume, suitable as a text or resource on the major AMS-related outcomes, issues, and methods. It explains how scientists and researchers succeeded in counting Carbon-14 atoms at an extraordinary level, examines the impact of AMS on the branches of scientific technology and historical research, provides an understanding of the chronology and significance of past and present environmental changes, details the advances in AMS equipment, technology, and methods as well as the expansion of AMS research

Accelerator mass spectrometry analyses of environmental radionuclides: sensitivity, precision and standardisation

Science.gov (United States)

Hotchkis; Fink; Tuniz; Vogt

2000-07-01

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. AMS allows an isotopic sensitivity as low as one part in 10(15) for 14C (5.73 ka), 10Be (1.6 Ma), 26Al (720 ka), 36Cl (301 ka), 41Ca (104 ka), 129I (16 Ma) and other long-lived radionuclides occurring in nature at ultra-trace levels. These radionuclides can be used as tracers and chronometers in many disciplines: geology, archaeology, astrophysics, biomedicine and materials science. Low-level decay counting techniques have been developed in the last 40-50 years to detect the concentration of cosmogenic, radiogenic and anthropogenic radionuclides in a variety of specimens. Radioactivity measurements for long-lived radionuclides are made difficult by low counting rates and in some cases the need for complicated radiochemistry procedures and efficient detectors of soft beta-particles and low energy x-rays. The sensitivity of AMS is unaffected by the half-life of the isotope being measured, since the atoms not the radiations that result from their decay, are counted directly. Hence, the efficiency of AMS in the detection of long-lived radionuclides is 10(6)-10(9) times higher than decay counting and the size of the sample required for analysis is reduced accordingly. For example, 14C is being analysed in samples containing as little as 20 microg carbon. There is also a world-wide effort to use AMS for the analysis of rare nuclides of heavy mass, such as actinides, with important applications in safeguards and nuclear waste disposal. Finally, AMS microprobes are being developed for the in-situ analysis of stable isotopes in geological samples, semiconductors and other materials. Unfortunately, the use of AMS is limited by the expensive accelerator technology required, but there are several attempts to develop compact AMS spectrometers at low (advances in AMS

Dating of two human fossil bones from Romania by accelerator mass spectrometry

International Nuclear Information System (INIS)

Olariu, Agata; Skog, Goeran; Hellborg, Ragnar; Stenstroem, Kristina; Faarinen, Mikko; Persson, Per; Alexandrescu, Emilian

2005-01-01

In this study we have dated two fossil remains found in Romania, by the method of radiocarbon using the technique of the accelerator mass spectrometry. The human fossil remains from Woman's cave, Baia de Fier, have been dated to the age 30150 ± 800 years BP, and the skull, from the Cioclovina cave has been dated to the age 29000 ± 700 years BP. These are among the most ancient dated human fossil remains from Romania, possibly belonging to the upper Paleolithic, the Aurignacian period. (authors)

Acceleration Modes and Transitions in Pulsed Plasma Accelerators

Science.gov (United States)

Polzin, Kurt A.; Greve, Christine M.

2018-01-01

accelerators was developed by Cheng, et al. The Coaxial High ENerGy (CHENG) thruster operated on the 10-microseconds timescales of pulsed plasma thrusters, but claimed high thrust density, high efficiency and low electrode erosion rates, which are more consistent with the deflagration mode of acceleration. Separate work on gas-fed pulsed plasma thrusters (PPTs) by Ziemer, et al. identified two separate regimes of performance. The regime at higher mass bits (termed Mode I in that work) possessed relatively constant thrust efficiency (ratio of jet kinetic energy to input electrical energy) as a function of mass bit. In the second regime at very low mass bits (termed Mode II), the efficiency increased with decreasing mass bit. Work by Poehlmann et al. and by Sitaraman and Raja sought to understand the performance of the CHENG thruster and the Mode I / Mode II performance in PPTs by modeling the acceleration using the Hugoniot Relation, with the detonation and deflagration modes representing two distinct sets of solutions to the relevant conservation laws. These works studied the proposal that, depending upon the values of the various controllable parameters, the accelerator would operate in either the detonation or deflagration mode. In the present work, we propose a variation on the explanation for the differences in performance between the various pulsed plasma accelerators. Instead of treating the accelerator as if it were only operating in one mode or the other during a pulse, we model the initial stage of the discharge in all cases as an accelerating current sheet (detonation mode). If the current sheet reaches the exit of the accelerator before the discharge is completed, the acceleration mode transitions to the deflagration mode type found in the quasi-steady MPD thrusters. This modeling method is used to demonstrate that standard gas-fed pulsed plasma accelerators, the CHENG thruster, and the quasi-steady MPD accelerator are variations of the same device, with the overall

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

Energy Technology Data Exchange (ETDEWEB)

Salehpour, M., E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Håkansson, K.; Possnert, G. [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Wacker, L.; Synal, H.-A. [Ion Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 (Switzerland)

2016-03-15

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 {sup 14,13,12}C{sup 3+} 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 {sup 14}C/{sup 12}C and the {sup 13}C/{sup 12}C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

Prospects for experiments on neutrino masses and mixing via neutrino oscillations at future accelerators

International Nuclear Information System (INIS)

Lanou, R.E. Jr.

1982-01-01

A study is made of the requirements necessary for improvement in our knowledge of limits in mass and mixing parameters for neutrinos via oscillation phenomena at accelerators. It is concluded that increased neutrino event rate (flux x energy) at modest energy machines (e.g., AGS and LAMPF) is the single most important requirement. This will permit smaller E/L ratios and refinement of systematics

Toward Understanding the Early Stags of an Impulsively Accelerated Coronal Mass Ejection

Science.gov (United States)

2010-08-09

B. E., & Howard, R. A . 2009, ApJ, 702, 901 Wood, B. E., Karovska , M., Chen, J., Brueckner, G. E., Cook, J. W., & Howard, R. A . 1999, ApJ, 512, 484...ar X iv :1 00 8. 11 71 v1 [ as tr o- ph .S R ] 6 A ug 2 01 0 Astronomy & Astrophysics manuscript no. bubble c© ESO 2010 August 9, 2010 Toward...understanding the early stages of an impulsively accelerated coronal mass ejection SECCHI observations S. Patsourakos1, A . Vourlidas2, and B. Kliem3,4

Dating of two paleolithic human fossils from Romania by accelerator mass spectrometry

International Nuclear Information System (INIS)

Olariu, Agata; Alexandrescu, Emilian; Skog, Goeran; Hellborg, Ragnar; Stenstroem, Kristina; Faarinen, Mikko; Persson, Per

2003-01-01

In this study, we have dated two human fossil remains from Romania by the method of radiocarbon using the technique of the accelerator mass spectrometry at the Pelletron system of Lund University, Sweden. Two fossil remains appear to be the most ancient human remains ever dated in our country: 1. A skull, a scapula and a tibia found in Baia de Fier in the Women's Cave, in Gorj county in the province Oltenia, by Constantin Nicolaescu-Plopsor in 1952; 2. A skull found in Cioclovina cave, near commune Bosorod, Hunedoara county in Transilvania by a worker at the exploitation of phosphate deposits in the year 1941. The skull was examined by Francisc Rainer, anthropologist, and Ioan Simionescu, geologist, who published a study. The lack of stratigraphic observations made very difficult the cultural and chronological assignments of this skull. These authors advanced the hypothesis that the skull belongs to the man of the type Homo sapiens fossilis. At the same time, a number of archaeologists believed that the skull might belong to a modern man, but there have been doubts about this matter. Under this circumstance, dating of the two skulls by physical analysis methods appears to be decisive. Samples of bone were taken from the scapula and tibia from Woman's cave, Baia de Fier and from the skull from Cioclovina cave. The content of Carbon 14 have been determined in the two samples by using the technique of accelerator mass spectrometry (AMS), performed at the AMS system of Lund University, in Sweden. Usually, the collagen amount sufficient for AMS measurements can be extracted from bone fragments with masses of 1 g or more (what provides 5 to 10% of the original collagen content). But, in the situation of the present studied fossil remains, because of the small quantity of bone samples and because the bones were very old, the determination of radiocarbon in the skulls was not so simple. For the preparation of the bone samples, we have essentially applied the Longin method

Microdroplets Accelerate Ring Opening of Epoxides

Science.gov (United States)

Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

2018-05-01

The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/ v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

Microdroplets Accelerate Ring Opening of Epoxides

Science.gov (United States)

Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

2018-03-01

The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

Synergy of decay spectroscopy and mass spectrometry for the study of exotic nuclides

CERN Document Server

Stanja, Juliane

With only two ingredients, atomic nuclei exhibit a rich structure depending on the ordering of the different proton- and neutron-occupied states. This ordering can give rise to excited states with exceptionally long half-lives, also known as isomers, especially near shell closures. On-line mass spectrometry can often be compromised by the existence of such states that may even be produced in higher proportion than the ground state. This thesis presents the first results obtained from a nuclear spectroscopy setup coupled with the high-resolution Penning-trap mass spectrometer ISOLTRAP, at CERN’s radioactive ion beam facility ISOLDE. The isomerism in the neutron-deficient thallium isotopes was investigated. The data on $^{184,190,193−195}$Tl allow an improvement of existing mass values as well as a mass-spin- state assignment in $^{ 190,193,194}$Tl. Due to the presence of the ground and isomeric state for $^{ 194}$Tl the excitation energy of the latter was determined for the first time experimentally. Syste...

Intracavity optogalvanic spectroscopy. An analytical technique for 14C analysis with subattomole sensitivity.

Science.gov (United States)

Murnick, Daniel E; Dogru, Ozgur; Ilkmen, Erhan

2008-07-01

We show a new ultrasensitive laser-based analytical technique, intracavity optogalvanic spectroscopy, allowing extremely high sensitivity for detection of (14)C-labeled carbon dioxide. Capable of replacing large accelerator mass spectrometers, the technique quantifies attomoles of (14)C in submicrogram samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity and detection via impedance variations, limits of detection near 10(-15) (14)C/(12)C ratios are obtained. Using a 15-W (14)CO2 laser, a linear calibration with samples from 10(-15) to >1.5 x 10(-12) in (14)C/(12)C ratios, as determined by accelerator mass spectrometry, is demonstrated. Possible applications include microdosing studies in drug development, individualized subtherapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon. The method can also be applied to detection of other trace entities.

Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

NARCIS (Netherlands)

Garner, C.R.; Park, K.B.; French, N.S.; Earnshaw, C.; Schipani, A.; Selby, A.M.; Byrne, L.; Siner, S.; Crawley, F.P.; Vaes, W.H.J.; Duijn, E. van; ligt, R. de; Varendi, H.; Lass, J.; Grynkiewicz, G.; Maruszak, W.; Turner, M.A.

2015-01-01

Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group.

Mass-Discrepancy Acceleration Relation: A Natural Outcome of Galaxy Formation in Cold Dark Matter Halos.

Science.gov (United States)

Ludlow, Aaron D; Benítez-Llambay, Alejandro; Schaller, Matthieu; Theuns, Tom; Frenk, Carlos S; Bower, Richard; Schaye, Joop; Crain, Robert A; Navarro, Julio F; Fattahi, Azadeh; Oman, Kyle A

2017-04-21

We analyze the total and baryonic acceleration profiles of a set of well-resolved galaxies identified in the eagle suite of hydrodynamic simulations. Our runs start from the same initial conditions but adopt different prescriptions for unresolved stellar and active galactic nuclei feedback, resulting in diverse populations of galaxies by the present day. Some of them reproduce observed galaxy scaling relations, while others do not. However, regardless of the feedback implementation, all of our galaxies follow closely a simple relationship between the total and baryonic acceleration profiles, consistent with recent observations of rotationally supported galaxies. The relation has small scatter: Different feedback implementations-which produce different galaxy populations-mainly shift galaxies along the relation rather than perpendicular to it. Furthermore, galaxies exhibit a characteristic acceleration g_{†}, above which baryons dominate the mass budget, as observed. These observations, consistent with simple modified Newtonian dynamics, can be accommodated within the standard cold dark matter paradigm.

Accelerators and Dinosaurs

CERN Multimedia

Turner, Michael Stanley

2003-01-01

Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

Molecular spectroscopy

International Nuclear Information System (INIS)

Kokh, Eh.; Zonntag, B.

1981-01-01

The latest investigation results on molecular spectroscopy with application of synchrotron radiation in the region of vacuum ultraviolet are generalized. Some results on investigation of excited, superexcited and ionized molecule states with the use of adsorption spectroscopy, photoelectron spectroscopy, by fluorescent and mass-spectrometric methods are considered [ru

Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry

International Nuclear Information System (INIS)

Lappin, Graham; Garner, R.Colin

2004-01-01

Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14 C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided. (orig.)

Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry.

Science.gov (United States)

Lappin, Graham; Garner, R Colin

2004-01-01

Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided.

Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

Science.gov (United States)

Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

2011-01-01

Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

First-year progress on research and development of a mass accelerator (MAID) as a driver for impact fusion, May 6, 1981-May 5, 1982

International Nuclear Information System (INIS)

1982-01-01

The objective of this program is to construct a small scale mass accelerator consisting of 10 plasma discharge modules, and perform experiments and analysis with the system so that reliable scaling laws can be obtained for the device. The effort is directed to determining whether a large scale version of such a plasma driven mass accelerator could be used as a driver for inertial fusion, or other energy-related applications

HEAVY ION LINEAR ACCELERATOR

Science.gov (United States)

Van Atta, C.M.; Beringer, R.; Smith, L.

1959-01-01

A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

IAEA meeting on accelerator mass spectrometry, Zagreb, Croatia, April 19-21, 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. It is of paramount importance to promote the use of AMS within the IAEA. This would be particularly beneficial for the following IAEA programs: Safeguards, Physical and chemical sciences, Human health, Food and agriculture, Radioactive waste management, Radiation safety, Industry and earth sciences. The IAEA is working in the area of development of reference materials, interlaboratory comparisons and quality assurance. This meeting recommends that this program further developed and extended to include all the AMS isotopes.

IAEA meeting on accelerator mass spectrometry, Zagreb, Croatia, April 19-21, 1995

International Nuclear Information System (INIS)

1995-01-01

Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. It is of paramount importance to promote the use of AMS within the IAEA. This would be particularly beneficial for the following IAEA programs: Safeguards, Physical and chemical sciences, Human health, Food and agriculture, Radioactive waste management, Radiation safety, Industry and earth sciences. The IAEA is working in the area of development of reference materials, interlaboratory comparisons and quality assurance. This meeting recommends that this program further developed and extended to include all the AMS isotopes

Single atom counting with accelerators

Energy Technology Data Exchange (ETDEWEB)

Woelfli, W [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

1984-02-01

Direct detection of radioisotopes with conventional mass spectrometers is possible when the potential background atoms, in particular stable isotopes of the same mass (isobars) or molecules of similar mass are present in sufficiently low concentrations. Most of the long lived radioisotopes of interest for dating purposes however, occur in such small concentrations that their peak in the mass spectrum is obscured by the stable isobar and molecule distributions. The key idea of the new AMS technique which allows us to measure directly such small concentrations is the acceleration of the sample atoms to MeV energies and to use various filter processes and particle identification techniques developed for nuclear physics research to eliminate the isobaric and molecular interferences. The detection methods used for each radioisotope depend on the dominant background atoms and these in turn depend on the specific accelerator used. The problems encountered in transforming an existing particle accelerator into a high precision dating tool are considerable and have been solved only recently for one type of accelerator, notably the tandem Van de Graaff. For this reason the description of the AMS method and some of its applications is restricted to this type of accelerator only.

Atom spectroscopy

International Nuclear Information System (INIS)

Kodling, K.

1981-01-01

Experiments on atom photoabsorption spectroscopy using synchrotron radiation in the 10-1000 eV range are reviewed. Properties of the necessary synchrotron radiation and the experiment on absorption spectroscopy are briefly described. Comparison with other spectroscopy methods is conducted. Some data on measuring photoabsorption, photoelectron emission and atom mass spectra are presented [ru

Comparison of accelerator mass spectrometric measurement with liquid scintillation counting measurement for the determination of 14C in environmental samples

International Nuclear Information System (INIS)

Yasuike, Kaeko; Yamada, Yoshimune; Amano, Hikaru

2010-01-01

The concentrations of organically-bound 14 C in tree-ring cellulose of a Japanese Black Pine grown in Shika-machi (37.0 deg. N, 136.8 deg. E) and those of a Japanese Cedar grown in Kanazawa (36.5 deg. N, 136.7 deg. E), Japan, were analyzed for the ring-years from 1989 to 1998 by the accelerator mass spectrometric measurement. The results were compared with those of the same samples analyzed by the liquid scintillation counting measurement to determine the reliability of liquid scintillation counting measurement. An important result of this study is that the sensitivity and reproducibility of accelerator mass spectrometric measurement was almost equal to that of liquid scintillation counting measurement.

Chemical analysis of surfaces by resonance ionization mass spectroscopy associated to ionic pulverization

International Nuclear Information System (INIS)

Kern, P.

1995-01-01

This work shows that if resonance ionization mass spectroscopy was first applied in isotopic separation, it's also an analyzing method adapted to the study of semi-conductor materials and thin foils. We have improved this technic: a neodymium laser coupled with a dye laser, a new argon ions gun, a gallium ions gun and a new collection optic for the secondary ions quadrupole spectrometer to allow quantitative and selective measurements. (S.G.). 84 refs

Synergy of decay spectroscopy and mass spectrometry for the study of exotic nuclides

Energy Technology Data Exchange (ETDEWEB)

Stanja, Juliane

2013-04-12

With only two ingredients, atomic nuclei exhibit a rich structure depending on the ordering of the different proton- and neutron-occupied states. This ordering can give rise to excited states with exceptionally long half-lives, also known as isomers, especially near shell closures. On-line mass spectrometry can often be compromised by the existence of such states that may even be produced in higher proportion than the ground state. This thesis presents the first results obtained from a nuclear spectroscopy setup coupled with the high-resolution Penning-trap mass spectrometer ISOLTRAP, at CERN's radioactive ion beam facility ISOLDE. The isomerism in the neutron-deficient thallium isotopes was investigated. The data on {sup 184,190,193-195}Tl allow an improvement of existing mass values as well as a mass-spin-state assignment in {sup 190,193,194}Tl. Due to the presence of the ground and isomeric state for {sup 194}Tl the excitation energy of the latter was determined for the first time experimentally. Systematic trends in the vicinity of the Z = 82 shell closure have been discussed.

Mass acceleration in a multi-module plasma jet for impact fusion. Final report, 21 May 1984-21 May 1985

International Nuclear Information System (INIS)

Burton, R.L.; Goldstein, S.A.; Tidman, D.A.; Massey, D.W.; Winsor, N.K.; Witherspoon, F.D.

1985-07-01

GT-Devices began work on multi-module mass accelerators for impact fusion in 1981. The technique employs sequentially switched high pressure plasma jets to accelerate a lightweight projectile in a circular barrel. The purpose of the work of the past 12 months was to improve the understanding of the plasma jet acceleration process, and to translate that understanding into verifiable results. Both goals have been accomplished. During the past year we conceived, designed, built and fired 325 shots on the Module Test Facility (MTF). This facility provided sufficient diagnostics to investigate a wide variety of geometries, plasmas and current pulses, so that rapid progress was made

Improving tritium exposure reconstructions using accelerator mass spectrometry

International Nuclear Information System (INIS)

Love, A.H.; Hunt, J.R.; Vogel, J.S.; Knezovich, J.P.

2004-01-01

Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were 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. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. (orig.)

Installation of a tandem-type accelerator mass spectrometer

International Nuclear Information System (INIS)

Mizushima, Toshihiko; Togawa, Orihiko; Mizutani, Yoshihiko; Yamamoto, Tadatoshi

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 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 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)

Improving tritium exposure reconstructions using accelerator mass spectrometry

Science.gov (United States)

Hunt, J. R.; Vogel, J. S.; Knezovich, J. P.

2010-01-01

Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were 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. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. PMID:14735274

Parallel reconstruction in accelerated multivoxel MR spectroscopy

NARCIS (Netherlands)

Boer, V. O.; Klomp, D. W. J.; Laterra, J.; Barker, P. B.

PurposeTo develop the simultaneous acquisition of multiple voxels in localized MR spectroscopy (MRS) using sensitivity encoding, allowing reduced total scan time compared to conventional sequential single voxel (SV) acquisition methods. MethodsDual volume localization was used to simultaneously

ANALYSIS OF IMPACT OF CHANGING THE SHOCK ABSORBER RESISTANCE FACTOR ON ACCELERATING THE VEHICLE SPRUNG MASS

Directory of Open Access Journals (Sweden)

P. Rozhkov

2017-12-01

Full Text Available The change of acceleration of the vehicle sprung mass while changing the coefficient of resistance of the adaptive pendant shock absorber has been analyzed. Presentation of disturbing influence is taken as a harmonic function containing the initial phase. Solution of the system of differential equations is carried out taking into account the initial conditions. The mathematical modeling of the impact of the vehicle sprung mass vibrations at various moments of time of forming the actuating signal on the change of the coefficient of resistance allowed to formulate requirements to the system of adaptive suspension control.

Joint Bratislava–Prague studies of radiocarbon and uranium in the environment using accelerator mass spectrometry and radiometric methods

Czech Academy of Sciences Publication Activity Database

Povinec, P. P.; Světlík, Ivo; Ješkovský, M.; Sivo, A.; John, J.; Špendlíková, I.; Němec, M.; Kučera, Jan; Richtáriková, M.; Breier, R.; Fejgl, Michal; Černý, Radek

2015-01-01

Roč. 304, č. 1 (2015), s. 67-73 ISSN 0236-5731 Institutional support: RVO:61389005 Keywords : Accelerator mass spectrometry * Atmosphere * Environmental radioactivity * Radiocarbon * Tree rings * Uranium Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.983, year: 2015

Improved detection limit for {sup 59}Ni using the technique of accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Persson, Per; Erlandsson, Bengt; Hellborg, Ragnar; Kiisk, Madis; Larsson, Ragnar; Skog, Goeran; Stenstroem, Kristina [Lund Univ. (Sweden). Dept. of Nuclear Physics

2002-11-01

59 Ni is produced by neutron activation in the stainless steel close to the core of a nuclear reactor. To be able to classify the different parts of the reactor with respect to their content of long-lived radionuclides before final storage it is important to measure the 59 Ni level. Accelerator mass spectrometry is an ultra-sensitive method for counting atoms, suitable for 59 Ni measurements. Improvements in the reduction of the background and in the chemical reduction of cobalt, the interfering isobar, have been made. This chemical purification is essential when using small tandem accelerators, <3 MV, combined with the detection of characteristic projectile X-rays. These improvements have lowered the detection limit for 59 Ni by a factor of twenty compared with the first value reported for the Lund AMS facility. Material from the Swedish nuclear industry has been analysed and examples of the results are presented.

Accelerated ice-sheet mass loss in Antarctica from 18-year satellite laser ranging measurements

Directory of Open Access Journals (Sweden)

Shuanggen Jin

2016-02-01

Full Text Available Accurate estimate of the ice-sheet mass balance in Antarctic is very difficult due to complex ice sheet condition and sparse in situ measurements. In this paper, the low-degree gravity field coefficients of up to degree and order 5 derived from Satellite Laser Ranging (SLR measurements are used to determine the ice mass variations in Antarctica for the period 1993–2011. Results show that the ice mass is losing with -36±13 Gt/y in Antarctica, -42±11 Gt/y in the West Antarctica and 6±10 Gt/y in the East Antarctica from 1993 to 2011. The ice mass variations from the SLR 5×5 have a good agreement with the GRACE 5×5, GRACE 5×5 (1&2 and GRACE (60×60 for the entire continent since 2003, but degree 5 from SLR is not sufficient to quantify ice losses in West and East Antarctica, respectively. The rate of ice loss in Antarctica is -28±17 Gt/y for 1993-2002 and -55±17 Gt/y for 2003-2011, indicating significant accelerated ice mass losses since 2003. Furthermore, the results from SLR are comparable with GRACE measurements.

Annual report of the Tandem Accelerator Center, University of Tsukuba. April 1, 1995 - March 31, 1996

International Nuclear Information System (INIS)

1996-10-01

This annual report includes the research activities from April, 1995 to March, 1996. The 12 UD Pelletron tandem accelerator has been operated successfully to provide sufficient beam time for experiments. The stable operation of the accelerator brought out steady advances in many investigations continued as long range projects. Those are polarization phenomena in nuclear reactions, the nonresonant breakup of Li-7, further refinement of continuum discretized coupled channels theory, fusion and fission in heavy ion reactions, nuclear structure physics by means of in-beam γ ray spectroscopy, solid state physics using fast ion beams, Moessbauer effect, NMR, and the application of accelerated ion beams to PIXE and accelerator mass spectrometry. As the new developments of experimental instruments, an ion source for micro-cluster beams and a pulsing system for low velocity cluster ions have been successfully constructed. A beam line producing proton micro-beam has been constructed. In this report, the accelerator and experimental facilities, the experiments and theories of nuclear physics, atomic and solid state physics, ion beam applications, publications, theses and seminars, and personnel are reported. (K.I.)

Physicochemical effects of cosmic rays in solids: analyses by mass spectrometry and by infrared spectroscopy

International Nuclear Information System (INIS)

Silveira, Enio F. da

2012-01-01

Full text: Cosmic Rays (CR) are studied since their discovery by Victor Hess in the years 1911-1913. Interestingly, the beginning of research in Physics in Brazil started with experiments on CR. B. Gross (INT/ Rio), G. Wataghin and G. Occhialini (USP) started their investigation on CR in 1934. F.X. Roser, the founder of the Physics Institute of PUC-Rio, worked with Hess when he got the Nobel Prize in 1936. C. Lattes got in 1947 the experimental data in Chacaltaya that conducted to the discovery of the meson pi (C. Powell, Nobel Prize in 1950). Nowadays, the Auger Project deals with extremely high energy extragalactic particles. Except for these ones, the origin, the energy and mass distributions of CR constituents and their capability of producing elementary particles are well known. Nevertheless, there is an enormous lack of information on the effects caused by the CR on inorganic and biological materials. This motivates measurements of relevant physicochemical data, such as sputtering yields, cross sections for inducing chemical reactions and crystalline structure parameters. A fascinating question about CR is if they are/were the responsible for the transformation of inorganic into organic material, synthesizing therefore pre-biotic molecules in whole Universe. Nuclear Physics instrumentation is well suited to answer this question, providing ion sources and ion accelerators from keV to GeV. Time-of-flight mass spectrometry and FTIR infrared spectroscopy are techniques able to monitor the physicochemical modifications induced by the RC beam analogs. Data obtained in the GANIL (France) and Van de Graaff (PUC-Rio) accelerators are presented. Abundant inorganic molecular species in space, such as H 2 O, CO, CO 2 and NH 3 , are condensed in laboratory and bombarded by H to Fe ions, from 10 -3 to 10 3 MeV/u, covering the CR range. New chemical species are identified; sputtering yields (Y), formation (σf ) and destruction (σd) cross sections are measured. An

Performance optimisation of a new-generation orthogonal-acceleration quadrupole-time-of-flight mass spectrometer.

Science.gov (United States)

Bristow, Tony; Constantine, Jill; Harrison, Mark; Cavoit, Fabien

2008-04-01

Orthogonal-acceleration quadrupole time-of-flight (oa-QTOF) mass spectrometers, employed for accurate mass measurement, have been commercially available for well over a decade. A limitation of the early instruments of this type was the narrow ion abundance range over which accurate mass measurements could be made with a high degree of certainty. Recently, a new generation of oa-QTOF mass spectrometers has been developed and these allow accurate mass measurements to be recorded over a much greater range of ion abundances. This development has resulted from new ion detection technology and improved electronic stability or by accurate control of the number of ions reaching the detector. In this report we describe the results from experiments performed to evaluate the mass measurement performance of the Bruker micrOTOF-Q, a member of the new-generation oa-QTOFs. The relationship between mass accuracy and ion abundance has been extensively evaluated and mass measurement accuracy remained stable (+/-1.5 m m/z units) over approximately 3-4 orders of magnitude of ion abundance. The second feature of the Bruker micrOTOF-Q that was evaluated was the SigmaFit function of the software. This isotope pattern-matching algorithm provides an exact numerical comparison of the theoretical and measured isotope patterns as an additional identification tool to accurate mass measurement. The smaller the value, the closer the match between theoretical and measured isotope patterns. This information is then employed to reduce the number of potential elemental formulae produced from the mass measurements. A relationship between the SigmaFit value and ion abundance has been established. The results from the study for both mass accuracy and SigmaFit were employed to define the performance criteria for the micrOTOF-Q. This provided increased confidence in the selection of elemental formulae resulting from accurate mass measurements.

Positron annihilation induced Auger electron spectroscopy and its implementation at accelerator based low energy positron factories

International Nuclear Information System (INIS)

Weiss, A.; Koeymen, A.R.; Mehl, D.; Lee, K.H.; Yang Gimo; Jensen, K.

1991-01-01

Positron annihilation induced auger electron spectroscopy (PAES) makes use of a beam of low energy positrons to excite Auger transitions by annihilating core electrons. The large secondary electron background usually present in Auger spectra can be eliminated by setting the positron beam energy well below the Auger electron energy. This allows true Auger lineshapes to be obtained. Further, because the positron is localized just outside the surface before it annihilates, PAES is extremely sensitive to the topmost atomic layer. Recent PAES results obtained at the University of Texas at Arlington will be presented. In addition, the use of high resolution energy analyzers with multichannel particle detection schemes to prevent problems due to the high data rates associated with accelerator based positron beams will be discussed. (orig.)

Accelerator development

International Nuclear Information System (INIS)

Anon.

1975-01-01

Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

Using accelerator mass spectrometry for radiocarbon dating of textiles

International Nuclear Information System (INIS)

Jull, A.J.T.

1997-01-01

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, 14 C in lunar samples by galactic and solar cosmic rays, studies of in situ 14 C produced by cosmic ray spallation in rocks and ice, and studies of 14 C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS 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

Mass acceleration in a multi-module plasma jet for impact fusion. Final report, 31 July 1985-30 July 1986

International Nuclear Information System (INIS)

Burton, R.L.; Goldstein, S.A.; Tidman, D.A.; Wang, S.Y.; Winsor, N.K.; Witherspoon, F.D.

1986-08-01

Successful development of a mass accelerator for impact fusion requires successful development of its components. The Advanced Impluse Module (AIM) is now operational, and is presently being used to povide a structured armature for electromagnetic gun experiments. Metals materials have been identified for the accelerator bore, and their limits identified and tested. A side-mounted, removable projectile detector and its circuitry has been developed. The next step is to use these components to achieve significantly higher velocities than have been achieved by our previous technology

Comparison between proton transfer reaction mass spectrometry and near infrared spectroscopy for the authentication of Brazilian coffee

NARCIS (Netherlands)

Monteiro, Pablo Inocêncio; Santos, Jânio Sousa; Alvarenga Brizola, Vitor Rafael; Pasini Deolindo, Carolina Turnes; Koot, Alex; Boerrigter-Eenling, Rita; Ruth, van Saskia; Georgouli, Konstantia; Koidis, Anastasios; Granato, Daniel

2018-01-01

In this study, proton-transfer reaction mass spectrometry (PTR-MS) and near-infrared spectroscopy (NIRS) were compared for the authentication of geographical and farming system origins of Brazilian coffees. For this purpose, n = 19 organic (ORG) and n = 26 conventional (CONV) coffees from

Making Mass Spectrometry See the Light: The Promises and Challenges of Cryogenic Infrared Ion Spectroscopy as a Bioanalytical Technique.

Science.gov (United States)

Cismesia, Adam P; Bailey, Laura S; Bell, Matthew R; Tesler, Larry F; Polfer, Nicolas C

2016-05-01

The detailed chemical information contained in the vibrational spectrum of a cryogenically cooled analyte ion would, in principle, make infrared (IR) ion spectroscopy a gold standard technique for molecular identification in mass spectrometry. Despite this immense potential, there are considerable challenges in both instrumentation and methodology to overcome before the technique is analytically useful. Here, we discuss the promise of IR ion spectroscopy for small molecule analysis in the context of metabolite identification. Experimental strategies to address sensitivity constraints, poor overall duty cycle, and speed of the experiment are intimately tied to the development of a mass-selective cryogenic trap. Therefore, the most likely avenues for success, in the authors' opinion, are presented here, alongside alternative approaches and some thoughts on data interpretation.

Study of water mass transfer dynamics in frescoes by dielectric spectroscopy

International Nuclear Information System (INIS)

Olmi, R.; Riminesi, C.

2008-01-01

The knowledge of moisture content (M C) is essential for determining the state of preservation of various types of hand-work: from building materials such as bricks and concrete, to objects of artistic value, in particular frescoes and mural paintings. In all above, moisture is the primary source of damages, as it affects the durability of porous materials. Dielectric properties of porous materials are strongly affected by the presence of water, suggesting dielectric spectroscopy as a suitable non-invasive diagnostic technique. The development of a quantitative relationship between M C and permittivity requires to investigate the dynamics of water mass transfer in porous media, and to determine its effect on the dielectric properties. In this paper a coupled mass transfer/dielectric problem is introduced and solved numerically, based on a finite element model. Results are compared to experimental dielectric measurements performed on plaster samples by the open coaxial method. The application of the dielectric technique to frescoes monitoring is proposed, showing the results obtained is an on-site study.

Annual report of the Tandem Accelerator Center, University of Tsukuba. April 1, 1994 - March 31, 1995

International Nuclear Information System (INIS)

1995-10-01

During the period from April 1994 to March 1995, the tandem accelerator was operated successfully to provide sufficient beam time for experiments. The following research activities are described in this annual report: 1)nuclear reaction studies aiming at the (p, n) threshold effect on the elastic scattering of protons on light nuclei, the measurement of the cross section of non-resonant breakup of 7 Li, the establishment of a new analyzing-power standard by the 12 C(d vector, p) 13 C reaction and the evaluation of the fission time scale for a hot compound nucleus; 2)nuclear structure physics by means of in-beam γ ray spectroscopy; 3)theoretical studies on nuclear collective motions and the structure of odd-odd nuclei; 4)radiation effects of low energy deuterons in silicon; 5)dynamics of collisions between heavy ions and C 60 clusters; 6)detailed investigation of the lattice disorder and some other properties of the surface of solid by ion-induced secondary electron spectroscopy; 7)the migration mechanism of self interstitial atoms by the measurement of internal friction for W specimens after the proton bombardment at low temperature; 8)Moessbauer studies on Fe/MgF 2 thin films; 9)the mechanism of phase transition and electron transport phenomena by NMR method; 10)elemental analyses by PIXE, ion luminescence and Rutherford back scattering; 11)tests of 14 C measurement for geophysical samples by accelerator mass spectrometry. In addition to these research works, the constructions of the ion source dedicated to the accelerator mass spectrometry and the irradiation system for PIXE with beams of submillimeter size have been continued as new technical developments. (J.P.N.)

Application of accelerator mass spectrometry on Environmental studies concerning ages of holocene fires in Central amazon forest

International Nuclear Information System (INIS)

Santos, G.M.; Gomes, P. R. S.; Anjos, R. M.; Lubian, J.; Cordeiro, R.C.; Turcq, B.; Sifeddine, A.; Di Tada, M.; Cresswell, R. G.; Fifield, L. K.

1999-01-01

The Accelerator Mass Spectrometry (AMS) technique was used to determine the radiocarbon age of Holocene fires in forests of the Amazon Region. Most of the ages were found to be within the 1000-1500 years range. These disturbances were probably caused by climatic anomalies, and they have modified the structure and dynamics of the region vegetation

Chemical separation of plutonium from air filters and preparation of filaments for resonance ionization mass spectroscopy

International Nuclear Information System (INIS)

Eberhardt, K.; Erdmann, N.; Funk, H.; Herrmann, G.; Naehler, A.; Passler, G.; Trautmann, N.; Urban, F.

1995-01-01

Resonance ionization mass spectroscopy (RIMS) is used for the determination of plutonium in environmental samples. A chemical procedure based on an ion-exchange technique for the separation of plutonium from a polycarbonate filter is described. The overall yield is about 60% as determined by α-particle spectroscopy. A technique for the subsequent preparation of samples for RIMS measurements is developed. Plutonium is electrode-posited as hydroxide and covered with a thin metallic layer. While heating such a sandwich filament the plutonium hydroxide is reduced to the metal and an atomic beam is evaporated from the surface, as required for RIMS. copyright American Institute of Physics 1995

Detection of 59Ni by accelerator mass spectrometry

International Nuclear Information System (INIS)

Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K.; Larsson, Ragnar; Skog, G.

1999-02-01

The aims of this project were to develop a method to measure the amount of 59 Ni in stainless steel and to determine the detection limit for this method. 59 Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of 59 Ni present as it governs the classification of the waste. If the amount of 59 Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of 59 Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of 59 Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for 59 Ni has been determined to 100±30 Bq per gram nickel (100±30 Bq/g) with the present status of the system

Development and data analysis of a position detector for AE$\\bar{g}$IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy)

CERN Document Server

Gligorova, Angela; Doser, Michael; Pacifico, Nicola

2015-03-13

AE$\\mathrm{\\bar{g}}$IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an antimatter experiment based at CERN, the European Organization for Nuclear Research, whose goal is to carry out the first direct measurement of the Earth’s gravitational acceleration on antimatter. The outcome of such measurement would be the first precision test of the Weak Equivalence Principle in a completely new area. According to WEP, all bodies fall with the same acceleration regardless of their mass and composition. AE$\\mathrm{\\bar{g}}$IS will attempt to achieve its aim by measuring the gravitational acceleration ($\\bar{g}$) for antihydrogen with 1$\\%$ relative precision. The first step towards the final goal is the formation of a pulsed, cold antihydrogen beam, which will be performed by a charge exchange reaction between laser excited (Rydberg) positronium and cold (100 mK) antiprotons. The antihydrogen atoms will be accelerated by an inhomogeneous electric field (Stark acceleration) to form a beam whose fr...

Nuclear spectroscopy with lithium ions

International Nuclear Information System (INIS)

Heiser, C.

1977-02-01

A survey of the state of nuclear spectroscopy with lithium ions is given. Proceeding from the physical and nuclear properties the specific topics arising by the acceleration of these ions are discussed. The results obtained from measurements of excitation functions of different lithium reactions, particularly of compound reactions, with several target nuclei are summarized. Besides compound reactions direct reactions are important, especially transfer reactions, elastic and inelastic scattering and exchange reactions. The results on high spin states obtained by in-beam gamma-spectroscopy are discussed in detail. Finally the possibilities are considered for accelerating lithium ions in the cyclotron U-120 and in the tandem generator EGP-10 of the ZfK. (author)

Feasibility studies of RFQ based 14C accelerator mass spectrometry

International Nuclear Information System (INIS)

Guo Zhiyu; Liu Kexin; Yan Xueqing; Xie Yi; Fang Jiaxun; Chen Jiaer

2007-01-01

Electrostatic accelerators with terminal voltage less than 1 MeV have been successfully used for 14 C AMS. This contribution shows that a small RFQ accelerator may also be suitable for AMS 14 C measurements. A well-designed RFQ accelerator can realize a low energy spread and high isotopic selection with a length of less than 1 m and reasonable power consumption. Compared with small tandem accelerators, a RFQ does not need isolation gas and can accept much higher beam currents. Its stripper would be at ground potential and there would be no further acceleration after stripping, so the background from charge exchange processes should be lower. The RFQ design and system are described

Microelectromechanical acceleration-sensing apparatus

Science.gov (United States)

Lee, Robb M [Albuquerque, NM; Shul, Randy J [Albuquerque, NM; Polosky, Marc A [Albuquerque, NM; Hoke, Darren A [Albuquerque, NM; Vernon, George E [Rio Rancho, NM

2006-12-12

An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

Center of Mass Acceleration Feedback Control of Standing Balance by Functional Neuromuscular Stimulation against External Postural Perturbations

Science.gov (United States)

Nataraj, Raviraj; Audu, Musa L.; Triolo, Ronald J.

2013-01-01

This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation (FNS) control system to restore standing function to a subject with complete, thoracic-level spinal cord injury (SCI). The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (> 89% variance explained) using three-dimensional (3-D) outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living. PMID:22987499

Dating of some fossil Romanian bones by accelerator mass spectrometry

International Nuclear Information System (INIS)

Olariu, Agata; Skog, Goeran; Emilian Alexandrescu; Hellborg, Ragnar; Stenstroem, Krstina; Faarinen, Mikko; Persson, Per

2002-01-01

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)

Design of the hydraulic shock absorbers characteristics using the acceleration of the sprung mass

Directory of Open Access Journals (Sweden)

Polach P.

2007-10-01

Full Text Available The force-velocity characteristics of the air-pressure-controlled shock absorbers produced in BRANO a.s. were designed on the basis of the relative deflections of the air springs. These characteristics are verified by means of another approach – the acceleration of the sprung mass criterion. The reference vehicle is the same as in the previous case – the SOR C 12 intercity bus. The bus multibody models created in the alaska simulation tool are used for the designed characteristics verification. The results of both approaches are compared.

Applying the accelerator

Energy Technology Data Exchange (ETDEWEB)

Barbalat, Oscar

1989-12-15

Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology.

Applying the accelerator

International Nuclear Information System (INIS)

Barbalat, Oscar

1989-01-01

Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology

Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom.

Science.gov (United States)

Barker, J; Garner, R C

1999-01-01

Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology

Annual report of the Tandem Accelerator Center, University of Tsukuba. April 1, 1996 - March 31, 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

The 12 UD Pelletron tandem accelerator has been operated successfully from April, 1996 to January, 1997. Although the operation of the accelerator became unstable in the middle of January, it was a short period. The research in the Tandem Accelerator Center covers wide fields, that is, polarization phenomena in nuclear reactions, the nonresonant breakup of Li-7, the further refinement of the CDCC theory, fusion and fission in heavy ion reactions, nuclear structure physics by means of in-beam {gamma} ray spectroscopy, solid state physics using fast ion bemas, Moessbauer effect, NMR, the application of accelerated ion beams to PIXE, and accelerator mass spectrometry. In addition, two major installations were carried out in this academic year. One is a small tandem accelerator which was moved from Electrotechnical Laboratory in Tsukuba, and the other is a system for the production and analysis of atomic clusters. The research activities at the accelerator and experimental facilities and on experimental nuclear physics, theoretical nuclear physics, atomic and solid state physics, cluster science, and ion beam application are reported in this book. Also the list of the publications by these groups is given. Ph. D. and M. Sc. theses are listed, and the speakers and the titles of seminars are reported. (K.I.)

Annual report of the Tandem Accelerator Center, University of Tsukuba. April 1, 1996 - March 31, 1997

International Nuclear Information System (INIS)

1997-06-01

The 12 UD Pelletron tandem accelerator has been operated successfully from April, 1996 to January, 1997. Although the operation of the accelerator became unstable in the middle of January, it was a short period. The research in the Tandem Accelerator Center covers wide fields, that is, polarization phenomena in nuclear reactions, the nonresonant breakup of Li-7, the further refinement of the CDCC theory, fusion and fission in heavy ion reactions, nuclear structure physics by means of in-beam γ ray spectroscopy, solid state physics using fast ion bemas, Moessbauer effect, NMR, the application of accelerated ion beams to PIXE, and accelerator mass spectrometry. In addition, two major installations were carried out in this academic year. One is a small tandem accelerator which was moved from Electrotechnical Laboratory in Tsukuba, and the other is a system for the production and analysis of atomic clusters. The research activities at the accelerator and experimental facilities and on experimental nuclear physics, theoretical nuclear physics, atomic and solid state physics, cluster science, and ion beam application are reported in this book. Also the list of the publications by these groups is given. Ph. D. and M. Sc. theses are listed, and the speakers and the titles of seminars are reported. (K.I.)

Composition and mechanisms analysis of aromatic telechelic oligomers by mass spectroscopy; Analyse de la composition et de mecanismes de polymerisation d`oligomeres telecheliques aromatiques par spectrometrie de masse

Energy Technology Data Exchange (ETDEWEB)

Damerval, V.

1997-10-22

The aim of this work was to apply mass spectrometry, on the one hand to the characterization of telechelic oligo-imides with oxazoline and lactane end-caps and, on the other hand to the determination of the thermal reticulation mechanism of nadimides. First bis-oxazoline and buslactane end-capped, oligomers used to form blocks copolymers were studied by liquid secondary ion mass spectroscopy (LSIMS) and Matrix-assisted laser desorption ionization time of flight spectroscopy (MALDI-TOF). An acetamide end-cap by-product was detected. Then the analysis was modified to avoid the formation of this by-product which was unable to copolymerize. Secondly, to circumvent the experimental difficulties related to crosslinked networks, the study of the thermal polymerization of nadimides was performed ones (LSIMS, electroscopy, MALDI-TOF) led to the determination of the polynadimide structure. Thanks to MS/MS studies the nature of the linkages and the structure of the end-caps were established. Finally, this work evidenced the opportunity to use mass spectrometry to analyze synthetic polymers. (author) 222 refs.

[Discussion on diagenesis of Xilingang pluton-constrained by X-ray Fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy].

Science.gov (United States)

Tang, Yu-Kun; Chen, Guo-Neng; Zhang, Ke; Huang, Hai-Hua

2013-05-01

The results on Xilingang pluton, mainly consisting of red beds, granites containing numerous debris of red beds and granites, obtained by X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy show: (1) Xilingang pluton from red beds, granites containing numerous debris of red beds to granites has obvious characteristics of decreasing silicon and alkali content, and rising ignition loss, dark mineral content and oxidation index; (2) Chondrite-normalized REE distribution curves and primitive mantle-normalized spider diagram for trace elements of redbed, granites containing numerous debris of red beds and granites have a good consistency, the distribution characteristics of elements are similar to Nanling transformation-type granite; (3) The value of Raman spectrogram characteristic peak of quartz crystal in Xilingang granite decreased from the center of quartz crystal, and FWHM is steady. According to the above, the authors believe that Xilingang granite formed was related to in-situ melting of red beds and underlying strata and magma consolidation. Volatile components were discharged continuously, and oxidation index decreased gradually in the melting process. In the process of diagenesis, the top of pluton tend to be an ongoing silicon and alkali increase, while TFeO and MgO continue to migrate to bottom, and crystallization environment is a relatively closed and steady system.

Discretization of space and time: mass-energy relation, accelerating expansion of the Universe, Hubble constant

OpenAIRE

Roatta , Luca

2017-01-01

Assuming that space and time can only have discrete values, we obtain the expression of the gravitational potential energy that at large distance coincides with the Newtonian. In very precise circumstances it coincides with the relativistic mass-energy relation: this shows that the Universe is a black hole in which all bodies are subjected to an acceleration toward the border of the Universe itself. Since the Universe is a black hole with a fixed radius, we can obtain the density of the Unive...

Determination of the antiproton-to-electron mass ratio by precision laser spectroscopy of $\\overline{p}He^{+}$

CERN Document Server

Hori, M; Eades, John; Gomikawa, K; Hayano, R S; Ono, N; Pirkl, Werner; Widmann, E; Torii, H A; Juhász, B; Barna, D; Horváth, D

2006-01-01

A femtosecond optical frequency comb and continuous-wave pulse- amplified laser were used to measure 12 transition frequencies of antiprotonic helium to fractional precisions of (9-16) 10/sup -9lifetimes hitherto unaccessible to our precision laser spectroscopy method. Comparisons with three-body QED calculations yielded an antiproton-to-electron mass ratio of M/sub pmacron//m/sub e/=1836.152 674(5).

Tandem Accelerator Laboratory annual report 1979

International Nuclear Information System (INIS)

Xenoulis, A.C.

1980-01-01

The activities presented cover the following topics: heavy ion reactions, gamma ray spectroscopy, applied atomic and nuclear physics, theoretical nuclear physics, data collection and processing, accelerator operation, as well as personnel and publications. (T.A.)

Tandem Accelerator Laboratory annual report 1978

International Nuclear Information System (INIS)

1979-01-01

The activities presented cover the following topics: heavy ion reactions, gamma ray spectroscopy, applied atomic and nuclear physics, theoretical nuclear physics, data collection and processing, accelerator operation, as well as personnel and publications. (T.A.)

Baryon spectroscopy at KAON

Energy Technology Data Exchange (ETDEWEB)

Comyn, Martin

1992-07-01

The unique opportunities for the study of baryon spectroscopy at the TRIUMF KAON Factory are outlined. Related issues in other areas of hadron spectroscopy are discussed. The complex of accelerators that comprise the TRIUMF KAON Factory, and the properties of the separated beams that will be available to experimenters, are described. Initial design considerations for detectors to be used in the study of hadron spectroscopy are presented, along with a proposed detector configuration. The progress towards realization of the TRIUMF KAON Factory is examined, and the timetable for the determination of the initial experimental programme and facilities is explained. 23 refs., 4 figs., 5 tabs.

Tandem Accelerator Laboratory annual report 1980

International Nuclear Information System (INIS)

Anagnostatos, G.S.

1981-01-01

The activities presented cover the following topics: heavy ion reactions, gamma ray spectroscopy, applied atomic and nuclear physics, theoretical nuclear physics, data collection and processing development, accelerator operation, as well as personnel and publications. (T.A.)

Human folate metabolism using 14C-accelerator mass spectrometry

International Nuclear Information System (INIS)

Arjomand, A; Bucholz, B A; Clifford, A J; Duecker, S R; Johnson, H; Schneider, P D; Zulim, R A.

1999-01-01

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

Fast parallel tandem mass spectral library searching using GPU hardware acceleration.

Science.gov (United States)

Baumgardner, Lydia Ashleigh; Shanmugam, Avinash Kumar; Lam, Henry; Eng, Jimmy K; Martin, Daniel B

2011-06-03

Mass spectrometry-based proteomics is a maturing discipline of biologic research that is experiencing substantial growth. Instrumentation has steadily improved over time with the advent of faster and more sensitive instruments collecting ever larger data files. Consequently, the computational process of matching a peptide fragmentation pattern to its sequence, traditionally accomplished by sequence database searching and more recently also by spectral library searching, has become a bottleneck in many mass spectrometry experiments. In both of these methods, the main rate-limiting step is the comparison of an acquired spectrum with all potential matches from a spectral library or sequence database. This is a highly parallelizable process because the core computational element can be represented as a simple but arithmetically intense multiplication of two vectors. In this paper, we present a proof of concept project taking advantage of the massively parallel computing available on graphics processing units (GPUs) to distribute and accelerate the process of spectral assignment using spectral library searching. This program, which we have named FastPaSS (for Fast Parallelized Spectral Searching), is implemented in CUDA (Compute Unified Device Architecture) from NVIDIA, which allows direct access to the processors in an NVIDIA GPU. Our efforts demonstrate the feasibility of GPU computing for spectral assignment, through implementation of the validated spectral searching algorithm SpectraST in the CUDA environment.

Photoelectron photoion molecular beam spectroscopy

International Nuclear Information System (INIS)

Trevor, D.J.

1980-12-01

The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed

Enhancing sample preparation capabilities for accelerator mass spectrometry radiocarbon and radiocalcium studies

International Nuclear Information System (INIS)

Taylor, R.E.

1991-01-01

With support provided by the LLNL Accelerator Mass Spectrometry Laboratory, the UCR Radiocarbon Laboratory continued its studies involving sample pretreatment and target preparation for both AMS radiocarbon ( 14 C) and radiocalcium ( 41 Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS 14 C-related studies, we have extended the development of a series of procedures which have, as their initial goal, the capability to combust several hundred microgram amounts of a chemically-pretreated organic sample and convert the resultant CO 2 to graphitic carbon which will consistently yield relatively high 13 C - ion currents and blanks which will yield, on a consistent basis, 14 C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP

Label-assisted mass spectrometry for the acceleration of reaction discovery and optimization

Science.gov (United States)

Cabrera-Pardo, Jaime R.; Chai, David I.; Liu, Song; Mrksich, Milan; Kozmin, Sergey A.

2013-05-01

The identification of new reactions expands our knowledge of chemical reactivity and enables new synthetic applications. Accelerating the pace of this discovery process remains challenging. We describe a highly effective and simple platform for screening a large number of potential chemical reactions in order to discover and optimize previously unknown catalytic transformations, thereby revealing new chemical reactivity. Our strategy is based on labelling one of the reactants with a polyaromatic chemical tag, which selectively undergoes a photoionization/desorption process upon laser irradiation, without the assistance of an external matrix, and enables rapid mass spectrometric detection of any products originating from such labelled reactants in complex reaction mixtures without any chromatographic separation. This method was successfully used for high-throughput discovery and subsequent optimization of two previously unknown benzannulation reactions.

Transition of Iodine Analysis to Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Watrous, Matthew George; Adamic, Mary Louise; Olson, John Eric; Baeck, D. L.; Fox, R. V.; Hahn, P. A.; Jenson, D. D.; Lister, T. E.

2015-01-01

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

Transition of Iodine Analysis to Accelerator Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

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

Accelerator mass spectrometry and the prehistoric occupation of the coast of rio de janeiro - brazil

International Nuclear Information System (INIS)

Damasio Macario, K.; Anjos, R.M.; Gomes, P.R.S.; Facure, A.D.; Elmore, M.; Coimbra, M.; Padron, I.; Najjar, R.; Kneip, L.; Lima, T.A.; Buarque, A.; Barbosa, M.; Seda, P.

2001-01-01

The Accelerator Mass Spectrometry (AMS) technique is a very attractive method for mass spectrometry, since it allows determination of concentrations with sensitivity down to 1 atom of isotope in 1015 atoms, using few milligrams samples. A Tandem accelerator is used as a magnetic and electrostatic analyzer. The determination of these extremely low concentrations of rare isotopes, accelerated to the MeV range, is measured by the direct counting of the atoms by nuclear detection techniques. The AMS technique has been implemented recently in Brazil, at the Pelletron 8UD Tandem accelerator (Sao Paulo), following many improvements on the ion source, VGM control, machine parameters control and detection system. In this contribution we report an important application on AMS on archaeological studies, performed at the Prime Lab (USA), on the dating of ceramics, bones, charcoals, nuts and shells samples of the of the coast of Rio de Janeiro. The main objective of this work is to improve the present knowledge on the occupation of Brazil by the Indians in the prehistoric period, studying archaeological sites located in Rio de Janeiro. Studies show that the Brazilian coast was first occupied in the beginning of the Holocene, with the settlements of the collectors of mollusk, builders of shell mounds, called S ambaquis . The word is of Tupi etymology, tamba meaning shellfish and ki to pile up. The Tupi were a horticultural/potter group who used to live on the Brazilian coast at the time of the European arrivals; they coined the term that describes the main characteristic of the sites - the accumulation of great quantities of mollusk shells. One of objectives of this research is to understand those societies functioning structure, spatial ordering, interaction in the environment and their transformation processes, from the study of their remains. It is intended to analyze the region occupation process dynamics and search for possible links between the pre-pottery population socio

Investigation of the spectroscopy and relaxation dynamics of benzaldehyde using molecular orbital calculations and laser ionization time-of-flight mass spectroscopy

Science.gov (United States)

da Silva, Maria Cristina Rodrigues

1998-11-01

Molecular orbital methods and laser ionization mass spectrometry measurements are used to investigate the spectroscopy and relaxation dynamics of benzaldehyde following excitation to its S2(/pi/pi/sp/*) state. Energies, equilibrium geometries and vibrational frequencies of ground and low-lying excited states of benzaldehyde neutral and cation determined by ab initio calculations provide a theoretical description of the electronic spectroscopy of benzaldehyde and of the changes occurring on excitation and ionization. The S2(/pi/pi/sp/*)[/gets]S0 excitation spectrum of jet-cooled benzaldehyde acquired using two-color laser ionization mass spectrometry techniques is interpreted with the aid of these calculations. The spectrum is dominated by the origin band and by transitions involving some of the ring modes consistent with the results of the molecular orbital calculations that indicate that the major geometric changes on excitation to S2 are located in the aromatic ring. Ten fundamental vibrations of the S2(/pi/pi/sp/*) state are assigned. The dissociation dynamics of benzaldehyde into benzene and carbon monoxide following excitation to its S2(/pi/pi/sp/*) state are investigated under jet- cooled conditions by two-color laser ionization mass spectrometry using a pump-probe technique. This experimental arrangement allows monitoring the benzaldehyde reactant and the benzene product ion signals as a function of the time delay between the excitation and ionization steps. A kinetic model is proposed to explain the observed biexponential decay of the benzaldehyde signal and the single exponential growth of the benzene product signal in terms of a sequential decay of two excited states of benzaldehyde, one of which leads to formation of benzene molecules in its lowest triplet state. Reactant disappearance and product appearance rates are determined for a number of vibronic transitions of the S2 state. They are found to increase with excitation energy without any indication

Interlaboratory study of the ion source memory effect in 36Cl accelerator mass spectrometry

International Nuclear Information System (INIS)

Pavetich, Stefan; Akhmadaliev, Shavkat; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Martschini, Martin; Merchel, Silke; Rugel, Georg; Steier, Peter

2014-01-01

Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of 36 Cl/Cl and 129 I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having 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, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural 35 Cl/ 37 Cl-ratio and samples highly-enriched in 35 Cl ( 35 Cl/ 37 Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion sources were widely spread between

Accelerator mass spectrometry researches at NIES-TERRA

International Nuclear Information System (INIS)

Shibata, Yasuyuki; Yoneda, Minoru; Tanaka, Atsushi; Uehiro, Takashi; Morita, Masatoshi; Uchida, Masao; Yoshinaga, Jun

2003-01-01

In the AMS facility at the National Institute for Environmental Studies (NIES-TERRA; Tandem accelerator for Environmental Research and Radiocarbon Analysis), several research programs have been proceeded, including a program, called GC-AMS, for the compound-specific 14 C analysis in environmental samples

High-throughput flow injection analysis mass spectroscopy with networked delivery of color-rendered results. 2. Three-dimensional spectral mapping of 96-well combinatorial chemistry racks.

Science.gov (United States)

Görlach, E; Richmond, R; Lewis, I

1998-08-01

For the last two years, the mass spectroscopy section of the Novartis Pharma Research Core Technology group has analyzed tens of thousands of multiple parallel synthesis samples from the Novartis Pharma Combinatorial Chemistry program, using an in-house developed automated high-throughput flow injection analysis electrospray ionization mass spectroscopy system. The electrospray spectra of these samples reflect the many structures present after the cleavage step from the solid support. The overall success of the sequential synthesis is mirrored in the purity of the expected end product, but the partial success of individual synthesis steps is evident in the impurities in the mass spectrum. However this latter reaction information, which is of considerable utility to the combinatorial chemist, is effectively hidden from view by the very large number of analyzed samples. This information is now revealed at the workbench of the combinatorial chemist by a novel three-dimensional display of each rack's complete mass spectral ion current using the in-house RackViewer Visual Basic application. Colorization of "forbidden loss" and "forbidden gas-adduct" zones, normalization to expected monoisotopic molecular weight, colorization of ionization intensity, and sorting by row or column were used in combination to highlight systematic patterns in the mass spectroscopy data.

Radiocarbon dating study of ancient iron artifacts with accelerator mass spectrometry

International Nuclear Information System (INIS)

Igaki, Kenzo; Nakamura, Toshio; Hirasawa, Masahiro; Kato, Masako; Sano, Masamichi.

1994-01-01

In order to study the correlation between the highly resistive property against corrosion and the production method of the ancient iron artifacts, it is essentially necessary to determine the accurate ages of them. 14 C dating with accelerator mass spectrometry was applied to the two ancient artifacts, a Japanese sword of wrought iron with a production age ranged from the Kamakura to the Muromachi period, estimation based on the fabrication technique, and a planning adze of cast iron with no definite origin. The former was dated as 880±150 y.B.P., corresponding to the calendar age ranged from AD 1021 to AD 1263, and the latter as 1720±160 y.B.P. with the calendar age ranged from AD 119 to AD 457 and from AD 483 to AD 508. These calibrated 14 C ages for both iron artifacts are consistent with the relevant ages conjectured by historical considerations. (author)

Prospects of real-time single-particle biological aerosol analysis: A comparison between laser-induced breakdown spectroscopy and aerosol time-of-flight mass spectrometry

International Nuclear Information System (INIS)

Beddows, D.C.S.; Telle, H.H.

2005-01-01

In this paper we discuss the prospects of real-time, in situ laser-induced breakdown spectroscopy applied for the identification and classification of bio-aerosols (including species of potential bio-hazard) within common urban aerosol mixtures. In particular, we address the issues associated with the picking out of bio-aerosols against common background aerosol particles, comparing laser-induced breakdown spectroscopy measurements with data from a mobile single-particle aerosol mass spectrometer (ATOFMS). The data from the latter provide statistical data over an extended period of time, highlighting the variation of the background composition. While single-particle bio-aerosols are detectable in principle, potential problems with small (∼ 1 μm size) bio-aerosols have been identified; constituents of the air mass other than background aerosols, e.g. gaseous CO 2 in conjunction with common background aerosols, may prevent unique recognition of the bio-particles. We discuss whether it is likely that laser-induced breakdown spectroscopy on its own can provide reliable, real-time identification of bio-aerosol in an urban environment, and it is suggested that more than one technique should be or would have to be used. A case for using a combination of laser-induced breakdown spectroscopy and Raman (and/or) laser-induced fluorescence spectroscopy is made

Acceleration of Gas Flow Simulations in Dual-Continuum Porous Media Based on the Mass-Conservation POD Method

KAUST Repository

Wang, Yi

2017-09-12

Reduced-order modeling approaches for gas flow in dual-porosity dual-permeability porous media are studied based on the proper orthogonal decomposition (POD) method combined with Galerkin projection. The typical modeling approach for non-porous-medium liquid flow problems is not appropriate for this compressible gas flow in a dual-continuum porous media. The reason is that non-zero mass transfer for the dual-continuum system can be generated artificially via the typical POD projection, violating the mass-conservation nature and causing the failure of the POD modeling. A new POD modeling approach is proposed considering the mass conservation of the whole matrix fracture system. Computation can be accelerated as much as 720 times with high precision (reconstruction errors as slow as 7.69 × 10−4%~3.87% for the matrix and 8.27 × 10−4%~2.84% for the fracture).

Acceleration of Gas Flow Simulations in Dual-Continuum Porous Media Based on the Mass-Conservation POD Method

KAUST Repository

Wang, Yi; Sun, Shuyu; Yu, Bo

2017-01-01

Reduced-order modeling approaches for gas flow in dual-porosity dual-permeability porous media are studied based on the proper orthogonal decomposition (POD) method combined with Galerkin projection. The typical modeling approach for non-porous-medium liquid flow problems is not appropriate for this compressible gas flow in a dual-continuum porous media. The reason is that non-zero mass transfer for the dual-continuum system can be generated artificially via the typical POD projection, violating the mass-conservation nature and causing the failure of the POD modeling. A new POD modeling approach is proposed considering the mass conservation of the whole matrix fracture system. Computation can be accelerated as much as 720 times with high precision (reconstruction errors as slow as 7.69 × 10−4%~3.87% for the matrix and 8.27 × 10−4%~2.84% for the fracture).

Effect of heating on the behaviors of hydrogen in C-TiC films with auger electron spectroscopy and secondary ion mass spectroscopy analyses

International Nuclear Information System (INIS)

Zou, Y.; Wang, L.W.; Huang, N.K.

2007-01-01

C-TiC films with a content of 75% TiC were prepared with magnetron sputtering deposition followed by Ar + ion bombardment. Effect of heating on the behaviors of hydrogen in C-TiC films before and after heating was studied with Auger Electron Spectroscopy and Secondary Ion Mass Spectroscopy (SIMS) analyses. SIMS depth profiles of hydrogen after H + ion implantation and thermal treatment show different hydrogen concentrations in C-TiC coatings and stainless steel. SIMS measurements show the existence of TiH, TiH 2 , CH 3 , CH 4 , C 2 H 2 bonds in the films after H + ion irradiation and the changes in the Ti LMM, Ti LMV and C KLL Auger line shape reveal that they have a good hydrogen retention ability after heating up to the temperature 393 K. All the results show that C-TiC coatings can be used as a hydrogen retainer or hydrogen permeable barrier on stainless steel to protect it from hydrogen brittleness

Results from the RACE [Ring ACceleration Experiment] Compact Torus Acceleration Experiment

International Nuclear Information System (INIS)

Hammer, J.H.; Hartman, C.W.; Eddleman, J.L.; Kusse, B.

1987-06-01

RACE (Ring ACceleration Experiment) is a proof-of-principle experiment aimed at demonstrating acceleration of magnetically confined compact torus plasma rings to directed kinetic energies well in excess of their magnetic and thermal energies. In the course of the first year of operation the following have been observed: successful formation of rings in the RACE geometry; acceleration of rings with large forces, F/sub accelerate/ ∼F/sub equilibrium/ without apparent degradation of the ring structure; peak velocities of ≅2.5 x 10 8 cm/sec; acceleration efficiency of >30% at speeds of 1.5 x 10 8 cm/sec inferred from trajectory and capacitor bank data; kinetic to magnetic energy ratios ∼10 were observed. Experiments in the near future will be aimed at confirmation of the mass/energy measurements by calorimetry and direct density measurements

RIKEN accelerator progress report, vol. 18

International Nuclear Information System (INIS)

Ambe, S.; Awaya, Y.; Gono, Y.; Inamura, T.; Kamitsubo, H.; Kitayama, S.; Odera, M.; Watanabe, T.; Yagi, E.

1985-06-01

The collaborative research using the 160 cm cyclotron and the variable frequency, heavy ion linear accelerator (RILAC) has been extensively performed in this year. In addition, an electrostatic accelerator (TANDETRON) of IMV and an ion implanter of 250 kV were dedicated to the collaborative research. During the past one year, the cyclotron was in good condition, and a new gas feed system was developed as the cyclotron ion source. The operation of the RILAC in a full 17 - 45 MHz range was realized. The TANDETRON has been steadily operated. The nuclear spectroscopy and reaction mechanism for heavy ion collision were studied. Instrument development was continued for the purpose of building the new experimental equipment for SSC. Experiments were carried out on the beam foil spectroscopy and atomic collision measuring ultra-violet ray, x-ray, Auger electrons and recoil ions. Moessbauer spectroscopy and perturbed angular correlation studies were continued. The creep and helium bubble formation in fusion reactor materials by bombarding with alpha particles and protons were studied in cooperation with the National Research Institute for Metals. The construction of the Riken Ring Cyclotron progressed. (Kako, I.)

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

Energy Technology Data Exchange (ETDEWEB)

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.

Virtual mass effects in two-phase flow. Topical report

International Nuclear Information System (INIS)

Cheng, L.Y.; Drew, D.A.; Lahey, R.T. Jr.

1978-03-01

The effect of virtual mass on phase separation during the acceleration of a two-phase mixture was studied. Virtual mass can be regarded as an induced inertia on the dispersed phase which is accelerating relative to the continuous phase, and it was found that the virtual mass acceleration is objective, implying an invariance with respect to reference frame. An objective form of the virtual acceleration was derived and required parameters were determined for limiting cases. Analyses determined that experiments on single bubble nozzle/diffuser flow cannot readily discriminate between various virtual mass acceleration models

Positron annihilation spectroscopy using high-energy photons

International Nuclear Information System (INIS)

Butterling, Maik; Jungmann, Marco; Krause-Rehberg, Reinhard; Krille, Arnold; Anwand, Wolfgang; Brauer, Gerhard; Cowan, Thomas E.; Hartmann, Andreas; Kosev, Krasimir; Schwengner, Ronald; Wagner, Andreas

2010-01-01

The superconducting electron accelerator ELBE (Electron Linac with high Brilliance and low Emittance) at the Research Centre Dresden-Rossendorf (Germany) serves as a high-intensity bremsstrahlung photon-source delivering a pulsed beam (26 MHz) with very short bunches (<5 ps). The photons are being converted into positrons by means of pair production inside the target material thus forming an intense positron source. The accelerator machine pulse is used as time reference allowing positron lifetime spectroscopy. We performed positron annihilation spectroscopy by pair production in different sample materials and used coincidence techniques to reduce the background due to scattered photons significantly in order resulting in spectra of extraordinary high quality. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Spectroscopy of multi-charged ions: a short review

International Nuclear Information System (INIS)

Berry, H.G.

1983-01-01

Recent and future applications of multiply charged ions to spectroscopy and atomic structure are discussed. The experimental techniques use either very fast ions produced in heavy ion accelerators, or slow ions produced directly both in electron beam ion sources and from collisions of fast accelerated ions. For the accelerated fast ions, spectroscopic measurements on using gas target excitation, solid foil excitation and laser excitation. In gas target excitation, both X-ray and electron spectroscopy have been applied to analyse atomic structures and secondary collision effects. Highlycharged secondary ions have also been trapped electro-magnetically for further similar studies in controlled conditions. Spectroscopic detection following solid foil interaction has led to atomic lifetime measurements, principally of metastable level, analysis of complex highly-ionized heavy ion spectra, and investigations of relativistic and QED effects in few electron ions

A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats.

Directory of Open Access Journals (Sweden)

Isabelle Savary-Auzeloux

Full Text Available Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months were subjected to unilateral hindlimb casting for 8 days (I0-I8 and then permitted to recover for 10 to 40 days (R10-R40. They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX (I0 to I8, AOX and leucine (AOX + LEU (I8 to R15 and LEU alone (R15 to R40. Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP and post absorptive (PA states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37% in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40 due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40 without difference in trypsin- and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states and could be a promising strategy to be tested during recovery from bed rest in humans.

Effects of rotation on MHD flow past an accelerated isothermal vertical plate with heat and mass diffusion

Directory of Open Access Journals (Sweden)

Muthucumaraswamy R.

2010-01-01

Full Text Available An exact analysis of rotation effects on unsteady flow of an incompressible and electrically conducting fluid past a uniformly accelerated infinite isothermal vertical plate, under the action of transversely applied magnetic field has been presented. The plate temperature is raised to Tw and the concentration level near the plate is also raised to C′w . The dimensionless governing equations are solved using Laplace-transform technique. The velocity profiles, temperature and concentration are studied for different physical parameters like thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that the velocity increases with increasing values of thermal Grashof number or mass Grashof number. It is also observed that the velocity increases with decreasing magnetic field parameter.

Development of heavy ion linear accelerators

International Nuclear Information System (INIS)

Bomko, V.A.; Khizhnyak, N.A.

1981-01-01

A review of the known heavy ion accelerators is given. It is stated that cyclic and linear accelerators are the most perspective ones in the energy range up to 10 MeV/nucleon according to universality in respect with the possibility of ion acceleration of the wide mass range. However, according to the accelerated beam intensity of the heavier ions the linear accelerators have considerable advantages over any other types of accelerators. The review of the known heavy ion linac structures permits to make the conclusion that a new modification of an accelerating structure of opposite pins excited on a H-wave is the most perspective one [ru

Secondary ion mass spectroscopy (SIMS)

International Nuclear Information System (INIS)

Naik, P.K.

1975-01-01

Secondary Ion Mass Spectrometry (SIMS) which is primarily a method for investigating the chemical composition of the uppermost atomic layer of solid surfaces is explained. In this method, the specimen is bombarded with a primary positive ion beam of small current density monolayer. Positive and negative ions sputtered from the specimen are mass analysed to give the surface chemical composition. The analytical system which consists of a primary ion source, a target manipulator and a mass spectrometer housed in an ultrahigh vacuum system is described. This method can also be used for profile measurements in thin films by using higher current densities of the primary ions. Fields of application such as surface reactions, semiconductors, thin films emission processes, chemistry, metallurgy are touched upon. Various aspects of this method such as the sputtering process, instrumentation, and applications are discussed. (K.B.)

Instruments for radiation measurement in life sciences (4). 7. Application of accelerator mass spectrometry for drug development. Human mass balance studies at discovery stage

International Nuclear Information System (INIS)

Miyaoka, Teiji

2005-01-01

Following the recent trend of Position Paper issued from European Agency for the Evaluation of Medicinal Products on the non-clinical safety studies to support clinical trials with a single micro dose, human mass balance studies at discovery stages were made with special interest in using AMS (accelerator mass spectrometry) with a small amount of hot (radioisotope-labeled) drug. This method was found to be effective for the purpose of screening in the clinical study for pharmaceutical development. To show an example of the test, 5, 50, 500μg/body of C14-ARA (α1A adrenoreceptor antagonist, 50 nCi or 1.85 kBq/body/dose) were given (cross over) to several persons to be inspected and C14-quantity in the blood plasma or urine was determined with AMS until after 168 hours or so. The results of the present experiment demonstrate that human mass balance study at discovery stages is possible with ultra high sensitive measuring systems such as AMS and PET (positron emission tomography). (S. Ohno)

A study for the fabulously of introducing an acceleration mass spectrometer facility (ABMs) for carbon-14 applications

International Nuclear Information System (INIS)

Aly, A.I.M.; Comsan, N.; Sadek, M.

2004-01-01

In this work a study was conducted to show the importance and feasibility of introducing an accelerating mass spectrometer facility for carbon-14 analysis in the environmental levels. The different applications of Carbon-14 (e.g. dating and identification of food additives of synthetic origin) are discussed. There are two methods for C- 14 measurements, beta decay counting and accelerator mass spectrometry (AMS). The beta decay method requires gram quantities of the sample carbon, compared to few milligram quantities in case of AMS method. The Central Lab. for Environmental Isotope Hydrology of the National Center for Nuclear Safety and Radiation Control has a Carbon-14 analysis facility based on beta decay counting using a liquid scintillation counter after sample preparation in the form of benzene through rather complicated chemical conversion steps. This strongly limits the capacity of the laboratory to about 100-150 samples per year. Also, the amount of sample required limits our expansion for some very important applications like dating of archaeological small samples and especially old bone samples which normally have a low concentration of organic compounds. These applications are only possible by using the AMS method. For some applications only AMS could be used e.g measuring C-14 in atmospheric gases such as methane and carbon dioxide is virtually impossible using decay counting but quite feasible with AMS. The importance of purchasing an AMS facility or upgrading the existing accelerator is discussed in view of the shortage of such a facility in Africa and the Middle East. Acquiring an AMS in Egypt will make it possible to accurately date the Egyptian antiquities and to act as a regional laboratory and to enter into new applications where the amount of sample is limiting

A new in-gas-laser ionization and spectroscopy laboratory for off-line studies at KU Leuven

International Nuclear Information System (INIS)

Kudryavtsev, Yu.; Creemers, P.; Ferrer, R.; Granados, C.; Gaffney, L.P.; Huyse, M.; Mogilevskiy, E.; Raeder, S.; Sels, S.; Van den Bergh, P.; Van Duppen, P.; Zadvornaya, A.

2016-01-01

The in-gas laser ionization and spectroscopy (IGLIS) technique is used to produce and to investigate short-lived radioactive isotopes at on-line ion beam facilities. In this technique, the nuclear reaction products recoiling out of a thin target are thermalized and neutralized in a high-pressure noble gas, resonantly ionized by the laser beams in a two-step process, and then extracted from the ion source to be finally accelerated and mass separated. Resonant ionization of radioactive species in the supersonic gas jet ensures very high spectral resolution because of essential reduction of broadening mechanisms. To obtain the maximum efficiency and the best spectral resolution, properties of the supersonic jet and the laser beams must be optimized. To perform these studies a new off-line IGLIS laboratory, including a new high-repetition-rate laser system and a dedicated off-line mass separator, has been commissioned. In this article, the specifications of the different components necessary to achieve optimum conditions in laser-spectroscopy studies of radioactive beams using IGLIS are discussed and the results of simulations are presented.

Comparing joint kinematics and center of mass acceleration as feedback for control of standing balance by functional neuromuscular stimulation.

Science.gov (United States)

Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

2012-05-06

The purpose of this study was to determine the comparative effectiveness of feedback control systems for maintaining standing balance based on joint kinematics or total body center of mass (COM) acceleration, and assess their clinical practicality for standing neuroprostheses after spinal cord injury (SCI). In simulation, controller performance was measured according to the upper extremity effort required to stabilize a three-dimensional model of bipedal standing against a variety of postural disturbances. Three cases were investigated: proportional-derivative control based on joint kinematics alone, COM acceleration feedback alone, and combined joint kinematics and COM acceleration feedback. Additionally, pilot data was collected during external perturbations of an individual with SCI standing with functional neuromuscular stimulation (FNS), and the resulting joint kinematics and COM acceleration data was analyzed. Compared to the baseline case of maximal constant muscle excitations, the three control systems reduced the mean upper extremity loading by 51%, 43% and 56%, respectively against external force-pulse perturbations. Controller robustness was defined as the degradation in performance with increasing levels of input errors expected with clinical deployment of sensor-based feedback. At error levels typical for body-mounted inertial sensors, performance degradation due to sensor noise and placement were negligible. However, at typical tracking error levels, performance could degrade as much as 86% for joint kinematics feedback and 35% for COM acceleration feedback. Pilot data indicated that COM acceleration could be estimated with a few well-placed sensors and efficiently captures information related to movement synergies observed during perturbed bipedal standing following SCI. Overall, COM acceleration feedback may be a more feasible solution for control of standing with FNS given its superior robustness and small number of inputs required.

Ion source memory in {sup 36}Cl accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Pavetich, Stefan; Akhmadaliev, Shavkat; Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany); Arnold, Maurice; Aumaitre, Georges; Bourles, Didier; Martschini, Martin [ASTER, Aix-en-Provence (France); Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Steier, Peter [VERA, Vienna (Austria)

2013-07-01

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 {sup 10}Be, {sup 26}Al and {sup 41}Ca. 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 {sup 35}Cl/{sup 37}Cl-ratio and samples containing highly enriched {sup 35}Cl({sup 35}Cl/{sup 37}Cl > 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.

Applications of accelerator mass spectrometry for pharmacological and toxicological research.

Science.gov (United States)

Brown, Karen; Tompkins, Elaine M; White, Ian N H

2006-01-01

The technique of accelerator mass spectrometry (AMS), known for radiocarbon dating of archeological specimens, has revolutionized high-sensitivity isotope detection in pharmacology and toxicology by allowing the direct determination of the amount of isotope in a sample rather than measuring its decay. It can quantify many isotopes, including 26Al, 14C, 41Ca, and 3H with detection down to attomole (10(-18)) amounts. Pharmacokinetic data in humans have been achieved with ultra-low levels of radiolabel. One of the most exciting biomedical applications of AMS with 14C-labeled potential carcinogens is the detection of modified proteins or DNA in tissues. The relationship between low-level exposure and covalent binding of genotoxic chemicals has been compared in rodents and humans. Such compounds include heterocyclic amines, benzene, and tamoxifen. Other applications range from measuring the absorption of 26Al to monitoring 41Ca turnover in bone. In epoxy-embedded tissue sections, high-resolution imaging of 14C label in cells is possible. The uses of AMS are becoming more widespread with the availability of instrumentation dedicated to the analysis of biomedical samples. Copyright 2005 Wiley Periodicals, Inc.

Sources and acceleration efficiencies for energetic particles in the heliosphere

International Nuclear Information System (INIS)

Kucharek, H; Moebius, E

2006-01-01

Shocks at solar wind stream interaction regions, coronal mass ejections and magnetospheric obstacles have long been known for their intimate link with particle acceleration. Much enhanced capabilities to determine mass and charge composition at interplanetary shocks with ACE and SOHO have enabled us to identify sources and acceleration processes for the energetic particles. Both solar wind and interstellar pickup ions are substantial sources for particle acceleration in corotating interaction regions and at coronal mass ejections driven shocks and that flare particles are re-accelerated. Suprathermal distributions, such as pickup ions and pre-existing flare populations are accelerated much more efficiently than particles out of the solar wind. Recent results of the termination shock crossing by Voyager I and the scientific goals of the upcoming IBEX mission will be discussed

Determination of long-lived radionuclide (10Be, 41Ca, 129I) concentrations in nuclear waste by accelerator mass spectrometry

International Nuclear Information System (INIS)

Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bertaux, Maite; Bourles, Didier; Arnold, Maurice

2013-01-01

Radiological characterization of nuclear waste is essential for storage sites management. However, most of Long-Lived Radionuclides (LLRN), important for long-term management, are difficult to measure since concentration levels are very low and waste matrices generally complex. In an industrial approach, LLRN concentrations are not directly measured in waste samples but assessed from scaling factors with respect to easily measured gamma emitters. Ideally, the key nuclide chosen ( 60 Co, 137 Cs) should be produced by a similar mechanism (fission or activation) as the LLRN of interest and should have similar physicochemical properties. However, the uncertainty on the scaling factors, determined from experimental and/or calculation data, can be quite important. Consequently, studies are performed to develop analytical procedures which would lead to determine precisely the concentration of LLRN in nuclear waste. In this context, the aim of this study was to determine the concentrations of three LLRN: 129 I (T 1/2 = 15.7*10 6 a), 41 Ca (T 1/2 = 9.94*10 4 a) and 10 Be (T 1/2 = 1.387*10 6 a) in spent resins used for primary fluid purification in Pressurized Water Reactors using Accelerator Mass Spectrometry (AMS) for measurement. The AMS technique combined mass spectrometry and nuclear physics to achieve highly efficient molecular and elemental isobars separation. Energies of several Million Electron-Volt transferred to the ions in the first accelerating part of specifically developed tandem accelerators lead to molecular isobars destruction through interaction with the argon gas used to strip the injected negative ions to positive ones. At the exit of the tandem accelerator, the energy acquired in both accelerating parts allows an elemental isobars separation based on their significantly different energy loss (dE) while passing through a thickness of matter dx that is proportional to their atomic number (Z) and inversely proportional to ions velocity (v) according to the

Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

Science.gov (United States)

Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

2013-01-25

By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

Design, simulations and test of a Time-of-Flight spectrometer for mass measurement of exotic beams from SPIRAL1/SPIRAL2 and γ-ray spectroscopy of N=Z nuclei close to 100Sn

International Nuclear Information System (INIS)

Chauveau, Pierre

2016-01-01

The new generation of nuclear facilities calls for new technological developments to produce, accelerate, manipulate and analyse exotic nuclei. The main topic of this thesis work was the simulation, design and test of a Multi-Reflection Time-of-Flight Mass spectrometer (MR-ToFMS) for fast mass separation and fast mass measurement of radioactive ions in the installations S3 and DESIR at SPIRAL2. Such a device could separate isobaric nuclei and provide SPIRAL2 with high purity beams. Also, its mass measurement capabilities would help to determine binding energies of exotic and superheavy nuclei with a high precision. This apparatus has been simulated with the SIMION 8.1 software and designed accordingly. First offline tests have been performed with a stable ion source at LPC Caen. In addition a low-aberration electrostatic deflector has been simulated and designed to operate with this MR-ToF-MS without spoiling its performances. This work also describes the analysis and results of the first online tests of a FEBIAD-type ion source intended to provide SPIRAL1 and SPIRAL2 radioactive beams of competitive intensities. Finally, we describe the analysis of a nuclear physics experiment, including the calibration of the different detectors and the gamma-spectroscopy of nuclei in the vicinity of the doubly magic 100 Sn. (author) [fr

Neural network based expert system for fault diagnosis of particle accelerators

International Nuclear Information System (INIS)

Dewidar, M.M.

1997-01-01

Particle accelerators are generators that produce beams of charged particles, acquiring different energies, depending on the accelerator type. The MGC-20 cyclotron is a cyclic particle accelerator used for accelerating protons, deuterons, alpha particles, and helium-3 to different energies. Its applications include isotope production, nuclear reaction, and mass spectroscopy studies. It is a complicated machine, it consists of five main parts, the ion source, the deflector, the beam transport system, the concentric and harmonic coils, and the radio frequency system. The diagnosis of this device is a very complex task. it depends on the conditions of 27 indicators of the control panel of the device. The accurate diagnosis can lead to a high system reliability and save maintenance costs. so an expert system for the cyclotron fault diagnosis is necessary to be built. In this thesis , a hybrid expert system was developed for the fault diagnosis of the MGC-20 cyclotron. Two intelligent techniques, multilayer feed forward back propagation neural network and the rule based expert system, are integrated as a pre-processor loosely coupled model to build the proposed hybrid expert system. The architecture of the developed hybrid expert system consists of two levels. The first level is two feed forward back propagation neural networks, used for isolating the faulty part of the cyclotron. The second level is the rule based expert system, used for troubleshooting the faults inside the isolated faulty part. 4-6 tabs., 4-5 figs., 36 refs

Analytical applications of spectroscopy

International Nuclear Information System (INIS)

Creaser, C.S.

1988-01-01

This book provides an up to date overview of recent developments in analytical spectroscopy, with a particular emphasis on the common themes of chromatography - spectroscopy combinations, Fourier transform methods, and data handling techniques, which have played an increasingly important part in the development of all spectroscopic techniques. The book contains papers originally presented at a conference entitled 'Spectroscopy Across The Spectrum' held jointly with the first 'International Near Infrared Spectroscopy Conference' at the University of East Anglia, Norwich, UK, in July 1987, which have been edited and rearranged with some additional material. Each section includes reviews of key areas of current research as well as short reports of new developments. The fields covered are: Near Infrared Spectroscopy; Infrared Spectroscopy; Mass Spectroscopy; NMR Spectroscopy; Atomic and UV/Visible Spectroscopy; Chemometrics and Data Analysis. (author)

SIS: an accelerator installation for heavy ions of high energy

International Nuclear Information System (INIS)

The two major sections of the report cover the scientific experimental program and the accelerator installation. Topics covered in the first include: heavy ion physics in the medium energy region; nuclear physics at relativistic energies; atomic physics loss and capture cross sections for electrons; spectroscopy of few-electron systems; atomic collision processes; biological experiments; nuclear track techniques in biology; and experiments with protons and secondary radiation. The second includes: concept for the total installation; technical description of the SIS 12; technical description of the SIS 100; status of the UNILAC injector; development options for the SIS installations; properties of the heavy ion beam; and structural work and technical supply provisions. In this SIS project proposal, an accelerator installation based on two synchrotrons is described with which atomic nuclei up to uranium can be accelerated to energies of more than 10 GeV/μ. With the SIS 12, which is the name of the first stage, heavy ion physics at intermediate energies can be pursued up to 500 MeV/μ. The second stage, a larger synchrotron, the SIS 100, has a diameter of 250 m. With this device, it is proposed to open up the domain of relativistic heavy ion physics up to 14 GeV/μ (for intermediate mass particles) and 10 GeV/μ (for uranium)

Detection of {sup 59}Ni by accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K. [Lund Univ. (Sweden). Dept. of Nuclear Physics; Larsson, Ragnar [Lund Univ. (Sweden). Chemical Engineering II; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

1999-02-01

The aims of this project were to develop a method to measure the amount of {sup 59}Ni in stainless steel and to determine the detection limit for this method. {sup 59}Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of {sup 59}Ni present as it governs the classification of the waste. If the amount of {sup 59}Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of {sup 59}Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of {sup 59}Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for {sup 59}Ni has been determined to 100{+-}30 Bq per gram nickel (100{+-}30 Bq/g) with the present status of the system 14 refs, 6 figs, 3 tabs

Interlaboratory study of the ion source memory effect in {sup 36}Cl accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Pavetich, Stefan, E-mail: s.pavetich@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Akhmadaliev, Shavkat [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Arnold, Maurice; Aumaître, Georges; Bourlès, Didier [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Buchriegler, Josef [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Golser, Robin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Keddadouche, Karim [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Martschini, Martin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Merchel, Silke; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Steier, Peter [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria)

2014-06-01

Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of {sup 36}Cl/Cl and {sup 129}I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having 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, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples highly-enriched in {sup 35}Cl ({sup 35}Cl/{sup 37}Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion

Concurrent Mass Measurement and Laser Spectroscopy for Unambiguous Isomeric State Assignment

Science.gov (United States)

Lascar, Daniel; Babcock, Carla; Henderson, Jack; Pearson, Matt

2017-09-01

Recent work by the TITAN group at TRIUMF on isomeric state mass measurements of odd-A, neutron-rich cadmium nuclei has shown a disconnect between experiment and theory in 127 g , mCd. The spin and parity assignments of the ground and isomeric states are assigned as 3/2+ and 11/2-, respectively, primarily via systematic arguments. Conversely, state of the art shell model and ab initio calculations show a reversal of the states, predicting a ground state of 11/2- and a 3/2+ isomer. Penning Trap Mass Spectrometry (PTMS) can measure the energy separation between the ground state and the isomer without ambiguity but cannot, on its own, comment on the spin and parity. Collinear Laser Spectroscopy (CLS) experiments have been performed on 127Cd and have elegantly demonstrated the existence of both 3/2+ and 11/2- states. What CLS cannot do, on its own, is assign an ordering to those states. If, however, a PTMS and CLS experiment could be performed concurrently using identical beams from the same facility then there exists sufficient information shared between both experiments that a definitive assignment can be made. We present a concept for a new slate of measurements using existing experimental facilities simultaneously, with shared resources, to definitively assign spin and parity for ground and isomeric states in short-lived nuclei.

Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin; Roos, Per

2013-01-01

An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement...... show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging...

Dehydration of Methylcyclohexanol Isomers in the Undergraduate Organic Laboratory and Product Analysis by Gas Chromatography-Mass Spectroscopy (GC-MS)

Science.gov (United States)

Clennan, Malgorzata M.; Clennan, Edward L.

2011-01-01

Dehydrations of "cis"- and "trans"-2-methylcyclohexanol mixtures were carried out with 60% sulfuric acid at 78-80 [degrees]C as a function of time and the products were identified by gas chromatography-mass spectroscopy (GC-MS) analysis. The compounds identified in the reaction mixtures include alkenes, 1-, 3-, and 4-methylcyclohexenes and…

Phytochemical Profile of Erythrina variegata by Using High-Performance Liquid Chromatography and Gas Chromatography-Mass Spectroscopy Analyses

OpenAIRE

Suriyavathana Muthukrishnan; Subha Palanisamy; Senthilkumar Subramanian; Sumathi Selvaraj; Kavitha Rani Mari; Ramalingam Kuppulingam

2016-01-01

Natural products derived from plant sources have been utilized to treat patients with numerous diseases. The phytochemical constituents present in ethanolic leaf extract of Erythrina variegata (ELEV) were identified by using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS) analyses. Shade dried leaves were powdered and extracted with ethanol for analyses through HPLC to identify selected flavonoids and through GC-MS to identify other molecules. Th...

Comparing joint kinematics and center of mass acceleration as feedback for control of standing balance by functional neuromuscular stimulation

Directory of Open Access Journals (Sweden)

Nataraj Raviraj

2012-05-01

Full Text Available Abstract Background The purpose of this study was to determine the comparative effectiveness of feedback control systems for maintaining standing balance based on joint kinematics or total body center of mass (COM acceleration, and assess their clinical practicality for standing neuroprostheses after spinal cord injury (SCI. Methods In simulation, controller performance was measured according to the upper extremity effort required to stabilize a three-dimensional model of bipedal standing against a variety of postural disturbances. Three cases were investigated: proportional-derivative control based on joint kinematics alone, COM acceleration feedback alone, and combined joint kinematics and COM acceleration feedback. Additionally, pilot data was collected during external perturbations of an individual with SCI standing with functional neuromuscular stimulation (FNS, and the resulting joint kinematics and COM acceleration data was analyzed. Results Compared to the baseline case of maximal constant muscle excitations, the three control systems reduced the mean upper extremity loading by 51%, 43% and 56%, respectively against external force-pulse perturbations. Controller robustness was defined as the degradation in performance with increasing levels of input errors expected with clinical deployment of sensor-based feedback. At error levels typical for body-mounted inertial sensors, performance degradation due to sensor noise and placement were negligible. However, at typical tracking error levels, performance could degrade as much as 86% for joint kinematics feedback and 35% for COM acceleration feedback. Pilot data indicated that COM acceleration could be estimated with a few well-placed sensors and efficiently captures information related to movement synergies observed during perturbed bipedal standing following SCI. Conclusions Overall, COM acceleration feedback may be a more feasible solution for control of standing with FNS given its

Structural Characterization of Laboratory Made Tholins by IRMPD Action Spectroscopy and Ultrahigh Resolution Mass Spectrometry

Science.gov (United States)

Thissen, R.; Somogyi, A.; Vuitton, V.; Bégué, D.; Lemaire, J.; Steinmetz, V.

2011-10-01

The complex organic material that is found on the surface and within the haze layer of Titan is attributed to chemistry occurring in its thick N2/CH4 atmosphere. Although several groups are producing in various laboratory setting the socalled tholins which have been investigated by using analytical methods including UV/Vis, fluorescence, IR, and MS1-5, these very complex organic mixtures still hold many unanswered questions, especially related to the potentiality for their prebiotic chemistry. In addition to tholins characterization and analysis, we recently investigated quantitatively the hydrolysis kinetics of tholins in pure and NH3 containing water at different temperatures.7-8 Our groups at UJF (Grenoble) and at U of Arizona (Tucson) have been collaborating on mass spectral analyses of tholins samples for several years.9 Here, we report our most recent results on the structural characterization of tholins by infrared multiphoton dissociation (IRMPD) action spectroscopy10 and ultrahigh resolution MS. IRMPD action spectroscopy is a recently developed technique that uses IR photons of variable wavelengths to activate ions trapped inside an ion trap. When photons are absorbed at a given wavelength, the selected ion fragments and this fragmentation is monitored as a function of wavelength, analog to an absorption spectrum (impossible to record otherwise because of the much reduced density). This technique can, therefore, be used to determine IR spectra of ions in the gas phase, and provides with very acute structural information. IRMPD action spectroscopy is often used to distinguish between structural isomers of isobaric ions. The drawback is that it requests for high power lasers. Only two Free Electron Lasers (FEL) are available in the world and allow to record spectra with reasonable resolution (20-25 cm-1). IRMPD action spectra of selected ions from tholins will be presented and discussed together with observed fragmentation processes that reveal structural

Accelerated Testing Of Photothermal Degradation Of Polymers

Science.gov (United States)

Kim, Soon Sam; Liang, Ranty Hing; Tsay, Fun-Dow

1989-01-01

Electron-spin-resonance (ESR) spectroscopy and Arrhenius plots used to determine maximum safe temperature for accelerated testing of photothermal degradation of polymers. Aging accelerated by increasing illumination, temperature, or both. Results of aging tests at temperatures higher than those encountered in normal use valid as long as mechanism of degradation same throughout range of temperatures. Transition between different mechanisms at some temperature identified via transition between activation energies, manifesting itself as change in slope of Arrhenius plot at that temperature.

Spectroscopy stepping stones

International Nuclear Information System (INIS)

Hammer, M.R.; Sturman, B.T.

2003-01-01

Determining the elemental composition of samples has long been a basic task of analytical science. Some very powerful and convenient approaches are based on the wavelength-specific absorption or emission of light by gas-phase atoms. Techniques briefly described as examples of analytical atomic spectrometry include atomic emission and absorption spectroscopy, inductively coupled plasma emission and mass spectroscopy and laser induced breakdown spectrometry

Acceleration of microparticle

CERN Document Server

Shibata, H

2002-01-01

A microparticle (dust) ion source has been installed at the high voltage terminal of the 3.75 MV single ended Van de Graaff electrostatic accelerator and a beam line for microparticle experiments has been build at High Fluence Irradiation Facility (HIT) of Research Center for Nuclear Science and Technology, the University of Tokyo. Microparticle acceleration has been successful in obtaining expected velocities of 1-20 km/s or more for micron or submicron sized particles. Development of in situ dust detectors and analyzers on board satellites and spacecraft in the expected mass and velocity range of micrometeoroids and investigation of hypervelocity impact phenomena by using time of flight mass spectrometry, impact flash or luminescence measurement and scanning electron or laser microscope observation for metals, ceramics, polymers and semiconductors bombarded by micron-sized particles were started three years ago. (author)

New accelerator mass spectrometry radiocarbon ages for the Mazama tephra layer from Kootenay National Park, British Columbia, Canada

International Nuclear Information System (INIS)

Hallett, D.J.; Hills, L.V.; Clague, J.J.

1997-01-01

Charcoal fragments recovered from the Mazama air-fall tephra layer in cores from Dog and Cobb lakes, Kootenay National Park, British Columbia, yielded accelerator mass spectrometry ages of 6720 ± 70 and 6760 ± 70 14 C years BP, respectively. These two new ages, together with other previously published radiocarbon ages on charcoal and twig fragments from Mazama air-fall deposits, indicate that the climatic eruption of Mount Mazama occurred 6730 ± 40 14 C years BP. (author)

Linear resonance acceleration of pellets

International Nuclear Information System (INIS)

Mills, R.G.

1978-01-01

A possible requirement for the acceleration of macroscopic pellets to velocities exceeding 10 4 meters per second implies the development of new apparatus. A satisfactory approach might be the linear resonance accelerator. Such apparatus would require the charging of pellets to very high values not yet demonstrated. The incompatibility of phase stability with radial stability in these machines may require abandoning phase stability and adopting feedback control of the accelerating voltage to accommodate statistical fluctuations in the charge to mass ratio of successive pellets

Acceleration of black hole universe

Science.gov (United States)

Zhang, T. X.; Frederick, C.

2014-01-01

Recently, Zhang slightly modified the standard big bang theory and developed a new cosmological model called black hole universe, which is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain all observations of the universe. Previous studies accounted for the origin, structure, evolution, expansion, and cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This paper investigates acceleration of the black hole universe and provides an alternative explanation for the redshift and luminosity distance measurements of type Ia supernovae. The results indicate that the black hole universe accelerates its expansion when it accretes the ambient matter in an increasing rate. In other words, i.e., when the second-order derivative of the mass of the black hole universe with respect to the time is positive . For a constant deceleration parameter , we can perfectly explain the type Ia supernova measurements with the reduced chi-square to be very close to unity, χ red˜1.0012. The expansion and acceleration of black hole universe are driven by external energy.

Search for Dark Photons with Accelerators

Directory of Open Access Journals (Sweden)

Merkel Harald

2014-01-01

Full Text Available A dark photon as the mediator of an interaction of the dark sector is a well motivated extension of the standard model. While possible dark matter particles are heavy and seem to be beyond the reach of current accelerators, the dark photon is not necessarily heavy and might have a mass in the range of existing accelerators. In recent years, an extensive experimental program at several accelerators for the search for dark photons were established. In this talk, recent results and progress in the determination of exclusion limits with accelerators is presented.

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio

International Nuclear Information System (INIS)

Keck, B.D.; Ognibene, T.; Vogel, J.S.

2010-01-01

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of 14 C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14 C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the 14 C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with 14 C corresponds to 30 fg equivalents. AMS

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

Energy Technology Data Exchange (ETDEWEB)

Keck, B D; Ognibene, T; Vogel, J S

2010-02-05

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2007-2009

International Nuclear Information System (INIS)

2010-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2007-2009 years: Nuclear Astrophysics; Solid State Astrophysics; Physics and Chemistry of Irradiation; Solid State Physics and cryogenic detectors; Solid State Physics, Condensed Matter and Irradiation; Structure of the Atomic Nucleus; Teaching and training activities; Spreading scientific culture; Administrative services; Electronics Group; Computer Department; Mechanics Department; RESET Service (Radiation-Environment-Safety- Maintenance-Work); SEMIRAMIS (ion source and ion beam handling)

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2010-2012

International Nuclear Information System (INIS)

2013-07-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2010-2012 years: Nuclear Astrophysics; Solid State Astrophysics; Physics and Chemistry of Irradiation; Solid State Physics Group; Condensed Matter and Irradiation: from fundamental to functional; Structure of the Atomic Nucleus; Teaching activities; Spreading scientific culture; Administrative services; Electronics Group; Computer Department; Mechanics Department; RESET Service (Radiation-Environment-Safety- Maintenance-Work); SEMIRAMIS (ion source and ion beam handling)

Accelerators and x-rays in cultural heritage investigations

International Nuclear Information System (INIS)

Heinz-Eberhard, Mahnke; Salomon, J.; Heinz-Eberhard, Mahnke; Denker, A.; Heinz-Eberhard, Mahnke

2009-01-01

In the following article a review is given on the use of accelerators in studies connected to our cultural heritage. It focuses on making use of the production and detection of x-rays as a general tool. At 'small accelerators', the proton induced x-ray emission (PIXE), especially when combined with Rutherford backscattering spectroscopy (RBS), has been developed to a very versatile and powerful technique for near-surface investigations. It is well complemented by larger facilities, synchrotron radiation sources as well as medium energy ion accelerators for high energy PIXE. With the development of small compact electron accelerators, a new generation of mono-energetic high-energy high-intensity x-ray sources will add a very comfortable complement in cultural heritage studies

Verification of the sputter-generated {sup 32}SF{sub n}{sup −} (n = 1–6) anions by accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Mane, R.G.; Surendran, P. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Sanjay [Physics Department, Agra College Agra, Agra 282002 (India); Nair, J.P.; Yadav, M.L. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Hemalatha, M. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Thomas, R.G.; Mahata, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kailas, S. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Gupta, A.K., E-mail: anit@tifr.res.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2016-01-01

Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase {sup 32}SF{sub n}{sup −} (n = 1–6) anions for all size ‘n’ can be readily generated from a variety of surfaces undergoing Cs{sup +} ion sputtering in the presence of high purity SF{sub 6} gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio {sup 34}SF{sub n}{sup −}/{sup 32}SF{sub n}{sup −} (n = 1–6) was found to be close to its natural abundance but not for all size ‘n’. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant {sup 32}SF{sub n}{sup −} (n = 1–6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

Determination of balloon gas mass and revised estimates of drag and virtual mass coefficients

Science.gov (United States)

Robbins, E.; Martone, M.

1993-01-01

In support of the NASA Balloon Program, small-scale balloons were flown with varying lifting gas and total system mass. Instrument packages were developed to measure and record acceleration and temperature data during these tests. Top fitting and instrument payload accelerations were measured from launch to steady state ascent and through ballast drop transients. The development of the small lightweight self-powered Stowaway Special instrument packages is discussed along with mathematical models developed to determine gas mass, drag and virtual mass coefficients.

Staging of RF-accelerating Units in a MEMS-based Ion Accelerator

Science.gov (United States)

Persaud, A.; Seidl, P. A.; Ji, Q.; Feinberg, E.; Waldron, W. L.; Schenkel, T.; Ardanuc, S.; Vinayakumar, K. B.; Lal, A.

Multiple Electrostatic Quadrupole Array Linear Accelerators (MEQALACs) provide an opportunity to realize compact radio- frequency (RF) accelerator structures that can deliver very high beam currents. MEQALACs have been previously realized with acceleration gap distances and beam aperture sizes of the order of centimeters. Through advances in Micro-Electro-Mechanical Systems (MEMS) fabrication, MEQALACs can now be scaled down to the sub-millimeter regime and batch processed on wafer substrates. In this paper we show first results from using three RF stages in a compact MEMS-based ion accelerator. The results presented show proof-of-concept with accelerator structures formed from printed circuit boards using a 3 × 3 beamlet arrangement and noble gas ions at 10 keV. We present a simple model to describe the measured results. We also discuss some of the scaling behaviour of a compact MEQALAC. The MEMS-based approach enables a low-cost, highly versatile accelerator covering a wide range of currents (10 μA to 100 mA) and beam energies (100 keV to several MeV). Applications include ion-beam analysis, mass spectrometry, materials processing, and at very high beam powers, plasma heating.

Role of excipients in hydrate formation kinetics of theophylline in wet masses studied by near-infrared spectroscopy

DEFF Research Database (Denmark)

Jørgensen, Anna C; Airaksinen, Sari; Karjalainen, Milja

2004-01-01

. Anhydrous theophylline was chosen as the hydrate-forming model drug compound and two excipients, silicified microcrystalline cellulose (SMCC) and alpha-lactose monohydrate, with different water absorbing properties, were used in formulation. An early stage of wet massing was studied with anhydrous...... theophylline and its 1:1 (w/w) mixtures with alpha-lactose monohydrate and SMCC with 0.1g/g of purified water. The changes in the state of water were monitored using near-infrared spectroscopy, and the conversion of the crystal structure was verified using X-ray powder diffraction (XRPD). SMCC decreased...... the hydrate formation rate by absorbing water, but did not inhibit it. The results suggest that alpha-lactose monohydrate slightly increased the hydrate formation rate in comparison with a mass comprising only anhydrous theophylline....

Accelerating particles in general relativity (stationary C-metric)

International Nuclear Information System (INIS)

Farhoosh, H.

1979-01-01

The purpose of this thesis is to study the physical and geometrical properties of uniformly accelerating particles in the general theory of relativity and it consists of four main parts. In the first part the structure of the Killing horizons in the static vacuum C-metric which represents the gravitational field of a uniformly accelerating Schwarzschild like particle (non-rotating and spherically symmetric) is studied. In the second part these results are generalized to include the effects of the rotation of the source. For small acceleration and small rotation this solution reveals the existance of three Killing horizons. Two the these horizons are the Schwarzschild and the Rindler surfaces which are mainly due to the mass and the acceleration of the particle, respectively. In part three the radial geodesic and non-geodesic motions in the static vacuum C-metric (non-rotating case) are investigated. The effect of the dragging of the inertial frame is also shown in this part. In part four the radiative behavior of the stationary charged C-metric representing the electro-gravitational field of a uniformly accelerating and rotating charged particle with magnetic monopole and the NUT-parameter are investigated. The physical quantities - the news function, mass loss, mass, charge and the multipole moments - are calculated. It is also shown in this part that the magnetic monopole in the presence of rotation and acceleration affects the electric charge

Methyl Radicals in Oxidative Coupling of Methane Directly Confirmed by Synchrotron VUV Photoionization Mass Spectroscopy

Science.gov (United States)

Luo, Liangfeng; Tang, Xiaofeng; Wang, Wendong; Wang, Yu; Sun, Shaobo; Qi, Fei; Huang, Weixin

2013-01-01

Gas-phase methyl radicals have been long proposed as the key intermediate in catalytic oxidative coupling of methane, but the direct experimental evidence still lacks. Here, employing synchrotron VUV photoionization mass spectroscopy, we have directly observed the formation of gas-phase methyl radicals during oxidative coupling of methane catalyzed by Li/MgO catalysts. The concentration of gas-phase methyl radicals correlates well with the yield of ethylene and ethane products. These results lead to an enhanced fundamental understanding of oxidative coupling of methane that will facilitate the exploration of new catalysts with improved performance. PMID:23567985

LEPTON ACCELERATION IN THE VICINITY OF THE EVENT HORIZON: HIGH-ENERGY AND VERY-HIGH-ENERGY EMISSIONS FROM ROTATING BLACK HOLES WITH VARIOUS MASSES

Energy Technology Data Exchange (ETDEWEB)

Hirotani, Kouichi; Pu, Hung-Yi; Lin, Lupin Chun-Che; Inoue, Makoto; Matsushita, Satoki [Academia Sinica, Institute of Astronomy and Astrophysics (ASIAA), P.O. Box 23-141, Taipei, Taiwan 10617, R.O.C. (China); Chang, Hsiang-Kuang; Kong, Albert K. H. [Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013, R.O.C. (China); Tam, Pak-Hin T., E-mail: hirotani@tiara.sinica.edu.tw [School of Physics and Astronomy, Sun Yat-Sen University, Zhuhai 519082 (China)

2016-12-20

We investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon, applying the pulsar outer-gap model to black hole (BH) magnetospheres. During a low accretion phase, the radiatively inefficient accretion flow (RIAF) cannot emit enough MeV photons that are needed to sustain the force-free magnetosphere via two-photon collisions. In such a charge-starved region (or a gap), an electric field arises along the magnetic field lines to accelerate electrons and positrons into ultra-relativistic energies. These relativistic leptons emit copious gamma rays via curvature and inverse-Compton (IC) processes. Some of such gamma rays collide with the submillimeter-IR photons emitted from the RIAF to materialize as pairs, which polarize to partially screen the original acceleration electric field. It is found that the gap gamma-ray luminosity increases with decreasing accretion rate. However, if the accretion rate decreases too much, the diminished RIAF soft photon field can no longer sustain a stationary pair production within the gap. As long as a stationary gap is formed, the magnetosphere becomes force-free outside the gap by the cascaded pairs, irrespective of the BH mass. If a nearby stellar-mass BH is in quiescence, or if a galactic intermediate-mass BH is in a very low accretion state, its curvature and IC emissions are found to be detectable with Fermi /LAT and imaging atmospheric Cherenkov telescopes (IACT). If a low-luminosity active galactic nucleus is located within about 30 Mpc, the IC emission from its supermassive BH is marginally detectable with IACT.

Characterization of TiAlN thin film annealed under O2 by in situ time of flight direct recoil spectroscopy/mass spectroscopy of recoiled ions and ex situ x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Tempez, A.; Bensaoula, A.; Schultz, A.

2002-01-01

The oxidation of an amorphous TiAlN coating has been studied by in situ direct recoil spectroscopy (DRS) and mass spectroscopy of recoiled ions (MSRI) and ex situ x-ray photoelectron spectroscopy (XPS). DRS and MSRI monitored the changes in surface composition as the sample was heated to 460 deg. C under an 18 O 2 pressure of 10 -6 Torr. Angular resolved XPS data were acquired for thickness-dependence information. The initial surface was partially oxidized from air exposure. Both DRS and XPS showed the Al-rich near surface and the presence of N in the subsurface. As shown by DRS and MSRI, oxidation at elevated temperatures yielded surface nitrogen loss and Ti enrichment. XPS confirmed the preferential formation of TiO 2 on the surface. This study also provides a comparison between the direct recoil (neutrals and ions) and the ionic recoil signals. In our conditions, the negative ionic fraction of all elements except H tracks their true surface content variations given by DRS. The results were compared with early work performed on identical samples. In this case the TiAlN film was oxidized with an O 2 pressure in the mTorr range and the surface changes are followed in situ by positive MSRI and XPS. This experiment also indicates that Al and N are buried under TiO 2 but from 600 deg. C

Laser wakefield accelerator based light sources: potential applications and requirements

Energy Technology Data Exchange (ETDEWEB)

Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

2015-01-15

In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

Dark spectroscopy at lepton colliders

Science.gov (United States)

Hochberg, Yonit; Kuflik, Eric; Murayama, Hitoshi

2018-03-01

Rich and complex dark sectors are abundant in particle physics theories. Here, we propose performing spectroscopy of the mass structure of dark sectors via mono-photon searches at lepton colliders. The energy of the mono-photon tracks the invariant mass of the invisible system it recoils against, which enables studying the resonance structure of the dark sector. We demonstrate this idea with several well-motivated models of dark sectors. Such spectroscopy measurements could potentially be performed at Belle II, BES-III and future low-energy lepton colliders.

Special relativity in beam trajectory simulation in small accelerators

International Nuclear Information System (INIS)

Pramudita Anggraita; Budi Santosa; Taufik; Emy Mulyani; Frida Iswinning Diah

2012-01-01

Calculation for trajectory simulation of particle beam in small accelerators should account special relativity effect in the beam motion, which differs between parallel and perpendicular direction to the beam velocity. For small electron beam machine of 300 keV, the effect shows up as the rest mass of electron is only 511 keV. Neglecting the effect yields wrong kinetic energy after 300 kV of dc acceleration. For a 13 MeV PET (positron emission tomography) baby cyclotron accelerating proton beam, the effect increases the proton mass by about 1.4% at the final energy. To keep the beam isochronous with the accelerating radiofrequency, a radial increase of the average magnetic field must be designed accordingly. (author)

Decay kinetics of nicotine/NNK-DNA adducts in vivo studied by accelerator mass spectrometry

International Nuclear Information System (INIS)

Sun, H.F.; He, L.; Liu, Y.F.; Liu, K.X.; Lu, X.Y.; Wang, J.J.; Ma, H.J.; Li, K.

2000-01-01

The decay kinetics of nicotine-DNA adducts and NNK-DNA adducts in mice liver after single dosing was studied by accelerator mass spectrometry (AMS). The decay is characterized by a two-stage process. The half-lives of nicotine-DNA adducts are 1.3 d (4-24 h) and 7.0 d (1-21 d), while for NNK-DNA adducts are 0.7 d (4-24 h) and 18.0 d (1-21 d). The relatively faster decay of nicotine-DNA adducts suggests that the genotoxicity of nicotine is weaker than that of NNK. The in vitro study shows that the metabolization of nicotine is necessary for the final formation of nicotine-DNA adducts, and nicotine Δ1'(5') iminium ion is a probable metabolite species that binds to DNA molecule covalently

Use of Accelerator Mass Spectrometry in Human Health and Molecular Toxicology.

Science.gov (United States)

Enright, Heather A; Malfatti, Michael A; Zimmermann, Maike; Ognibene, Ted; Henderson, Paul; Turteltaub, Kenneth W

2016-12-19

Accelerator mass spectrometry (AMS) has been adopted as a powerful bioanalytical method for human studies in the areas of pharmacology and toxicology. The exquisite sensitivity (10 -18 mol) of AMS has facilitated studies of toxins and drugs at environmentally and physiologically relevant concentrations in humans. Such studies include risk assessment of environmental toxicants, drug candidate selection, absolute bioavailability determination, and more recently, assessment of drug-target binding as a biomarker of response to chemotherapy. Combining AMS with complementary capabilities such as high performance liquid chromatography (HPLC) can maximize data within a single experiment and provide additional insight when assessing drugs and toxins, such as metabolic profiling. Recent advances in the AMS technology at Lawrence Livermore National Laboratory have allowed for direct coupling of AMS with complementary capabilities such as HPLC via a liquid sample moving wire interface, offering greater sensitivity compared to that of graphite-based analysis, therefore enabling the use of lower 14 C and chemical doses, which are imperative for clinical testing. The aim of this review is to highlight the recent efforts in human studies using AMS, including technological advancements and discussion of the continued promise of AMS for innovative clinical based research.

LeRC rail accelerators: test designs and diagnostic techniques

International Nuclear Information System (INIS)

Zana, L.M.; Kerslake, W.R.; Sturman, J.C.; Wang, S.Y.; Terdan, F.F.

1984-01-01

The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. 15 references

Frontier applications of electrostatic accelerators

Science.gov (United States)

Liu, Ke-Xin; Wang, Yu-Gang; Fan, Tie-Shuan; Zhang, Guo-Hui; Chen, Jia-Er

2013-10-01

Electrostatic accelerator is a powerful tool in many research fields, such as nuclear physics, radiation biology, material science, archaeology and earth sciences. Two electrostatic accelerators, one is the single stage Van de Graaff with terminal voltage of 4.5 MV and another one is the EN tandem with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at the Institute of Heavy Ion Physics. Many applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented.

Operational experience of the ATLAS accelerator

Energy Technology Data Exchange (ETDEWEB)

Den Hartog, P K; Bogaty, J M; Bollinger, L M; Clifft, B E; Craig, S L; Harden, R E; Markovich, P; Munson, F H; Nixon, J M; Pardo, R C; Phillips, D R; Shepard, K W; Tilbrook, I R; Zinkmann, G P [Argonne National Lab., IL (USA). Physics Div.

1990-02-01

The ATLAS accelerator consists of a HVEC model FN tandem accelerator injecting into a linac of independently-phased niobium superconducting resonators. The accelerator provides beams with masses 6 {le} A {le} 127 and with energies ranging up to 20 MeV/A for the lightest ions and 4 MeV/A for the heaviest ions. Portions of the linac have been in operation since 1978 and, over the last decade, more than 35000 h of operating experience have been accumulated. The long-term stability of niobium resonators, and their feasibility for use in heavy-ion accelerators is now well established. (orig.).

Spatially inhomogeneous acceleration of electrons in solar flares

Science.gov (United States)

Stackhouse, Duncan J.; Kontar, Eduard P.

2018-04-01

The imaging spectroscopy capabilities of the Reuven Ramaty high energy solar spectroscopic imager (RHESSI) enable the examination of the accelerated electron distribution throughout a solar flare region. In particular, it has been revealed that the energisation of these particles takes place over a region of finite size, sometimes resolved by RHESSI observations. In this paper, we present, for the first time, a spatially distributed acceleration model and investigate the role of inhomogeneous acceleration on the observed X-ray emission properties. We have modelled transport explicitly examining scatter-free and diffusive transport within the acceleration region and compare with the analytic leaky-box solution. The results show the importance of including this spatial variation when modelling electron acceleration in solar flares. The presence of an inhomogeneous, extended acceleration region produces a spectral index that is, in most cases, different from the simple leaky-box prediction. In particular, it results in a generally softer spectral index than predicted by the leaky-box solution, for both scatter-free and diffusive transport, and thus should be taken into account when modelling stochastic acceleration in solar flares.

Variable Acceleration Force Calibration System (VACS)

Science.gov (United States)

Rhew, Ray D.; Parker, Peter A.; Johnson, Thomas H.; Landman, Drew

2014-01-01

Conventionally, force balances have been calibrated manually, using a complex system of free hanging precision weights, bell cranks, and/or other mechanical components. Conventional methods may provide sufficient accuracy in some instances, but are often quite complex and labor-intensive, requiring three to four man-weeks to complete each full calibration. To ensure accuracy, gravity-based loading is typically utilized. However, this often causes difficulty when applying loads in three simultaneous, orthogonal axes. A complex system of levers, cranks, and cables must be used, introducing increased sources of systematic error, and significantly increasing the time and labor intensity required to complete the calibration. One aspect of the VACS is a method wherein the mass utilized for calibration is held constant, and the acceleration is changed to thereby generate relatively large forces with relatively small test masses. Multiple forces can be applied to a force balance without changing the test mass, and dynamic forces can be applied by rotation or oscillating acceleration. If rotational motion is utilized, a mass is rigidly attached to a force balance, and the mass is exposed to a rotational field. A large force can be applied by utilizing a large rotational velocity. A centrifuge or rotating table can be used to create the rotational field, and fixtures can be utilized to position the force balance. The acceleration may also be linear. For example, a table that moves linearly and accelerates in a sinusoidal manner may also be utilized. The test mass does not have to move in a path that is parallel to the ground, and no re-leveling is therefore required. Balance deflection corrections may be applied passively by monitoring the orientation of the force balance with a three-axis accelerometer package. Deflections are measured during each test run, and adjustments with respect to the true applied load can be made during the post-processing stage. This paper will

Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research.

Science.gov (United States)

Redondo, L M; Silva, J Fernando; Canacsinh, H; Ferrão, N; Mendes, C; Soares, R; Schipper, J; Fowler, A

2010-07-01

A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

Determination of the first ionization potential of actinides by resonance ionization mass spectroscopy

International Nuclear Information System (INIS)

Koehler, S.; Albus, F.; Dibenberger, R.; Erdmann, N.; Funk, H.; Hasse, H.; Herrmann, G.; Huber, G.; Kluge, H.; Nunnemann, M.; Passler, G.; Rao, P.M.; Riegel, J.; Trautmann, N.; Urban, F.

1995-01-01

Resonance ionization mass spectroscopy (RIMS) is used for the precise determination of the first ionization potential of transuranium elements. The first ionization potentials (IP) of americium and curium have been measured for the first time to IP Am =5.9738(2) and IP Cm =5.9913(8) eV, respectively, using only 10 12 atoms of 243 Am and 248 Cm. The same technique was applied to thorium, neptunium, and plutonium yielding IP T H =6.3067(2), IP N P =6.2655(2), and IP Pu =6.0257(8) eV. The good agreement of our results with the literature data proves the precision of the method which was additionally confirmed by the analysis of Rydberg seris of americium measured by RIMS. copyright American Institute of Physics 1995

Leptoquarks: Neutrino masses and related accelerator signals

International Nuclear Information System (INIS)

Aristizabal Sierra, D.; Hirsch, M.; Kovalenko, S. G.

2008-01-01

Leptoquark-Higgs interactions induce mixing between leptoquark (LQ) states with different chiralities once the electroweak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the neutrino mass matrix and explore the constraints on the parameter space enforced by the assumption that LQ-loops explain current neutrino oscillation data. LQs will be produced at the CERN LHC, if their masses are at or below the TeV scale. Since the fermionic decays of LQs are governed by the same Yukawa couplings, which are responsible for the nontrivial neutrino mass matrix, several decay branching ratios of LQ states can be predicted from measured neutrino data. Especially interesting is that large lepton flavor violating rates in muon and tau final states are expected. In addition, the model predicts that, if kinematically possible, heavier LQs decay into lighter ones plus either a standard model Higgs boson or a Z 0 /W ± gauge boson. Thus, experiments at the LHC might be able to exclude the LQ mechanism as an explanation of neutrino data.

Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

Directory of Open Access Journals (Sweden)

Eliades J.

2012-04-01

Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

Using accelerator mass spectrometry for radiocarbon dating of textiles

Energy Technology Data Exchange (ETDEWEB)

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.

Mass

International Nuclear Information System (INIS)

Quigg, Chris

2007-01-01

In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

A dedicated AMS setup for medium mass isotopes at the Cologne FN tandem accelerator

Science.gov (United States)

Schiffer, M.; Altenkirch, R.; Feuerstein, C.; Müller-Gatermann, C.; Hackenberg, G.; Herb, S.; Bhandari, P.; Heinze, S.; Stolz, A.; Dewald, A.

2017-09-01

AMS measurements of medium mass isotopes, e.g. of 53Mn and 60Fe, are gaining interest in various fields of operation, especially geoscience. Therefore a dedicated AMS setup has been built at the Cologne 10 MV FN tandem accelerator. This setup is designed to obtain a sufficient suppression of the stable isobars at energies around 100 MeV. In this contribution we report on the actual status of the new setup and the first in-beam tests of its individual components. The isobar suppression is done with (dE/dx) techniques using combinations of energy degrader foils with an electrostatic analyzer (ESA) and a time of flight (ToF) system, as well as a (dE/dx),E gas ionization detector. Furthermore, the upgraded ion source and its negative ion yield measurement for MnO- are presented.

Operational experience of the ATLAS accelerator

International Nuclear Information System (INIS)

Den Hartog, P.K.; Bogaty, J.M.; Bollinger, L.M.

1989-01-01

The ATLAS accelerator consists of a HVEC model FN tandem accelerator injecting into a linac of independently-phased niobium superconducting resonators. The accelerator provides beams with masses from 6≤A≤127 and with energies ranging up to 20 MeV/A for the lightest ions and 4 MeV/A for the heaviest ions. Portions of the linac have been in operation since 1978 and, over the last decade, more than 35,000 hours of operating experience have been accumulated. The long-term stability of niobium resonators, and their feasibility for use in heavy-ion accelerators is now well established. 11 refs., 3 figs., 1 tab

UV Photodissociation Action Spectroscopy of Haloanilinium Ions in a Linear Quadrupole Ion Trap Mass Spectrometer

Science.gov (United States)

Hansen, Christopher S.; Kirk, Benjamin B.; Blanksby, Stephen J.; O'Hair, Richard. A. J.; Trevitt, Adam J.

2013-06-01

UV-vis photodissociation action spectroscopy is becoming increasingly prevalent because of advances in, and commercial availability of, ion trapping technologies and tunable laser sources. This study outlines in detail an instrumental arrangement, combining a commercial ion-trap mass spectrometer and tunable nanosecond pulsed laser source, for performing fully automated photodissociation action spectroscopy on gas-phase ions. The components of the instrumentation are outlined, including the optical and electronic interfacing, in addition to the control software for automating the experiment and performing online analysis of the spectra. To demonstrate the utility of this ensemble, the photodissociation action spectra of 4-chloroanilinium, 4-bromoanilinium, and 4-iodoanilinium cations are presented and discussed. Multiple photoproducts are detected in each case and the photoproduct yields are followed as a function of laser wavelength. It is shown that the wavelength-dependent partitioning of the halide loss, H loss, and NH3 loss channels can be broadly rationalized in terms of the relative carbon-halide bond dissociation energies and processes of energy redistribution. The photodissociation action spectrum of (phenyl)Ag2 + is compared with a literature spectrum as a further benchmark.

Advances in atomic spectroscopy

CERN Document Server

Sneddon, J

2000-01-01

This fifth volume of the successful series Advances in Atomic Spectroscopy continues to discuss and investigate the area of atomic spectroscopy.It begins with a description of the use of various atomic spectroscopic methods and applications of speciation studies in atomic spectroscopy. The emphasis is on combining atomic spectroscopy with gas and liquid chromatography. In chapter two the authors describe new developments in tunable lasers and the impact they will have on atomic spectroscopy. The traditional methods of detection, such as photography and the photomultiplier, and how they are being replaced by new detectors is discussed in chapter three. The very active area of glow discharge atomic spectrometry is presented in chapter four where, after a brief introduction and historical review, the use of glow discharge lamps for atomic spectroscopy and mass spectrometry are discussed. Included in this discussion is geometry and radiofrequency power. The future of this source in atomic spectroscopy is also dis...

New positron annihilation spectroscopy techniques for thick materials

International Nuclear Information System (INIS)

Selim, F.A.; Wells, D.P.; Harmon, J.F.; Kwofie, J.; Erikson, G.; Roney, T.

2003-01-01

The Idaho Accelerator Center (IAC) has developed new techniques for positron annihilation spectroscopy (PAS) by using highly penetrating γ-rays to create positrons inside the material via pair production. Two sources of γ-rays have been employed. Bremsstrahlung beams from small-electron linacs (6 MeV) were used to generate positrons inside the material to perform Doppler-broadening spectroscopy. A 2 MeV proton beam was used to obtain coincident γ-rays from 27 Al target and enable lifetime and Doppler-broadening spectroscopy. This technique successfully measured stress/strain in thick samples, and showed promise to extend PAS into a variety of applications

Accelerator microanalysis

International Nuclear Information System (INIS)

Tuniz, C.

1997-01-01

Particle accelerators have been developed more than sixty years ago to investigate nuclear and atomic phenomena. A major shift toward applications of accelerators in the study of materials structure and composition in inter-disciplinary projects has been witnessed in the last two decades. The Australian Nuclear Science and Technology Organisation (ANSTO) has developed advanced research programs based on the use of particle and photon beams. Atmospheric pollution problems are investigated at the 3 MV Van de Graff accelerator using ion beam analysis techniques to detect toxic elements in aerosol particles. High temperature superconductor and semiconductor materials are characterised using the recoil of iodine and other heavy ions produced at ANTARES, the 10-MV Tandem accelerator. A heavy-ion microprobe is presently being developed at ANTARES to map elemental concentrations of specific elements with micro-size resolution. An Accelerator mass Spectrometry (AMS) system has been developed at ANSTO for the ultra-sensitive detection of Carbon-14, Iodine-129 and other long-lived radioisotopes. This AMS spectrometer is a key instrument for climate change studies and international safeguards. ANSTO is also managing the Australian Synchrotron Research program based on facilities developed at the Photon Factory (Japan) and at the Advanced Photon Source (USA). Advanced projects in biology, materials chemistry, structural condensed matter and other disciplines are being promoted by a consortium involving Australian universities and research institutions. This paper will review recent advances in the use of particle accelerators, with a particular emphasis on applications developed at ANSTO and related to problems of international concern, such as global environmental change, public health and nuclear proliferation

Electron spectroscopy with fast heavy ions

International Nuclear Information System (INIS)

Schneider, D.

1983-01-01

Since about 1970 the spectroscopy of Auger-electrons and characteristic x-rays following energetic ion-atom collisions has received a great deal of attention. An increasing number of accelerators, capable of providing a large number of projectile ion species over a wide range of projectile energies, became available for studying ion-atom collision phenomena. Many charged particles from protons up to heavy ions like uranium can be accelerated to energies ranging over six orders of magnitude. This allows us to study systematically a great variety of effects accompanied by dynamic excitation processes of the atomic shells in either the projectile- or target-atoms. The studies yield fundamental information regarding the excitation mechanism (e.g., Coulomb and quasi-molecular excitation) and allow sensitive tests of atomic structure theories. This information in turn is valuable to other fields in physics like plasma-, astro-, or solid-state (surface) physics. It is a characteristic feature of fast heavy-ion accelerators that they can produce highly stripped ion species which have in turn the capability to highly ionize neutral target atoms or molecules in a single collision. The ionization process, mainly due to the strong electrical fields that are involved, allows us to study few-electron atoms with high atomic numbers Z. High resolution spectroscopy performed with these atoms allows a particularly good test of relativistic and QED effects. The probability of producing these few electron systems is determined by the charge state and the velocity of the projectile ions. In this contribution the possibilities of using electron spectroscopy as a tool to investigate fast ion-atom collisions is discussed and demonstrated with a few examples. 30 references

Inferring the Composition of Super-Jupiter Mass Companions of Pulsars with Radio Line Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ray, Alak; Loeb, Abraham, E-mail: akr@tifr.res.in, E-mail: aloeb@cfa.harvard.edu [Institute of Theory and Computation, Center for Astrophysics, Harvard University 60 Garden Street, Cambridge, MA 02138 (United States)

2017-02-10

We propose using radio line spectroscopy to detect molecular absorption lines (such as OH at 1.6–1.7 GHz) before and after the total eclipse of black widow and other short orbital period binary pulsars with low-mass companions. The companion in such a binary may be ablated away by energetic particles and high-energy radiation produced by the pulsar wind. The observations will probe the eclipsing wind being ablated by the pulsar and constrain the nature of the companion and its surroundings. Maser emission from the interstellar medium stimulated by a pulsar beam might also be detected from the intrabinary medium. The short temporal resolution allowed by the millisecond pulsars can probe this medium with the high angular resolution of the pulsar beam.

Halide ions complex and deprotonate dipicolinamides and isophthalamides: assessment by mass spectrometry and UV-visible spectroscopy.

Science.gov (United States)

Carasel, I Alexandru; Yamnitz, Carl R; Winter, Rudolph K; Gokel, George W

2010-12-03

The F(-), Cl(-), and Br(-) binding selectivity of bis(p-nitroanilide)s of dipicolinic and isophthalic acids was studied by using competitive electrospray mass spectrometry and UV-Visible spectroscopy. Both hosts prefer binding Cl(-) over either F(-) or Br(-). Host deprotonation was observed to some extent in all experiments in which the host was exposed to halide ions. When F(-) was present, host deprotonation was often the major process, whereas little deprotonation was observed by Cl(-) or Br(-), which preferred complexation. A solution of either host changed color when mixed with a F(-), H(2)PO(4)(-), di- or triphenylacetate solution.

INTEGRAL FIELD SPECTROSCOPY OF SUPERNOVA EXPLOSION SITES: CONSTRAINING THE MASS AND METALLICITY OF THE PROGENITORS. I. TYPE Ib AND Ic SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Kuncarayakti, Hanindyo; Maeda, Keiichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Doi, Mamoru; Morokuma, Tomoki; Hashiba, Yasuhito [Institute of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Aldering, Greg [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Arimoto, Nobuo [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Pereira, Rui [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne Cedex (France); Usuda, Tomonori, E-mail: hanindyo.kuncarayakti@ipmu.jp [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' ohoku Place, Hilo, HI 96720 (United States)

2013-08-01

Integral field spectroscopy of 11 Type Ib/Ic supernova (SN Ib/Ic) explosion sites in nearby galaxies has been obtained using UH88/SNIFS and Gemini-N/GMOS. The use of integral field spectroscopy enables us to obtain both spatial and spectral information about the explosion site, enabling the identification of the parent stellar population of the SN progenitor star. The spectrum of the parent population provides metallicity determination via strong-line method and age estimation obtained via comparison with simple stellar population models. We adopt this information as the metallicity and age of the SN progenitor, under the assumption that it was coeval with the parent stellar population. The age of the star corresponds to its lifetime, which in turn gives the estimate of its initial mass. With this method we were able to determine both the metallicity and initial (zero-age main sequence) mass of the progenitor stars of SNe Ib and Ic. We found that on average SN Ic explosion sites are more metal-rich and younger than SN Ib sites. The initial mass of the progenitors derived from parent stellar population age suggests that SN Ic has more massive progenitors than SN Ib. In addition, we also found indication that some of our SN progenitors are less massive than {approx}25 M{sub Sun }, indicating that they may have been stars in a close binary system that have lost their outer envelope via binary interactions to produce SNe Ib/Ic, instead of single Wolf-Rayet stars. These findings support the current suggestions that both binary and single progenitor channels are in effect in producing SNe Ib/Ic. This work also demonstrates the power of integral field spectroscopy in investigating SN environments and active star-forming regions.

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

International Nuclear Information System (INIS)

Vogel, J.S.

2005-01-01

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 14 C-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 3 H or 14 C as common isotopic labels, but AMS contributes to elemental tracing with certain radioisotopes having very long lives, such as 26 AL or 41 Ca. Calcium-41 is a particularly useful isotope in biomedical research because it is used

Electric fields in accelerating conductors: measurement of the EMF in rotationally accelerating coils

Energy Technology Data Exchange (ETDEWEB)

Moorhead, G.F.; Opat, G.I.

1996-06-06

The acceleration of an electric conductor is predicted to produce an electric filed proportional to m/q where `m`is the free mass and `q` the charge of the carriers of the electric current. In certain configurations this leads to a measurable electromagnetic field (EMF). In this paper is reported a measurement of the EMF induced by rotationally accelerating coils of aluminium and copper wire. The measured EMFs are found to agree with the theoretical predictions to within the error estimates. 23 refs., 1 tab., 4 figs.

Electric fields in accelerating conductors: measurement of the EMF in rotationally accelerating coils

International Nuclear Information System (INIS)

Moorhead, G.F.; Opat, G.I.

1996-01-01

The acceleration of an electric conductor is predicted to produce an electric filed proportional to m/q where 'm'is the free mass and 'q' the charge of the carriers of the electric current. In certain configurations this leads to a measurable electromagnetic field (EMF). In this paper is reported a measurement of the EMF induced by rotationally accelerating coils of aluminium and copper wire. The measured EMFs are found to agree with the theoretical predictions to within the error estimates. 23 refs., 1 tab., 4 figs

Challenges to Constraining Exoplanet Masses via Transmission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Batalha, Natasha E. [Department of Astronomy and Astrophysics, Pennsylvania State University, State College, PA 16802 (United States); Kempton, Eliza M.-R. [Department of Physics, Grinnell College, 1116 8th Avenue, Grinnell, IA 50112 (United States); Mbarek, Rostom, E-mail: neb149@psu.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2017-02-10

MassSpec , a method for determining the mass of a transiting exoplanet from its transmission spectrum alone, was proposed by de Wit and Seager. The premise of this method relies on the planet’s surface gravity being extracted from the transmission spectrum via its effect on the atmospheric scale height, which in turn determines the strength of absorption features. Here, we further explore the applicability of MassSpec to low-mass exoplanets—specifically those in the super-Earth size range for which radial velocity determinations of the planetary mass can be extremely challenging and resource intensive. Determining the masses of these planets is of the utmost importance because their nature is otherwise highly unconstrained. Without knowledge of the mass, these planets could be rocky, icy, or gas-dominated. To investigate the effects of planetary mass on transmission spectra, we present simulated observations of super-Earths with atmospheres made up of mixtures of H{sub 2}O and H{sub 2}, both with and without clouds. We model their transmission spectra and run simulations of each planet as it would be observed with James Webb Space Telescope using the NIRISS, NIRSpec, and MIRI instruments. We find that significant degeneracies exist between transmission spectra of planets with different masses and compositions, making it impossible to unambiguously determine the planet’s mass in many cases.

Challenges to Constraining Exoplanet Masses via Transmission Spectroscopy

International Nuclear Information System (INIS)

Batalha, Natasha E.; Kempton, Eliza M.-R.; Mbarek, Rostom

2017-01-01

MassSpec , a method for determining the mass of a transiting exoplanet from its transmission spectrum alone, was proposed by de Wit and Seager. The premise of this method relies on the planet’s surface gravity being extracted from the transmission spectrum via its effect on the atmospheric scale height, which in turn determines the strength of absorption features. Here, we further explore the applicability of MassSpec to low-mass exoplanets—specifically those in the super-Earth size range for which radial velocity determinations of the planetary mass can be extremely challenging and resource intensive. Determining the masses of these planets is of the utmost importance because their nature is otherwise highly unconstrained. Without knowledge of the mass, these planets could be rocky, icy, or gas-dominated. To investigate the effects of planetary mass on transmission spectra, we present simulated observations of super-Earths with atmospheres made up of mixtures of H 2 O and H 2 , both with and without clouds. We model their transmission spectra and run simulations of each planet as it would be observed with James Webb Space Telescope using the NIRISS, NIRSpec, and MIRI instruments. We find that significant degeneracies exist between transmission spectra of planets with different masses and compositions, making it impossible to unambiguously determine the planet’s mass in many cases.

Radiocarbon dating by accelerator mass spectrometry: some recent results and applications

International Nuclear Information System (INIS)

Hedges, R.E.M.

1987-01-01

14 C differs from other nuclides measured by accelerator mass spectrometry (AMS) in that an extensive database of dates already exists. AMS dates should therefore have comparable accuracy, and the measurement of isotopic ratios to better than 1%, which was an important technical goal, has been reached. The main advantage of being able to date samples 1000 times smaller than previously lies in the extra selectivity that can be employed. This is reflected in the results and applications. Selection can apply at several levels; from objects that formerly contained too little carbon, to the choice of archaeological material, to the extraction of specific chemical compounds from a complex environmental sample. This is particularly useful in removing uncertainty regarding the validity of a date, since a given sample may comprise carbon atoms from different sources each with their own 14 C 'age'. Examples from archaeological and environmental research illustrating these points are given. 14 C dating by AMS differs from conventional radiocarbon dating by having the potential to measure much lower levels of 14 C, and therefore should double the time span of the method. This potential has not yet been realized because of sample contamination effects, and work in progress to reduce these is described. (author)

The hydroxylation of passive oxide films on X-70 steel by dissolved hydrogen studied by nuclear reaction analysis, Auger electron spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy

International Nuclear Information System (INIS)

Zhang Chunsi; Luo Jingli; Munoz-Paniagua, David; Norton, Peter R.

2006-01-01

Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron and its alloys, especially towards pitting corrosion. Electrochemical techniques have been used to show that the passive films are changed by dissolved hydrogen in an alloy substrate, but direct confirmation of the chemical and compositional profiles and changes has been missing. In this paper we report the direct profiling and compositional analysis of the 4 nm passive film on X-70 steel by Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and nuclear reaction analysis (NRA) while hydrogen (deuterium) is charged into the alloy samples from the reverse, unpassivated side. The only route for D to the passive film is therefore by dissolution and diffusion. We show that the original duplex structure of the passive film is converted to a more continuous film containing hydroxyl groups, by reaction with the dissolved hydrogen. This conversion of the oxide ions to hydroxyl groups can lead to more rapid reaction and replacement with (e.g.) Cl - , which is known to enhance pitting. These results are entirely consistent with previous electrochemical studies and provide the first direct confirmation of models on the formation and role of hydroxyl groups derived from these earlier studies

Impurity production and acceleration in CTIX

Energy Technology Data Exchange (ETDEWEB)

Buchenauer, D. [Sandia National Laboratories, MS-9161, P.O. Box 969, Livermore, CA 94550 (United States)], E-mail: dabuche@sandia.gov; Clift, W.M. [Sandia National Laboratories, MS-9161, P.O. Box 969, Livermore, CA 94550 (United States); Klauser, R.; Horton, R.D. [CTIX Group, University of California at Davis, Davis, CA 95616 (United States); Howard, S.J. [General Fusion Inc., Burnaby, BC V5A 3H4 (Canada); Brockington, S.J. [HyperV Technologies Corp., Chantilly, VA 20151 (United States); Evans, R.W.; Hwang, D.Q. [CTIX Group, University of California at Davis, Davis, CA 95616 (United States)

2009-06-15

The Compact Toroid Injection Experiment (CTIX) produces a high density, high velocity hydrogen plasma that maintains its configuration in free space on a MHD resistive time scale. In order to study the production and acceleration of impurities in the injector, several sets of silicon collector probes were exposed to spheromak-like CT's exiting the accelerator. Elemental analysis by Auger Electron Spectroscopy indicated the presence of O, Al, Fe, and Cu in films up to 200 A thickness (1000 CT interactions). Using a smaller number of CT interactions (10-20), implantation of Fe and Cu was measured by Auger depth profiling. The amount of impurities was found to increase with accelerating voltage and number of CT interactions while use of a solenoidal field reduced the amount. Comparison of the implanted Fe and Cu with TRIM simulations indicated that the impurities were traveling more slowly than the hydrogen CT.

Accelerator mass spectrometry at Arizona: geochronology of the climate record and connections with the ocean

International Nuclear Information System (INIS)

Jull, A.J.T.; Burr, G.S.; Beck, J.W.; Donahue, D.J.; Biddulph, D.; Hatheway, A.L.; Lange, T.E.; McHargue, L.R.

2003-01-01

There are many diverse uses of accelerator mass spectrometry (AMS). Carbon-14 studies at our laboratory include much research related to paleoclimate, both with 14 C as a tracer of past changes in environmental conditions as observed in corals, marine sediments and many terrestrial records. Terrestrial records such as forest fires can also show the influence of oceanic oscillations, whether they are short-term such as ENSO, or on the millennial time scale. In tracer applications, we have developed the use of 129 I as well as 14 C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson for several of these fields and hope to give some idea of the breadth of these studies

Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

Directory of Open Access Journals (Sweden)

J.T. Jull

2002-01-01

Full Text Available There are many diverse uses of accelerator mass spectrometry (AMS. 14C studies at our laboratory include much research related to paleoclimate, with 14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation, or on the millennial time scale. In tracer applications, we have developed the use of 129I as well as 14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

Pelletron ion accelerator facilities at Inter University Accelerator Centre

International Nuclear Information System (INIS)

Chopra, S.

2011-01-01

Inter University Accelerator Centre has two tandem ion accelerators, 15UD Pelletron and 5SDH-2 Pelletron, for use in different areas of research. Recently Accelerator Mass Spectrometry facility has also been added to to the existing experimental facilities of 15UD Pelletron. In these years many modifications and up gradations have been performed to 15UD Pelletron facility. A new MCSNICS ion source has been procured to produce high currents for AMS program. Two foils stripper assemblies ,one each before and after analyzing magnet, have also been added for producing higher charge state beams for LINAC and for experiments requiring higher charge states of accelerated beams. A new 1.7 MV Pelletron facility has also been recently installed at IUAC and it is equipped with RBS and Channelling experimental facility. There are two beam lines installed in the system and five more beam lines can be added to the system. A clean chemistry laboratory with all the modern facilities has also been developed at IUAC for the chemical processing of samples prior to the AMS measurements. The operational description of the Pelletron facilities, chemical processing of samples, methods of measurements and results of AMS measurements are being presented. (author)

Genotoxicity study on nicotine and nicotine-derived nitrosamine by accelerator mass spectrometry

International Nuclear Information System (INIS)

Li, X.S.; Wang, H.F.; Shi, J.Y.; Wang, X.Y.; Liu, Y.F.; Li, K.; Lu, X.Y.; Wang, J.J.; Liu, K.X.; Guo, Z.Y.

1997-01-01

The authors have studied DNA adduction with 14 C-labelled nicotine and nicotine-derived nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), by accelerator mass spectrometry (AMS) in mouse liver at doses equivalent to low-level exposure of humans. The dose ranges of nicotine and NNK administered were from 0.4 μg to 4.0 x 10 2 μg·kg -1 , and from 0.1 μg to 2.0 x 10 4 μg·kg -1 , respectively. In the exposure of mice to either nicotine or NNK, the number of DNA adducts increased linearly with increasing dose. The detection limit of DNA adducts was 1 adduct per 10 11 nucleotide molecules. This limit is 1-4 orders of magnitude lower than that of other techniques used for quantification of DNA adducts. The results of the animal experiments enabled us to speculate that nicotine is a potential carcinogen. According to the procedure for 14 C-labelled-NNK synthesis, the authors discuss the ultimate chemical speciation of NNK bound to DNA. From the animal tests the authors derived a directly perceivable relation between tobacco consumption and DNA adduction as the carcinogenic risk assessment

Evaluation of 14C abundance in soil respiration using accelerator mass spectrometry

International Nuclear Information System (INIS)

Koarashi, Jun; Iida, Takao; Moriizumi, Jun; Asano, Tomohiro

2004-01-01

To clarify the behavior of 14 C in terrestrial ecosystems, 14 C abundance in soil respiration was evaluated in an urban forest with a new method involving a closed chamber technique and 14 C measurement by accelerator mass spectrometry (AMS). Soil respiration had a higher Δ 14 C than the contemporary atmosphere. This indicates that a significant portion of soil respiration is derived from the decomposition of soil organic matter enriched in 14 C by atmospheric nuclear weapons tests, with a notable time lag between atmospheric 14 C addition and re-emission from soil. On the other hand, δ 14 C in soil respiration demonstrated that 14 C abundance ratio itself in soil-respired CO 2 is not always high compared with that in atmospheric CO 2 because of the isotope fractionation during plant photosynthesis and microbial decomposition of soil organic matter. The Δ 14 C in soil respiration was slightly lower in August than in March, suggesting a relatively high contribution of plant root respiration and decomposition of newly accumulated and/or 14 C-depleted soil organic matter to the total soil respiration in August

Accelerator and Fusion Research Division: 1987 summary of activities

International Nuclear Information System (INIS)

1988-04-01

An overview of the design and the initial studies for the Advanced Light Source is given. The research efforts for the Center for X-Ray Optics include x-ray imaging, multilayer mirror technology, x-ray sources and detectors, spectroscopy and scattering, and synchrotron radiation projects. The Accelerator Operations highlights include the research by users in nuclear physics, biology and medicine. The upgrade of the Bevalac is also discussed. The High Energy Physics Technology review includes the development of superconducting magnets and superconducting cables. A review of the Heavy-Ion Fusion Accelerator Research is also presented. The Magnetic Fusion Energy research included the development of ion sources, accelerators for negative ions, diagnostics, and theoretical plasma physics

Accelerator and Fusion Research Division: 1987 summary of activities

Energy Technology Data Exchange (ETDEWEB)

1988-04-01

An overview of the design and the initial studies for the Advanced Light Source is given. The research efforts for the Center for X-Ray Optics include x-ray imaging, multilayer mirror technology, x-ray sources and detectors, spectroscopy and scattering, and synchrotron radiation projects. The Accelerator Operations highlights include the research by users in nuclear physics, biology and medicine. The upgrade of the Bevalac is also discussed. The High Energy Physics Technology review includes the development of superconducting magnets and superconducting cables. A review of the Heavy-Ion Fusion Accelerator Research is also presented. The Magnetic Fusion Energy research included the development of ion sources, accelerators for negative ions, diagnostics, and theoretical plasma physics. (WRF)

Accelerator mass spectrometry in biomedical research

International Nuclear Information System (INIS)

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

1993-01-01

Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10 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 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. 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. 3 H, 41 Ca and 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

Spectroscopy of 186 Pb with mass identification

International Nuclear Information System (INIS)

Baxter, A.M.; Byrne, A.P.; Australian National Univ., Canberra, ACT; Dracoulis, G.D.; Janssens, R.V.F.; Bearden, I.G.; Henry, R.G.

1993-10-01

Transitions in the very neutron-deficient isotope 186 Pb have been identified in mass-gated, recoil-γ and recoil-γ-γ coincidence data obtained with a Fragment Mass Analyser and Compton-suppressed Ge-detector array. The results of the present work confirm and extend a band of levels tentatively proposed in earlier work done elsewhere, and provide a definitive mass assignment of the observed transitions. The band observed in 186 Pb bears a very close resemblance to the yrast band in the isotones 184 Hg, supporting the view that the 186 Pb band is built upon a prolate structure. 11 refs., 4 figs., 1 tab

Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

2016-05-15

Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

Science.gov (United States)

Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

2016-05-01

Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

Annual report of the Tandem Accelerator Center, University of Tsukuba

International Nuclear Information System (INIS)

Furuno, K.; Shima, K.; Komatsubara, T.

1992-09-01

This annual report includes the research activities and the technical developments carried out at the Tandem Accelerator Center in University of Tsukuba for the period from April 1991 to March 1992. Research activities covered the following subjects. Experimental investigations were made on 1) nuclear spectroscopy of high-spin rotational states and high-spin isomers in odd-odd nuclei, anomalous Fermi-coupling constant in the β decay of 35 Ar and the search for new isotopes around the mass number 90; 2) polarization phenomena in nuclear reactions; 3) the application of energetic heavy ions to solid state physics; 4) the properties of defects in metal produced by proton irradiation; 5) the magnetic properties of LiVO 2 by NMR; 6) off line Moessbauer studies; and 7) the mechanism of micro-cluster formation at the surface of material by heavy-ion bombardment. Theoretical work pertinent to the nuclear collective motion and the relativistic mean-field theory is also included in this report. (J.P.N.)

High temperature experiment for accelerator inertial fusion

International Nuclear Information System (INIS)

Lee, E.P.

1985-01-01

The High Temperature Experiment (HTE) is intended to produce temperatures of 50-100 eV in solid density targets driven by heavy ion beams from a multiple beam induction linac. The fundamental variables (particle species, energy number of beamlets, current and pulse length) must be fixed to achieve the temperature at minimum cost, subject to criteria of technical feasibility and relevance to the development of a Fusion Driver. The conceptual design begins with an assumed (radiation-limited) target temperature and uses limitations due to particle range, beamlet perveance, and target disassembly to bound the allowable values of mass number (A) and energy (E). An accelerator model is then applied to determine the minimum length accelerator, which is a guide to total cost. The accelerator model takes into account limits on transportable charge, maximum gradient, core mass per linear meter, and head-to-tail momentum variation within a pulse

Application of accelerator mass spectrometry to environmental research, Trial of GC-AMS

International Nuclear Information System (INIS)

Shibata, Yasuyuki

2003-01-01

The accelerator analysis facility of the National Institute for Environmental Studies, which aims to develop a new device capable of measuring "1"4C age for each compound, is promoting the study to establish the GC-AMS that combines two-dimensional gas chromatograph (GC) and accelerator mass spectrometry (AMS). The on-line GC-AMS system for the metabolic measurement of "1"4C-labeled compounds for medicinal biochemical research is a system, in which a GC-separated sample is continuously converted into CO_2 in a combustion tube and introduced directly to a gas ion source to continuously measure "1"4C. In the "1"4C detection experiment, the concentration of CO_2 gas was changed using a helium introduction line and a sample injection valve, and CO_2 gas plus helium gas were introduced into the gas ion source. As a result, it was found that the online GC-AMS has feasibility and high potential capability. For off-line GC-AMS for environmental samples, after purification with preparative gas chromatography, the sample is converted to graphite in a vacuum line and applied to common AMS measurement. The authors collected Northwest Pacific Ocean bottom sediment cores, and performed the extraction and purification of fatty acids of specific stratigraphy and the "1"4C measurement of each compound. The age of the compound derived from the surface layer planktons was the result capable of indicating the sedimentary age of the stratigraphy. In addition, as an application study to explore the source of pollutants in the environment using "1"4C as a tracer representing the characteristics of each source, the authors started to conduct the research choosing atmospheric dust samples. As a starting point, the authors attempted to measure the "1"4C concentration of vehicle exhaust particles and incinerator fly ash particles respectively. There was hardly any "1"4C in vehicle exhaust particles. (A.O.)

"1"4C ages and calendar years of Japanese swords measured with accelerator mass spectrometry

International Nuclear Information System (INIS)

Nagata, Kazuhiro; Matsubara, Akihiro; Kokubu, Yoko; Nakamura, Toshio

2016-01-01

Steel of Japanese swords has been produced with Tatara process from iron sand and charcoal. Carbon dissolved in steel was absorbed from wooden charcoal fuel during the production of the steel. From the decay of "1"4C activity in the steel, the "1"4C age of Japanese sword can be determined. The "1"4C ages of 4 Japanese swords were measured with accelerator mass spectrometry and calibrated to calendar years. Each "1"4C age provided plural calendar year periods with definite probabilities, and one of the periods agreed with the production year of each sword that was determined from the sword master's name cut in the grip of his sword after taking the age range of charcoal used for steel production and usage for several generations of the same names of sword masters into account. (author)

Adduction of DNA with MTBE and TBA in mice studied by accelerator mass spectrometry.

Science.gov (United States)

Yuan, Y; Wang, H F; Sun, H F; Du, H F; Xu, L H; Liu, Y F; Ding, X F; Fu, D P; Liu, K X

2007-12-01

Methyl tert-butyl ether (MTBE) is a currently worldwide used octane enhancer substituting for lead alkyls and gasoline oxygenate. Our previous study using doubly (14)C-labeled MTBE [(CH(3))(3) (14)CO(14)CH(3)] has shown that MTBE binds DNA to form DNA adducts at low dose levels in mice. To elucidate the mechanism of the binding reaction, in this study, the DNA adducts with singly (14)C-labeled MTBE, which was synthesized from (14)C-methanol and tert-butyl alcohol (TBA), or (14)C-labeled TBA in mice have been measured by ultra sensitive accelerator mass spectrometry. The results show that the methyl group of MTBE and tert-butyl alcohol definitely form adducts with DNA in mouse liver, lung, and kidney. The methyl group of MTBE is the predominant binding part in liver, while the methyl group and the tert-butyl group give comparable contributions to the adduct formation in lung and kidney.

Effective Acceleration Model for the Arrival Time of Interplanetary Shocks driven by Coronal Mass Ejections

Science.gov (United States)

Paouris, Evangelos; Mavromichalaki, Helen

2017-12-01

In a previous work (Paouris and Mavromichalaki in Solar Phys. 292, 30, 2017), we presented a total of 266 interplanetary coronal mass ejections (ICMEs) with as much information as possible. We developed a new empirical model for estimating the acceleration of these events in the interplanetary medium from this analysis. In this work, we present a new approach on the effective acceleration model (EAM) for predicting the arrival time of the shock that preceds a CME, using data of a total of 214 ICMEs. For the first time, the projection effects of the linear speed of CMEs are taken into account in this empirical model, which significantly improves the prediction of the arrival time of the shock. In particular, the mean value of the time difference between the observed time of the shock and the predicted time was equal to +3.03 hours with a mean absolute error (MAE) of 18.58 hours and a root mean squared error (RMSE) of 22.47 hours. After the improvement of this model, the mean value of the time difference is decreased to -0.28 hours with an MAE of 17.65 hours and an RMSE of 21.55 hours. This improved version was applied to a set of three recent Earth-directed CMEs reported in May, June, and July of 2017, and we compare our results with the values predicted by other related models.

A comparative study of 129I content in environmental standard materials IAEA-375, NIST SRM 4354 and NIST SRM 4357 by Thermal Ionization Mass Spectrometry and Accelerator Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Olson, John; Adamic, Mary; Snyder, Darin; Brookhart, Jacob; Hahn, Paula; Watrous, Matthew

2016-11-01

Iodine environmental measurements have consistently been backed up in the literature by standard materials like IAEA-375, Chernobyl Soil. There are not many other sources of a certified reference material for 129I content for mass spectrometry measurements. Some that have been found in the literature include NIST-4354 and NIST-4357. They are still available at the time of this writing. They don’t have certified content or isotopic values. There has been some work in the literature to show that iodine is present, but there hasn’t been enough to establish a consensus value. These materials have been analyzed at INL through two separate mass spectrometry techniques. They involve a combustion method of the starting material in oxygen, followed by TIMS analysis and a leaching preparation analyzed by accelerator mass spectrometry. Combustion/TIMS preparation of NIST SRM-4354 resulted in a 129I/127I ratio of 1.92 x 10-6 which agrees with AMS measurements which measured the 129I/127I ratio to be 1.93 x 10-6.

Advances in fast-atom-bombardment mass spectroscopy

International Nuclear Information System (INIS)

Hemling, M.E.

1986-01-01

A comparison of fast atom bombardment and field desorption mass spectrometry was made to determine relative sensitivity and applicability. A series of glycosphingolipids and a series of protected oligonucleotides of known structure were analyzed to ascertain the potential utility of fast atom bombardment mass spectrometry in the structural elucidation of novel compounds in these classes. Negative ion mass markers were also developed. Fast atom bombardment was found to be one-to-two orders of magnitude more sensitive than field desorption based on the analysis of a limited number of compounds from several classes. Superior sensitivity was not universal and field desorption was clearly better in certain cases. In the negative ion mode in particular, fast atom bombardment was found to be a useful tool for the determination of the primary structure of glycosphingolipids and oligonucleotides. Carbohydrate sequence and branching information, and a fatty acid and lipid base composition were readily obtained from the mass spectra of glycosphingolipids while bidirectional nucleotide sequence, nucleotide base, and protecting group assignments were obtained for oligonucleotides. Based on this knowledge, a tentative structure of a human peripheral nervous system glycosphingolipid implicated in certain cases of disorders such as amyotrophic lateral sclerosis, Lou Gehrig's Disease, was proposed. Suitable negative ion mass markers were found in dispersions of poly(ethylene) and poly(propylene)glycols in a triethylenetetramine matrix, a matrix which also proved useful in the analysis of glycosphingolipids. These polyglycol dispersions provided ions for calibration to 2300 daltons

Metabolic profiling of yeast culture using gas chromatography coupled with orthogonal acceleration accurate mass time-of-flight mass spectrometry: application to biomarker discovery.

Science.gov (United States)

Kondo, Elsuida; Marriott, Philip J; Parker, Rhiannon M; Kouremenos, Konstantinos A; Morrison, Paul; Adams, Mike

2014-01-07

Yeast and yeast cultures are frequently used as additives in diets of dairy cows. Beneficial effects from the inclusion of yeast culture in diets for dairy mammals have been reported, and the aim of this study was to develop a comprehensive analytical method for the accurate mass identification of the 'global' metabolites in order to differentiate a variety of yeasts at varying growth stages (Diamond V XP, Yea-Sacc and Levucell). Microwave-assisted derivatization for metabolic profiling is demonstrated through the analysis of differing yeast samples developed for cattle feed, which include a wide range of metabolites of interest covering a large range of compound classes. Accurate identification of the components was undertaken using GC-oa-ToFMS (gas chromatography-orthogonal acceleration-time-of-flight mass spectrometry), followed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) for data reduction and biomarker discovery. Semi-quantification (fold changes in relative peak areas) was reported for metabolites identified as possible discriminative biomarkers (p-value 2), including D-ribose (four fold decrease), myo-inositol (five fold increase), L-phenylalanine (three fold increase), glucopyranoside (two fold increase), fructose (three fold increase) and threitol (three fold increase) respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Tau/Charm Factory Accelerator Report

OpenAIRE

M. E. BiaginiINFN, Laboratori Nazionali Frascati, Italy; R. BoniINFN, Laboratori Nazionali Frascati, Italy; M. BoscoloINFN, Laboratori Nazionali Frascati, Italy; A. ChiarucciINFN, Laboratori Nazionali Frascati, Italy; R. CiminoINFN, Laboratori Nazionali Frascati, Italy; A. ClozzaINFN, Laboratori Nazionali Frascati, Italy; A. DragoINFN, Laboratori Nazionali Frascati, Italy; S. GuiducciINFN, Laboratori Nazionali Frascati, Italy; C. LigiINFN, Laboratori Nazionali Frascati, Italy; G. MazzitelliINFN, Laboratori Nazionali Frascati, Italy; R. RicciINFN, Laboratori Nazionali Frascati, Italy; C. SanelliINFN, Laboratori Nazionali Frascati, Italy; M. SerioINFN, Laboratori Nazionali Frascati, Italy; A. StellaINFN, Laboratori Nazionali Frascati, Italy; S. TomassiniINFN, Laboratori Nazionali Frascati, Italy

2014-01-01

The present Report concerns the current status of the Italian Tau/Charm accelerator project and in particular discusses the issues related to the lattice design, to the accelerators systems and to the associated conventional facilities. The project aims at realizing a variable energy Flavor Factory between 1 and 4.6 GeV in the center of mass, and succeeds to the SuperB project from which it inherits most of the solutions proposed in this document. The work comes from a cooperation involving t...

Mass spectrometric comparison of swift heavy ion-induced and anaerobic thermal degradation of polymers

Science.gov (United States)

Lima, V.; Hossain, U. H.; Walbert, T.; Seidl, T.; Ensinger, W.

2018-03-01

The study of polymers irradiated by highly energetic ions and the resulting radiation-induced degradation is of major importance for space and particle accelerator applications. The mechanism of ion-induced molecular fragmentation of polyethylene, polyethyleneimine and polyamide was investigated by means of mass spectrometry and infrared spectroscopy. The results show that the introduction of nitrogen and oxygen into the polymer influences the stability rendering aliphatic polymers with heteroatoms less stable. A comparison to thermal decomposition data from literature reveals that ion-induced degradation is different in its bond fracture mechanism. While thermal degradation starts at the weakest bond, which is usually the carbon-heteroatom bond, energetic ion irradiation leads in the first step to scission of all types of bonds creating smaller molecular fragments. This is due to the localized extreme energy input under non-equilibrium conditions when the ions transfer kinetic energy onto electrons. These findings are of relevance for the choice of polymers for long-term application in both space and accelerator facilities.

Accelerator System Development at High Voltage Engineering

International Nuclear Information System (INIS)

Klein, M. G.; Gottdang, A.; Haitsma, R. G.; Mous, D. J. W.

2009-01-01

Throughout the years, HVE has continuously extended the capabilities of its accelerator systems to meet the rising demands from a diverse field of applications, among which are deep level ion implantation, micro-machining, neutron production for biomedical research, isotope production or accelerator mass spectrometry. Characteristic for HVE accelerators is the coaxial construction of the all solid state power supply around the acceleration tubes. With the use of solid state technology, the accelerators feature high stability and very low ripple. Terminal voltages range from 1 to 6 MV for HVE Singletrons and Tandetrons. The high-current versions of these accelerators can provide ion beams with powers of several kW. In the last years, several systems have been built with terminal voltages of 1.25 MV, 2 MV and 5 MV. Recently, the first system based on a 6 MV Tandetron has passed the factory tests. In this paper we describe the characteristics of the HVE accelerator systems and present as example recent systems.

CEBAF at higher energies: Working group report on hadron spectroscopy and production

Energy Technology Data Exchange (ETDEWEB)

Barnes, T. [Oak Ridge National Laboratory, TN (United States)]| [Univ. of Tennessee, Knoxville (United States); Napolitano, J. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1994-04-01

This report summarizes topics in hadron spectroscopy and production which could be addressed at CEBAF with an energy upgrade to E{sub {gamma}} = 8 GeV and beyond. The topics discussed include conventional meson and baryon spectrocopy, spectroscopy of exotica (especially molecules and hybrids), CP and CPT tests using {phi} mesons, and new detector and accelerator options.

Seismic structural response analysis using consistent mass matrices having dynamic coupling

International Nuclear Information System (INIS)

Shaw, D.E.

1977-01-01

The basis for the theoretical development of this paper is the linear matrix equations of motion for an unconstrained structure subject to support excitation. The equations are formulated in terms of absolute displacement, velocity and acceleration vectors. By means of a transformation of the absolute response vectors into displacements, velocities and accelerations relative to the support motions, the homogeneous equations become non-homogeneous and the non-homogeneous boundary conditions become homogeneous with relative displacements, velocities and accelerations being zero at support points. The forcing function or inertial loading vector is shown to consist of two parts. The first part is comprised of the mass matrix times the suppport acceleration function times a vector of structural displacements resulting from a unit vector of support displacements in the direction of excitation. This inertial loading corresponds to the classical seismic loading vector and is indeed the only loading vector for lumped-mass systems. The second part of he inertial loading vectors consists of the mass matrix times the support acceleration function times a vector of structural accelerations resulting from unit support accelerations in the direction of excitation. This term is not present in classical seismic analysis formulations and results from the presence of off-diagonal terms in the mass matrices which give rise to dynamic coupling through the mass matrix. Thus, for lumped-mass models, the classical formulation of the inertial loading vector is correct. However, if dynamic coupling terms are included through off-diagonal terms in the mass matrix, an additional inertia loading vector must be considered

Accelerated Optimization in the PDE Framework: Formulations for the Manifold of Diffeomorphisms

KAUST Repository

Sundaramoorthi, Ganesh

2018-04-04

We consider the problem of optimization of cost functionals on the infinite-dimensional manifold of diffeomorphisms. We present a new class of optimization methods, valid for any optimization problem setup on the space of diffeomorphisms by generalizing Nesterov accelerated optimization to the manifold of diffeomorphisms. While our framework is general for infinite dimensional manifolds, we specifically treat the case of diffeomorphisms, motivated by optical flow problems in computer vision. This is accomplished by building on a recent variational approach to a general class of accelerated optimization methods by Wibisono, Wilson and Jordan, which applies in finite dimensions. We generalize that approach to infinite dimensional manifolds. We derive the surprisingly simple continuum evolution equations, which are partial differential equations, for accelerated gradient descent, and relate it to simple mechanical principles from fluid mechanics. Our approach has natural connections to the optimal mass transport problem. This is because one can think of our approach as an evolution of an infinite number of particles endowed with mass (represented with a mass density) that moves in an energy landscape. The mass evolves with the optimization variable, and endows the particles with dynamics. This is different than the finite dimensional case where only a single particle moves and hence the dynamics does not depend on the mass. We derive the theory, compute the PDEs for accelerated optimization, and illustrate the behavior of these new accelerated optimization schemes.

Accelerated Optimization in the PDE Framework: Formulations for the Manifold of Diffeomorphisms

KAUST Repository

Sundaramoorthi, Ganesh; Yezzi, Anthony

2018-01-01

We consider the problem of optimization of cost functionals on the infinite-dimensional manifold of diffeomorphisms. We present a new class of optimization methods, valid for any optimization problem setup on the space of diffeomorphisms by generalizing Nesterov accelerated optimization to the manifold of diffeomorphisms. While our framework is general for infinite dimensional manifolds, we specifically treat the case of diffeomorphisms, motivated by optical flow problems in computer vision. This is accomplished by building on a recent variational approach to a general class of accelerated optimization methods by Wibisono, Wilson and Jordan, which applies in finite dimensions. We generalize that approach to infinite dimensional manifolds. We derive the surprisingly simple continuum evolution equations, which are partial differential equations, for accelerated gradient descent, and relate it to simple mechanical principles from fluid mechanics. Our approach has natural connections to the optimal mass transport problem. This is because one can think of our approach as an evolution of an infinite number of particles endowed with mass (represented with a mass density) that moves in an energy landscape. The mass evolves with the optimization variable, and endows the particles with dynamics. This is different than the finite dimensional case where only a single particle moves and hence the dynamics does not depend on the mass. We derive the theory, compute the PDEs for accelerated optimization, and illustrate the behavior of these new accelerated optimization schemes.

The ROSPHERE γ-ray spectroscopy array

Energy Technology Data Exchange (ETDEWEB)

Bucurescu, D.; Căta-Danil, I.; Ciocan, G.; Costache, C.; Deleanu, D.; Dima, R. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); Filipescu, D. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); Extreme Light Infrastructure Nuclear Physics - ELI-NP, Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); Florea, N.; Ghiţă, D.G.; Glodariu, T.; Ivaşcu, M.; Lică, R.; Mărginean, N.; Mărginean, R. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); Mihai, C., E-mail: cmihai@tandem.nipne.ro [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); Negret, A.; Niţă, C.R.; Olăcel, A.; Pascu, S.; Sava, T. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN-HH, R-077125 Bucharest (Romania); and others

2016-11-21

The ROmanian array for SPectroscopy in HEavy ion REactions (ROSPHERE) has been designed as a multi-detector setup dedicated to γ-ray spectroscopy studies at the Bucharest 9 MV Tandem accelerator. Consisting of up to 25 detectors (either Compton suppressed HPGe detectors or fast LaBr{sub 3}(Ce) scintillator detectors) together with a state of the art plunger device, ROSPHERE is a powerful tool for lifetime measurements using the Recoil Distance Doppler Shift (RDDS) and the in-beam Fast Electronic Scintillation Timing (FEST) methods. The array's geometry, detectors, electronics and data acquisition system are described. Selected results from the first experimental campaigns are also presented.

Future HEP Accelerators: The US Perspective

Energy Technology Data Exchange (ETDEWEB)

Bhat, Pushpalatha [Fermilab; Shiltsev, Vladimir [Fermilab

2015-11-02

Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN through its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed and are currently under consideration for the medium- and long-term future programs of accelerator-based HEP research. In this paper, we briefly review the post-LHC energy frontier options, both for lepton and hadron colliders in various regions of the world, as well as possible future intensity frontier accelerator facilities.

{sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

Energy Technology Data Exchange (ETDEWEB)

Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

1999-03-01

The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

Clock hypothesis of relativity theory, maximal acceleration, and Mössbauer spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Potzel, W., E-mail: wpotzel@ph.tum.de [Technische Universität München, Physik-Department E15 (Germany)

2016-12-15

Results obtained several years ago using the high-resolution 93.3 keV Mössbauer resonance in {sup 67}ZnO and β{sup ′}-brass have been reanalyzed with the notion that the clock hypothesis of Special Relativity Theory is not sufficient, but that a maximal acceleration a{sub m} exists and that an acceleration a contributes to the temperature dependence of the center shift by a term ±(1/2)(a/a{sub m}){sup 2}. The significance of the sign of this term is discussed in detail. For both substances a lower limit of a{sub m}>1.5⋅10{sup 21}m/s {sup 2} is inferred which is more than two orders of magnitude larger than - and thus excludes - the value a{sub m}=1⋅10{sup 19}m/s {sup 2} suggested by {sup 57}Fe rotor experiments.

Measurements of natural levels of 14C in human's and rat's tissues by accelerator mass spectrometry in Korea

International Nuclear Information System (INIS)

Cho, S.Y.; Khu, H.J.; Kang, J.H.; Yoon, M.Y.; Kim, J.C.

2005-01-01

Accelerator mass spectrometry (AMS) is the most sensitive, safe and precise analytical method for quantifying long-lived isotope in biomedical research with animals as well as human beings. In Korea, AMS Laboratory has been operating successfully for years measuring especially archaeological samples for 14 C dating. In this year, a biological sample pretreatment facility was setup to work on biomedical applications. As a preliminary study, we have measured the natural background levels of 14 C in tissues and blood of humans and rats have been measured. The results were agreed with the other reported levels and gave stable and reproducible results within 1-2%. (author)

Wet-cleaning of MgO(001): Modification of surface chemistry and effects on thin film growth investigated by x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy

OpenAIRE

Le Febvrier, Arnaud; Jensen, Jens; Eklund, Per

2017-01-01

The effect of the wet-cleaning process using solvents and detergent on the surface chemistry of MgO(001) substrate for film deposition was investigated. Six different wet-cleaning processes using solvent and detergent were compared. The effect on film growth was studied by the example system ScN. The surface chemistry of the cleaned surface was studied by x-ray photoelectron spectroscopy and the film/substrate interface after film growth was investigated by time-of-flight secondary ion mass s...

Analysis of Cultural Heritage by Accelerator Techniques and Analytical Imaging

Science.gov (United States)

Ide-Ektessabi, Ari; Toque, Jay Arre; Murayama, Yusuke

2011-12-01

In this paper we present the result of experimental investigation using two very important accelerator techniques: (1) synchrotron radiation XRF and XAFS; and (2) accelerator mass spectrometry and multispectral analytical imaging for the investigation of cultural heritage. We also want to introduce a complementary approach to the investigation of artworks which is noninvasive and nondestructive that can be applied in situ. Four major projects will be discussed to illustrate the potential applications of these accelerator and analytical imaging techniques: (1) investigation of Mongolian Textile (Genghis Khan and Kublai Khan Period) using XRF, AMS and electron microscopy; (2) XRF studies of pigments collected from Korean Buddhist paintings; (3) creating a database of elemental composition and spectral reflectance of more than 1000 Japanese pigments which have been used for traditional Japanese paintings; and (4) visible light-near infrared spectroscopy and multispectral imaging of degraded malachite and azurite. The XRF measurements of the Japanese and Korean pigments could be used to complement the results of pigment identification by analytical imaging through spectral reflectance reconstruction. On the other hand, analysis of the Mongolian textiles revealed that they were produced between 12th and 13th century. Elemental analysis of the samples showed that they contained traces of gold, copper, iron and titanium. Based on the age and trace elements in the samples, it was concluded that the textiles were produced during the height of power of the Mongol empire, which makes them a valuable cultural heritage. Finally, the analysis of the degraded and discolored malachite and azurite demonstrates how multispectral analytical imaging could be used to complement the results of high energy-based techniques.

Cyclotron method for heavy ion acceleration

International Nuclear Information System (INIS)

Gikal, B.N.; Gul'bekyan, G.G.; Kutner, V.B.; Oganesyan, R.Ts.

1984-01-01

Studies on heavy ion beams in a wide range of masses (up to uranium) and energies disclose essential potential opportunities for solution of both fundamental scientific and significant economical problems. A cyclotron method for heavy ion acceleration is considered. Development of low and medium energy heavy ion accelerators is revealed. The design of a complex comprising two isochronous cyclotrons which is planned to be constrdcted 1n the JINR is described. The cyclotron complex includes the U-400 and the U-400 M cyclotrons and it is intended for acceleration of both 35-20 MeV/nucleon superheavy ions such as Xe-U and 120 MeV/nucleon light ions. Certain systems of the accelerators are described. Prospects of the U-400 and the U-400 M development are displayed

Miniature Piezoelectric Macro-Mass Balance

Science.gov (United States)

Sherrit, Stewart; Trebi-Ollennu, Ashitey; Bonitz, Robert G.; Bar-Cohen, Yoseph

2010-01-01

Mass balances usually use a strain gauge that requires an impedance measurement and is susceptible to noise and thermal drift. A piezoelectric balance can be used to measure mass directly by monitoring the voltage developed across the piezoelectric balance, which is linear with weight or it can be used in resonance to produce a frequency change proportional to the mass change (see figure). The piezoelectric actuator/balance is swept in frequency through its fundamental resonance. If a small mass is added to the balance, the resonance frequency shifts down in proportion to the mass. By monitoring the frequency shift, the mass can be determined. This design allows for two independent measurements of mass. Additionally, more than one sample can be verified because this invention allows for each sample to be transported away from the measuring device upon completion of the measurement, if required. A piezoelectric actuator, or many piezoelectric actuators, was placed between the collection plate of the sampling system and the support structure. As the sample mass is added to the plate, the piezoelectrics are stressed, causing them to produce a voltage that is proportional to the mass and acceleration. In addition, a change in mass delta m produces a change in the resonance frequency with delta f proportional to delta m. In a microgravity environment, the spacecraft could be accelerated to produce a force on the piezoelectric actuator that would produce a voltage proportional to the mass and acceleration. Alternatively, the acceleration could be used to force the mass on the plate, and the inertial effects of the mass on the plate would produce a shift in the resonance frequency with the change in frequency related to the mass change. Three prototypes of the mass balance mechanism were developed. These macro-mass balances each consist of a solid base and an APA 60 Cedrat flextensional piezoelectric actuator supporting a measuring plate. A similar structure with 3 APA

Electrospray ionizer for mass spectrometry of aerosol particles

Science.gov (United States)

He, Siqin; Hogan, Chris; Li, Lin; Liu, Benjamin Y. H.; Naqwi, Amir; Romay, Francisco

2017-09-19

A device and method are disclosed to apply ESI-based mass spectroscopy to submicrometer and nanometer scale aerosol particles. Unipolar ionization is utilized to charge the particles in order to collect them electrostatically on the tip of a tungsten rod. Subsequently, the species composing the collected particles are dissolved by making a liquid flow over the tungsten rod. This liquid with dissolved aerosol contents is formed into highly charged droplets, which release unfragmented ions for mass spectroscopy, such as time-of-flight mass spectroscopy. The device is configured to operate in a switching mode, wherein aerosol deposition occurs while solvent delivery is turned off and vice versa.

Accelerator mass spectrometry for analysis of 10Be. Applications in marine geology

International Nuclear Information System (INIS)

Segl, M.

1985-01-01

Using the Accelerator Mass Spectrometry the behaviour of long-lived (half time 1.5 Million years) cosmogenic isotopes 10 Be in a marine environment was examined. The geochemical behaviour of 10 Be in oceans was examined in a water profile of the eastern Atlantic and on sediment cores from the eastern Atlantic and the Antarctica. The retention period in oceans was calculated from the water profile to be 700-1000 years. The examination of sedimentary cores showed, that the 10 Be flow into the sediment in areas of high bioproductivity surpasses the production rate. Comparison of 10 Be flow with 230 Th flow into the examined sedimentary cores showed a period of retention of 10 Be in the ocean of only about 400 years. Changes in the sedimentation rate and changes in the mineralogical composition correlate with paleooceanographic events, the start of the Antarctica icing 14 million years ago, changes in the deep water circulation 6.5 million years ago and the icing over of the northern hemisphere 3 million years ago. The same paleooceanographic events find correlation with the inside structure of a total of 16 manganese nodes and crusts from diverse parts of the ocean which were also dated with 10 Be. (orig./DG) [de

Intracavity OptoGalvanic Spectroscopy not suitable for ambient level radiocarbon detection.

Science.gov (United States)

Paul, Dipayan; Meijer, Harro A J

2015-09-01

IntraCavity OptoGalvanic Spectroscopy as a radiocarbon detection technique was first reported by the Murnick group at Rutgers University, Newark, NJ, in 2008. This technique for radiocarbon detection was presented with tremendous potentials for applications in various fields of research. Significantly cheaper, this technique was portrayed as a possible complementary technique to the more expensive and complex accelerator mass spectrometry. Several groups around the world started developing this technique for various radiocarbon related applications. The IntraCavity OptoGalvanic Spectroscopy setup at the University of Groningen was constructed in 2012 in close collaboration with the Murnick group for exploring possible applications in the fields of radiocarbon dating and atmospheric monitoring. In this paper we describe a systematic evaluation of the IntraCavity OptoGalvanic Spectroscopy setup at Groningen for radiocarbon detection. Since the IntraCavity OptoGalvanic Spectroscopy setup was strictly planned for dating and atmospheric monitoring purposes, all the initial experiments were performed with CO2 samples containing contemporary levels and highly depleted levels of radiocarbon. Because of recurring failures in differentiating the two CO2 samples, with the radiocarbon concentration 3 orders of magnitude apart, CO2 samples containing elevated levels of radiocarbon were prepared in-house and experimented with. All results obtained thus far at Groningen are in sharp contrast to the results published by the Murnick group and rather support the results put forward by the Salehpour group at Uppsala University. From our extensive test work, we must conclude that the method is unsuited for ambient level radiocarbon measurements, and even highly enriched CO2 samples yield insignificant signal.

Accurate determination of 129I concentrations and 129I/137Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

2014-01-01

Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low 129 I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO 3 /HClO 4 , (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured 129 I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of 129 I/ 137 Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 129 I in spent resins using accelerator mass spectrometry. • The treatment procedure included microwave acid digestion of samples, iodine extraction by CL resins and AgI precipitation. • Developed first on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • 129 I concentrations ranged from 4 to 12 ng/g of dry resin. • Results are in agreement with previous measurements and support reference values currently used for nuclear resin management

Characterization and Accelerated Ageing of UHMWPE Used in Orthopedic Prosthesis by Peroxide

Science.gov (United States)

Rocha, Magda; Mansur, Alexandra; Mansur, Herman

2009-01-01

Ultra-high molecular weight polyethylene (UHMWPE) has been the most commonly used bearing material in total joint arthroplasty. Wear and oxidation fatigue resistance of UHMWPE are regarded as two important mechanical properties to extend the longevity of knee prostheses. Though accelerated in vitro protocols have been developed to test the relative oxidation resistance of various types of UHMWPE, its mechanism is not accurately understood yet. Thus, in the present study an accelerated ageing of UHMWPE in hydrogen peroxide solution was performed and relative oxidation was extensively characterized by Fourier Transformed Infrared Spectroscopy (FTIR) spectroscopy and the morphological changes were analyzed by Scanning Electron Microscopy (SEM). Different chemical groups of UHMWPE associated with the degradation reaction were monitored for over 120 days in order to evaluate the possible oxidation mechanism(s) which may have occurred. The results have provided strong evidence that the oxidation mechanism is rather complex, and two stages with their own particular first-order kinetics reaction patterns have been clearly identified. Furthermore, hydrogen peroxide has proven to be an efficient oxidative medium to accelerate ageing of UHMWPE.

The acceleration of particles at propagating interplanetary shocks

Science.gov (United States)

Prinsloo, P. L.; Strauss, R. D. T.

2017-12-01

Enhancements of charged energetic particles are often observed at Earth following the eruption of coronal mass ejections (CMEs) on the Sun. These enhancements are thought to arise from the acceleration of those particles at interplanetary shocks forming ahead of CMEs, propagating into the heliosphere. In this study, we model the acceleration of these energetic particles by solving a set of stochastic differential equations formulated to describe their transport and including the effects of diffusive shock acceleration. The study focuses on how acceleration at halo-CME-driven shocks alter the energy spectra of non-thermal particles, while illustrating how this acceleration process depends on various shock and transport parameters. We finally attempt to establish the relative contributions of different seed populations of energetic particles in the inner heliosphere to observed intensities during selected acceleration events.

Preparation of rhodium target for cyclone-30 accelerator

International Nuclear Information System (INIS)

Deng Xuesong; Li Dakang; Xie Xiangqian; Li Chao

2002-01-01

The rhodium target for Cyclone-30 accelerator is prepared by pulse electroplating method. The effects of pulse parameters, rhodium concentration, acidity and temperature on the properties of the target layer are studied, and the optimal process is determined. The rhodium target, mass thickness is more than 150 mg/cm 2 , adapts to producing 103 Pd on Cyclone-30 accelerator

Optical Fiber Sensing Based on Reflection Laser Spectroscopy

Directory of Open Access Journals (Sweden)

Gianluca Gagliardi

2010-03-01

Full Text Available An overview on high-resolution and fast interrogation of optical-fiber sensors relying on laser reflection spectroscopy is given. Fiber Bragg-gratings (FBGs and FBG resonators built in fibers of different types are used for strain, temperature and acceleration measurements using heterodyne-detection and optical frequency-locking techniques. Silica fiber-ring cavities are used for chemical sensing based on evanescent-wave spectroscopy. Various arrangements for signal recovery and noise reduction, as an extension of most typical spectroscopic techniques, are illustrated and results on detection performances are presented.

Forensic Sampling and Analysis from a Single Substrate: Surface-Enhanced Raman Spectroscopy Followed by Paper Spray Mass Spectrometry.

Science.gov (United States)

Fedick, Patrick W; Bills, Brandon J; Manicke, Nicholas E; Cooks, R Graham

2017-10-17

Sample preparation is the most common bottleneck in the analysis and processing of forensic evidence. Time-consuming steps in many forensic tests involve complex separations, such as liquid and gas chromatography or various types of extraction techniques, typically coupled with mass spectrometry (e.g., LC-MS). Ambient ionization ameliorates these slow steps by reducing or even eliminating sample preparation. While some ambient ionization techniques have been adopted by the forensic community, there is significant resistance to discarding chromatography as most forensic analyses require both an identification and a confirmation technique. Here, we describe the use of a paper substrate, the surface of which has been inkjet printed with silver nanoparticles, for surface enhanced Raman spectroscopy (SERS). The same substrate can also act as the paper substrate for paper spray mass spectrometry. The coupling of SERS and paper spray ionization creates a quick, forensically feasible combination.

Future accelerators using micro-fabrication technology

International Nuclear Information System (INIS)

Maschke, A.W.

1983-01-01

Historically, each generation of new accelerators has produced a thousand-fold increase over their predecessors. Thus, the d.c. accelerators were surpassed by weak focusing cyclotrons and synchrotrons. Then strong focusing machines surpassed the weak focusing ones, and now we are in the process of designing machines for 10 to 20 TeV. This paper is devoted to the study of the next generation of accelerators which we can contemplate will be in the range of 1000 TeV. The radiation loss in a circular machine would correspond to approximately 20 TeV/turn. It is clear then that the future generation of accelerators will have to be linear accelerators. Furthermore, since the center of mass energy of a 1000 TeV machine is only approximately 1.5 TeV, these linacs will be built in pairs and operated primarily as linear colliders. This meas that the average beam power in one of the devices will be quite large. This in turn leads us toward high efficiency acceleration schemes, capable of high repetition rates. The poor efficiency of laser accelerators and other exotic proposals make them poor candidates for a future generation collider

RF-Based Accelerators for HEDP Research

CERN Document Server

Staples, John W; Keller, Roderich; Ostroumov, Peter; Sessler, Andrew M

2005-01-01

Accelerator-driven High-Energy Density Physics experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the "warm dense matter" regime. Traditionally the province of induction linacs, RF-based acceleration may be a viable alternative with recent breakthroughs in accelerating structures and high-field superconducting solenoids. A reference design for an RF-based accelerator for HEDP research is presented using 15 T solenoids and multiple-gap RF structures configured with either multiple parallel beams (combined at the target) or a single beam and a small stacking ring that accumulates 1 microcoulomb of charge. In either case, the beam is ballistically compressed with an induction linac core providing the necessary energy sweep and injected into a plasma-neutralized drift compression channel resulting in a 1 mm radius beam spot 1 nanosecond long at a thin foil or low-density target.

Heavy ion acceleration at the AGS

International Nuclear Information System (INIS)

Lee, Y.Y.

1989-01-01

The Brookhaven AGS is alternating gradient synchrotron, 807 meters in circumference, which was originally designed for only protons. Using the 15 MV Brookhaven Tandem Van de Graaff as an injector, the AGS started to accelerate heavy ions of mass lighter than sulfur. Because of the relatively poor vacuum (∼10 -8 Torr), the AGS is not able to accelerate heavier ions which could not be fully stripped of electrons at the Tandem energy. When the AGS Booster, which is under construction, is completed the operation will be extended to all species of heavy ions including gold and uranium. Because ultra-high vacuum (∼10 -11 Torr) is planned, the Booster can accelerate partially stripped elements. The operational experience, the parameters, and scheme of heavy ion acceleration will be presented in detail from injection to extraction, as well as future injection into the new Relativistic Heavy Ion Collider (RHIC). A future plan to improve intensity of the accelerator will also be presented. 5 figs., 4 tabs

ELYSE, a new picosecond electron accelerator at Orsay

International Nuclear Information System (INIS)

Belloni, J.D.; Gaillard, M.; Monard, H.; Larbre, J.-P.; Gobert, F.; Mostafavi, M.; Lampre, I.; Marignier, J.-L.

2003-01-01

ELYSE is a new instrument allowing to study fast kinetics processes at picosecond range by the complementary techniques of pulse radiolysis and laser photochemistry which was installed by the Laboratoire de Chimie Physique, University Paris-Sud, at Orsay. It was designed and constructed by the Linear Accelerator Laboratory, Orsay. The accelerator is a RF photocathode electron gun type which will deliver electron pulses of less than 5 ps FWHM. The Cs 2 Te cathode was chosen because of its high efficiency and long life time. Photoelectrons are generated by a picosecond synchronized laser system with a normal incidence. The charge per pulse is 1 nC with a dark current less than 1 % and a repetition frequency 1 to 50 Hz. Other detailed specifications of the accelerator, of the laser and of the optical spectroscopy detection set-up are described

Cosmological and astrophysical neutrino mass measurements

DEFF Research Database (Denmark)

Abazajian, K.N.; Calabrese, E.; Cooray, A.

2011-01-01

Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach.......Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach....

Gas chromatography with simultaneous detection: Ultraviolet spectroscopy, flame ionization, and mass spectrometry.

Science.gov (United States)

Gras, Ronda; Luong, Jim; Haddad, Paul R; Shellie, Robert A

2018-05-08

An effective analytical strategy was developed and implemented to exploit the synergy derived from three different detector classes for gas chromatography, namely ultraviolet spectroscopy, flame ionization, and mass spectrometry for volatile compound analysis. This strategy was achieved by successfully hyphenating a user-selectable multi-wavelength diode array detector featuring a positive temperature coefficient thermistor as an isothermal heater to a gas chromatograph. By exploiting the non-destructive nature of the diode array detector, the effluent from the detector was split to two parallel detectors; namely a quadrupole mass spectrometer and a flame ionization detector. This multi-hyphenated configuration with the use of three detectors is a powerful approach not only for selective detection enhancement but also for improvement in structural elucidation of volatile compounds where fewer fragments can be obtained or for isomeric compound analysis. With the diode array detector capable of generating high resolution gas phase spectra, the information collected provides useful confirmatory information without a total dependence on the chromatographic separation process which is based on retention time. This information-rich approach to chromatography is achieved without incurring extra analytical time, resulting in improvements in compound identification accuracy, analytical productivity, and cost. Chromatographic performance obtained from model compounds was found to be acceptable with a relative standard deviation of the retention times of less than 0.01% RSD, and a repeatability at two levels of concentration of 100 and 1000 ppm (v/v) of less than 5% (n = 10). With this configuration, correlation of data between the three detectors was simplified by having near identical retention times for the analytes studied. Copyright © 2018 Elsevier B.V. All rights reserved.

Issues in light meson spectroscopy: The case for meson spectroscopy at CEBAF

Energy Technology Data Exchange (ETDEWEB)

Godfrey, S. [Carleton Univ., Ottawa (Canada)

1994-04-01

The author reviews some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional q{bar q} mesons. The author therefore begins by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section the author discusses the opportunities that CEBAF can offer for the study of meson spectroscopy.

Nucleus spectroscopy: extreme masses and deformations

International Nuclear Information System (INIS)

Theisen, Ch.

2009-12-01

The author proposes a synthesis of research activities performed since 1995 in the field of experimental nuclear physics, and more particularly in the investigation of two nucleus extreme states: deformation on the one hand, heavy and very heavy nuclei on the other hand. After a presentation of the context of investigations on deformation, rotation, and heavy nuclei, he gives an overview of developments regarding instruments (gamma spectrometers, detection of fission fragments, and detection at the focal plane of spectrometers or separators) and analysis techniques. Experiments and results are then reported and discussed, concerning super-deformed states with a high angular moment, spectroscopy of neutron-rich nuclei, very heavy nuclei close to nucleus map borders. He finally draws perspectives for middle and long term studies on the heaviest nuclei

Breakdown Studies for the CLIC Accelerating

CERN Document Server

Calatroni, S; Kovermann, J; Taborelli, M; Timko, H; Wuensch, W; Durabekova, F; Nordlund, K; Pohjonen, A; Kuronen, A

2010-01-01

Optimizing the design and the manufacturing of the CLIC RF accelerating structures for achieving the target value of breakdown rate at the nominal accelerating gradient of 100 MV/m requires a detailed understanding of all the steps involved in the mechanism of breakdown. These include surface modification under RF fields, electron emission and neutral evaporation in the vacuum, arc ignition and consequent surface modification due to plasma bombardment. Together with RF tests, experiments are conducted in a simple DC test set-up instrumented with electrical diagnostics and optical spectroscopy. The results are also used for validating simulations which are performed using a wide range of numerical tools (MD coupled to electrostatic codes, PIC plasma simulations) able to include all the above phenomena. Some recent results are presented in this paper

Associations between accelerated glacier mass wastage and increased summer temperature in coastal regions

Science.gov (United States)

Dyurgerov, M.; McCabe, G.J.

2006-01-01

Low-elevation glaciers in coastal regions of Alaska, the Canadian Arctic, individual ice caps around the Greenland ice sheet, and the Patagonia Ice Fields have an aggregate glacier area of about 332 ?? 103 km 2 and account for approximately 42% of all the glacier area outside the Greenland and Antarctic ice sheets. They have shown volume loss, especially since the end of the 1980s, increasing from about 45% in the 1960s to nearly 67% in 2003 of the total wastage from all glaciers on Earth outside those two largest ice sheets. Thus, a disproportionally large contribution of coastal glacier ablation to sea level rise is evident. We examine cumulative standardized departures (1961-2000 reference period) of glacier mass balances and air temperature data in these four coastal regions. Analyses indicate a strong association between increases in glacier volume losses and summer air temperature at regional and global scales. Increases in glacier volume losses in the coastal regions also coincide with an accelerated rate of ice discharge from outlet glaciers draining the Greenland and West Antarctic ice sheets. These processes imply further increases in sea level rise. ?? 2006 Regents of the University of Colorado.

Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

International Nuclear Information System (INIS)

Blumenthal, G.R.; Mathews, W.G.

1979-01-01

The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

Using Dark Matter Haloes to Learn about Cosmic Acceleration: A New Proposal for a Universal Mass Function

Science.gov (United States)

Prescod-Weinstein, Chanda; Afshordi, Niayesh

2011-01-01

Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit or overpredict the development of observed large-scale structures. Traditional approaches to studies of structure formation in the presence of dark energy or a modified gravity implement a modified Press-Schechter formalism, which relates the linear overdensities to the abundance of dark matter haloes at the same time. We critically examine the universality of the Press-Schechter formalism for different cosmologies, and show that the halo abundance is best correlated with spherical linear overdensity at 94% of collapse (or observation) time. We then extend this argument to ellipsoidal collapse (which decreases the fractional time of best correlation for small haloes), and show that our results agree with deviations from modified Press-Schechter formalism seen in simulated mass functions. This provides a novel universal prescription to measure linear density evolution, based on current and future observations of cluster (or dark matter) halo mass function. In particular, even observations of cluster abundance in a single epoch will constrain the entire history of linear growth of cosmological of perturbations.

Compact toroid formation, compression, and acceleration

International Nuclear Information System (INIS)

Degnan, J.H.; Bell, D.E.; Baca, G.P.; Dearborn, M.E.; Douglas, M.R.; Englert, S.E.; Englert, T.J.; Holmes, J.H.; Hussey, T.W.; Kiuttu, G.F.; Lehr, F.M.; Marklin, G.J.; Mullins, B.W.; Peterkin, R.E.; Price, D.W.; Roderick, N.F.; Ruden, E.L.; Turchi, P.J.; Coffey, S.K.; Seiler, S.W.; Bird, G.

1992-01-01

Research on the formation, compression, and acceleration of milligram Compact Toroids (CTs) will be discussed. This includes experiments with 2-stage coaxial gun discharges and calculations including 2D- MHD. The CTs are formed by 110 μf, 70 KV, 2 MA, 3 μs rise time discharges into 2 mg gas puffs in a 90 cm inner diameter, 7.6 cm gap coaxial gun with approximately 0.15 Tesla of radial-axial initial magnetic field. Reconnection at the neck of the toroidal magnetized plasma bubble extracted from the first stage gun forms the CT. Trapping, relaxation to a minimum energy Taylor state is observed with magnetic probe arrays. Low energy (few hundred KJ, 2 MA) acceleration in straight coaxial geometry, and high energy acceleration using a conical compression stage are discussed. The Phillips Laboratory 1,300 μf, 120 KV, 9.4 MJ SHIVA STAR capacitor bank is used for the acceleration discharge. The charging and triggering of the 36-module bank has been modified to permit use of any multiple of three modules. Highlights of fast photography, current, voltage, magnetic probe array, optical spectroscopy, interferometry, VUV, and higher energy radiation data and 2D-MHD calculations will be presented. Considerably more detail is presented in companion papers

Penetration of bomb radiocarbon in the tropical Indian Ocean measured by means of accelerator mass spectrometry

International Nuclear Information System (INIS)

Bard, E.; Arnold, M.; Maurice, P.; Monfray, P.; Duplessy, J.C.; Oestlund, H.G.

1988-01-01

Radiocarbon measurements performed on seawater samples by means of accelerator mass spectrometry (AMS) enable to reduce by a factor of 2000 the water sample size needed for the 14 C measurements. Therefore no chemical treatment on board the oceanographic vessel is required. Seventy-four AMS 14 C determinations on samples collected in the tropical-equatorial Indian Ocean during the second leg of the INDIGO program (1986) are presented and compared with the β-counting results obtained during the same campaign and the GEOSECS program (1978). A pronounced reduction of the equatorial 14 C deficit suggests that substantial amounts of bomb- 14 C are associated with the westward flowing Pacific water which enters the Indian Ocean via passages through the Indonesia Archipelago and/or to meridional mixing with 14 C-rich water of the southern subtropical gyre. (orig.)

On the elemental analysis of different cigarette brands using laser induced breakdown spectroscopy and laser-ablation time of flight mass spectrometry

Science.gov (United States)

Ahmed, Nasar; Umar, Zeshan A.; Ahmed, Rizwan; Aslam Baig, M.

2017-10-01

We present qualitative and quantitative analysis of the trace elements present in different brands of tobacco available in Pakistan using laser induced breakdown spectroscopy (LIBS) and Laser ablation Time of Flight Mass Spectrometer (LA-TOFMS). The compositional analysis using the calibration free LIBS technique is based on the observed emission spectra of the laser produced plasma plume whereas the elemental composition analysis using LA-TOFMS is based on the mass spectra of the ions produced by laser ablation. The optical emission spectra of these samples contain spectral lines of calcium, magnesium, sodium, potassium, silicon, strontium, barium, lithium and aluminum with varying intensities. The corresponding mass spectra of the elements were detected in LA-TOF-MS with their composition concentration. The analysis of different brands of cigarettes demonstrates that LIBS coupled with a LA-TOF-MS is a powerful technique for the elemental analysis of the trace elements in any solid sample.

Application of X-ray spectroscopy in nondestructive photon activation analysis

International Nuclear Information System (INIS)

Weise, H.-P.; Segebade, Chr.

1977-01-01

The use of X-ray spectroscopy for the qualitative and quantitative analysis of samples activated by 30 MeV bremsstrahlung from an electron linear accelerator. Detection limits are calculated from the measured X-ray spectra and compared with those for γ-ray spectroscopy. In general, the detection limits for γ-ray and X-ray spectroscopy are comparable. Higher sensitivities for X-ray spectroscopy are observed when only low intensity γ-rays are emitted by the activation products. X-ray spectroscopy should be applied in three cases: (a) low γ-ray emission probability, (b) extremely complicated γ-ray spectrum, (c) overlapping of γ-ray lines from different elements. γ-ray spectroscopy should be preferred for the analysis of light elements for two reasons: very strong absorption of low energy X-rays (low Z) within the sample, low X-ray emission probability for the activation products of light elements. Therefore no attempt was made to use X-ray spectroscopy for the analysis of elements below Ti. Some practical applications of X-ray spectroscopy in nondestructive multielement analysis are quoted. (T.G.)

26Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

International Nuclear Information System (INIS)

Kobayashi, Koichi; Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi.

1990-01-01

Accelerator mass spectrometry (AMS) was applied for 26 Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26 Al as a tracer. When 26 Al was intraperitoneally injected into rats, a considerable amount of 26 Al was incorporated into the cerebrum after 5-35 days of the injection. (author)

First accelerator mass spectrometry {sup 14}C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities

Energy Technology Data Exchange (ETDEWEB)

Stafford, T.W. Jr.; Semken, H.A. Jr.; Graham, R.W.; Klippel, W.F.; Markova, A.; Smirnov, N.G.; Southon, J.

1999-10-01

Worldwide late Pleistocene terrestrial mammal faunas are characterized by stratigraphic associations of species that now have exclusive geographic ranges. These have been interpreted as either taphonomically mixed or representative of communities that no longer exist. Accelerator mass spectrometry {sup 14}C dates (n = 60) on single bones of stratigraphically associated fossil micromammals from two American and two Russian sites document for the first time that currently allopatric mammals occurred together between 12,000 and 22,000 yr B.P. on two continents. The existence of mammal communities without modern analogs demonstrates that Northern Hemisphere biological communities are ephemeral and that many modern biomes are younger than 12 ka. Future climate change may result in new nonanalog communities.

Application of tandem accelerator mass spectrometor to the chronological study of archaeological samples on Ryukyu Islands

International Nuclear Information System (INIS)

Taira, Hatsuo; Higa, Kenichi; Nakai, Nobuyuki; Nakamura, Toshio.

1987-01-01

Along with the urbanization of rural areas on Ryukyu Islands, many shell mounds and pre-historic sites have been found in resent years. Chrological studies of shell samples from these mounds will lead to the better understanding of cultural background for the pre-historic human activities on the Ryukyu Islands. C-14 dating by beta counting is the common method to obtain the ages of the archaeological samples. It is, however, very limitted in obtaining the absolute ages by the above mehtod due to the large sample sizes required and time consuming. There are many newly obtained archaeological samples left unstudied in detail. The alternate is a method called Tandem Accelerator Mass Spectrometer (AMS) installed at Nagoya University, which is composed of the tandem type accelerator to measure very low concentration of C-14 in archaeological samples. The system has been designed particularly to measure the radio-carbon and has advantages of being small sample size and very little time consuming for C-14 measurement as compared with the beta counting. It is the aim of this work to apply the above AMS for obtaining the absolute ages of the archaeological samples. The results agreed well with those estimated by the Erthenware method (relative method of dating), which ranged from 500 to 6000 y.b.p. The results may be helpful for the chronological arrangement of the samples and for the understanding of pre-historical human activities on the Ryukyu Islands. (author)

Mass transfer coefficient in disturbed flow due to orifice for flow accelerated corrosion in nuclear power plant

International Nuclear Information System (INIS)

Prasad, Mahendra; Gaikwad, Avinash J.; Sridharan, Arunkumar; Parida, Smrutiranjan

2015-01-01

The flow of fluid in pipes cause corrosion wherein the inner surface of pipe becomes progressively thinner and susceptible to failure. This form of corrosion dependent on flow dynamics is called Flow Accelerated Corrosion (FAC) and has been observed in Nuclear Power Plants (NPPs). Mass transfer coefficient (MTC) is related to extent of wall thinning and it changes from its value in a straight pipe (with same fluid parameters) for flow in orifices, bends, junctions etc. due to gross disturbance of the velocity profile. This paper presents two-dimensional computational fluid dynamics (CFD) simulations for an orifice configuration in a straight pipe. Turbulent model K- ω with shear stress transport and transition flow was the model used for simulation studies. The mass transfer boundary layer (MTBL) thickness δ mtbl is related to the Schmidt number (Sc) and hydrodynamic boundary layer thickness δ h , as δ mtbl ~ δh/(Sc 1/3 ). MTBL is significantly smaller than δ h and hence boundary layer meshing was carried out deep into δ mtbl . Uniform velocity profile was applied at the inlet. Post orifice fluid shows large recirculating flows on the upper and lower wall. At various locations after orifice, mass transfer coefficient is calculated and compared with the value in straight pipe with fully developed turbulent flow. The MTC due to the orifice increases and it is correlated with enhanced FAC in region after orifice. (author)

Quantitation of 14C-oxaliplatin concentrations in human serum samples by using accelerator mass spectrometry

International Nuclear Information System (INIS)

Kobayashi, Takeshi; Toyoguchi, Teiko; Kato, Kazuhiro; Tokanai, Fuyuki; Shiraishi, Tadashi

2013-01-01

The understanding of human pharmacokinetics is important for development of new drugs. Microdosing studies have been proposed as means of obtaining human pharmacokinetics information at early stages of drug development. Accelerator mass spectrometry (AMS) has high detection sensitivity and is expected to play an important role in microdose trials. In this study, we used the AMS microdosing facility at Yamagata University to measure the concentration of 14 C in 14 C-oxaliplatin-spiked serum samples. The calibration curve of 14 C concentration in serum was linear, and the correlation coefficient was 0.9994. The precision, accuracy, and stability values obtained (freeze and thaw cycles, and short- and long-term stability) satisfied the criteria. The mean background 14 C concentrations in samples of 6 healthy Japanese volunteers were 1.635dpm/mL in blood and 0.56dpm/mL in plasma. These results suggest the suitability of AMS-based quantitation for analyzing samples from microdosing studies. (author)

Kinetics of Beta-14[14C] Carotene in a Human Subject Using Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Dueker, S.R.; Lin, Y.; Follett, J.R.; Clifford, A.J.; Buchholz, B.A.

2000-01-01

β-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of β-[ 14 C]carotene (200 nanoCuries; 0.57 (micro)mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed β-carotene was lost slowly via urine in accord with the slow body turnover of β-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between β-carotene and retinyl esters (vitamin A) derived from intestinal metabolism

On the application of low-energy electrostatic accelerators

International Nuclear Information System (INIS)

Petkov, I.; Khristov, H.

1982-01-01

The scientific and applied problems which can be solved by small electrostatic accelerators have been reviewed. Problems connected with thermonuclear fusion, nuclear astrophysics, element and isotope analysis, and detector calibration have been considered, as well as applications of beams of accelerated microparticles of picogram and nanogram masses. Some particular research examples are presented, and the corresponding experimental setup is descibed. The problems pointed out are of a considerable scientific and practical interest for the application of the 2 MV-electrostatic accelerator which is being developed in INRNE, Sofia. (authors)

PREFACE: 6th Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS11)

Science.gov (United States)

Lupi, Stefano; Perucchi, Andrea

2012-05-01

This volume of Journal of Physics: Conference Series is dedicated to a subset of papers related to the work presented at the 6th edition of the international Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS), held in Trieste, Italy, September 4-8 2011. Previous editions of the conference were held in Porquerolles (France), Lake Tahoe (USA), Rathen (Germany), Awaji (Japan), and Banff (Canada). This edition was organized and chaired by Stefano Lupi (Roma La Sapienza) and co-chaired by Andrea Perucchi (Elettra), with the support of the Italian Synchrotron Light Laboratory ELETTRA, which was honored to host the WIRMS workshop in its tenth anniversary. The 6th WIRMS edition addressed several different topics, ranging from biochemistry to strongly correlated materials, from geology to conservation science, and from forensics to the study of cometary dusts. Representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities. This edition was attended by 88 participants, including representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities, who enjoyed the stimulating scientific presentations, several detailed discussions, and the beautiful weather and scenery of the Trieste gulf. Participants came from 16 different nations and four continents, including many young scientists, six of which were supported by the organizers. There were 45 scientific talks divided in 11 sessions: Facilities, Microspectroscopy (I, II, III), Time-Resolved Spectroscopies, Extreme Conditions, Condensed Matter, Near-Field, Imaging, THz Techniques and High-Resolution Spectroscopy. 37 posters were also presented at two very lively evening poster sessions. We would like to use the opportunity of writing this preface to thank all the participants of the workshop for the very high level of their scientific contribution and for the very friendly atmosphere

Review of ion accelerators

International Nuclear Information System (INIS)

Alonso, J.

1990-06-01

The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here

Improved 36Cl performance at the ASTER HVE 5 MV accelerator mass spectrometer national facility

International Nuclear Information System (INIS)

Finkel, R.; Arnold, M.; Aumaître, G.; Benedetti, L.; Bourlès, D.; Keddadouche, K.; Merchel, S.

2013-01-01

The HVE 5 MV ASTER AMS national facility at CEREGE was accepted in 2007. Since then we have continued to optimize performance for 36 Cl. Cl-36 analyses use AgCl, a Cs negative ion sputter source, Ar stripping to +5 in the terminal of the Tandetron™ accelerator at 5 MV and a silicon nitride post-acceleration stripper foil to enhance suppression of 36 S relative to 36 Cl. The major challenges to obtaining the desired performance for Earth science applications are ion source memory, mass fractionation effects, 36 S isobar suppression and sensitivity. Redesign of the SO110 ion source by HVE to change the size of the aperture and the shape of cathode significantly reduced ion source memory to less than ∼0.1%, a level that can be compensated for by matching standards to samples. We observe small systematic drifts in 35 Cl/ 37 Cl ratios over time, the source of which is not yet determined. Measurement of standards indicates that this effect limits the precision of 35 Cl/ 37 Cl ratio determination to about 2%. 36 S is suppressed in several ways. First, the sample chemistry has been designed to reduce S to low levels. Second, cathodes are constructed of low-S nickel, enabling direct target loading without the use of AgBr pre-packing. Third, a post-acceleration Si 3 N 4 stripper foil differentially absorbs energy from 36 Cl and 36 S. A subsequent electrostatic deflector is then able to suppress 36 S by a factor of ∼240 relative to 36 Cl. Differential energy loss in the detector further suppresses 36 S by about 10 −4 , for an overall suppression factor of 4 × 10 −7 . 36 S count rates are typically equivalent to a background 36 Cl/Cl of ∼10 −15 . At typical 35 Cl currents of ∼20 μA Cl 5+ samples with 36 Cl/ 35 Cl of 6 × 10 −14 can be measured to ±5% statistical uncertainty with 1 h of analysis time. Typical machine blanks have 36 Cl/Cl ∼2 × 10 −15 .

VLHC accelerator physics

Energy Technology Data Exchange (ETDEWEB)

Michael Blaskiewicz et al.

2001-11-01

A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

GPI Spectroscopy of the Mass, Age, and Metallicity Benchmark Brown Dwarf HD 4747 B

Science.gov (United States)

Crepp, Justin R.; Principe, David A.; Wolff, Schuyler; Giorla Godfrey, Paige A.; Rice, Emily L.; Cieza, Lucas; Pueyo, Laurent; Bechter, Eric B.; Gonzales, Erica J.

2018-02-01

The physical properties of brown dwarf companions found to orbit nearby, solar-type stars can be benchmarked against independent measures of their mass, age, chemical composition, and other parameters, offering insights into the evolution of substellar objects. The TRENDS high-contrast imaging survey has recently discovered a (mass/age/metallicity) benchmark brown dwarf orbiting the nearby (d = 18.69 ± 0.19 pc), G8V/K0V star HD 4747. We have acquired follow-up spectroscopic measurements of HD 4747 B using the Gemini Planet Imager to study its spectral type, effective temperature, surface gravity, and cloud properties. Observations obtained in the H-band and K 1-band recover the companion and reveal that it is near the L/T transition (T1 ± 2). Fitting atmospheric models to the companion spectrum, we find strong evidence for the presence of clouds. However, spectral models cannot satisfactorily fit the complete data set: while the shape of the spectrum can be well-matched in individual filters, a joint fit across the full passband results in discrepancies that are a consequence of the inherent color of the brown dwarf. We also find a 2σ tension in the companion mass, age, and surface gravity when comparing to evolutionary models. These results highlight the importance of using benchmark objects to study “secondary effects” such as metallicity, non-equilibrium chemistry, cloud parameters, electron conduction, non-adiabatic cooling, and other subtleties affecting emergent spectra. As a new L/T transition benchmark, HD 4747 B warrants further investigation into the modeling of cloud physics using higher resolution spectroscopy across a broader range of wavelengths, polarimetric observations, and continued Doppler radial velocity and astrometric monitoring.

The transmission theory of electrostatic analyzer in six dimensional phase space and the concept design of a supersensitive mass spectrometer beam line for HI-13 tandem accelerator

International Nuclear Information System (INIS)

Guan Xialing; Cao Qingxi; Zhang Jie; Ye Jingping

1986-01-01

It follows from the motion equations of charged particle in curvilinear coordinates system that the transfer matrix of electrostatic analyzer was derived in six dimensional phase space. In accordance with these matrixes, the concept design of the supersensitive mass spectrometer beam line for HI-13 tandem accelerator was calculated

Hadron physics at the new CW electron accelerators

International Nuclear Information System (INIS)

Burkert, V.D.

1990-01-01

Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states

Two-colour dip spectroscopy of jet-cooled molecules

Science.gov (United States)

Ito, Mitsuo

In optical-optical double resonance spectroscopy, the resonance transition from an intermediate state to a final state can be detected by a dip of the signal (fluorescence or ion) associated with the intermediate state. This method probing the signal of the intermediate state may be called `two-colour dip spectroscopy'. Various kinds of two-colour dip spectroscopy such as two-colour fluorescence/ion dip spectroscopy, two-colour ionization dip spectroscopy employing stimulated emission, population labelling spectroscopy and mass-selected ion dip spectroscopy with dissociation were briefly described, paying special attention to their characteristics in excitation, detection and application. They were extensively and successfully applied to jet-cooled large molecules and provided us with new useful information on the energy and dynamics of excited molecules.

Characterization of urban aerosol using aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

Science.gov (United States)

Cleveland, M. J.; Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Lefer, B.; Rappenglück, B.

2012-07-01

Particulate matter was measured during August and September of 2006 in Houston as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer. Aerosol was dominated by sulfate (4.1 ± 2.6 μg m-3) and organic material (5.5 ± 4.0 μg m-3), with contributions of organic material from both primary (˜32%) and secondary (˜68%) sources. Secondary organic aerosol appears to be formed locally. In addition, 29 aerosol filter samples were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy to determine relative concentrations of organic functional groups. Houston aerosols are less oxidized than those observed elsewhere, with smaller relative contributions of carbon-oxygen double bonds. These particles do not fit 1H NMR source apportionment fingerprints for identification of secondary, marine, and biomass burning organic aerosol, suggesting that a new fingerprint for highly urbanized and industrially influenced locations be established.

XXII Conference on spectroscopy. Summaries of reports

International Nuclear Information System (INIS)

2001-01-01

XXII Conference on spectroscopy took place 8-12 October 2001 in Zvenigorod, Moscow region. The recent advantages in the field of atomic and molecular spectroscopy were discussed. The current methods for elemental spectra analysis were considered. They are based on both traditional atomic emission, adsorption and Raman spectroscopic techniques and on introduction of the mass spectroscopy with the high-temperature plasma atomizer. The particular attention was given the application of spectroscopic methods for plasma diagnostics and air pollution control [ru

Study of the meson mass spectroscopy with a potential model inspired in the quantum chromodynamics

International Nuclear Information System (INIS)

Bernardini, Alex Eduardo de

2001-01-01

Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate (Γ(q q-bar → e - e + )). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)

Accelerating cosmologies from exponential potentials

International Nuclear Information System (INIS)

Neupane, Ishwaree P.

2003-11-01

It is learnt that exponential potentials of the form V ∼ exp(-2cφ/M p ) arising from the hyperbolic or flux compactification of higher-dimensional theories are of interest for getting short periods of accelerated cosmological expansions. Using a similar potential but derived for the combined case of hyperbolic-flux compactification, we study a four-dimensional flat (or open) FRW cosmologies and give analytic (and numerical) solutions with exponential behavior of scale factors. We show that, for the M-theory motivated potentials, the cosmic acceleration of the universe can be eternal if the spatial curvature of the 4d spacetime is negative, while the acceleration is only transient for a spatially flat universe. We also briefly discuss about the mass of massive Kaluza-Klein modes and the dynamical stabilization of the compact hyperbolic extra dimensions. (author)

Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

Energy Technology Data Exchange (ETDEWEB)

Turteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-04-08

The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

Energy Technology Data Exchange (ETDEWEB)

Tuerteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-03-21

The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

Preliminary Determination of Activation Products for a Varian Truebeam Linear Accelerator.

Science.gov (United States)

Waller, Edward; Ram, Rohan; Steadman, Ian

2017-09-01

Medical linear accelerators used to treat various forms of cancers are operated at a number of different energies. A by-product of the high-energy photons produced by accelerators is activation of components within the machine itself and its surrounding bunker. The activation products pose radiological and regulatory challenges during the operation of the accelerator as well as when it is time for final decommissioning. The Varian TrueBeam is a new state-of-the-art linear accelerator now operating in the Canadian market. There is currently limited information on the production of its activation products and the resulting impacts on operation and decommissioning. In this paper, activation products in the Varian TrueBeam accelerator are experimentally determined by performing gamma spectroscopy using a portable high purity germanium detector. A total of 10 isotopes are identified for the conditions tested, which include Na, Al, Mn, Ni, Cu, Cu, Br, Sb, Sb, W. The half-lives of these isotopes range from 2.3 min to 60.2 d. These preliminary results indicate that a decommissioning case similar to other radiotherapy accelerators can be made.

High-Resolution, Long-Slit Spectroscopy of VY Canis Majoris: The Evidence for Localized High Mass Loss Events

Science.gov (United States)

Humphreys, Roberta M.; Davidson, Kris; Ruch, Gerald; Wallerstein, George

2005-01-01

High spatial and spectral resolution spectroscopy of the OH/IR supergiant VY CMa and its circumstellar ejecta reveals evidence for high mass loss events from localized regions on the star occurring over the past 1000 yr. The reflected absorption lines and the extremely strong K I emission lines show a complex pattern of velocities in the ejecta. We show that the large, dusty northwest arc, expanding at ~50 km s-1 with respect to the embedded star, is kinematically distinct from the surrounding nebulosity and was ejected about 400 yr ago. Other large, more filamentary loops were probably expelled as much as 800-1000 yr ago, whereas knots and small arcs close to the star resulted from more recent events 100-200 yr ago. The more diffuse, uniformly distributed gas and dust is surprisingly stationary, with little or no velocity relative to the star. This is not what we would expect for the circumstellar material from an evolved red supergiant with a long history of mass loss. We therefore suggest that the high mass loss rate for VY CMa is a measure of the mass carried out by these specific ejections accompanied by streams or flows of gas through low-density regions in the dust envelope. VY CMa may thus be our most extreme example of stellar activity, but our results also bring into question the evolutionary state of this famous star. In a separate appendix, we discuss the origin of the very strong K I and other rare emission lines in its spectrum.

Non-Halal biomarkers identification based on Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Time of Flight Mass Spectroscopy (GC-TOF MS) techniques

Science.gov (United States)

Witjaksono, Gunawan; Saputra, Irwan; Latief, Marsad; Jaswir, Irwandi; Akmeliawati, Rini; Abdelkreem Saeed Rabih, Almur

2017-11-01

Consumption of meat from halal (lawful) sources is essential for Muslims. The identification of non-halal meat is one of the main issues that face consumers in meat markets, especially in non-Islamic countries. Pig is one of the non-halal sources of meat, and hence pig meat and its derivatives are forbidden for Muslims to consume. Although several studies have been conducted to identify the biomarkers for nonhalal meats like pig meat, these studies are still in their infancy stages, and as a result there is no universal biomarker which could be used for clear cut identification. The purpose of this paper is to use Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Time of Flight Mass Spectroscopy (GC-TOF MS) techniques to study fat of pig, cow, lamb and chicken to find possible biomarkers for pig fat (lard) identification. FTIR results showed that lard and chicken fat have unique peaks at wavenumbers 1159.6 cm-1, 1743.4 cm-1, 2853.1 cm-1 and 2922.5 cm-1 compared to lamb and beef fats which did not show peaks at these wavenumbers. On the other hand, GC/MS-TOF results showed that the concentration of 1,2,3-trimethyl-Benzene, Indane, and Undecane in lard are 250, 14.5 and 1.28 times higher than their concentrations in chicken fat, respectively, and 91.4, 2.3 and 1.24 times higher than their concentrations in cow fat, respectively. These initial results clearly indicate that there is a possibility to find biomarkers for non-halal identification.

Recent results of studies of acceleration of compact toroids

International Nuclear Information System (INIS)

Hammer, J.H.; Hartman, C.W.; Eddleman, J.

1984-01-01

The observed gross stability and self-contained structure of compact toroids (CT's) give rise to the possibility, unique among magnetically confined plasmas, of translating CT's from their point of origin over distances many times their own length. This feature has led us to consider magnetic acceleration of CT's to directed kinetic energies much greater than their stored magnetic and thermal energies. A CT accelerator falls in the very broad gap between traditional particle accelerators at one extreme, which are limited in the number of particles per bunch by electrostatic repulsive forces, and mass accelerators such as rail guns at the other extreme, which accelerate many particles but are forced by the stress limitations of solids to far smaller accelerations. A typical CT has about a Coulomb of particles, weighs 10 micrograms and can be accelerated by magnetic forces of several tons, leading to an acceleration on the order of 10 11 gravities

Accelerator Physics Section progress report

International Nuclear Information System (INIS)

Coote, G.E.

1986-05-01

This report summarizes the work of the Accelerator Physics Section of the Institute of Nuclear Sciences during the period January-December 1985. Applications of the EN-tandem accelerator included 13 N production for tracer experiments in plants and animals, hydrogen profiling with a 19 F beam and direct detection of heavy ions with a surface barrier detector. Preparations for accelerator mass spectrometry continued steadily, with the commissioning of the pulsed EHT supply which selects the isotope to be accelerated, routine detection of 14 C ions, and completion of a sputter ion source with an eight position target wheel. It was shown that the hydrogen content of a material could be derived from a simultaneous measurement of the transmission of neutrons and gamma rays from a neutron source or accelerator target. The 11 CO 2 produced at the 3 MV accelerator was used in two studies of translocation in a large number of plant species: the effects of small quantities of SO 2 in the air, and the effect of cooling a short length of the stem. The nuclear microprobe was applied to studies of carbon pickup during welding of stainless steel, determination of trace elements in soil and vegetation and the measurement of sodium depth profiles in obsidian - in particular the effect of rastering the incident proton beams

COMPLIS: COllinear spectroscopy Measurements using a Pulsed Laser Ion Source

CERN Multimedia

2002-01-01

A Pulsed Laser spectroscopy experiment has been installed for the study of hyperfine structure and isotope shift of refractory and daughter elements from ISOLDE beams. It includes decelerated ion-implantation, element-selective laser ionization, magnetic and time-of-flight mass separation. The laser spectroscopy has been performed on the desorbed atoms in a set-up at ISOLDE-3 but later on high resolution laser collinear spectroscopy with the secondary pulsed ion beam is planned for the Booster ISOLDE set-up. During the first operation time of ISOLDE-3 we restricted our experiments to Doppler-limited resonant ionization laser and $\\gamma$-$\\gamma$ nuclear spectroscopy on neutron deficient platinum isotopes of even mass number down to A~=~186 and A~=~179 respectively. These isotopes have been produced by implantation of radioactive Hg and their subsequent $\\beta$-decay.