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Sample records for auger emitter dependent

  1. Internal Auger emitters: effects on spermatogenesis and oogenesis in mice

    International Nuclear Information System (INIS)

    Rao, D.V.; Mylavarapu, V.B.; Sastry, K.S.R.; Howell, R.W.

    1988-01-01

    The in vivo biological effects of Auger emitters are investigated using [A] spermatogenesis in mouse testis, and [B] oogenesis in mouse ovary as experimental models. Spermhead survival and induction of abnormal sperm, following intratesticular administration of radiopharmaceuticals, were the end points in Model A. Of interest in Model B is primary oocyte survival after intraperitoneal injection of the radiochemicals. The effectiveness of the Auger emitter is determined relative to its beta emitting companion or external X-rays in the absence of such an analogue. Results reveal pronounced effects of Auger emitters on all end points, not dependent on mode of administration. The efficacy of the Auger emitter is related intimately to its subcellular distribution, which, is governed by the chemical form of the carrier molecule. Conventional dosimetry is inadequate and biophysically meaningful dosimetric approaches are needed to understand in vivo effects of Auger emitters. (author)

  2. Auger electron emitters: Insights gained from in vitro experiments

    International Nuclear Information System (INIS)

    Makrigiorgos, G.; Adelstein, S.J.; Kassis, A.I.

    1990-01-01

    This paper outlines the evolution of the current rationale for research into the biological effects of tissue-incorporated Auger electron emitters. The first section is a brief review of the research conducted by several groups in the last fifteen years. The second section describes the in vitro model used in our studies, dosimetric calculations, experimental techniques and recent findings. The third section focuses on the use of Auger electron emitters as in vitro microprobes for the investigation of the radiosensitivity of distinct subcellular components. Examination of the biological effects of the Auger electron emitter 125 I located in different cellular compartments of a single cell line (V 79 hamster lung fibroblast) verifies that DNA is the critical cell structure for radiation damage and that the sensitive sites are of nanometer dimensions. The data from incorporation of several Auger electron emitters at the same location within DNA suggest that there are no saturation effects from the decay of these isotopes (i.e. all the emitted energy is biologically effective) and provide some insight into which of the numerous physical mechanisms accompanying the Auger decay are most important in causing cell damage. Finally the implications of Auger electron emission for radiotherapy and radiation protection in diagnostic nuclear medicine are detailed and further research possibilities are suggested. (orig.)

  3. Therapy with high LET Radioisotopes: Can sufficient levels of attractive Auger and alpha emitters be produced to make their use practical?

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.; Mirzadeh, S.; Stabin, M.; Brill, A.B.

    2005-01-01

    Because of localized energy deposition within a very small volume, cellular targeted therapy with high linear energy transfer (LET) Auger-electron and alpha-particle emitting radioisotopes is of great interest. While the energy deposition from alpha particles usually encompasses several cell diameters, the dose from Auger electrons is confined to a single cell. Two major challenges for broader use of Alpha and Auger emitters are the efficient and cost effective routine production of sufficient levels of these radioisotopes, and the availability of targeting molecules to which the radioisotopes can be attached for cellular delivery of sufficient levels of activity for effective therapy. Examples of several Alpha-and Auger-emitting radioisotopes of current interest are presented. Alpha- and Auger electron-emitting radioisotopes can be produced in accelerators (A) and nuclear reactors (R), and several alpha emitter congeners (i.e. thorium-229) can be obtained from uranium decay products. The challenge for reactor production, is the availability and exploitation of methods - other then the usual radiative (n,γ) production route which will provide no-carrier-added (nca) or the high specific activity radioisotopes of interest. The submitted manuscript has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes High LET radioisotopes of current interest which are in the initial stages of development and/or which demonstrate practical use in clinical trials include several alpha-emitters, in particular bismuth-213 - and also the actinium-225 parent - astatine-211 and bismuth-212. Extensive experimental studies have been reported with Auger iododeoxyuridine (IdUR) radiolabeled with the iodine-125 emitter-labeled. However, development of production

  4. Auger Emitting Radiopharmaceuticals for Cancer Therapy

    Science.gov (United States)

    Falzone, Nadia; Cornelissen, Bart; Vallis, Katherine A.

    Radionuclides that emit Auger electrons have been of particular interest as therapeutic agents. This is primarily due to the short range in tissue, controlled linear paths and high linear energy transfer of these particles. Taking into consideration that ionizations are clustered within several cubic nanometers around the point of decay the possibility of incorporating an Auger emitter in close proximity to the cancer cell DNA has immense therapeutic potential thus making nuclear targeted Auger-electron emitters ideal for precise targeting of cancer cells. Furthermore, many Auger-electron emitters also emit γ-radiation, this property makes Auger emitting radionuclides a very attractive option as therapeutic and diagnostic agents in the molecular imaging and management of tumors. The first requirement for the delivery of Auger emitting nuclides is the definition of suitable tumor-selective delivery vehicles to avoid normal tissue toxicity. One of the main challenges of targeted radionuclide therapy remains in matching the physical and chemical characteristics of the radionuclide and targeting moiety with the clinical character of the tumor. Molecules and molecular targets that have been used in the past can be classified according to the carrier molecule used to deliver the Auger-electron-emitting radionuclide. These include (1) antibodies, (2) peptides, (3) small molecules, (4) oligonucleotides and peptide nucleic acids (PNAs), (5) proteins, and (6) nanoparticles. The efficacy of targeted radionuclide therapy depends greatly on the ability to increase intranuclear incorporation of the radiopharmaceutical without compromising toxicity. Several strategies to achieve this goal have been proposed in literature. The possibility of transferring tumor therapy based on the emission of Auger electrons from experimental models to patients has vast therapeutic potential, and remains a field of intense research.

  5. Production and dosimetric aspects of the potent Auger emitter Co-58m for targeted radionuclide therapy of small tumours

    DEFF Research Database (Denmark)

    Thisgaard, Helge; Elema, Dennis Ringkjøbing; Jensen, Mikael

    2011-01-01

    Based on theoretical calculations, the Auger emitter 58mCo has been identified as a potent nuclide for targeted radionuclide therapy of small tumors. During the production of this isotope, the coproduction of the long-lived ground state 58gCo is unfortunately unavoidable, as is ingrowth of the gr...

  6. Angular dependence of Auger signals from a GaAs (111) surface

    International Nuclear Information System (INIS)

    Barnard, W.O.

    1984-03-01

    This dissertation is concerned with the angular dependence of the L 3 M 4 M 4 1067 eV Ga and L 3 M 4 M 4 1228 eV As Auger electron signals from a (111) GaAs surface, using a system which is equipped with a cylindrical mirror analyser. Following a detailed discussion of the Auger process, a review is given of angular effects in the emission excitation and detection of Auger signals. Present theories are discussed and an empirical theory is developed to test the experimental results obtained in this study. The experimental procedures and equipment used are presented. It was found that the Auger signals show a strong variation with the angle of rotation about the normal of a GaAs surface. Furthermore, the nature of the angular spectra of the Ga and As signals are interchanged when the electron beam incident surface is changed from (111) to (111). The main features of the angular variation of the quasi-elastic backscattered signal is reflected in the corresponding Ga and As Auger angular spectra. The angular dependence of the quasi-elastic backscattered signal can be explained semi-quantitatively in terms of the empirical theory. Theoretical arguments are presented which suggest that the Auger signals should show an angular dependence similar to the quasi-elastic backscattered signal. Evidence was found that geometric screening-off of underlying atoms by surface and near surface atoms influence the Auger yield

  7. A new calculational method to assess the therapeutic potential of Auger electron emission

    International Nuclear Information System (INIS)

    Humm, J.L.; Charlton, D.E.

    1989-01-01

    This paper discusses a new computer code to estimate the efficacy of Auger electron sources in cancer therapy. Auger electron emission accompanies the decay of many radionuclides already commonly used in nuclear medicine, for example; 99m Tc and 201 Tl. The range of these electrons is in general sub-cellular, therefore, the toxicity of the source depends on the site of decay relative to the genetic material of the cell. Electron track structure methods have been used which enable the study of energy deposition from Auger sources down to the Angstrom level. A figure for the minimum energy required per single strand break is obtained by fitting our energy deposition calculations for 125 I decays in a model of the DNA to experimental data on break lengths from 125 I labeled plasmid fragments. This method is used to investigate the efficiency of double strand break production by other Auger sources which have potential value for therapy. The high RBE of Auger sources depends critically on the distance between the source and target material. The application of Auger emitters for therapy may necessitate a carrier molecule that can append the source to the DNA. Many DNA localizing agents are known in the field of chemotherapy, some of which could be carrier molecules for Auger sources; the halogenated thymidine precursors are under scrutiny in this field. The activation of Auger cascades in situ by high energy, collimated X ray and neutron beams is also assessed

  8. 135La as an auger-electron emitter for targeted internal radiotherapy

    DEFF Research Database (Denmark)

    Fonslet, Jesper; Lee, Boon Quan; Tran, Thuy A.

    2018-01-01

    Introduction: 135La has favorable nuclear and chemical properties for Auger-based targeted internal radiotherapy. Here we present detailed investigations of the production, emissions, imaging characteristics, and dosimetry related to 135La therapy. Methods and Results: 135La was produced by 16.5 Me....... The generated Auger spectrum was used to recalculate cellular S-factors. Conclusion: 135La was produced with high specific activity, reactivity, radionuclidic purity, and yield. The emission spectrum and the dosimetry are favorable for internal radionuclide therapy. ....... recovered > 98 % of the 135La with an effective molar activity of 70 ±20 GBq/µmol. To better assess cellular and organ dosimetry of this nuclide, we have recalculated the X-ray and Auger emission spectra using a Monte Carlo model accounting for effects of multiple vacancies during the Auger cascade...

  9. 135La as an Auger-electron emitter for targeted internal radiotherapy

    Science.gov (United States)

    Fonslet, J.; Lee, B. Q.; Tran, T. A.; Siragusa, M.; Jensen, M.; Kibédi, T.; E Stuchbery, A.; Severin, G. W.

    2018-01-01

    135La has favorable nuclear and chemical properties for Auger-based targeted internal radiotherapy. Here we present detailed investigations of the production, emissions, and dosimetry related to 135La therapy. 135La was produced by 16.5 MeV proton irradiation of metallic natBa on a medical cyclotron, and was isolated and purified by trap-and-release on weak cation-exchange resin. The average production rate was 407  ±  19 MBq µA-1 (saturation activity), and the radionuclidic purity was 98% at 20 h post irradiation. Chemical separation recovered  >  98 % of the 135La with an effective molar activity of 70  ±  20 GBq µmol-1. To better assess cellular and organ dosimetry of this nuclide, we have calculated the x-ray and Auger emission spectra using a Monte Carlo model accounting for effects of multiple vacancies during the Auger cascade. The generated Auger spectrum was used to calculate cellular S-factors. 135La was produced with high specific activity, reactivity, radionuclidic purity, and yield. The emission spectrum and the dosimetry are favorable for internal radionuclide therapy.

  10. Auger radiation targeted into DNA: a therapy perspective

    Energy Technology Data Exchange (ETDEWEB)

    Buchegger, Franz [University Hospital of Lausanne CHUV, Service of Nuclear Medicine, Lausanne (Switzerland); University Hospital of Lausanne, Service of Nuclear Medicine, Lausanne (Switzerland); Perillo-Adamer, Florence; Bischof Delaloye, Angelika [University Hospital of Lausanne CHUV, Service of Nuclear Medicine, Lausanne (Switzerland); Dupertuis, Yves M. [University Hospital of Geneva, Service of Nutrition, Geneva (Switzerland)

    2006-11-15

    Auger electron emitters that can be targeted into DNA of tumour cells represent an attractive systemic radiation therapy goal. In the situation of DNA-associated decay, the high linear energy transfer (LET) of Auger electrons gives a high relative biological efficacy similar to that of {alpha} particles. In contrast to {alpha} radiation, however, Auger radiation is of low toxicity when decaying outside the cell nucleus, as in cytoplasm or outside cells during blood transport. The challenge for such therapies is the requirement to target a high percentage of all cancer cells. An overview of Auger radiation therapy approaches of the past decade shows several research directions and various targeting vehicles. The latter include hormones, peptides, halogenated nucleotides, oligonucleotides and internalising antibodies. Here, we will discuss the basic principles of Auger electron therapy as compared with vector-guided {alpha} and {beta} radiation. We also review some radioprotection issues and briefly present the main advantages and disadvantages of the different targeting modalities that are under investigation. (orig.)

  11. Auger radiation targeted into DNA: a therapy perspective

    International Nuclear Information System (INIS)

    Buchegger, Franz; Perillo-Adamer, Florence; Bischof Delaloye, Angelika; Dupertuis, Yves M.

    2006-01-01

    Auger electron emitters that can be targeted into DNA of tumour cells represent an attractive systemic radiation therapy goal. In the situation of DNA-associated decay, the high linear energy transfer (LET) of Auger electrons gives a high relative biological efficacy similar to that of α particles. In contrast to α radiation, however, Auger radiation is of low toxicity when decaying outside the cell nucleus, as in cytoplasm or outside cells during blood transport. The challenge for such therapies is the requirement to target a high percentage of all cancer cells. An overview of Auger radiation therapy approaches of the past decade shows several research directions and various targeting vehicles. The latter include hormones, peptides, halogenated nucleotides, oligonucleotides and internalising antibodies. Here, we will discuss the basic principles of Auger electron therapy as compared with vector-guided α and β radiation. We also review some radioprotection issues and briefly present the main advantages and disadvantages of the different targeting modalities that are under investigation. (orig.)

  12. WE-AB-204-12: Dosimetry at the Sub-Cellular Scale of Auger-Electron Emitter 99m-Tc in a Mouse Single Thyroid Follicle Model

    Energy Technology Data Exchange (ETDEWEB)

    Taborda, A; Benabdallah, N; Desbree, A [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-roses (France)

    2015-06-15

    Purpose: To perform a dosimetry study at the sub-cellular scale of Auger-electron emitter 99m-Tc using a mouse single thyroid cellular model to investigate the contribution of the 99m-Tc Auger-electrons to the absorbed dose and possible link to the thyroid stunning in in vivo experiments in mice, recently reported in literature. Methods: The simulation of S-values for Auger-electron emitting radionuclides was performed using both the recent MCNP6 software and the Geant4-DNA extension of the Geant4 toolkit. The dosimetric calculations were validated through comparison with results from literature, using a simple model of a single cell consisting of two concentric spheres of unit density water and for six Auger-electron emitting radionuclides. Furthermore, the S-values were calculated using a single thyroid follicle model for uniformly distributed 123-I and 125-I radionuclides and compared with published S-values. After validation, the simulation of the S-values was performed for the 99m-Tc radionuclide within the several mouse thyroid follicle cellular compartments, considering the radiative and non-radiative transitions of the 99m-Tc radiation spectrum. Results: The calculated S-values using MCNP6 are in good agreement with the results from literature, validating its use for the 99m-Tc S-values calculations. The most significant absorbed dose corresponds to the case where the radionuclide is uniformly distributed in the follicular cell’s nucleus, with a S-value of 7.8 mGy/disintegration, due mainly to the absorbed Auger-electrons. The results show that, at a sub-cellular scale, the emitted X-rays and gamma particles do not contribute significantly to the absorbed dose. Conclusion: In this work, MCNP6 was validated for dosimetric studies at the sub-cellular scale. It was shown that the contribution of the Auger-electrons to the absorbed dose is important at this scale compared to the emitted photons’ contribution and can’t be neglected. The obtained S

  13. Temperature and carrier-density dependence of Auger and radiative recombination in nitride optoelectronic devices

    International Nuclear Information System (INIS)

    Kioupakis, Emmanouil; Yan, Qimin; Steiauf, Daniel; Van de Walle, Chris G

    2013-01-01

    Nitride light-emitting diodes are a promising solution for efficient solid-state lighting, but their performance at high power is affected by the efficiency-droop problem. Previous experimental and theoretical work has identified Auger recombination, a three-particle nonradiative carrier recombination mechanism, as the likely cause of the droop. In this work, we use first-principles calculations to elucidate the dependence of the radiative and Auger recombination rates on temperature, carrier density and quantum-well confinement. Our calculated data for the temperature dependence of the recombination coefficients are in good agreement with experiment and provide further validation on the role of Auger recombination in the efficiency reduction. Polarization fields and phase-space filling negatively impact device efficiency because they increase the operating carrier density at a given current density and increase the fraction of carriers lost to Auger recombination. (paper)

  14. DNA damage by Auger emitters

    International Nuclear Information System (INIS)

    Martin, R.F.; d'Cunha, Glenn; Gibbs, Richard; Murray, Vincent; Pardee, Marshall; Allen, B.J.

    1988-01-01

    125 I atoms can be introduced at specific locations along a defined DNA target molecule, either by site-directed incorporation of an 125 I-labelled deoxynucleotide or by binding of an 125 I-labelled sequence-selective DNA ligand. After allowing accumulation of 125 I decay-induced damage to the DNA, application of DNA sequencing techniques enables positions of strand breaks to be located relative to the site of decay, at a resolution corresponding to the distance between adjacent nucleotides [0.34 nm]. Thus, DNA provides a molecular framework to analyse the extent of damage following [averaged] individual decay events. Results can be compared with energy deposition data generated by computer-simulation methods developed by Charlton et al. The DNA sequencing technique also provides information about the chemical nature of the termini of the DNA chains produced following Auger decay-induced damage. In addition to reviewing the application of this approach to the analysis of 125 I decay induced DNA damage, some more recent results obtained by using 67 Ga are also presented. (author)

  15. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    International Nuclear Information System (INIS)

    Thisgaard, H.

    2008-08-01

    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development of this

  16. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, H.

    2008-08-15

    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development

  17. Summary Report of Consultants' Meeting on Auger Electron Emission Data Needs for Medical Applications

    International Nuclear Information System (INIS)

    Noy, Roberto Capote; Chung, Hyun Kyung; Bartschat, Klaus; Dong, Chenzhong; Jonsson, Per; Kibedi, Tibor; Kondev, Filip G.; Nikjoo, Hooshang; Palffy, Adriana

    2013-11-01

    A summary is given of a Consultants' Meeting on 'Auger Electron Emission Data Needs for Medical Applications'. Participants assessed and reviewed detailed atomic and nuclear data needs for a number of Auger emitters deemed as potentially suitable for applications in nuclear medicine and radiotherapy. Technical discussions are described in this report, along with recommendations for future work, along with recommendations for future work. Presentations by the consultants at the meeting are available at http://www-nds.iaea.org/index-meeting-crp/CM-Auger-2013/. (author)

  18. Photon energy dependent intensity variations observed in Auger spectra of free argon clusters

    International Nuclear Information System (INIS)

    Lundwall, M; Lindblad, A; Bergersen, H; Rander, T; Oehrwall, G; Tchaplyguine, M; Peredkov, S; Svensson, S; Bjoerneholm, O

    2006-01-01

    Photon energy dependent intensity variations are experimentally observed in the L 2,3 M 2,3 M 2,3 Auger spectra of argon clusters. Two cluster sizes are examined in the present study. Extrinsic scattering effects, both elastic and inelastic, involving the photoelectron are discussed and suggested as the explanation of the variations in the Auger signal. The atoms in the first few coordination shells surrounding the core-ionized atom are proposed to be the main targets for the scattering processes

  19. The possible role of solitons in energy transfer in DNA: the relevance of studies with Auger emitters

    International Nuclear Information System (INIS)

    Baverstock, K.F.; Cundall, R.B.

    1988-01-01

    The interpretation of some experiments in which ionising energy is directly absorbed by DNA involve postulates that large scale energy migration takes place in DNA over long distances (kilobase pairs). A possible mechanism for such processes is provided by solitary vibrational waves called solitons. (Solitons arise when a pseudo-one dimensional system with non-linear characteristics suffers a large local transitory displacement from equilibrium). Various synthetic polymers, such as polyacetylene are known, to sustain solitons and various physical properties of biopolymers such as DNA can be described in terms of 'open states' associated with inplane rotation of a group of the hydrogen bonded bases which has solitonic properties. The absorption of ionising energy by DNA systems can provide the transient displacement from equilibrium necessary to set-up wave conditions appropriate for soliton production. Auger emitters would be particularly well suited for inducing solitons and offer the possibility for causing ionising energy to be 'injected' into the DNA molecule at a specific point in the molecular sequence. Experiments to test the hypothesis that this event causes long range energy transfer are discussed. (author)

  20. Cytotoxicity of Auger effect and radiosensitization of iododeoxyuridine

    International Nuclear Information System (INIS)

    Shinohara, Kunio

    1989-01-01

    The cytotoxicity of Auger effect will have advantages for cancer treatment over x-rays in many points such as; (1) higher killing efficiency, (2) lower oxygen enhancement ratio, (3) no difference in the lethality under the temperature between +4degC and -196degC, (4) highly localized effect (mainly within 1.5-2.0 nm), and (5) less difference in the sensitivities of the cells in different stages of cell cycle. These advantages are those of high LET radiations. The use of Auger effect in cancer treatment has been studied in two ways: the use of radioisotopes of Auger emitters and the induction of Auger effect following to the photoelectric effect by external x-rays of proper energy. The latter method is called photon activation therapy by Fairchild et al. The experimental evidences for the induction of Auger effect were obtained with the use of radioprotectors in HeLa cells labeled with iododeoxyuridine irradiated with low energy x-rays. The cytotoxicity of Auger effect was characterized as that it is more difficult to be protected by cysteamine or DMSO and is protectable by DMSO but not protectable in part by cysteamine. The experimental data in HeLa cells labeled with iododeoxyuridine irradiated with synchrotron radiation were not in accord with the quantitative estimate by Fairchild et al. We corrected their equation and found that the contribution of Auger effect was small in the sensitization effect of iododeoxyuridine. It is concluded that the induction of Auger effect by the irradiation with monochromatic x-rays (via photoelectric effect) is not an effective method for cancer therapy. Rather the use of conventional sensitization effect of iododeoxyuridine is worth to be considered again in combination with other methods such as brachytherapy with a small source or hyperthermia. It should be noted that the new mode for the use of Auger effect in cancer therapy has been proposed recently. (author)

  1. Measured emittance dependence on injection method in laser plasma accelerators

    Science.gov (United States)

    Barber, Samuel; van Tilborg, Jeroen; Schroeder, Carl; Lehe, Remi; Tsai, Hai-En; Swanson, Kelly; Steinke, Sven; Nakamura, Kei; Geddes, Cameron; Benedetti, Carlo; Esarey, Eric; Leemans, Wim

    2017-10-01

    The success of many laser plasma accelerator (LPA) based applications relies on the ability to produce electron beams with excellent 6D brightness, where brightness is defined as the ratio of charge to the product of the three normalized emittances. As such, parametric studies of the emittance of LPA generated electron beams are essential. Profiting from a stable and tunable LPA setup, combined with a carefully designed single-shot transverse emittance diagnostic, we present a direct comparison of charge dependent emittance measurements of electron beams generated by two different injection mechanisms: ionization injection and shock induced density down-ramp injection. Notably, the measurements reveal that ionization injection results in significantly higher emittance. With the down-ramp injection configuration, emittances less than 1 micron at spectral charge densities up to 2 pC/MeV were measured. This work was supported by the U.S. DOE under Contract No. DE-AC02-05CH11231, by the NSF under Grant No. PHY-1415596, by the U.S. DOE NNSA, DNN R&D (NA22), and by the Gordon and Betty Moore Foundation under Grant ID GBMF4898.

  2. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with 125I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    International Nuclear Information System (INIS)

    Morgenroth, Agnieszka; Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard; Mottaghy, Felix M.; Reske, Sven N.

    2011-01-01

    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue 125 I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([ 125 I]ITdU). Methods: Cellular uptake and DNA incorporation of [ 125 I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [ 125 I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [ 125 I]ITdU was proven by clonogenic assay. Results: [ 125 I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [ 125 I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [ 125 I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [ 125 I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a novel treatment strategy for overcoming

  3. Development of DNA-based radiopharmaceuticals carrying Auger-electron emitters for anti-gene radiotherapy

    International Nuclear Information System (INIS)

    Panyutin, I.G.; Winters, T.A.; Feinendegen, L.E.; Neumann, R.D.

    2000-01-01

    Targeting of radiation damage to specific DNA sequences is the essence of antigene radiotherapy. This technique also provides a tool to study molecular mechanisms of DNA repair on a defined, single radio damaged site. It was achieved such sequence-specific radio damage by combining the highly localized DNA damage produced by the decay of Auger-electron-emitters such as 125 I with the sequence-specific action of triplex-forming oligonucleotides (TFO). TFO complementary to polypurine-polypyrimidine regions of human genes were synthesized and labeled with 125 I-dCTP by the primer extension method. 125 I-TFO were delivered into cells with several delivery systems. In addition, human enzymes capable of supporting DNA single-strand-break repair were isolated and assessed for their role in the repair of this lesion. Also, the mutagenicity and repairability of 125 I-TFO-induced double strand breaks (DSB) were assessed by repair of plasmid possessing a site-specific DSB lesion. Using plasmids containing target polypurine-polypyrimidine tracts, it was obtained the fine structure of sequence-specific DNA breaks produced by decay of 125 I with single-nucleotide resolution. It was showed that the designed 125 I-TFO in nanomolar concentrations could bind to and introduce double-strand breaks into the target sequences in situ, i.e., within isolated nuclei and intact digitonin-permeabilized cells. It was also showed 125 I-TFO-induced DSB to be highly mutagenic lesions resulting in a mutation frequency of nearly 80%, with deletions comprising the majority of mutations. The results obtained demonstrate the ability of 125 I-TFO to target specific sequences in their natural environment - within eukaryotic nucleus. Repair of 125 I-TFO-induced DNA damage should typically result in mutagenic gene inactivation

  4. Evaluation of new iodinated acridine derivatives for targeted radionuclide therapy of melanoma using {sup 125}I, an Auger electron emitter

    Energy Technology Data Exchange (ETDEWEB)

    Gardette, M.; Papon, J.; Bonnet, M.; Labarre, P.; Miot-Noirault, E.; Madelmont, J. C.; Chezal, J. M.; Moins, N. [UMR 990, INSERM, Universite d' Auvergne, Clermont-Ferrand (France); Desbois, N. [EA 3660, Universite de Bourgogne, Dijon (France); Wu, T. D.; Guerquin-Kern, J. L. [U 759 INSERM, Institute Curie, Orsay (France)

    2013-06-01

    The full text of the publication follows. The increasing incidence of melanoma and the lack of effective therapy on the disseminated form have led to an urgent need for new specific therapies. Several iodo-benzamides or analogs are known to possess specific affinity for melanoma tissue. New hetero-aromatic derivatives have been designed with a cytotoxic moiety and termed DNA intercalating agents. These compounds could be applied in targeted radionuclide therapy using {sup 125}I, Auger electrons emitter which gives high-energetic localized irradiation. Two iodinated acridine derivatives have been reported to present an in vivo kinetic profile conducive to application in targeted radionuclide therapy. The aim of the present study was to perform a preclinical evaluation of these compounds. The DNA intercalating property was confirmed for both compounds. After radiolabeling with {sup 125}I, the two compounds induced in vitro a significant radiotoxicity on B16F0 melanoma cells. The acridine compound, ICF01040, appeared more radio toxic than the acridone compound, ICF01035. While cellular uptake was similar for both compounds, SIMS analysis and in vitro protocol showed a stronger affinity for melanin with ICF01035, which was able to induce a predominant scavenging process in the melanosome and restrict access to the nucleus. Nevertheless, an important radiotoxicity was measured for the two compounds while the nuclear accumulation was low. Indeed, even if nuclear localization remains the main target sensitive to Auger electrons, the cell membrane remains sensitive to {sup 125}I decays. So, these compounds may induce secondary toxic effects of irradiation, such as membrane lipid damage. Conducted to current experiments are evaluate such hypothesis. Taken together, these results suggest that ICF01040 is a better candidate for application in targeted radionuclide therapy using {sup 125}I. The next step will be in vivo evaluation, where high tumoral vectorization gives

  5. Auger decay of 1σg and 1σu hole states of the N2 molecule. II. Young-type interference of Auger electrons and its dependence on internuclear distance

    International Nuclear Information System (INIS)

    Cherepkov, N. A.; Semenov, S. K.; Schoeffler, M. S.; Titze, J.; Petridis, N.; Jahnke, T.; Cole, K.; Schmidt, L. Ph. H.; Czasch, A.; Jagutzki, O.; Schmidt-Boecking, H.; Doerner, R.; Akoury, D.; Williams, J. B.; Landers, A. L.; Osipov, T.; Lee, S.; Prior, M. H.; Belkacem, A.; Weber, Th.

    2010-01-01

    Theoretical two-center interference patterns produced (i) by the K-shell photoionization process of the N 2 molecule and (ii) by the Auger decay process of the K-shell hole state of the N 2 molecule are compared for the case of equal photo- and Auger-electron energies of about 360 eV. The comparison shows that both the angular distribution of the photoelectrons and the angular distribution of the Auger electrons of equal energy in the molecular frame are primarily defined by the Young interference. The experimental data for the angular resolved K-shell Auger electrons as a function of the kinetic-energy release (KER) obtained earlier [Phys. Rev. A 81, 043426 (2010)] have been renormalized in order to visualize the angular variation in the regions of low Auger-electron intensities. That renormalized data are compared with the corresponding theoretical results. From the known behavior of the potential energy curves, the connection between the KER and the internuclear distance can be established. Since the Young interference pattern is sensitive to the internuclear distance in the molecule, from the measured KER dependence of the Young interference pattern one can trace the behavior of the Auger-electron angular distribution for different molecular terms as a function of internuclear distance. The results of that analysis are in a good agreement with the corresponding theoretical predictions.

  6. Wet chemical treatment of boron doped emitters on n-type (1 0 0) c-Si prior to amorphous silicon passivation

    Energy Technology Data Exchange (ETDEWEB)

    Meddeb, H., E-mail: hosny.meddeb@gmail.com [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Research and Technology Center of Energy, Photovoltaic Department, Borj-Cedria Science and Technology Park, BP 95, 2050 (Tunisia); University of Carthage, Faculty of Sciences of Bizerta (Tunisia); Bearda, T.; Recaman Payo, M.; Abdelwahab, I. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Abdulraheem, Y. [Electrical Engineering Department, College of Engineering & Petroleum, Kuwait University, P.O. Box 5969, 13060 Safat (Kuwait); Ezzaouia, H. [Research and Technology Center of Energy, Photovoltaic Department, Borj-Cedria Science and Technology Park, BP 95, 2050 (Tunisia); Gordon, I.; Szlufcik, J. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Poortmans, J. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Department of Electrical Engineering (ESAT), K.U. Leuven, 3001 Leuven (Belgium); Faculty of Sciences, University of Hasselt, Martelarenlaan 42, 3500 Hasselt (Belgium)

    2015-02-15

    Highlights: • The influence of the cleaning process using different HF-based cleaning on the amorphous silicon passivation of homojunction boron doped emitters is analyzed. • The effect of boron doping level on surface characteristics after wet chemical cleaning: For heavily doped surfaces, the reduction in contact angle was less pronounced, which proves that such surfaces are more resistant to oxide formation and remain hydrophobic for a longer time. In the case of low HF concentration, XPS measurements show higher oxygen concentrations for samples with higher doping level, probably due to the incomplete removal of the native oxide. • Higher effective lifetime is achieved at lower doping for all considered different chemical pre-treatments. • A post-deposition annealing improves the passivation level yielding emitter saturation currents determined by Auger recombination in the order of 70 fA/cm{sup 2} and below. • The dominance of Auger recombination over other type of B-induced defects on lifetime quality in the case of our p+ emitter. - Abstract: The influence of the cleaning process on the amorphous silicon passivation of homojunction emitters is investigated. A significant variation in the passivation quality following different cleaning sequences is not observed, even though differences in cleaning performance are evident. These results point out the effectiveness of our cleaning treatment and provide a hydrogen termination for intrinsic amorphous silicon passivation. A post-deposition treatment improves the passivation level yielding emitter saturation currents determined by Auger recombination in the order of 70 fA/cm{sup 2} and below.

  7. Production and dosimetric aspects of the potent Auger emitter 58mCo for targeted radionuclide therapy of small tumors

    International Nuclear Information System (INIS)

    Thisgaard, H.; Elema, D.R.; Jensen, M.

    2011-01-01

    Purpose: Based on theoretical calculations, the Auger emitter 58m Co has been identified as a potent nuclide for targeted radionuclide therapy of small tumors. During the production of this isotope, the coproduction of the long-lived ground state 58g Co is unfortunately unavoidable, as is ingrowth of the ground state following the isomeric decay of 58m Co. The impact of 58g Co as a β + - and γ-emitting impurity should be included in the dosimetric analysis. The purpose of this study was to investigate this critical part of dosimetry based on experimentally determined production yields of 58m Co and 58g Co using a low-energy cyclotron. Also, the cellular S-values for 58m Co have been calculated and are presented here for the first time. Methods: 58m Co was produced via the 58 Fe(p,n) 58m Co nuclear reaction on highly enriched 58 Fe metal. In addition, radiochemical separations of produced radio-cobalt from nat Fe target material were performed. The theoretical subcellular dosimetry calculations for 58m Co and 58g Co were performed using the MIRD formalism, and the impact of the increasing ground state impurity on the tumor-to-normal-tissue dose ratios (TND) per disintegration as a function of time after end of bombardment (EOB) was calculated. Results: 192 ± 8 MBq of 58m Co was produced in the irradiation corresponding to a production yield of 10.7 MBq/μAh. The activity of 58g Co was measured to be 0.85% ± 0.04% of the produced 58m Co activity at EOB. The radio-cobalt yields in the rapid separations were measured to be >97% with no detectable iron contaminations in the cobalt fractions. Due to the unavoidable coproduction and ingrowth of the long-lived ground state 58g Co, the TND and the potency of the 58m Co decrease with time after EOB. If a future treatment with a 58m Co labeled compound is not initiated before, e.g., 21 h after EOB, the resulting TND will be approximately 50% of the TND of 'pure' 58m Co as a result of the increased normal tissue dose from

  8. TU-H-CAMPUS-TeP3-05: Evaluation of the Microscopic Dose Enhancement in the Nanoparticle-Enhanced Auger Therapy

    International Nuclear Information System (INIS)

    Sung, W; Jung, S; Ye, S

    2016-01-01

    Purpose: The aim of this study is to apply Monte Carlo simulations to investigate the nanoparticle dose enhancement for Auger therapy. Methods: Two nanoparticle fabrications were considered: nanoshell and nanosphere. In the first step, a single nanoparticle was irradiated with Auger emitters. The electrons were scored in a phase space at the outer surface of the nanoparticle with Geant4-Penelope. In the second step, the previously recorded phase space was used as a source and placed at the center of a cell-size water phantom. The nanoscale dose was evaluated in water around the nanoparticle with Geant4-DNA. The dose enhancement factor (DEF) is defined as the ratio of doses with and without nanoparticles. The nanoparticles were replaced by corresponding water nanoparticle with the same size and volume source which represents typical situation of Auger emitters without nanoparticle. Various sizes/materials of nanoparticles and isotopes were considered. Results: Nanoshell - Microscopic dose was increased up to 130% at 20 – 100 nm distances from the surface of Au- 125 I nanoshell. However, dose at less than 20 nm distance was reduced due to absorbed low energy electrons in gold nanoshell. The amounts and regions of the dose enhancement were dependent on nanoshell size, materials, and isotopes. Nanosphere - The increased amounts of electrons up to 300% and reduced average energy with nanosphere were observed compared with water nanoparticle. We observed localized dose enhancement (up to a factor 3.6) in the immediate vicinity (< 50 nm) of Au- 125 I nanosphere. The dose enhancement patterns vary according to nanosphere sizes and isotopes. Conclusion: We conclude that Auger therapy with nanoparticles can lead to change of electron energy spectrum and dose enhancements at certain range. The dose enhancement patterns vary according to nanoparticle sizes, materials, and isotopes. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the

  9. Quantification of Radiation-induced DNA Damage following intracellular Auger-Cascades

    DEFF Research Database (Denmark)

    Fredericia, Nina Pil Møntegaard

    2017-01-01

    Purpose: The aim my PhD study and the topic of this thesis is to investigate the radiotoxicity and the Relative Biological effectiveness (RBE) of intracellular Auger cascades. A special focus is kept on obtaining reliable absorbed dose calculations and using matched dose rate profiles for the Auger......-values (SC-values). The work can be divided into three steps; Examination of the bio-kinetics of the Auger emitter 131Cs used in the study, calculations of the SC-values and finally the measurement of the RBE of intracellular 131Cs decays, through ƴH2AX and clonogenic cell survival assay. Methods: A series....../(Bq*Sec)/pL for HeLa nuclei and from 7.45*10-4 to 7.63 *10-4 Gy/(Bq*Sec)/pL for V79 nuclei. The SC-values were shown to be were very robust and almost independent of cellular and nuclear size. A RBE value of 1 was obtained for HeLa cells using ƴH2AX assays. RBE values of 4.5 ± 0.5 and 3.8 ± 0.8 were obtained for He...

  10. Production and dosimetric aspects of the potent Auger emitter {sup 58m}Co for targeted radionuclide therapy of small tumors

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, H.; Elema, D.R.; Jensen, M. [PET and Cyclotron Unit, Nuclear Medicine Department, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense, Denmark and Institute of Clinical Research, University of Southern Denmark, Winsloewparken 19, DK-5000 Odense (Denmark); The Hevesy Laboratory, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, DK-4000 Roskilde (Denmark)

    2011-08-15

    Purpose: Based on theoretical calculations, the Auger emitter {sup 58m}Co has been identified as a potent nuclide for targeted radionuclide therapy of small tumors. During the production of this isotope, the coproduction of the long-lived ground state {sup 58g}Co is unfortunately unavoidable, as is ingrowth of the ground state following the isomeric decay of {sup 58m}Co. The impact of {sup 58g}Co as a {beta}{sup +}- and {gamma}-emitting impurity should be included in the dosimetric analysis. The purpose of this study was to investigate this critical part of dosimetry based on experimentally determined production yields of {sup 58m}Co and {sup 58g}Co using a low-energy cyclotron. Also, the cellular S-values for {sup 58m}Co have been calculated and are presented here for the first time. Methods: {sup 58m}Co was produced via the {sup 58}Fe(p,n){sup 58m}Co nuclear reaction on highly enriched {sup 58}Fe metal. In addition, radiochemical separations of produced radio-cobalt from {sup nat}Fe target material were performed. The theoretical subcellular dosimetry calculations for {sup 58m}Co and {sup 58g}Co were performed using the MIRD formalism, and the impact of the increasing ground state impurity on the tumor-to-normal-tissue dose ratios (TND) per disintegration as a function of time after end of bombardment (EOB) was calculated. Results: 192 {+-} 8 MBq of {sup 58m}Co was produced in the irradiation corresponding to a production yield of 10.7 MBq/{mu}Ah. The activity of {sup 58g}Co was measured to be 0.85% {+-} 0.04% of the produced {sup 58m}Co activity at EOB. The radio-cobalt yields in the rapid separations were measured to be >97% with no detectable iron contaminations in the cobalt fractions. Due to the unavoidable coproduction and ingrowth of the long-lived ground state {sup 58g}Co, the TND and the potency of the {sup 58m}Co decrease with time after EOB. If a future treatment with a {sup 58m}Co labeled compound is not initiated before, e.g., 21 h after EOB, the

  11. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with {sup 125}I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morgenroth, Agnieszka, E-mail: amorgenroth@ukaachen.de [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Mottaghy, Felix M. [Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Reske, Sven N. [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany)

    2011-10-15

    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue {sup 125}I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([{sup 125}I]ITdU). Methods: Cellular uptake and DNA incorporation of [{sup 125}I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [{sup 125}I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [{sup 125}I]ITdU was proven by clonogenic assay. Results: [{sup 125}I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [{sup 125}I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [{sup 125}I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [{sup 125}I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a

  12. Modeling of LMM-MVV Auger-Auger Coincidence Spectra From Solids

    Science.gov (United States)

    Sundaramoorthy, R.; Weiss, A. H.; Hulbert, S. L.; Bartynski, R. A.

    2006-03-01

    Atoms that are highly excited due to the presence of a hole in an inner shell often relax via an Auger transition. This auto-ionizing process results in a final state with two or more holes from an Auger cascade. We present results of the direct measurements of the second and third Auger decays in this sequence. We have measured the Mn MVV Auger spectra from a single-crystal sample of MnO in time coincidence with Auger electrons emitted from prior Mn LMM Auger decays and find these to be much wider than the MVV spectrum measured in time coincidence with M core photoelectron emission. We present a model which attributes the increased energy width of the MVV transitions that follow LMM decays to the rearrangement of ``not so innocent'' bystander hole(s) in the valence band. The energetics of the Auger cascade process are modeled mathematically in terms of correlation integral(s) and convolution integral(s) over the valence band density of states. Comparisons with recent Auger-Auger coincidence studies of Ag and Pd will be made. Acknowledgements: Welch Foundation, NSF DMR98-12628, NSF DMR98-01681, and DOE DE-AC02-98CH10886.

  13. Differential Auger spectrometry

    International Nuclear Information System (INIS)

    Strongin, M.; Varma, M.N.; Anne, J.

    1976-01-01

    A differential Auger spectroscopy method is given for increasing the sensitivity of micro-Auger spectroanalysis of the surfaces of dilute alloys, by alternately periodically switching an electron beam back and forth between an impurity free reference sample and a test sample containing a trace impurity. The Auger electrons from the samples produce representative Auger spectrum signals which cancel to produce an Auger test sample signal corresponding to the amount of the impurity in the test samples

  14. Modelling of radiation risk induced by radon and sources of Auger electrons

    International Nuclear Information System (INIS)

    Boem, R.

    2003-01-01

    This thesis follows the national and worldwide radon research and application Auger radionuclides in nuclear medicine. Results of this thesis can be summarised into several points: (1) For the prediction of cancer risk following the exposure, it is also necessary to consider the mean cycle time of target cells. From our analyses it can be concluded that the mean cycle time of target cells should exceed 100 days. (2) The value of excess relative risk is for smokers ERR/WLM = (2.4-4.1)x10 -3 WLM -1 and that of the nonsmokers ERR/WLM=(4.2-10.7)x10 -3 WLM -1 , considering the underground medium. Excess relative risk for the nonsmokers ERR/(Bq m -3 ) = (1.0-3.5) Bq -1 m 3 and for smokers ERR/(Bq m -3 ) = (0.3-1.2) 10 -3 Bq -1 m 3 is supposed in dwellings. (3) Microdosimetric models are very helpful and suitable for prediction of the radon risk for underground conditions, as well as for indoor radon risk evaluation and they are also able to take into account the influence of the smoking habit. (4) The spatial distribution of energy deposition events and their magnitude is an essential input to evaluate the effects of radiation on biological systems. Therefore, for the calculation of deposited energy from the DNA incorporated Auger emitters, it is necessary at the DNA level to employ the MC calculation. In an effort to save computer time and memory it is possible to use the fitted function for monoenergetic electrons for estimation of at least relative radiotoxicity. The value of energy deposited in a small volume (sphere of diameter 2 nm) can be considered as the first estimation of an Auger emitter's radiotoxicity. (author)

  15. Quantum coherence in the time-resolved Auger measurement

    Energy Technology Data Exchange (ETDEWEB)

    Smirnova, Olga; Yakovlev, Vladislav S; Scrinzi, Armin

    2003-12-19

    We present a quantum mechanical model of the attosecond-XUV (extreme ultraviolet) pump and laser probe measurement of an Auger decay [Drescher et al., Nature (London) 419, 803 (2002)10.1038/nature01143] and investigate effects of quantum coherence. The time-dependent Schroedinger equation is solved by numerical integration and in analytic form. We explain the transition from a quasiclassical energy shift of the spectrum to the formation of sidebands and the enhancement of high- and low-energy tails of the Auger spectrum due to quantum coherence between photoionization and Auger decay.

  16. A computer simulation of auger electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ragheb, M S; Bakr, M H.S. [Dept. Of Accellerators and Ion Sources, Division of Basic Nuclear Sciences, NRC, Atomic Energy Authority, (Egypt)

    1997-12-31

    A simulation study of Auger electron spectroscopy was performed to reveal how far the dependency between the different parameters governing the experimental behavior affects the peaks. The experimental procedure followed by the AC modulation technique were reproduced by means of a computer program. It generates the assumed output Auger electron peaks, exposes them to a retarding AC modulated field and collects the resulting modulated signals. The program produces the lock-in treatment in order to demodulate the signals revealing the Auger peaks. It analyzes the spectrum obtained giving the peak positions and energies. Comparison between results of simulation and the experimental data showed good agreement. The peaks of the spectrum obtained depend upon the amplitude, frequency and resolution of the applied modulated signal. The peak shape is effected by the rise time, the slope and the starting potential of the retarding field. 4 figs.

  17. Average L-shell fluorescence, Auger, and electron yields

    International Nuclear Information System (INIS)

    Krause, M.O.

    1980-01-01

    The dependence of the average L-shell fluorescence and Auger yields on the initial vacancy distribution is shown to be small. By contrast, the average electron yield pertaining to both Auger and Coster-Kronig transitions is shown to display a strong dependence. Numerical examples are given on the basis of Krause's evaluation of subshell radiative and radiationless yields. Average yields are calculated for widely differing vacancy distributions and are intercompared graphically for 40 3 subshell yields in most cases of inner-shell ionization

  18. High energy resolution and first time-dependent positron annihilation induced Auger electron spectroscopty

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Jakob

    2010-04-03

    It was the aim of this thesis to improve the existing positron annihilation induced Auger spectrometer at the highly intense positron source NEPOMUC (NEutron induced POsitron source MUniCh) in several ways: Firstly, the measurement time for a single spectrum should be reduced from typically 12 h to roughly 1 h or even less. Secondly, the energy resolution, which amounted to {delta}E/E{approx}10%, should be increased by at least one order of magnitude in order to make high resolution positron annihilation induced Auger spectroscopy (PAES)-measurements of Auger transitions possible and thus deliver more information about the nature of the Auger process. In order to achieve these objectives, the PAES spectrometer was equipped with a new electron energy analyzer. For its ideal operation all other components of the Auger analysis chamber had to be adapted. Particularly the sample manipulation and the positron beam guidance had to be renewed. Simulations with SIMION {sup registered} ensured the optimal positron lens parameters. After the adjustment of the new analyzer and its components, first measurements illustrated the improved performance of the PAES setup: Firstly, the measurement time for short overview measurements was reduced from 3 h to 420 s. The measurement time for more detailed Auger spectra was shortened from 12 h to 80 min. Secondly, even with the reduced measurement time, the signal to noise ratio was also enhanced by one order of magnitude. Finally, the energy resolution was improved to {delta}E/E < 1. The exceptional surface sensitivity and elemental selectivity of PAES was demonstrated in measurements of Pd and Fe, both coated with Cu layers of varying thickness. PAES showed that with 0.96 monolayer of Cu on Fe, more than 55% of the detected Auger electrons stem from Cu. In the case of the Cu coated Pd sample 0.96 monolayer of Cu resulted in a Cu Auger fraction of more than 30% with PAES and less than 5% with electron induced Auger spectroscopy

  19. Auger North: The Pierre Auger Observatory in the Northern Hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Mantsch, Paul M.; /Fermilab

    2009-01-01

    Results from Auger South have settled some fundamental issues about ultra-high energy (UHE) cosmic rays and made clear what is needed now to identify the sources of these particles, to uncover the acceleration process, to establish the particle types, and to test hadronic interaction properties at extreme energies. The cosmic rays above 55 EeV are key. Auger North targets this high energy frontier by increasing the collecting power of the Auger Observatory by a factor of eight for those high energy air showers. Particles above about 40 EeV have been shown to be subject to propagation energy loss, as predicted by Greisen, Zatsepin and Kuzmin (GZK) in 1966. Moreover, it is now evident that there is a detectable flux of particles from extragalactic sources within the GZK sphere. The inhomogeneous distribution of matter in the local universe imprints its anisotropy on the arrival directions of cosmic rays above 55 EeV. The challenge is to collect enough of those arrival directions to identify the class of astrophysical accelerators and measure directly the brightest sources. Auger North will increase the event rate from 25 per year to 200 per year and give the Auger Observatory full sky exposure. The Auger Observatory also has the capability to detect UHE photons and neutrinos from discrete sources or from the decays of GZK pions. With the expanded aperture of Auger North, the detection of GZK photons and neutrinos will provide a complementary perspective of the highest energy phenomena in the contemporary universe. Besides being an observatory for UHE cosmic rays, photons, and neutrinos, the Auger Observatory will serve as a laboratory for the study of hadronic interactions with good statistics over a wide range of center-of-mass energies above what can be reached at the LHC. Auger North will provide statistical power at center-of-mass energies above 250 TeV where the alternative extrapolations of hadronic cross sections diverge. Auger North is ready to go. The

  20. Auger North: The Pierre Auger Observatory in the Northern Hemisphere

    International Nuclear Information System (INIS)

    Mantsch, Paul M.

    2009-01-01

    Results from Auger South have settled some fundamental issues about ultra-high energy (UHE) cosmic rays and made clear what is needed now to identify the sources of these particles, to uncover the acceleration process, to establish the particle types, and to test hadronic interaction properties at extreme energies. The cosmic rays above 55 EeV are key. Auger North targets this high energy frontier by increasing the collecting power of the Auger Observatory by a factor of eight for those high energy air showers. Particles above about 40 EeV have been shown to be subject to propagation energy loss, as predicted by Greisen, Zatsepin and Kuzmin (GZK) in 1966. Moreover, it is now evident that there is a detectable flux of particles from extragalactic sources within the GZK sphere. The inhomogeneous distribution of matter in the local universe imprints its anisotropy on the arrival directions of cosmic rays above 55 EeV. The challenge is to collect enough of those arrival directions to identify the class of astrophysical accelerators and measure directly the brightest sources. Auger North will increase the event rate from 25 per year to 200 per year and give the Auger Observatory full sky exposure. The Auger Observatory also has the capability to detect UHE photons and neutrinos from discrete sources or from the decays of GZK pions. With the expanded aperture of Auger North, the detection of GZK photons and neutrinos will provide a complementary perspective of the highest energy phenomena in the contemporary universe. Besides being an observatory for UHE cosmic rays, photons, and neutrinos, the Auger Observatory will serve as a laboratory for the study of hadronic interactions with good statistics over a wide range of center-of-mass energies above what can be reached at the LHC. Auger North will provide statistical power at center-of-mass energies above 250 TeV where the alternative extrapolations of hadronic cross sections diverge. Auger North is ready to go. The

  1. 3 to 15 keV Ar+ induced Auger electron emission from Si and Ar

    International Nuclear Information System (INIS)

    Kempf, J.; Kaus, G.

    1977-01-01

    Ar + induced Auger electrons from Si and Ar were investigated at bombardment energies between 3-15 keV and target currents of a few μA. The Auger electron yields were compared with secondary ion yields of Si and Ar by simultaneous SIMS-AES measurements. In the ion induced Auger spectra of Si five Auger peaks and in the Ar spectra three Auger peaks were observed. The ion induced Auger electron yield of Si and Ar were found to be strongly dependent upon the primary ion energy. 'Bulk like' and 'atomic like' Auger transitions of ion induced Auger electrons of Si were observed. (orig.) [de

  2. Auger emission from solid surfaces bombarded with ions

    International Nuclear Information System (INIS)

    Grizzi, Oscar.

    1986-01-01

    The Auger electron emission from Be, Na, Mg, Al and Si bombarded with 0,5-20 KeV noble gas ions is studied. Sharp structures of the Auger electron spectra of Na and Be were identified. A Monte Carlo program was adapted to simulate the colision cascade in the solid, inner shell excitations and Auger decays. From the comparision of experimental and simulated Auger intensities, the relative role of symmetric and asymmetric collisions in Be K- and Al L-shell excitation were evaluated. In the case of Be, the discussion of the exciting processes to higher projectile energies was extended. To this end, the simulation to early measurements of Be K X-ray yields was applied. From this analysis, information about the variations of the fluorescence yield and outer-shell occupation numbers of Be with projectile energy was obtained. The study of the shape of the sharp Auger structures and their dependence with the energy and incidence projectile angle gives information about the collisional processes, inner hole lifetimes and Auger decays. From the evaluation of the energy and angular distribution of the excited sputtered atoms and the interaction between them and the metallic-surface, the energy shift distributions in the Auger energies were obtained. From the comparison of these distributions with the experimental atomic peaks, the main causes of the broadening of these peaks were determined. (M.E.L.) [es

  3. From The Pierre Auger Observatory to AugerPrime

    Science.gov (United States)

    Parra, Alejandra; Martínez Bravo, Oscar; Pierre Auger Collaboration

    2017-06-01

    In the present work we report the principal motivation and reasons for the new stage of the Pierre Auger Observatory, AugerPrime. This upgrade has as its principal goal to clarify the origin of the highest energy cosmic rays through improvement in studies of the mass composition. To accomplished this goal, AugerPrime will use air shower universality, which states that extensive air showers can be completely described by three parameters: the primary energy E 0, the atmospheric shower depth of maximum X max, and the number of muons, Nμ . The Auger Collaboration has planned to complement its surface array (SD), based on water-Cherenkov detectors (WCD) with scintillator detectors, calls SSD (Scintillator Surface Detector). These will be placed at the top of each WCD station. The SSD will allow a shower to shower analysis, instead of the statistical analysis that the Observatory has previously done, to determine the mass composition of the primary particle by the electromagnetic to muonic ratio.

  4. High energy resolution and first time-dependent positron annihilation induced Auger electron spectroscopty

    International Nuclear Information System (INIS)

    Mayer, Jakob

    2010-01-01

    It was the aim of this thesis to improve the existing positron annihilation induced Auger spectrometer at the highly intense positron source NEPOMUC (NEutron induced POsitron source MUniCh) in several ways: Firstly, the measurement time for a single spectrum should be reduced from typically 12 h to roughly 1 h or even less. Secondly, the energy resolution, which amounted to ΔE/E∼10%, should be increased by at least one order of magnitude in order to make high resolution positron annihilation induced Auger spectroscopy (PAES)-measurements of Auger transitions possible and thus deliver more information about the nature of the Auger process. In order to achieve these objectives, the PAES spectrometer was equipped with a new electron energy analyzer. For its ideal operation all other components of the Auger analysis chamber had to be adapted. Particularly the sample manipulation and the positron beam guidance had to be renewed. Simulations with SIMION registered ensured the optimal positron lens parameters. After the adjustment of the new analyzer and its components, first measurements illustrated the improved performance of the PAES setup: Firstly, the measurement time for short overview measurements was reduced from 3 h to 420 s. The measurement time for more detailed Auger spectra was shortened from 12 h to 80 min. Secondly, even with the reduced measurement time, the signal to noise ratio was also enhanced by one order of magnitude. Finally, the energy resolution was improved to ΔE/E 2,3 VV-transition with PAES. Thus, within this thesis two objectives were achieved: Firstly, the PAES spectrometer was renewed and improved by at least one order of magnitude with respect to the signal to noise ratio, the measurement time and the energy resolution. Secondly, several measurements have been carried out, demonstrating the high performance of the spectrometer. Amongst them are first dynamic PAES measurements and a high resolution measurement of the CuM 2,3 VV

  5. Accelerator based Production of Auger-Electron-emitting Isotopes for Radionuclide Therapy

    DEFF Research Database (Denmark)

    Thisgaard, Helge

    Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron...... isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able...

  6. Auger Prime the new stage of the Pierre Auger Observatory, using Universality

    International Nuclear Information System (INIS)

    Parra, Alejandra; Martínez, Oscar; Salazar, Humberto

    2016-01-01

    The Pierre Auger Observatory is currently in an update stage denominated AugerPrime. The Observatory will have scintillator detectors on top of each of the surface stations (WCD). The main goal of AugerPrime is to improve the studies on mass composition for ultra high energy cosmic rays, for this purpose AugerPrime will use Universality. The model will parameterize the signal in four principal components, the objective is an adequate discrimination of the muonic and electromagnetic components. We are interested in the discrimination of these two components using simulations. To do that, we are working with OfflineTrunk (the official software of the Collaboration). Our work is focused on the development of some modules for analysis and study of the signal from AugerPrime. (paper)

  7. Dosimetry of internal emitters - quo vadis?

    International Nuclear Information System (INIS)

    Reddy, A.R.; Nagaratnam, A.; Jain, S.C.; Gupta, M.M.; Mehta, S.C.

    1999-01-01

    The dosimetry of internally administered radiopharmaceuticals in nuclear medicine procedures using MIRD formalisms and dosimetry in the case of intakes of radionuclides and ICRP methodology for the purpose of radiological protection are well established working practices. It should, however, be remembered that dose or dose coefficients calculated refer to a reference individual, defined in terms of a mathematical phantom established on the basis of certain biokinetic reference parameters. The reference individual represents a typical caucasian adult of West Europe or North American origin. Recently, some attempts have been made to define a Reference Asian and a Reference Indian individual and to assess the effects of anatomical differences and changes in the biokinetics of radiopharmaceuticals and other radionuclides in these different reference individuals on the estimation of dose and dose coefficients in relation to the intake of internal radionuclides. The assessment of doses to the embryo/fetus due to intake of radionuclides by pregnant women, local dose estimates, microdosimetry, radiobiology and radiation protection aspects relating to Auger electron emitters represent other areas of active research in the area of dosimetry of internal emitters. The present review summarises these different aspects of work. (orig.) [de

  8. Auger Physicists visit CMS

    CERN Multimedia

    Hoch, Michael

    2012-01-01

    Visit at CERN P5 CMS in the experimental cavern Alan Watson, Auger Spokesperson Emeritus, University of Leeds; Jim Cronin, Nobel Laureate, Auger Spokesperson Emeritus, University of Chicago; Jim Virdee, CMS Former Spokesperson, Imperial College; Jim Matthews, Auger Co-Spokesperson, Louisiana State University

  9. Auger spectrometry of atoms and molecules

    International Nuclear Information System (INIS)

    Krause, M.O.

    1994-01-01

    The author discusses the importance of Auger spectrometry at synchrotron radiation centers. First, he explains how a high energy photon source such as the APS (Advanced Photon Source) could be used to help provide missing spectral information about the shell structure of some elements. The missing data occurs mainly at higher energies in the 1--10 keV ranges as for the K-shells of Z = 30 to 60 elements and the L-shells for Z = 30 to 100 elements. He explains how even though Auger electron spectrometry does not depend on synchrotron radiation it can greatly benefit from this variable photon source as it allows one to select the Auger line group that is most suitable for a specific purpose. Most significantly, a continuous photon source becomes indispensable when one is interested in threshold effects. Lastly, he discusses coherence effects between different inner-shell vacancy states by way of some recent work done at Daresbury

  10. Photoion Auger-electron coincidence measurements near threshold

    International Nuclear Information System (INIS)

    Levin, J.C.; Biedermann, C.; Keller, N.; Liljeby, L.; Short, R.T.; Sellin, I.A.; Lindle, D.W.

    1990-01-01

    The vacancy cascade which fills an atomic inner-shell hole is a complex process which can proceed by a variety of paths, often resulting in a broad distribution of photoion charge states. We have measured simplified argon photoion charge distributions by requiring a coincidence with a K-LL or K-LM Auger electron, following K excitation with synchrotron radiation, as a function of photon energy, and report here in detail the argon charge distributions coincident with K-L 1 L 23 Auger electrons. The distributions exhibit a much more pronounced photon-energy dependence than do the more complicated non-coincident spectra. Resonant excitation of the K electron to np levels, shakeoff of these np electrons by subsequent decay processes, double-Auger decay, and recapture of the K photoelectron through postcollision interaction occur with significant probability. 17 refs

  11. Theory of the Auger effect in an intense acoustic noise field

    International Nuclear Information System (INIS)

    Doan Nhat Quang.

    1995-10-01

    A study is given of the effect on Auger processes produced by an intense acoustic noise flux affecting charge carriers via deformation-potential interaction. The calculation of Auger coefficients is carried out within a semiclassical approach to the acoustic noise field and non-degenerate carrier statistics. Simple analytic expressions are then obtained, which expose an exponential dependence of the Auger coefficients on flux intensity. The Auger recombination is found, in analogy with the case of piezoelectric noise field, to be strongly enhanced as compared to that in no-noise conditions by up to several orders of magnitude at high flux intensity, short acoustic wavelength, small carrier concentration and low temperature. (author). 29 refs, 4 figs, 1 tab

  12. The assessment and management of risks associated with exposures to short-range Auger- and beta-emitting radionuclides. State of the art and proposals for lines of research

    International Nuclear Information System (INIS)

    Paquet, F; Biau, A; Barbey, P; Bardiès, M; Blanchardon, E; Chetioui, A; Lebaron-Jacobs, L; Pasquier, J L

    2013-01-01

    dosimetry directly. The imperfections of the alternative approaches proposed so far should not discourage efforts. Protection against exposure to Auger and low-energy beta emitters would benefit from mechanistic studies, dedicated to the study of energy depositions of the radionuclides in various cellular structures, but also from radiotoxicological studies to define the relative biological effectiveness of the various Auger emitters used in medicine and of certain low-energy beta emitters, whose behaviour may depend greatly on their chemical form during intake. The scientific expertise, as well as the human and physical resources needed to conduct these studies, is available. They could be now mobilised into international low-dose research programmes, in order to ultimately improve the protection of people exposed to these specific radionuclides. (review)

  13. Dependence of simulated positron emitter yields in ion beam cancer therapy on modeling nuclear fragmentation

    DEFF Research Database (Denmark)

    Lühr, Armin; Priegnitz, Marlen; Fiedler, Fine

    2014-01-01

    In ion beam cancer therapy, range verification in patients using positron emission tomography (PET) requires the comparison of measured with simulated positron emitter yields. We found that (1) changes in modeling nuclear interactions strongly affected the positron emitter yields and that (2) Monte...... Carlo simulations with SHIELD-HIT10A reasonably matched the most abundant PET isotopes 11C and 15O. We observed an ion-energy (i.e., depth) dependence of the agreement between SHIELD-HIT10A and measurement. Improved modeling requires more accurate measurements of cross-section values....

  14. Theory of K-MM radiative-Auger transitions

    International Nuclear Information System (INIS)

    Baptista, G.B.

    1975-01-01

    Presently available calculations of transition probabilities for radiative-Auger and double-Auger processes are based on shake-off theory. In this theory, such processes are thought of as being due to electron core rearrangement associated with de-excitation of an inner shell vacancy. It is suggested that radiative-Auger processes result from the interaction of two electrons with one another and the radiation field in the presence of an inner shell vacancy, while double-Auger processes result from the interaction of an electron with two electrons in the presence of a similar vacancy. Expressions for the transition probabilities of these processes are derived in second order time dependent perturbation theory. The interaction is taken as the sum of the Coulomb interaction and electron-field interaction of the electrons involved. This approach allows calculation of the detailed photon or electron energy distribution resulting from such processes, as well as the relative and absolute transition rates involved. As a specific example of this approach the transition probability for the K-MM radiative-Auger effect in argon is calculated and compared with available experimental data. Scaled Thomas-Fermi wavefunctions are used to calculate the total transition probability which is found to be 2.68 x 10 -4 eV/h-bar In addition, the spectral distribution of emitted photons is obtained, and agreement both in magnitude and with the general features of the experimental data is excellent

  15. DEPTH MEASUREMENT OF DISRUPTED LAYER ON SILICON WAFER SURFACE USING AUGER SPECTROSCOPY METHOD

    Directory of Open Access Journals (Sweden)

    V. A. Solodukha

    2016-01-01

    Full Text Available The paper proposes a method for depth measurement of a disrupted layer on silicon wafer surface which is based on application of Auger spectroscopy with the precision sputtering of surface silicon layers and registration of the Auger electron yield intensity. In order to measure the disrupted layer with the help of Auger spectroscopy it is necessary to determine dependence of the released Auger electron amount on sputtering time (profile and then the dependence is analyzed. Silicon amount in the disrupted layer is less than in the volume. While going deeper the disruptive layer is decreasing that corresponds to an increase of atom density in a single layer. The essence of the method lies in the fact the disruptive layer is removed by ion beam sputtering and detection of interface region is carried out with the help of registration of the Auger electron yield intensity from the sputtered surface up to the moment when it reaches the value which is equal to the Auger electron yield intensity for single-crystal silicon. While removing surface silicon layers the registration of the Auger electron yield intensity from silicon surface makes it possible to control efficiently a presence of the disrupted layer on the silicon wafer surface. In this case depth control locality is about 1.0 nm due to some peculiarities of Auger spectroscopy method. The Auger electron yield intensity is determined automatically while using Auger spectrometer and while removing the disrupted layer the intensity is gradually increasing. Depth of the disrupted layer is determined by measuring height of the step which has been formed as a result of removal of the disrupted layer from the silicon wafer surface. Auger spectroscopy methods ensures an efficient depth control surface disruptions at the manufacturing stages of silicon wafers and integrated circuits. The depth measurement range of disruptions constitutes 0.001–1.000 um.

  16. Auger processes in ion-surface collisions

    International Nuclear Information System (INIS)

    Zampieri, Guillermo.

    1985-01-01

    Bombardment of solid targets with low-energy noble gas ions can produce Auger electron emission from the target atoms and/or from the projectiles. In the case of Auger emission from the projectile, Auger emission was observed during the bombardment of Na, Mg, Al and Si with Ne + ions. This emission was studied as a function of the energy, incidence angle and charge state of the projectile. From the analysis, it is concluded that the emission originates in the decay in vacuum of excited and reflected Ne atoms, moving outside the surface. Auger emission was not observed during the bombardment of K, V and Ni with Ar + ions; Zr and Cs with Kr + , and Xe + ions, respectively; and Li and Be with He + ions. In the case of Auger emission from the target, studies of certain aspects of the Na, Mg and Al Auger electron emission spectra were made. The results allow to identify two components in the Auger feature, coresponding to two kinds of Auger transition. The total spectra results from the superposition of both kinds of emission. Auger spectra from K obtained during Ar + and K + bombardment of K-implanted Be, Mg, Al and Cu were also analyzed. Similar to the Na, Mg and Al Auger spectra, the K Auger feature is composed of an atomic like peak superimposed on a bandlike structure. Both components correspond to Auger transitions in K atoms with a 3p vacancy, occuring in vacuum and inside the solid, respectively. (M.E.L.) [es

  17. Comparison of the PCI distortion effects on the Auger lineshape for electron and photon impact ionization

    International Nuclear Information System (INIS)

    Paripas, B.; Vitez, G.; Vikor, Gy.; Tokesi, K.; Sankari, R.; Calo, A.

    2005-01-01

    The distortion effects of the post-collision interaction (PCI) on the Ar LMM Auger electron lineshape for electron and photon impact ionization have been calculated. The calculations were based on the eikonal model of Kuchiev and Sheinerman [Sov. Phys. - Tech. Phys. 32 (1987) 879]. It is shown that the Auger peak asymmetry depends on the emission angle of the Auger electron relative to the primary beam (and the polarization vector of the photon beam). At a given excess energy, defined as the difference between the impact energy and the binding energy, the absolute value of the Auger peak asymmetry is always larger for electron impact ionization than for photoionization. At the same time, the angular dependence of the PCI distortion is stronger for photoionization. In both cases the Auger peak asymmetry has a maximum when the energy of the ejected electron and that of the Auger electron are nearly equal. The calculations are in good agreement with our previous experimental results

  18. Study on cell survival, induction of apoptosis and micronucleus formation in SCL-II and RTiV3 cells after exposure to the Auger electron emitter Tc-99m

    International Nuclear Information System (INIS)

    Kadenbach, K.; Kriehuber, R.; Weiss, D.G.

    2003-01-01

    Full text: Cell survival, induction of apoptosis and micronucleus (MN) formation have been investigated in the human squamous cell carcinoma cell line SCL-II and in the rat tracheal cell line RTiV3 after exposure to the Auger electron emitter Tc-99m. Cells were either acutely gamma(Co-60)-irradiated (0.78 Gy/min) or exposed to Tc-99m-Pertechnetate (25-300 MBq/20ml) for 24 h under cell culture conditions and assayed for cell survival (Colony-forming assay), micronucleus formation (Cytochalasin B assay) and the frequency of apoptotic cells (Fluorescence microscopy). Analytical dosimetrical models have been applied to derive the absorbed dose corresponding to the accumulated decays of Tc-99m. Absorbed doses up to 1.3 Gy could be achieved after Tc-99m exposure leading to no significant cell killing in this dose range except at one dose point (0.25 Gy) in SCL-II cells. MN formation was consistently lower when compared to Co-60 irradiated cells and showed a linear dose-response. The apoptotic response in SCL-II cells after Tc-99m exposure was described best by a 3rd order polynomial and increased apoptosis induction could be observed at much lower doses (0.25 Gy) in comparison to the reference radiation (0.8 Gy). The relative biological effectiveness (RBE) has been determined for MN formation and apoptosis induction and was found to be in the range of 0.1- 1.3 for both investigated biological endpoints, depending on which mathematical model for describing the dose-effect curve was used. Up-take experiments revealed an activity concentration ratio cells vs. medium of 1.2 after 16 h up to 24 h of exposure. No increased biological effectiveness of Tc-99m applied as Sodium-Pertechnetate could be observed in the investigated cell lines in comparison to gamma-irradiation. Induction of apoptosis is slightly increased after Tc-99m exposure in SCL-II cells and it has to be further evaluated, if this is due to the emitted Auger-component. A passive up-take mechanism of Tc-99m is

  19. Ion induced Auger spectroscopy

    International Nuclear Information System (INIS)

    Thomas, E.W.; Legg, K.O.; Metz, W.A.

    1980-01-01

    Auger electron spectra are induced by impact of heavy ions (e.g. Ar + ) on surfaces; it has been suggested that analysis of such spectra would be a useful technique for surface analysis. We have examined the Auger spectra for various projectile-target combinations and present as representative data the spectra for 100 keV Ar + impact on Al, Cr, Mn, Fe and Co. For a projectile incident on a species of higher nuclear charge the spectrum is dominated by Auger lines from the projectile, broadened considerably by the Doppler effect due to the projectile's motion. The spectra are not characteristic of the target and therefore offer no opportunity for surface analysis. For a projectile incident on a target of lower nuclear charge the spectrum is that of the target species but the spectrum is consistent with the source being sputtered excited atoms; the Auger electrons do not come from the surface. We conclude that the ion induced Auger spectra are in general not a convenient method for surface analysis. (orig.)

  20. Auger ACCESS—Remote Controlling and Monitoring the Pierre Auger Observatory

    Science.gov (United States)

    Jejkal, Thomas

    2013-10-01

    Ultra high energy cosmic rays are the most energetic particles in the universe. They are measured to have energies of up to 1020 eV and occur at a rate of about once per square kilometer per century. To increase the probability of detecting one of these events, a huge detector covering a large area is needed. The Pierre Auger Collaboration build up an observatory covering 3000 square kilometers of the Pampa Amarilla close to Malargüe for this purpose. Until now, the Auger Observatory has been controlled exclusively via the local network for security and performance reasons. As local operation is associated with high travel costs, the Auger ACCESS project, started in 2005, has constructed a secure, operable and sustainable solution for remote control and monitoring. The implemented solution includes Grid technologies for secured access and infrastructure virtualization for building up a fully featured testing environment for the Auger Observatory. Measurements showed only a negligible delay for communicating with the observatory in Argentina, which allows the establishment of remote control rooms in the near future for full remote operation and remarkable cost reduction.

  1. Auger recombination in sodium iodide

    Science.gov (United States)

    McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

    2014-03-01

    Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

  2. Observation of suppressed Auger mechanism in type-I quantum well structures with delocalized electron-hole wavefunctions

    Energy Technology Data Exchange (ETDEWEB)

    Hassani Nia, Iman; Fathipour, Vala; Mohseni, Hooman, E-mail: hmohseni@ece.northwestern.edu [Bio-Inspired Sensors and Optoelectronics Laboratory (BISOL), Department of Electrical Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

    2015-08-15

    We report the first observation of non-threshold Auger mechanism for a quantum well structure with Type-I band alignment. Excitation-dependent photoluminescence measurements were used to extract the Auger recombination coefficients from 77 K up to room temperature. The results verify the role of interface mediated momentum exchange as well as suppression of Auger recombination for delocalized electron-hole wavefunctions.

  3. Vertical-Screw-Auger Conveyer Feeder

    Science.gov (United States)

    Walton, Otis (Inventor); Vollmer, Hubert J. (Inventor)

    2016-01-01

    A conical feeder is attached to a vertically conveying screw auger. The feeder is equipped with scoops and rotated from the surface to force-feed regolith the auger. Additional scoops are possible by adding a cylindrical section above the conical funnel section. Such then allows the unit to collect material from swaths larger in diameter than the enclosing casing pipe of the screw auger. A third element includes a flexible screw auger. All three can be used in combination in microgravity and zero atmosphere environments to drill and recover a wide area of subsurface regolith and entrained volatiles through a single access point on the surface.

  4. Auger coefficient in GaInN-based laser structures

    Energy Technology Data Exchange (ETDEWEB)

    Draeger, Alexander Daniel; Netzel, Carsten; Brendel, Moritz; Joenen, Holger; Rossow, Uwe; Hangleiter, Andreas [Institut fuer Angewandte Physik, TU Braunschweig (Germany)

    2010-07-01

    Todays GaInN-based light emitting devices such as LEDs and laser diodes show excellent properties in terms of quantum efficiency or threshold current in the violet-blue spectral region. With increasing wavelength towards the green this performance decreases strongly. In particular at longer wavelengths, the quantum efficiency decreases for higher current densities, called the efficiency droop. This phenomenon is still subject to intensive research and different mechanisms such as Auger recombination, losses due to dislocations and carrier escape have been named as possible explanations. We combine optical gain measurements using the variable stripe length technique with model calculations of the optical gain spectra to derive the carrier lifetime. From the dependence of the inverse effective lifetime on carrier density we determine the recombination coefficients for radiative, nonradiative and Auger recombination. The Auger coefficients we obtained are about 1-2 x 10{sup -31} cm{sup 6}/s for GaInN quantum wells with 2.5eVAuger recombination seems to contribute to laser threshold.

  5. Energy dependence of the emittance of damping ring beams

    International Nuclear Information System (INIS)

    Stiening, R.

    1985-01-01

    The energy at which the SLC damping rings are operated was chosen to be 1.21 GeV. At the time that that specification was made, the repetition rate of the SLC was expected to be 180 Hz. It is now anticipated that the repetition rate during the initial year of operation of the SLC will be 120 Hz. The following curves which show the output emittance of the damping rings as a function of input emittance and energy suggest that there is a range of energies over which the rings can be operated without changing the SLC luminosity. It should be noted that in the era of polarized beams, the damping ring energy will be fixed at the design value on account of the spin precession required in the LTR and RTL transport lines. The SLC design output emittance of the damping rings is 3 x 10 -5 radian-meters. Because of space charge disruption and quantum emission downstream of the damping rings, much lower values than the design value may not have a large beneficial effect on the luminosity. 3 figures

  6. Temperature dependence of photoluminescence spectra of bilayer two-dimensional electron gases in LaAlO3/SrTiO3 superlattices: coexistence of Auger recombination and single-carrier trapping

    Directory of Open Access Journals (Sweden)

    H. J. Harsan Ma

    2015-06-01

    Full Text Available We report emerging photoluminescence (PL of bilayer two-dimensional electron gases (2DEG in LaAlO3/SrTiO3 (LAO/STO systems. A strong blue PL emerges in bilayer-2DEGs in LAO/STO/LAO/STO which doesn’t show in LAO/STO. PL band in bilayer-2DEGs includes both nearly temperature independent Auger recombination and temperature dependent free electron trapping while it crossovers from Auger recombination to single carrier trapping in LAO/STO. The PL signal of free electron trapping appears at high temperatures and it is much stronger than Auger recombination in the conducting channel in bilayer 2DEGs. This observation shows that high mobility carriers dominate the carrier dynamics in bilayer-2DEGs in LAO/STO superlattices.

  7. Rare Earth Garnet Selective Emitter

    Science.gov (United States)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    impurities, in the development of solid state laser crystals. Doping, dependent on the particular ion and crystal structure, may be as high as 100 at. % (complete substitution of yttrium ion with the rare earth ion). These materials have high melting points, 1940 C for YAG (Yttrium Aluminum Garnet), and low emissivity in the near infrared making them excellent candidates for a thin film selective emitter. As previously stated, the spectral emittance of a rare earth emitter is characterized by one or more well defined emission bands. Outside the emission band the emittance(absorptance) is much lower. Therefore, it is expected that emission outside the band for a thin film selective emitter will be dominated by the emitter substrate. For an efficient emitter (power in the emission band/total emitted power) the substrate must have low emittance, epsilon(sub S). This paper presents normal spectral emittance, epsilon(sub lambda), measurements of holmium(Ho) and erbium (Er) doped YAG thin film selective emitters at (1500 K), and compares those results with the theoretical spectral emittance.

  8. Cooperative spontaneous emission of nano-emitters with inter-emitter coupling in a leaky microcavity

    International Nuclear Information System (INIS)

    Hong, Suc-Kyoung; Nam, Seog Woo; Yang, Hyung Jin

    2015-01-01

    We study the spontaneous emission from a few two-level nano-emitters placed in a leaky microcavity with Lorentzian spectral density near a critically damped regime. Collective features of the spontaneous emission are investigated by numerical analysis of the excitation dynamics when initially one nano-emitter is totally excited but we do not know which one. The results show that there are three decay rates in the excitation dynamics, two for simple exponential decays and one for damped oscillatory decay. The excitation dynamics is found to critically depend on the regime of the system. It is shown that the spontaneous emission is enhanced or suppressed depending on whether the system is in the underdamped or overdamped regime, respectively. On the other hand, the cooperative spontaneous emission is suppressed in the underdamped while it is enhanced in the overdamped regime. Furthermore, the effect of the direct inter-emitter coupling on the breaking of the cooperativeness of the spontaneous emission is shown as well. (paper)

  9. Observing Femtosecond Fragmentation Using Ultrafast X-ray-Induced Auger Spectra

    Directory of Open Access Journals (Sweden)

    Thomas J. A. Wolf

    2017-07-01

    Full Text Available Molecules often fragment after photoionization in the gas phase. Usually, this process can only be investigated spectroscopically as long as there exists electron correlation between the photofragments. Important parameters, like their kinetic energy after separation, cannot be investigated. We are reporting on a femtosecond time-resolved Auger electron spectroscopy study concerning the photofragmentation dynamics of thymine. We observe the appearance of clearly distinguishable signatures from thymine′s neutral photofragment isocyanic acid. Furthermore, we observe a time-dependent shift of its spectrum, which we can attribute to the influence of the charged fragment on the Auger electron. This allows us to map our time-dependent dataset onto the fragmentation coordinate. The time dependence of the shift supports efficient transformation of the excess energy gained from photoionization into kinetic energy of the fragments. Our method is broadly applicable to the investigation of photofragmentation processes.

  10. Resonant Auger studies of metallic systems

    International Nuclear Information System (INIS)

    Coulthard, I.; Antel, W. J. Jr.; Frigo, S. P.; Freeland, J. W.; Moore, J.; Calaway, W. S.; Pellin, M. J.; Mendelsohn, M.; Sham, T. K.; Naftel, S. J.

    2000-01-01

    Results of resonant Auger spectroscopy experimental are presented for Cu, Co, and oxidized Al. Sublifetime narrowing of Auger spectra and generation of sublifetime narrowed absorption spectra constructed from Auger yield measurements were observed. Resonant Auger yields are used to identify three chemical states of oxidized Al. Partial absorption yield spectra were derived giving detailed electronic information and thickness information for the various chemical states of the bulk metal, the passivating aluminum oxide layer, and the metal-oxide interface region. In addition, the total absorption yield spectrum for the oxidized Al sample was constructed from the partial yield data, supporting the consistency of our method. (c) 2000 American Vacuum Society

  11. 30 CFR 819.13 - Auger mining: Coal recovery.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: Coal recovery. 819.13 Section 819....13 Auger mining: Coal recovery. (a) Auger mining shall be conducted so as to maximize the utilization and conservation of the coal in accordance with § 816.59 of this chapter. (b) Auger mining shall be...

  12. Auger electron spectroscopy

    International Nuclear Information System (INIS)

    Gopalaraman, C.P.

    1975-01-01

    General features of electron excited Auger electron spectroscopy (AES) which is a nondestructive technique for the analysis of surfaces upto about 15 Adeg depth with a detection limit of about 0.1% of a monolayer. Methods of measuring the Auger electron energies and recent improvements in the instrumentation are reviewed. Typical energy resolution is found to be about 0.5% which is specially suited for the detection of light elements. It is widely used in metallurgy, surface chemistry and thin film studies. (K.B.)

  13. Atomic Auger spectroscopy: Historical perspective and recent highlights

    International Nuclear Information System (INIS)

    Mehlhorn, W.

    2000-01-01

    The non-radiating decay of an inner-shell ionized atom by the emission of an electron was discovered by Pierre Auger in cloud-chamber experiments in the years 1923 to 1926. The first spectroscopic investigation of Auger electrons was performed by Robinson and Cassie in 1926, marking the birth date of Auger spectroscopy. The following seven decades of Auger spectroscopy will be divided into three periods. In the first period (1926-1960) Auger spectroscopy was mainly connected with β-ray spectroscopy where inner-shell ionization of atoms in the solid state was caused either by γ-conversion or by electron capture. The second period (beginning in 1960) is characterized by the external excitation of gas-phase or free metallic atoms, opening Auger spectroscopy to electron energies in the range of few eV to few keV. The third period (beginning in 1977/78) is characterized by the use of synchrotron radiation with its outstanding properties of tunability, polarization and narrow-band high intensity for the excitation and ionization of inner-shell electrons. Finally, two recent highlights of Auger spectroscopy, the interference between photo- and Auger electron with equal energies and an 'almost' complete experiment for Auger decay, will be presented

  14. Study of Thermal-Field Emission Properties and Investigation of Temperature dependent Noise in the Emission Current form vertical Carbon nanotube emitters

    KAUST Repository

    Kolekar, Sadhu

    2017-05-05

    We have investigated temperature dependent field electron emission characteristics of vertical carbon nanotubes (CNTs). The generalized expression for electron emission from well defined cathode surface is given by Millikan and Lauritsen [1] for the combination of temperature and electric field effect. The same expression has been used to explain the electron emission characteristics from vertical CNT emitters. Furthermore, this has been applied to explain the electron emission for different temperatures ranging from room temperature to 1500 K. The real-time field electron emission images at room temperature and 1500 K are recorded by using Charge Coupled Device (CCD), in order to understand the effect of temperature on electron emission spots in image morphology (as indicated by ring like structures) and electron emission spot intensity of the emitters. Moreover, the field electron emission images can be used to calculate the total number of emitters per cm2 for electron emission. The calculated number of emitters per cm2 is 4.5x107 and, the actual number emitters per cm2 present for electron emission calculated from Atomic Force Microscopy (AFM) data is 1.2x1012. The measured Current-Voltage (I-V) characteristics obey the Folwer-Nordheim (F-N) type behavior. The fluctuations in the emission current are recorded at different temperatures and, temperature dependence of power spectral density obeys power law relation s(f)=I2/f2 with that of emission current and frequency.

  15. 30 CFR 77.1505 - Auger holes; blocking.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auger holes; blocking. 77.1505 Section 77.1505 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... § 77.1505 Auger holes; blocking. Auger holes shall be blocked with highwall spoil or other suitable...

  16. 30 CFR 77.1500 - Auger mining; planning.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auger mining; planning. 77.1500 Section 77.1500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... § 77.1500 Auger mining; planning. Auger mining shall be planned and conducted by the operator to insure...

  17. Field emission characteristics of a small number of carbon fiber emitters

    Directory of Open Access Journals (Sweden)

    Wilkin W. Tang

    2016-09-01

    Full Text Available This paper reports an experiment that studies the emission characteristics of small number of field emitters. The experiment consists of nine carbon fibers in a square configuration. Experimental results show that the emission characteristics depend strongly on the separation between each emitter, providing evidence of the electric field screening effects. Our results indicate that as the separation between the emitters decreases, the emission current for a given voltage also decreases. The authors compare the experimental results to four carbon fiber emitters in a linear and square configurations as well as to two carbon fiber emitters in a paired array. Voltage-current traces show that the turn-on voltage is always larger for the nine carbon fiber emitters as compared to the two and four emitters in linear configurations, and approximately identical to the four emitters in a square configuration. The observations and analysis reported here, based on Fowler-Nordheim field emission theory, suggest the electric field screening effect depends critically on the number of emitters, the separation between them, and their overall geometric configuration.

  18. Assessment and management of risks associated with exposures to Auger- and beta-emitting radionuclides. Recommendations and proposals for lines of research; L'evaluation et la gestion des risques associes aux expositions aux radionucleides emetteurs Auger et beta. Avis et propositions de pistes de recherche

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    steps leading to the genesis of radiation-induced pathologies. This approach has recognised limitations but is intended to provide a simple system for exposure management. The heuristic deficits of the other approaches that could be an alternative to the current radiological protection system should not discourage efforts. The radiological protection system can and should be improved in order to take into account any specific characteristics of radionuclides or certain exposure situations. Protection against exposure to Auger and beta emitters would benefit from mechanistic studies, dedicated to the study of energy depositions of transmitters in various cellular structures, but also radio-toxicological studies to define the relative biological efficacy of each Auger emitter used in medicine, and certain beta emitters, whose behaviour may highly depend on their chemical form during intake. The scientific expertise as well as the human and physical resources needed to conduct these studies have been identified and are available. They should now be mobilised in order to improve the protection of people exposed to these particular radionuclides. (authors)

  19. Core-valence coupling in the Ru 4p photoexcitation/Auger decay process: Auger-photoelectron coincidence spectroscopy study

    International Nuclear Information System (INIS)

    Gotter, R.; Siu, W.-K.; Bartynski, R. A.; Hulbert, S. L.; Wu, Xilin; Zitnik, M.; Nozoye, H.

    2000-01-01

    The N 23 VV Auger spectrum of Ru has been measured in coincidence with 4p 1/2 and with 4p 3/2 photoelectrons. Unlike other metals that exhibit bandlike Auger decays, we find that the two Auger spectra are not shifted by the difference in core level binding energies. A consistent description of these transitions and the core level line shape requires consideration of the relativistic multiplet splitting in the intermediate core hole state and two-valence-hole Auger final state. The results suggest that the large linewidth of the 4p levels is primarily due to multiplet splitting, and that an N 2 (N 3 N 45 )N 45 N 45 super-Coster-Kronig transition is only a minor decay channel. (c) 2000 The American Physical Society

  20. 30 CFR 77.1502 - Auger holes; restriction against entering.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auger holes; restriction against entering. 77... UNDERGROUND COAL MINES Auger Mining § 77.1502 Auger holes; restriction against entering. No person shall be permitted to enter an auger hole except with the approval of the MSHA Coal Mine Safety and Health District...

  1. Operations of and Future Plans for the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Performance and operation of the Surface Detectors of the Pierre Auger Observatory; (2) Extension of the Pierre Auger Observatory using high-elevation fluorescence telescopes (HEAT); (3) AMIGA - Auger Muons and Infill for the Ground Array of the Pierre Auger Observatory; (4) Radio detection of Cosmic Rays at the southern Auger Observatory; (5) Hardware Developments for the AMIGA enhancement at the Pierre Auger Observatory; (6) A simulation of the fluorescence detectors of the Pierre Auger Observatory using GEANT 4; (7) Education and Public Outreach at the Pierre Auger Observatory; (8) BATATA: A device to characterize the punch-through observed in underground muon detectors and to operate as a prototype for AMIGA; and (9) Progress with the Northern Part of the Pierre Auger Observatory.

  2. Radiation-induced biologic bystander effect elicited in vitro by targeted radiopharmaceuticals labeled with alpha-, beta-, and auger electron-emitting radionuclides.

    Science.gov (United States)

    Boyd, Marie; Ross, Susan C; Dorrens, Jennifer; Fullerton, Natasha E; Tan, Ker Wei; Zalutsky, Michael R; Mairs, Robert J

    2006-06-01

    Recent studies have shown that indirect effects of ionizing radiation may contribute significantly to the effectiveness of radiotherapy by sterilizing malignant cells that are not directly hit by the radiation. However, there have been few investigations of the importance of indirect effects in targeted radionuclide treatment. Our purpose was to compare the induction of bystander effects by external beam gamma-radiation with those resultant from exposure to 3 radiohaloanalogs of metaiodobenzylguanidine (MIBG): (131)I-MIBG (low-linear-energy-transfer [LET] beta-emitter), (123)I-MIBG (potentially high-LET Auger electron emitter), and meta-(211)At-astatobenzylguanidine ((211)At-MABG) (high-LET alpha-emitter). Two human tumor cell lines-UVW (glioma) and EJ138 (transitional cell carcinoma of bladder)-were transfected with the noradrenaline transporter (NAT) gene to enable active uptake of MIBG. Medium from cells that accumulated the radiopharmaceuticals or were treated with external beam radiation was transferred to cells that had not been exposed to radioactivity, and clonogenic survival was determined in donor and recipient cultures. Over the dose range 0-9 Gy of external beam radiation of donor cells, 2 Gy caused 30%-40% clonogenic cell kill in recipient cultures. This potency was maintained but not increased by higher dosage. In contrast, no corresponding saturation of bystander cell kill was observed after treatment with a range of activity concentrations of (131)I-MIBG, which resulted in up to 97% death of donor cells. Cellular uptake of (123)I-MIBG and (211)At-MABG induced increasing recipient cell kill up to levels that resulted in direct kill of 35%-70% of clonogens. Thereafter, the administration of higher activity concentrations of these high-LET emitters was inversely related to the kill of recipient cells. Over the range of activity concentrations examined, neither direct nor indirect kill was observed in cultures of cells not expressing the NAT and, thus

  3. The participant Coster-Kronig preceded Auger transition in the resonant L2,3-M2,3V Auger electron spectrum of Ti metal

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2008-01-01

    The L 2,3 -M 2,3 V resonant Auger electron spectroscopy (RAES) spectrum of Ti metal measured by Le Fevre et al. [P. Le Fevre, J. Danger, H. Magnan, D. Chandesris, J. Jupille, S. Bourgeois, M.-A. Arrio, R. Gotter, A. Verdini, A. Morgante, Phys. Rev. B69 (2004) 155421] is analyzed in the light of relaxation and decay of the resonantly excited L 2,3 -hole states. The relaxation time of the resonantly excited L 2,3 -hole state to the fully relaxed (screened) one is much shorter than the L 2,3 -hole Auger decay time, whereas the participant Coster-Kronig (CK) decay time of the resonantly excited L 2 -hole state to the fully relaxed L 3 -hole state at the L 2 resonance is as short as the relaxation time of the resonantly excited L 2 -hole state to the fully relaxed one. The excited electron is predominantly either rapidly decoupled from the L 2,3 -hole decay or annihilated by the participant CK decay. Thus, near the L 2,3 edges the L 2,3 -M 2,3 V RAES spectral peak appears at constant kinetic energy. The L 2,3 -M 2,3 V RAES spectrum shows a normal L 2,3 -M 2,3 V Auger decay profile not modulated by the density of empty d states probed by the resonant excitation. Not only the relaxation time but also the participant CK decay time depends on photon energy because they depend on the density of empty d states probed by the resonant excitation. As a result, the L 2,3 X-ray absorption spectroscopy spectral line broadening depends on photon energy

  4. Nonintercepting emittance monitor

    International Nuclear Information System (INIS)

    Miller, R.H.; Clendenin, J.E.; James, M.B.; Sheppard, J.C.

    1983-08-01

    A nonintercepting emittance monitor is a helpful device for measuring and improving particle beams in accelerators and storage rings as it allows continuous monitoring of the beam's distribution in phase space, and perhaps closed loop computer control of the distributions. Stripline position monitors are being investigated for use as nonintercepting emittance monitors for a beam focused by a FODO array in the first 100 meters of our linear accelerator. The technique described here uses the signal from the four stripline probes of a single position monitor to measure the quadrupole mode of the wall current in the beam pipe. This current is a function of the quadrupole moment of the beam, sigma 2 /sub x/ - sigma 2 /sub y/. In general, six independent measurements of the quadrupole moment are necessary to determine the beam emittance. This technique is dependent on the characteristically large variations of sigma 2 /sub x/ - sigma 2 /sub y/ in a FODO array. It will not work in a focusing system where the beam is round at each focusing element

  5. Assessment and management of risks associated with exposures to Auger- and beta-emitting radionuclides. Recommendations and proposals for lines of research

    International Nuclear Information System (INIS)

    2010-01-01

    steps leading to the genesis of radiation-induced pathologies. This approach has recognised limitations but is intended to provide a simple system for exposure management. The heuristic deficits of the other approaches that could be an alternative to the current radiological protection system should not discourage efforts. The radiological protection system can and should be improved in order to take into account any specific characteristics of radionuclides or certain exposure situations. Protection against exposure to Auger and beta emitters would benefit from mechanistic studies, dedicated to the study of energy depositions of transmitters in various cellular structures, but also radio-toxicological studies to define the relative biological efficacy of each Auger emitter used in medicine, and certain beta emitters, whose behaviour may highly depend on their chemical form during intake. The scientific expertise as well as the human and physical resources needed to conduct these studies have been identified and are available. They should now be mobilised in order to improve the protection of people exposed to these particular radionuclides. (authors)

  6. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  7. X-ray-excited Auger and photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Weightman, P.

    1982-01-01

    This article reviews developments in the understanding of x-ray-excited Auger and photoelectron spectra in the light of theoretical developments in atomic, molecular and solid-state physics. After reviewing progress in XPS and AES separately emphasis is placed on the inter-relationship between the two fields: Auger rates, for example, are the dominant contribution to core-level XPS linewidths and by combining XPS and AES it is possible to deduce information about Coster-Kronig processes which are difficult to study directly. An account is given of how the combination of measurements of environmentally dependent shifts in XPS and AES energies allows one to isolate initial- and final-state contributions which can then be related to the results of other experimental techniques. There is a brief discussion of many-electron effects and a discussion of how the combination of XPS and AES spectra involving valence levels enables the effects of hole-state localisation to be studied. (author)

  8. The Pierre Auger project

    International Nuclear Information System (INIS)

    Mantsch, P.M.

    1996-01-01

    The Pierre Auger project is a broadly based international effort to make a detailed study of cosmic rays at the highest energies. Two air shower detectors are proposed, one to be placed in the Northern Hemisphere and one in the Southern Hemisphere. Each installation will consist of an array of 1600 particle detectors spread over 3000 km 2 with a solid angle acceptance of 2 sr for cosmic ray air showers. Eah installation will also have an atmospheric fluorescence detector viewing the volume above the surface array. These two air shower detector techniques working together form a powerful instrument for the proposed research. The objectives of the Pierre Auger project are to measure the arrival direction, energy, and mass composition of 60 events per year above an energy of 10 20 eV and 6000 events per year above 10 19 eV. A collaboration is now being formed with the goal of having the Pierre Auger observatory in operation by 2001

  9. 30 CFR 819.15 - Auger mining: Hydrologic balance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: Hydrologic balance. 819.15... MINING § 819.15 Auger mining: Hydrologic balance. (a) Auger mining shall be planned and conducted to minimize disturbances of the prevailing hydrologic balance in accordance with the requirements of §§ 816.41...

  10. Emittance preservation

    Energy Technology Data Exchange (ETDEWEB)

    Kain, V; Arduini, G; Goddard, B; Holzer, B J; Jowett, J M; Meddahi, M; Mertens, T; Roncarolo, F; Schaumann, M; Versteegen, R; Wenninger, J [European Organization for Nuclear Research, Geneva (Switzerland)

    2012-07-01

    Emittance measurements during the LHC proton run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. This presentation will show the emittance preservation throughout the different parts of the LHC cycle and discuss the current limitations on emittance determination. An overview of emittance preservation through the injector complex as function of bunch intensity will also be given. Possible sources for the observed blow-up and required tests in 2012 will be presented. Possible improvements of emittance diagnostics and analysis tools for 2012 will be shown.

  11. 30 CFR 819.21 - Auger mining: Protection of underground mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: Protection of underground mining. 819.21 Section 819.21 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT... STANDARDS-AUGER MINING § 819.21 Auger mining: Protection of underground mining. Auger holes shall not extend...

  12. Inactivation of bacteriophage T1 by the Auger effect following phosphorus resonance absorption of monoenergetic synchrotron radiation

    International Nuclear Information System (INIS)

    Furusawa, Yoshiya; Maezawa, Hiroshi; Suzuki, Kenshi; Kobayashi, Katsumi; Suzuki, Masao; Hieda, Kotaro

    1992-01-01

    Killing effect on bacteriophage T1 by the Auger cascade of phosphorus in DNA following K shell photoabsorption was studied with monoenergetic X rays obtained from synchrotron radiations. Phages embedded in nutrient broth were irradiated under vacuum with X rays at the resonance peak (2,153 eV), and below (2,147 eV) and above (2,159 eV) the peak. The corresponding mean lethal exposures (D 0 ) were 554, 332 and 434 kR, respectively. The Auger enhancements, as an energy dependent fractional increment of phase sensitivity, were 0.67 at 2,153 eV and 0.28 at 2,159 eV. Using the DNA absorption spectrum measured in this experiment, photoionization cross sections of Scofield (17), and the Auger yield after creation of a K shell vacancy, the number of phosphorus Auger cascades in one phage DNA at D 0 were calculated to be 0.00, 0.98 and 0.25 at 2,147, 2,153 and 2,159 eV, respectively. Comparison between the Auger enhancement of phage killing and the number of Auger cascades indicated that one phosphorus Auger cascade in phage DNA caused about 0.41 (at 2,153 eV) or 0.84 (at 2,159 eV) lethal events

  13. Measurement of the Auger lifetime in GaInAsSb/GaSb heterostructures using the photoacoustic technique

    International Nuclear Information System (INIS)

    Riech, I.; Gomez-Herrera, M. L.; Diaz, P.; Mendoza-Alvarez, J. G.; Herrera-Perez, J. L.; Marin, E.

    2001-01-01

    We have studied Ga x In 1-x As y Sb 1-y /GaSb heterostructures for x=0.84 and y=0.14 using the photoacoustic technique with the heat transmission configuration. A theoretical model, which includes all the possible nonradiative recombination mechanisms that contribute to heat generation, was developed to calculate the photoacoustic signal for this type of heterostructure. The Auger recombination lifetime τ Auger was determined by fitting our experimental results to the calculated frequency dependence of the theoretical photoacoustic signal. The obtained value for τ Auger is compatible with those reported in the literature for semiconductors with band-gap energies below and above 0.5 eV, the energy region where there is a lack of experimental τ Auger values. Copyright 2001 American Institute of Physics

  14. Emittance growth rates for displaced beams

    International Nuclear Information System (INIS)

    Anderson, O.A.

    1993-05-01

    Emittance growth rates have been previously analyzed for nonuniform beams in linear channels and for initially uniform mismatched beams in nonlinear channels. These studies were for centered beams. Additional emittance growth can arise in cases where the beam is initially displaced. The purpose of this study is to obtain growth rates for displaced beams. This work differs from studies involving random displacement of electrodes. Our analysis assumes instead that the focusing system is perfectly aligned but that the beam is initially displaced with respect to the equilibrium axis. If the focusing force is slightly nonlinear, we find a gradual transfer of the potential energy of beam displacement into kinetic energy associated with emittance growth. We present explicit results for the emittance growth distance as a function of the nonlinearity of the channel. These results will have practical importance for designers of accelerators and transport systems when setting realistic tolerances for initial beam alignment. These tolerances will depend on the nonlinearity and the length of the system

  15. Strong nonlinearity-induced correlations for counterpropagating photons scattering on a two-level emitter

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara; Mørk, Jesper

    2015-01-01

    We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could be quanti......We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could...

  16. Biexciton Auger Recombination Differs in Hybrid and Inorganic Halide Perovskite Quantum Dots.

    Science.gov (United States)

    Eperon, Giles E; Jedlicka, Erin; Ginger, David S

    2018-01-04

    We use time-resolved photoluminescence measurements to determine the biexciton Auger recombination rate in both hybrid organic-inorganic and fully inorganic halide perovskite nanocrystals as a function of nanocrystal volume. We find that the volume scaling of the biexciton Auger rate in the hybrid perovskites, containing a polar organic A-site cation, is significantly shallower than in the fully inorganic Cs-based nanocrystals. As the nanocrystals become smaller, the Auger rate in the hybrid nanocrystals increases even less than expected, compared to the fully inorganic nanocrystals, which already show a shallower volume dependence than other material systems such as chalcogenide quantum dots. This finding suggests there may be differences in the strength of Coulombic interactions between the fully inorganic and hybrid perovskites, which may prove to be crucial in selecting materials to obtain the highest performing devices in the future, and hints that there could be something "special" about the hybrid materials.

  17. Recommended Auger-electron kinetic energies for 42 elemental solids

    International Nuclear Information System (INIS)

    Powell, C.J.

    2010-01-01

    An analysis is presented of Auger-electron kinetic energies (KEs) from four data sources for 65 Auger transitions in 45 elemental solids. For each data source, a single instrument had been used to measure KEs for many elements. In order to compare KEs from two sources, it was necessary to recalibrate the energy scales of each instrument using recommended reference data. Mean KEs are given for most of the Auger transitions for which there were at least two independent measurements and for which differences from the mean KEs were considered acceptably small. In several cases, comparisons were made to published KE data to resolve discrepancies. We are able to recommend mean KEs for 59 Auger transitions from 42 elemental solids and to provide estimates of the uncertainties of these KEs. This compilation should be useful for the determination of chemical shifts of Auger peaks in Auger electron spectroscopy and X-ray photoelectron spectroscopy.

  18. Dependence of the modulation response of quantum dot based nanocavity devices on the number of emitters

    DEFF Research Database (Denmark)

    Lorke, Michael; Nielsen, Torben Roland; Mørk, Jesper

    2011-01-01

    A microscopic theory is used to study the dynamical properties of semiconductor quantum dot based nanocavity laser systems. The carrier kinetics and photon populations are determined using a fully quantum mechanical treatment of the light‐matter coupling. In this work, we investigate the dependency...... of the modulation response in such devices on the number of emitters coupled to the cavity mode. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)...

  19. Experimental investigation of pyrolysis of rice straw using bench-scale auger, batch and fluidized bed reactors

    International Nuclear Information System (INIS)

    Nam, Hyungseok; Capareda, Sergio C.; Ashwath, Nanjappa; Kongkasawan, Jinjuta

    2015-01-01

    Energy conversion efficiencies of three pyrolysis reactors (bench-scale auger, batch, and fluidized bed) were investigated using rice straw as the feedstock at a temperature of 500 °C. The highest bio-oil yield of 43% was obtained from the fluidized bed reactor, while the maximum bio-char yield of 48% was obtained from the batch reactor. Similar bio-oil yields were obtained from the auger and batch type reactors. The GCMS and FTIR were used to evaluate the liquid products from all reactors. The best quality bio-oil and bio-char from the batch reactor was determined to have a heating value of 31 MJ/kg and 19 MJ/kg, respectively. The highest alkali mineral was found in the bio-char produced from the auger reactor. The energy conversion efficiencies of the three reactors indicated that the majority of the energy (50–64%) was in the bio-char products from the auger and batch reactors, while the bio-oil from the fluidized bed reactor contained the highest energy (47%). A Sankey diagram has been produced to show the flows of product energy from each pyrolysis process. The result will help determine which conversion process would be optimal for producing specific products of bio-char, bio-oil, and gas depending on the needs. - Highlights: • Pyrolysis products from auger, batch, and fluidized bed reactor were examined. • O/C ratios of bio-oils stayed in specific ranges depending on the process reactors. • The largest quantity of bio-oil from fluidized, while the best quality from batch. • The highest alkali concentration of 37 g/kg included in the auger based bio-char. • Sankey diagram was used to understand the energy distribution from reactors.

  20. Chemical information from Auger electron spectroscopy

    International Nuclear Information System (INIS)

    Madden, H.H.

    1981-01-01

    The nature of chemical information in Auger electron spectroscopy (AES) data is reviewed with special emphasis on data from solid surface systems. Two strategies are most frequently used to extract this information: (i) measuring and analyzing energy (chemical) shifts in Auger peaks; and (ii) making use of the shapes of Auger signals to determine the chemical environment at the site of the initial core hole. Chemical shift data are primarily illustrated by highlighting the interaction of oxygen with solids; and analyses of these data based on core-level binding-energy shifts, relaxation, and hole--hole interactions are outlined and discussed. Auger transitions that involve valence electrons are usually those for which lineshapes are taken as indications of the local chemistry at the initial core-hole site. Attempts at extracting valence band density-of-states information from lineshapes are proving successful and this approach to the surface chemical information in AES is illustrated with the aid of examples dealing with the interaction of silicon with hydrogen and with oxygen. The use of the AES lineshapes simply as ''fingerprints'' of the core-hole-site chemistry is examined and illustrated by examples which include studies of silicon nitride properties, of solid surface properties related to catalytic reactions, and of passive films on iron. Auger decay activated desorption processes are briefly examined and found to promise new and unique chemical information when combined with conventional AES. Some gas phase AES studies are also briefly reviewed

  1. Very bright, near-infrared single photon emitters in diamond

    Directory of Open Access Journals (Sweden)

    D. W. M. Lau

    2013-09-01

    Full Text Available We demonstrate activation of bright diamond single photon emitters in the near infrared range by thermal annealing alone, i.e., without ion implantation. The activation is crucially dependent on the annealing ambient. The activation of the single photon emitters is only observed when the sample is annealed in forming gas (4% H2 in Ar above temperatures of 1000 °C. By contrast, no emitters are activated by annealing in vacuum, oxygen, argon or deuterium. The emitters activated by annealing in forming gas exhibit very bright emission in the 730-760 nm wavelength range and have linewidths of ∼1.5-2.5 nm at room temperature.

  2. Investigating the gas phase emitter effect of caesium and cerium in ceramic metal halide lamps in dependence on the operating frequency

    Energy Technology Data Exchange (ETDEWEB)

    Ruhrmann, C; Westermeier, M; Bergner, A; Awakowicz, P; Mentel, J [Ruhr University Bochum, Electrical Engineering and Plasma Technology, D-44780 Bochum (Germany); Luijks, G M J F, E-mail: juergen.mentel@ruhr-uni-bochum.de [Philips Lighting, GBU HID, PO box 80020, 5600JM Eindhoven (Netherlands)

    2011-09-07

    The work function and with it the temperature of tungsten electrodes in HID lamps can be lowered and the lifetime of lamps increased by the gas phase emitter effect. A determination of the emitter effect of Cs and Ce is performed by phase resolved measurements of the electrode tip temperature T{sub tip}({psi}), plasma temperature T{sub pl}({psi}) and particle densities N({psi}) by means of pyrometric, optical emission and broadband absorption spectroscopy in dependence on the operating frequency. The investigated HID lamps are ceramic metal halide lamps with transparent discharge vessels made of YAG, filled with a buffer gas consisting of Ar, Kr and predominantly Hg and seeded with CsI or CeI{sub 3}. In the YAG lamp seeded with CsI and CeI{sub 3} as well as in a YAG lamp seeded with DyI{sub 3} (corresponding results can be found in a preceding paper) a gas phase emitter effect is observed in the cathodic phase due to a Cs, Ce or Dy ion current. In the YAG lamp seeded with CsI the phase averaged coverage of the electrode surface with emitter atoms decreases and the electrode temperature rises with increasing frequency, whereas the emitter effect of Ce and Dy is extended to the anodic phase, which leads to a decreased average temperature T{sub tip}({psi}) with increasing frequency. This different behaviour of the averaged values of T{sub tip}({psi}) for increasing frequency is caused by the differing adsorption energies E{sub a} of the respective emitter materials. In spite of the influence of E{sub a} on the coverage of the electrode with emitter atoms, the cathodic gas phase emitter effect produces in the YAG lamps seeded with CsI, CeI{sub 3} and DyI{sub 3} a general reduction in the electrode tip temperature T{sub tip}({psi}) in comparison with a YAG lamp with Hg filling only.

  3. Internal dynamics and emittance growth in space-charge-dominated beams

    International Nuclear Information System (INIS)

    Anderson, O.A.

    1987-01-01

    Previous analytical studies have related transverse rms emittance growth in nonuniform beams to changes in the beam density profile, but the time evolution of the process has not been analyzed. Our new approach analyzes the internal motion of the beam and from this obtains the explicit time dependence of the rms emittance. It is shown to reach its peak value explosively in about one quarter of a plasma period. The subsequent behavior depends on the uniformity of the initial density profile. We derive a uniformity criterion that determines whether or not the emittance oscillates periodically and present examples of density profiles for which the emittance returns to its initial value and then continues to oscillate. We discuss a class of continuous initial profiles that lead to discontinuous shocklike behavior (with partial irreversibility of the oscillations) and a class of segmented profiles for which the emittance jumps to its maximum value in one fourth of a plasma period and remains at that value with essentially no further change. (author)

  4. Xe N4,5O-OOO satellite Auger spectrum

    International Nuclear Information System (INIS)

    Partanen, L; Huttula, M; Heinaesmaeki, S; Aksela, H; Aksela, S

    2007-01-01

    The N 4,5 O 1,2,3 -O 1,2,3 O 2,3 O 2,3 Auger transitions, appearing as a satellite structure in the N 4,5 -OO Auger spectrum of xenon, were studied in detail. By measuring the N 4,5 O-OOO satellite Auger spectrum both below and above the 4p ionization threshold, we were able to separate the satellite production via the direct photo-double ionization and the Auger cascade from the 4p states. The N 3 -N 4,5 O 2,3 Coster-Kronig transitions and the subsequent N 4,5 O 2,3 -O 2,3 O 2,3 O 2,3 satellite Auger transitions were calculated using the HF wavefunctions and the most intense satellite lines were assigned. The Xe N 4,5 O-OOO satellite spectrum was compared with the previously studied Kr M 4,5 N-NNN satellite Auger spectrum. The 5s orbital in Xe was found to reveal more pronounced electron correlation than the 4s orbital in Kr

  5. 30 CFR 819.11 - Auger mining: General.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: General. 819.11 Section 819.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS SPECIAL PERMANENT PROGRAM PERFORMANCE STANDARDS-AUGER MINING § 819...

  6. The gas phase emitter effect of lanthanum within ceramic metal halide lamps and its dependence on the La vapor pressure and operating frequency

    Energy Technology Data Exchange (ETDEWEB)

    Ruhrmann, C.; Hoebing, T.; Bergner, A.; Groeger, S.; Awakowicz, P.; Mentel, J. [Electrical Engineering and Plasma Technology, Ruhr University Bochum, D-44780 Bochum (Germany); Denissen, C.; Suijker, J. [Philips Lighting, Category Professional Lamps, P.O. Box 80020, NL-5600JM Eindhoven (Netherlands)

    2015-08-07

    The gas phase emitter effect increases the lamp lifetime by lowering the work function and, with it, the temperature of the tungsten electrodes of metal halide lamps especially for lamps in ceramic vessels due to their high rare earth pressures. It is generated by a monolayer on the electrode surface of electropositive atoms of certain emitter elements, which are inserted into the lamp bulb by metal iodide salts. They are vaporized, dissociated, ionized, and deposited by an emitter ion current onto the electrode surface within the cathodic phase of lamp operation with a switched-dc or ac-current. The gas phase emitter effect of La and the influence of Na on the emitter effect of La are studied by spatially and phase-resolved pyrometric measurements of the electrode tip temperature, La atom, and ion densities by optical emission spectroscopy as well as optical broadband absorption spectroscopy and arc attachment images by short time photography. An addition of Na to the lamp filling increases the La vapor pressure within the lamp considerably, resulting in an improved gas phase emitter effect of La. Furthermore, the La vapor pressure is raised by a heating of the cold spot. In this way, conditions depending on the La vapor pressure and operating frequency are identified, at which the temperature of the electrodes becomes a minimum.

  7. A low-emittance lattice for SPEAR

    International Nuclear Information System (INIS)

    Safranek, J.; Wiedemann, H.

    1992-01-01

    The design and implementation of a low emittance lattice for the SPEAR storage ring including measurements of the performance of the lattice are presented (J. Safranek, Ph. D. thesis, Stanford University, 1991). The low emittance lattice is designed to optimize the performance of SPEAR as a synchrotron radiation source while keeping SPEAR hardware changes at a minimum. The horizontal emittance of the electron beam in the low emittance lattice is reduced by a factor of 4 from the previous lattice. This reduces the typical horizontal source size and divergence of the photon beams by a factor of 2 each and increases the photon beam brightness. At 3 GeV the horizontal emittance is 129 π nm rad, which makes the low emittance lattice the lowest emittance, runnning synchroton radiation source in the world in the 1.5 to 4.0 GeV energy range for the emittance scaled to 3 GeV. The measured vertical emittance was reduced to half that typically seen at SPEAR in the past. The brightness of the photon beams was further incrased by reducing β y at the insertion devices to 1.1 m and reducing the energy dispersion at the insertion devices by more than a factor of 2 on average. The horizontal despersion at the rf cavities was reduced by a factor of nearly 4 which gives much less problems with synchrobetatron resonances. The dynamic and physical apertures of the lattice are large, giving long beam lifetimes and easy injection of electrons. The measurements of the linear optics and intensity dependent phenomena gave resonable agreement with the design . The overall performance of the machine was very good. Injection rates of 10 to 20 mA/min and larger were achieved routinely, and 100 mA total current was stored. Repeated ramping of stored beam from the injection energy of 2.3 GeV to the running energy of 3.0 GeV was achieved with very little beam loss. This low emittance configuration is expected to be the operating configuration for SPEAR starting in January 1992. (orig.)

  8. Ab Initio Analysis of Auger-Assisted Electron Transfer.

    Science.gov (United States)

    Hyeon-Deuk, Kim; Kim, Joonghan; Prezhdo, Oleg V

    2015-01-15

    Quantum confinement in nanoscale materials allows Auger-type electron-hole energy exchange. We show by direct time-domain atomistic simulation and analytic theory that Auger processes give rise to a new mechanism of charge transfer (CT) on the nanoscale. Auger-assisted CT eliminates the renown Marcus inverted regime, rationalizing recent experiments on CT from quantum dots to molecular adsorbates. The ab initio simulation reveals a complex interplay of the electron-hole and charge-phonon channels of energy exchange, demonstrating a variety of CT scenarios. The developed Marcus rate theory for Auger-assisted CT describes, without adjustable parameters, the experimental plateau of the CT rate in the region of large donor-acceptor energy gap. The analytic theory and atomistic insights apply broadly to charge and energy transfer in nanoscale systems.

  9. Effective applications of auger electron spectroscopy

    International Nuclear Information System (INIS)

    Golnabi, H.

    1996-01-01

    The goal of this study is to explore different aspects of the AES process and to present the new techniques which can be used effectively for analytical purposes. More emphasis is given to AES data acquisition, sensitivity factor and Auger intensity. The experimental details of a typical scanning Auger microprobe (SAM) is also presented. Applications of AES to selected systems such as microelectronic devices, superconductors, an in metallurgy are described

  10. Photoelectron-Auger electron coincidence spectroscopy of free molecules: New experiments

    International Nuclear Information System (INIS)

    Ulrich, Volker; Barth, Silko; Lischke, Toralf; Joshi, Sanjeev; Arion, Tiberiu; Mucke, Melanie; Foerstel, Marko; Bradshaw, Alex M.; Hergenhahn, Uwe

    2011-01-01

    Photoelectron-Auger electron coincidence spectroscopy probes the dicationic states produced by Auger decay following the photoionization of core or inner valence levels in atoms, molecules or clusters. Moreover, the technique provides valuable insight into the dynamics of core hole decay. This paper serves the dual purpose of demonstrating the additional information obtained by this technique compared to Auger spectroscopy alone as well as of describing the new IPP/FHI apparatus at the BESSY II synchrotron radiation source. The distinguishing feature of the latter is the capability to record both the photoelectron and Auger electron with good energy and angle resolution, for which purpose a large hemispherical electrostatic analyser is combined with several linear time-of-flight spectrometers. New results are reported for the K-shell photoionization of oxygen (O 2 ) and the subsequent KVV Auger decay. Calculations in the literature for non-coincident O 2 Auger spectra are found to be in moderately good agreement with the new data.

  11. Evaluations of carbon nanotube field emitters for electron microscopy

    Science.gov (United States)

    Nakahara, Hitoshi; Kusano, Yoshikazu; Kono, Takumi; Saito, Yahachi

    2009-11-01

    Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I- V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6×109 A/m 2 sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy.

  12. Carrier dynamics and surface vibration-assisted Auger recombination in porous silicon

    Science.gov (United States)

    Zakar, Ammar; Wu, Rihan; Chekulaev, Dimitri; Zerova, Vera; He, Wei; Canham, Leigh; Kaplan, Andrey

    2018-04-01

    Excitation and recombination dynamics of the photoexcited charge carriers in porous silicon membranes were studied using a femtosecond pump-probe technique. Near-infrared pulses (800 nm, 60 fs) were used for the pump while, for the probe, we employed different wavelengths in the range between 3.4 and 5 μ m covering the medium wavelength infrared range. The data acquired in these experiments consist of simultaneous measurements of the transmittance and reflectance as a function of the delay time between the pump and probe for different pump fluences and probe wavelengths. To evaluate the results, we developed an optical model based on the two-dimensional Maxwell-Garnett formula, incorporating the free-carrier Drude contribution and nonuniformity of the excitation by the Wentzel-Kramers-Brillouin model. This model allowed the retrieval of information about the carrier density as a function of the pump fluence, time, and wavelength. The carrier density data were analyzed to reveal that the recombination dynamics is governed by Shockley-Read-Hall and Auger processes, whereas the diffusion has an insignificant contribution. We show that, in porous silicon samples, the Auger recombination process is greatly enhanced at the wavelength corresponding to the infrared-active vibrational modes of the molecular impurities on the surface of the pores. This observation of surface-vibration-assisted Auger recombination is not only for porous silicon in particular, but for low-dimension and bulk semiconductors in general. We estimate the time constants of Shockley-Read-Hall and Auger processes, and demonstrate their wavelength dependence for the excited carrier density in the range of 1018-10191 /cm3 . We demonstrate that both processes are enhanced by up to three orders of magnitude with respect to the bulk counterpart. In addition, we provide a plethora of the physical parameters evaluated from the experimental data, such as the dielectric function and its dependence on the

  13. Influence of the partial temporal coherence of short FEL pulses on two-colour photoionization and photoinduced Auger decay of atoms

    International Nuclear Information System (INIS)

    Kazansky, A K; Sazhina, I P; Kabachnik, N M

    2013-01-01

    The influence of the partial temporal coherence of free electron laser (FEL) radiation on the sidebands arising in the electron spectra of laser-assisted photoionization and photoinduced Auger decay of atoms is theoretically analysed. A simple model is developed which describes the inner-shell photoionization by a short (femtosecond) FEL pulse and the following Auger decay in a strong field of an infrared laser. The model is based on the time-dependent approach and uses the strong field approximation for both photo- and Auger electrons. Particular calculations have been carried out for Ne 1s photoionization and KLL Auger emission. We demonstrate that the temporal coherence of FEL pulses influences the line widths in the photoelectron spectrum. For a small coherence time the sidebands in this spectrum cannot be resolved. On the other hand, our calculations show that in the Auger electron spectrum the sidebands are practically independent of the coherence time of the ionizing pulse.

  14. Impact of Optics on CSR-Related Emittance Growth in Bunch Compressor Chicanes

    CERN Document Server

    Limberg, Torsten

    2005-01-01

    The dependence of emittance growth due to Coherent Synchrotron Radiation (CSR) in bunch compressor chicanes on optics has been noticed and empirically studied in the past. We revisit the subject, suggesting a model to explain slice emittance growth dependence on chicane optics. A simplified model to calculate projected emittance growth when it is mainly caused by transverse slice centroid offsets is presented. It is then used to find optimal compensation of centroid kicks in the single chicanes of a two-stage compression system by adjusting the phase advance of the transport in between and the ration of the compression factors.

  15. Can We Reconcile the TA Excess and Hotspot with Auger Observations?

    Energy Technology Data Exchange (ETDEWEB)

    Globus, Noemie; Piran, Tsvi [Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Allard, Denis; Parizot, Etienne; Lachaud, Cyril [Laboratoire Astroparticule et Cosmologie, Université Paris Diderot/CNRS, 10 rue A. Domon et L. Duquet, F-75205 Paris Cedex 13 (France)

    2017-02-20

    The Telescope Array (TA) shows a 20° hotspot as well as an excess of ultra-high-energy cosmic-rays (UHECRs) above 50 EeV when compared with the Auger spectrum. We consider the possibility that both the TA excess and hotspot are due to a dominant source in the northern sky. We carry out detailed simulations of UHECR propagation in both the intergalactic medium and the Galaxy, using different values for the intergalactic magnetic field. We consider two general classes of sources: transients and steady, adopting a mixed UHECR composition that is consistent with the one found by Auger. The spatial location of the sources is drawn randomly. We generate Auger-like and TA-like data sets from which we determine the spectrum, the sky maps, and the level of anisotropy. We find that, while steady sources are favored over transients, it is unlikely to account for all the currently available observational data. While we reproduce fairly well the Auger spectrum for the vast majority of the simulated data sets, most of the simulated data sets with a spectrum compatible with that of TA (at most a few percent depending on density model tested) show a much stronger anisotropy than the one observed. We find that the rare cases in which both the spectrum and the anisotropy are consistent require a steady source within ∼10 Mpc, to account for the flux excess, and a strong extragalactic magnetic field ∼10 nG, to reduce the excessive anisotropy.

  16. Low-emittance Storage Rings

    CERN Document Server

    Wolski, Andrzej

    2014-01-01

    The effects of synchrotron radiation on particle motion in storage rings are discussed. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. The inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the damping times are derived. Then, it is shown that quantum radiation effects lead to excitation of the beam emittances. General expressions for the equilibrium longitudinal and horizontal (natural) emittances are derived. The impact of lattice design on the natural emittance is discussed, with particular attention to the special cases of FODO-, achromat- and theoretical-minimum-emittance-style lattices. Finally, the effects of betatron coupling and vertical dispersion (generated by magnet alignment and lattice tuning errors) on the vertical emittance are considered.

  17. Evaluations of carbon nanotube field emitters for electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Hitoshi, E-mail: nakahara@nagoya-u.jp [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kusano, Yoshikazu; Kono, Takumi; Saito, Yahachi [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2009-11-30

    Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I-V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6x10{sup 9} A/m{sup 2} sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy.

  18. Effect of interface roughness on Auger recombination in semiconductor quantum wells

    Science.gov (United States)

    Tan, Chee-Keong; Sun, Wei; Wierer, Jonathan J.; Tansu, Nelson

    2017-03-01

    Auger recombination in a semiconductor is a three-carrier process, wherein the energy from the recombination of an electron and hole pair promotes a third carrier to a higher energy state. In semiconductor quantum wells with increased carrier densities, the Auger recombination becomes an appreciable fraction of the total recombination rate and degrades luminescence efficiency. Gaining insight into the variables that influence Auger recombination in semiconductor quantum wells could lead to further advances in optoelectronic and electronic devices. Here we demonstrate the important role that interface roughness has on Auger recombination within quantum wells. Our computational studies find that as the ratio of interface roughness to quantum well thickness is increased, Auger recombination is significantly enhanced. Specifically, when considering a realistic interface roughness for an InGaN quantum well, the enhancement in Auger recombination rate over a quantum well with perfect heterointerfaces can be approximately four orders of magnitude.

  19. Preservation of low slice emittance in bunch compressors

    Directory of Open Access Journals (Sweden)

    S. Bettoni

    2016-03-01

    Full Text Available Minimizing the dilution of the electron beam emittance is crucial for the performance of accelerators, in particular for free electron laser facilities, where the length of the machine and the efficiency of the lasing process depend on it. Measurements performed at the SwissFEL Injector Test Facility revealed an increase in slice emittance after compressing the bunch even for moderate compression factors. The phenomenon was experimentally studied by characterizing the dependence of the effect on beam and machine parameters relevant for the bunch compression. The reproduction of these measurements in simulation required the use of a 3D beam dynamics model along the bunch compressor that includes coherent synchrotron radiation. Our investigations identified transverse effects, such as coherent synchrotron radiation and transverse space charge as the sources of the observed emittance dilution, excluding other effects, such as chromatic effects on single slices or spurious dispersion. We also present studies, both experimental and simulation based, on the effect of the optics mismatch of the slices on the variation of the slice emittance along the bunch. After a corresponding reoptimization of the beam optics in the test facility we reached slice emittances below 200 nm for the central slices along the longitudinal dimension with a moderate increase up to 300 nm in the head and tail for a compression factor of 7.5 and a bunch charge of 200 pC, equivalent to a final current of 150 A, at about 230 MeV energy.

  20. Auger spectra of alkanes

    International Nuclear Information System (INIS)

    Rye, R.R.; Jennison, D.R.; Houston, J.E.

    1980-01-01

    The gas-phase Auger line shapes of the linear alkanes C 1 through C 6 and of neopentane are presented and analyzed. The general shape of the spectra are characteristic of carbon in a tetrahedral environment with the major feature in all cases occurring at approx.249 eV. The relatively large spectral changes found between methane and ethane results from the direct interaction of the terminal methyl groups in ethane, and the spectra of the higher alkanes are shown to be a composite of contributions from terminal methyl and interior methylene group carbon atoms. Theoretical analysis based on a one-electron approximation is shown to be capable of making a molecular orbital assignment by comparing calculated vertical transitions to features in the Auger spectra of ethane and propane, and, in the case of ethane, of differentiating between the 2 E/sub g/ and 2 A/sub 1g/ assignment of the ground state of (C 2 H 6 ) + . A one-electron based molecular orbital treatment, however, is shown to partially break down in propane and neopentane. Analysis of neopentane and the observed absence of any noticeable major peak energy shift with increasing molecular size (as predicted by the one-electron treatment) suggests that some Auger final states occur in which both valence holes are localized on the same subunit of the molecule

  1. System tests, initial operation and first data of the AMIGA muon detector for the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Pontz, Michael

    2013-07-01

    Investigating the energy region between 10{sup 17} eV and 4 x 10{sup 18} eV for primary cosmic particles will lead to a deeper understanding of the origin of cosmic rays. Effects of the transition from galactic to extragalactic origin are expected to be visible in this region. The knowledge of the composition of cosmic rays strongly depends on the hadronic interaction models, which are applied in the air shower reconstruction. Directly determining the number of muons from an air shower on ground level will improve the precision of the composition measurements by reducing the dependence on the models. The Pierre Auger Observatory is facing these challenges with an upgrade of the original detector setup. A denser sub-array of water Cherenkov detectors and a dedicated muon detector (MD) array constitute the AMIGA enhancement (Auger Muon and Infill for the Ground Array). Additional fluorescence telescopes constitute HEAT (High Elevation Auger Telescopes). Seven MD modules have been installed until mid 2012 in a first hexagon at the site of the Pierre Auger Observatory in Malarguee, Argentina. The corresponding readout electronics, and 19 more of these setups, were assembled and tested in Siegen to assure correct functionality. The detectors were incorporated in the trigger structure of the original surface detector (SD) array of the Pierre Auger Observatory and are now taking data synchronously. In the framework of this thesis, system tests have been developed, a pre-unitary cell (PUC) of seven modules has been successfully operated and their trigger has been synchronised with the SD trigger. First data from the MD have been analysed and have been combined with data from the SD.

  2. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  3. Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for sidereal modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.

  4. KLL resonant Auger transitions in metallic Cu and Ni

    International Nuclear Information System (INIS)

    Koever, L.; Berenyi, Z.; Cserny, I.

    2004-01-01

    Complete text of publication follows. KLL Auger spectra of 3d transition metals contain important information on the effects of the solid environment on deep core Auger transitions. Following the changes in the spectra when fine tuning the exciting photon energy across the K-shell ionization threshold with high energy resolution is informative concerning the possible resonant processes, expected to indicate the single-step nature of threshold Auger emission. The satellite structures in these spectra are strongly related to the unoccupied local electronic states above the Fermi level, as well as to the excitation, relaxation and screening processes associated with core hole ionization. In spite of the fundamental significance of the phenomena mentioned above, even non resonant high energy resolution studies of KLL Auger spectra of 3d transition metals (using laboratory X-ray sources) are very scarce due to the demanding experimental conditions requested. A very efficient tool for studying these phenomena is the Tunable High Energy XPS developed at HASYLAB which provides unique conditions, photon x and energy resolution for deep core Auger spectroscopy. Using the THE-XPS instrument at the BW2 beamline the high energy resolution (ΔE = 0.2 eV) KL 2,3 L 2,3 Auger spectra of polycrystalline Cu and Ni foils were measured with the Scienta SES-200 hemispherical analyzer. In the high energy range Cu 2p photo-electron peaks appearing in the Cu KLL Auger spectra due to the excitation by internal Cu K X-rays and trusted value for the Cu 2p3/2 binding energy were used for energy calibration. The exciting photon energy range was tuned up to about 50 eV above the K absorption edge and for the resonant energy region to 5 eV (Cu KLL) and 4 eV (Ni KLL) below threshold ensuring a photon beam with an energy width of about 1.1 eV. The evolution of the satellite structure as a function of excitation energy above threshold indicates di rent behaviour for particular satellites, making

  5. Emittance Growth due to Crab Cavity Ramping for LHC Beam-1 Lattice

    CERN Document Server

    Morita, A

    2008-01-01

    In LHC upgrade scenarios using global crab crossing, it is desired to turn on the crab cavity only at top energy. Turning on the crab cavity could increase the emittance of the stored beam, since the transverse kick of the crab cavity excites betatron oscillations. For a sufficiently slow ramping speed of the crab cavity voltage, however, the changes in z-dependent closed orbit are sufficiently adiabatic that the emittance growth becomes negligible. In order to determine the safe ramping speed of the LHC crab-cavity voltage, the dependence of the emittance growth on the ramping speed is estimated via a 6D particle-tracking simulation.

  6. Experimental studies of fundamental aspects of Auger emission process in Cu(100) and Ag(100)

    Science.gov (United States)

    Joglekar, Prasad Vivek

    Auger spectra at the low energies are accompanied by large contributions unrelated to the Auger transition. The Auger unrelated contributions can obscure the Auger peak and affect the quantitative analysis of the materials under investigation. In this dissertation we present a methodology to measure experimentally the Auger unrelated contributions and eliminate it from the Auger spectrum for obtaining an Auger spectrum inherent to the Auger transition. We used Auger Photoelectron Coincidence Spectroscopy (APECS) to obtain the Auger spectrum. APECS measures the Auger spectrum in coincidence with the core energy level and thus discriminating the contributions arising from secondary electrons and electrons arising from the non-Auger transition. Although APECS removes most of the Auger unrelated contributions, it cannot distinguish the contribution which is measured in coincidence with the inelastically scattered valence band electrons emitted at the core energy. To measure this inelastically scattered valence band contribution we did a series of measurements on Ag(100) to study NVV Auger spectrum in coincidence with 4p energy level and Cu(100) to study MVV Auger spectrum in coincidence with 3p energy level. The coincidence detection of the core and Auger-valence electrons was achieved by the two cylindrical mirror analyzers (CMAs). One CMA was fixed over a range of energies in between VB and core energy level while other CMA scanned corresponding low energy electrons from 0 to70eV. The spectrums measured were fit to a parameterized function which was extrapolated to get an estimate of inelastically scattered valence band electrons. The estimated contribution was subtracted for the Ag and Cu APECS spectrum to obtain a spectrum solely due to Auger transition with inelastically scattered Auger electron and multi Auger decay contributions associated with the transition. In the latter part of this dissertation, we propose a theoretical model based on the spectral intensity

  7. Emittance growth and tune spectra at PETRA III

    International Nuclear Information System (INIS)

    Wanzenberg, R.

    2011-08-01

    At DESY the PETRA ring has been converted into a synchrotron radiation facility, called PETRA III. 20 damping wigglers have been installed to achieve an emittance of 1 nm. The commissioning with beam started in April 2009 and user runs have been started in 2010. The design current is 100 mA and the bunch to bunch distance is 8 ns for one particular filling pattern with 960 bunches. At a current of about 50 mA a strong vertical emittance increase has been observed. During machine studies it was found that the emittance increase depends strongly on the bunch filling pattern. For the user operation a filling scheme has been found which mitigates the increase of the vertical emittance. In August 2010 PETRA III has been operated without damping wigglers for one week. The vertical emittance growth was not significantly smaller without wigglers. Furthermore tune spectra at PETRA III show characteristic lines which have been observed at other storage rings in the connection with electron clouds. Measurements at PETRA III are presented for different bunch filling patterns and with and without wiggler magnets. (orig.)

  8. Spermatogonial cell killing by radiolabeled methionine: a comparative study of the effects of Se-17, S-35, and H-3

    International Nuclear Information System (INIS)

    Rao, D.V.; Govelitz, G.F.; Sastry, K.S.R.; Howell, R.W.

    1986-01-01

    Spermatogenesis in the testes of mice offers an effective experimental model to investigate the biological effects and the dosimetry of Auger electron emitters in vivo, aspects that are not yet well understood. Killing of the radiosensitive spermatogonia by intratesticularly localized radionuclides is the biological effect of interest, manifesting as reduced sperm-head population four to six weeks after the initial administration of the radionuclides. The authors present here results of a comparative study of the effects of the Auger-emitter, 75 Se, and the beta-emitters, 35 S and 3 H, when these radionuclides are attached to methionine, and hence distributed similarly in the testis and in the cytoplasmic protein fractions of the spermatogonial cells. The sperm-head survival is assayed on the 36th day post-injection, when the sperm-head population reaches its minimum after the initial intratesticular administration of the radionuclides. In all the three cases, the survival fractions display similar dependence on the conventionally calculated average dose to the organ. These results show the adequacy of conventional dosimetry when 75 Se is localized in the cytoplasm of the cells, and emphasize the relative inefficiency of Auger electrons emitted from cytoplasmic decay sites in irradiating the radiosensitive DNA in the cells. 21 references, 4 figures, 4 tables

  9. Relativistic Calculations and Measurements of Energies, Auger Rates, and Lifetimes.

    Science.gov (United States)

    1982-12-01

    Research and Industry, Denton, Texas, 8-10 November 1982. 7. B. Crasemann: "Efectos Relativ’sticos y de QED Sobre las Transiciones Rayos - X y Auger Entre...INNER-SHELL IONIZATION BY PROTONS X -RAY EMISSION BREIT INTERACTION AUGER TRANSITIONS DIRAC-HARTREE-SLATER COMPUTATIONS SYNCHROTRON RADIATION RESONANT...computations, including relativistic and quantum- electrodynamic effects, of atomic energy levels and of x -ray and Auger transitions in atoms with one or

  10. Analysis of angular dependent Auger spectroscopy (ADAS) based on a quasiatomic model

    International Nuclear Information System (INIS)

    Davis, H.L.

    1977-01-01

    Calculated results are presented which are in good agreement with published M 2 , 3 VV Cu (100) ADAS data. The calculations are based on a quasiatomic model where each individual Auger emission is a partial wave of definite (l,m) character, but (l,m) may differ from emission to emission. The (l,m) emission weights have been estimated by fitting the data with a linear combination of calculated intensities for (l,m) up to l = 5. It is found that surprisingly few (l,m) values are necessary to obtain reasonable fits to the data, and the best fits occur for combinations of (l,m) intensities in which the l = 3 waves were most heavily weighted

  11. Auger electron spectroscopy of alloy surfaces

    International Nuclear Information System (INIS)

    Overbury, S.H.; Somorjai, G.A.

    1975-03-01

    Regular solution models are used to predict surface segregation of the constituent of lowest surface free energy in homogeneous multicomponent systems. Analysis of the Auger electron emission intensities from alloys yield the surface composition and the depth distribution of the composition near the surface. Auger Electron Spectroscopy (AES) studies of the surface composition of the Ag--Au and Pb--In systems have been carried out as a function of bulk composition and temperature. Although these alloys have very different regular solution parameters their surface compositions are predictable by the regular solution models. (U.S.)

  12. Quantitative Auger analysis of Nb-Ge superconducting alloys

    International Nuclear Information System (INIS)

    Buitrago, R.H.

    1980-01-01

    The feasibility of using Auger electron analysis for quantitative analysis was investigated by studying Nb 3 Ge thin-film Auger data with different approaches. A method base on elemental standards gave consistent quantitative values with reported Nb-Ge data. Alloy sputter yields were also calculated and results were consistent with those for pure elements

  13. Experimental investigation of thermal emittance components of copper photocathode

    Directory of Open Access Journals (Sweden)

    H. J. Qian

    2012-04-01

    Full Text Available With progress of photoinjector technology, thermal emittance has become the primary limitation of electron beam brightness. Extensive efforts have been devoted to study thermal emittance, but experiment results differ between research groups and few can be well interpreted. Besides the ambiguity of photoemission mechanism, variations of cathode surface conditions during cathode preparation, such as work function, field enhancement factor, and surface roughness, will cause thermal emittance differences. In this paper, we report an experimental study of electric field dependence of copper cathode quantum efficiency (QE and thermal emittance in a radio frequency (rf gun, through which in situ cathode surface parameters and thermal emittance contributions from photon energy, Schottky effect, and surface roughness are extracted. It is found the QE of a copper cathode illuminated by a 266 nm UV laser increased substantially to 1.5×10^{-4} after cathode cleaning during rf conditioning, and a copper work function of 4.16 eV, which is much lower than nominal value (4.65 eV, was measured. Experimental results also show a thermal emittance growth as much as 0.92  mm mrad/mm at 50  MV/m due to the cathode surface roughness effect, which is consistent with cathode surface morphology measurements.

  14. Comments on Auger electron production by Ne/sup +/ bombardment of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, S V; Ferrante, J [National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center

    1979-09-01

    In this letter, the authors first report rather conclusive experimental evidence showing that the Ne Auger signal is due to asymmetric Ne-metal collisions and not symmetric Ne-Ne collisions. Next it is shown that the Ne Auger signal is in fact observable by Ne/sup +/ bombardment of Si and with signal strength comparable to that of the Si Auger signal for 3 keV incident ion energy. Finally, they comment on some trends in the relative amplitudes of the 21.9 and 25.1 eV Ne Auger signals as a function of incident ion energy and target species.

  15. Line optical and Auger data acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Wall, W E; Stevenson, J R [Georgia Inst. of Tech., Atlanta (USA). School of Physics

    1978-06-01

    A software/hardware package has been developed for use with an 8K DEC PDP-8/L or /I minicomputer, providing real time acquisition and manipulation of optical reflectivity, Auger, and photoemission data. Optical data and Auger or photoemission data may be acquired simultaneously. Provisions have been included for the addition of a scanning rotating ellipsometer. Synchrotron radiation from an electron storage ring has been the primary optical source. Optical reflectivity is measured using single photon counting with a ratio technique that samples a portion of the incident light with one detector and the reflected light with a second detector. Differential Auger or photoemission data is acquired using a cylindrical mirror electron energy analyzer under computer control in a signal averaging mode of operation. Direct electron distribution curves may be displayed using a numerical integration routine. Software was written in assembly language to conserve available memory; however, a modular approach was used to allow easy additions and modifications to experiments. Data arrays may be manipulated and stored as single variables.

  16. Microprocessor monitored Auger spectrometer

    International Nuclear Information System (INIS)

    Sapin, Michel; Ghaleb, Dominique; Pernot, Bernard.

    1982-05-01

    The operation of an Auger spectrometer, used for studying surface impurity diffusion, has been fully automatized with the help of a microprocessor. The characteristics, performance and practical use of the system are described together with the main advantage for the experimentator [fr

  17. Decoupling Intensity Radiated by the Emitter in Distance Estimation from Camera to IR Emitter

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Luna Vázquez

    2013-05-01

    Full Text Available Various models using radiometric approach have been proposed to solve the problem of estimating the distance between a camera and an infrared emitter diode (IRED. They depend directly on the radiant intensity of the emitter, set by the IRED bias current. As is known, this current presents a drift with temperature, which will be transferred to the distance estimation method. This paper proposes an alternative approach to remove temperature drift in the distance estimation method by eliminating the dependence on radiant intensity. The main aim was to use the relative accumulated energy together with other defined models, such as the zeroth-frequency component of the FFT of the IRED image and the standard deviation of pixel gray level intensities in the region of interest containing the IRED image. By using the abovementioned models, an expression free of IRED radiant intensity was obtained. Furthermore, the final model permitted simultaneous estimation of the distance between the IRED and the camera and the IRED orientation angle. The alternative presented in this paper gave a 3% maximum relative error over a range of distances up to 3 m.

  18. Studies of fluorescence and Auger decay following inner-shell photoionization

    International Nuclear Information System (INIS)

    Levin, J.C.; Armen, G.B.

    2004-01-01

    Near inner-shell absorption edges, Auger and fluorescence spectra which characterize the first step of a complex cascade process exhibit properties which are well described by radiationless and radiative resonant Raman scattering theory. We present comparisons of our recent data and theory for Auger decay of argon K vacancies, xenon L vacancies, and of fluorescence decay of xenon L vacancies. A theoretical unification of Auger decay and fluorescence decay is presented which clarifies the similarities and differences between the two processes

  19. Summary of Auger-Related Entanglement Incidents Occurring Inside Agricultural Confined Spaces.

    Science.gov (United States)

    Cheng, Y H; Field, W E

    2016-04-01

    Entanglements in energized equipment, including augers found in agricultural workplaces, have historically been a significant cause of traumatic injury. Incidents involving augers located inside agricultural confined spaces (primarily grain storage structures and forage silos), although relatively rare events, are a widely recognized problem due to the relative severity of the resulting injuries and the complexities of victim extrication. However, this problem is neither well documented nor elucidated in the research literature, other than anecdotal observations relating to medical treatment of auger-related injuries and citations for non-compliance with federal and state workplace safety regulations. A review of nearly 1,650 cases documented in the Purdue Agricultural Confined Spaces Incident Database from 1964 to 2013 identified 167 incidents involving entanglement in an energized auger that occurred while the victim was working inside an agricultural confined space. These incidents primarily included in-floor unloading augers, sweep augers, stirring augers, and auger components found on silo unloaders. Cases involving portable tube augers used to handle grain outside grain storage structures were not included. Based on analysis of the data, approximately 98% of known victims were male, with the 21-45 age group reporting the largest number of incidents. Nearly one-third (32.3%) of incidents were fatal, and lower limb amputation was the most frequently reported injury type. (It is believed that non-fatal incidents are grossly under-reported in the data set due to a lack of comprehensive reporting requirements, especially for most farms, feedlots, and seed processing operations, which are generally exempt from compliance with OSHA machine guarding, confined-space, and grain-handling standards.) The type of auger identified most frequently as the agent of injury was the exposed in-floor auger (48), which frequently resulted in amputation of one or more lower limbs

  20. New Method for Determination of Electrically Inactive Phosphorus in n-type Emitters

    OpenAIRE

    Steyer, Michael; Dastgheib-Shirazi, Amir; Hahn, Giso; Terheiden, Barbara

    2015-01-01

    The precise knowledge of the amount and the location in depth of inactive phosphorus in an n-type emitter is still a challenge. As a new approach, we determine the total amount of phosphorus (P dose) in the emitter stepwise in dependence of etching depth with the characterization tool ICP-OES. A comparison of the data with the electrically active P concentration profile measured by ECV allows to determine in which depths electrically inactive phosphorus is present. For a highly doped emitter,...

  1. Strand breaks in plasmid DNA following positional changes of Auger-electron-emitting radionuclides

    International Nuclear Information System (INIS)

    Adelstein, S.J.; Kassis, A.I.

    1996-01-01

    The purpose of our studies is to elucidate the kinetics of DNA strand breaks caused by low-energy Auger electron emitters in close proximity to DNA. Previously we have studied the DNA break yields in plasmids after the decay of indium-111 bound to DNA or free in solution. In this work, we compare the DNA break yields in supercoiled DNA of iodine-125 decaying close to DNA following DNA intercalation, minor-groove binding, or surface binding, and at a distance form DNA. Supercoiled DNA, stored at 4 C to accumulate radiation dose from the decay of 125 I, was then resolved by gel electrophoresis into supercoiled, nicked circular, and linear forms, representing undamaged DNA, single-strand breaks, and double-strand breaks respectively. DNA-intercalated or groove-bound 125 I is more effective than surface-bound radionuclide or 125 I free in solution. The hydroxyl radical scavenger DMSO protects against damage by 125 I free in solution but has minimal effect on damage by groove-bound 125 I. (orig.)

  2. Quantitative Auger depth profiling of LPCVD and PECVD silicon nitride films

    International Nuclear Information System (INIS)

    Keim, E.G.; Aite, K.

    1989-01-01

    Thin silicon nitride films (100-210 nm) with refractive indices varying from 1.90 to 2.10 were deposited on silicon substrates by low pressure chemical vapour deposition (LPCVD) and plasma enhanced chemical vapour deposition (PECVD). Rutherford backscattering spectrometry (RBS), ellipsometry, surface profiling measurements and Auger electron spectroscopy (AES) in combination with Ar + sputtering were used to characterize these films. We have found that the use of (p-p)heights of the Si LVV and N KLL Auger transitions in the first derivative of the energy distribution (dN(E)/dE) leads to an accurate determination of the silicon nitride composition in Auger depth profiles over a wide range of atomic Si/N ratios. Moreover, we have shown that the Si KLL Auger transition, generally considered to be a better probe than the low energy Si LVV Auger transition in determining the chemical composition of silicon nitride layers, leads to deviating results. (orig.)

  3. Auger recombination in Dirac materials: A tangle of many-body effects

    Science.gov (United States)

    Alymov, Georgy; Vyurkov, Vladimir; Ryzhii, Victor; Satou, Akira; Svintsov, Dmitry

    2018-05-01

    The peculiar electron dispersion in Dirac materials makes lowest-order Auger processes prohibited or marginally prohibited by energy and momentum conservation laws. Thus, Auger recombination (AR) in these materials is very sensitive to many-body effects. We incorporate them at the level of the G W approximation into the nonequilibrium Green's functions approach to AR and study the role of dynamic screening, spectrum broadening, and renormalization in the case of weakly pumped undoped graphene. We find that incorrect treatment of many-body effects can lead to an order-of-magnitude error in the recombination rate. We show that the AR time depends weakly (sublinearly) on the background dielectric constant, which limits the possibility to control recombination by the choice of substrate. However, the AR time can be considerably prolonged by placing graphene under a metal gate or by introducing a band gap. With carrier cooling taken into account, our results comply with experiments on photoexcited graphene.

  4. Few emitters in a cavity: from cooperative emission to individualization

    International Nuclear Information System (INIS)

    Auffeves, A; Portolan, S; Gerace, D; Drezet, A; Franca Santos, M

    2011-01-01

    We study the temporal correlations of the field emitted by an electromagnetic resonator coupled to a mesoscopic number of two-level emitters that are incoherently pumped by a weak external drive. We solve the master equation of the system for increasing number of emitters and as a function of the cavity quality factor, and we identify three main regimes characterized by well-distinguished statistical properties of the emitted radiation. For small cavity decay rates, the emission events are uncorrelated and the number of photons in the emitted field becomes larger than one, resembling the build-up of a laser field inside the cavity. At intermediate decay rates (as compared with the emitter-cavity coupling) and for a few emitters, the statistics of the emitted radiation is bunched and strikingly dependent on the parity of the number of emitters. The latter property is related to the cooperativity of the emitters mediated by their coupling to the cavity mode, and its connection with steady-state subradiance is discussed. Finally, in the bad cavity regime the typical situation of emission from a collection of individual emitters is recovered. We also analyze how the cooperative behavior evolves as a function of pure dephasing, which allows us to recover the case of a classical source made of an ensemble of independent emitters, similar to what is obtained for a very leaky cavity. State-of-the-art techniques of Q-switch of resonant cavities, allied with the recent capability of tuning single emitters in and out of resonance, suggest this system to be a versatile source of different quantum states of light.

  5. Few emitters in a cavity: from cooperative emission to individualization

    Energy Technology Data Exchange (ETDEWEB)

    Auffeves, A; Portolan, S [CEA/CNRS/UJF Joint Team ' Nanophysics and Semiconductors' , Institut Neel-CNRS, BP 166, 25 Rue des Martyrs, 38042 Grenoble Cedex 9 (France); Gerace, D [Dipartimento di Fisica ' Alessandro Volta' and UdR CNISM, Universita di Pavia, via Bassi 6, 27100 Pavia (Italy); Drezet, A [Institut Neel-CNRS, BP 166, 25 Rue des Martyrs, 38042 Grenoble Cedex 9 (France); Franca Santos, M, E-mail: msantos@fisica.ufmg.br [Departamento de Fisica, Universidade Federal de Minas Gerais, Belo Horizonte, CP 702, 30123-970 (Brazil)

    2011-09-15

    We study the temporal correlations of the field emitted by an electromagnetic resonator coupled to a mesoscopic number of two-level emitters that are incoherently pumped by a weak external drive. We solve the master equation of the system for increasing number of emitters and as a function of the cavity quality factor, and we identify three main regimes characterized by well-distinguished statistical properties of the emitted radiation. For small cavity decay rates, the emission events are uncorrelated and the number of photons in the emitted field becomes larger than one, resembling the build-up of a laser field inside the cavity. At intermediate decay rates (as compared with the emitter-cavity coupling) and for a few emitters, the statistics of the emitted radiation is bunched and strikingly dependent on the parity of the number of emitters. The latter property is related to the cooperativity of the emitters mediated by their coupling to the cavity mode, and its connection with steady-state subradiance is discussed. Finally, in the bad cavity regime the typical situation of emission from a collection of individual emitters is recovered. We also analyze how the cooperative behavior evolves as a function of pure dephasing, which allows us to recover the case of a classical source made of an ensemble of independent emitters, similar to what is obtained for a very leaky cavity. State-of-the-art techniques of Q-switch of resonant cavities, allied with the recent capability of tuning single emitters in and out of resonance, suggest this system to be a versatile source of different quantum states of light.

  6. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the average depth of shower maximum and its fluctuations with the Pierre Auger Observatory; (2) Study of the nuclear mass composition of UHECR with the surface detectors of the Pierre Auger Observatory; (3) Comparison of data from the Pierre Auger Observatory with predictions from air shower simulations: testing models of hadronic interactions; (4) A Monte Carlo exploration of methods to determine the UHECR composition with the Pierre Auger Observatory; (5) The delay of the start-time measured with the Pierre Auger Observatory for inclined showers and a comparison of its variance with models; (6) UHE neutrino signatures in the surface detector of the Pierre Auger Observatory; and (7) The electromagnetic component of inclined air showers at the Pierre Auger Observatory.

  7. Operation of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Rodriguez Martino, Julio

    2011-01-01

    While the work to make data acquisition fully automatic continues, both the Fluorescence Detectors and the Surface Detectors of the Pierre Auger Observatory need some kind of attention from the local staff. In the first case, the telescopes are operated and monitored during the moonless periods. The ground array only needs monitoring, but the larger number of stations implies more variables to consider. AugerAccess (a high speed internet connection) will give the possibility of operating and monitoring the observatory from any place in the world. This arises questions about secure access, better control software and alarms. Solutions are already being tested and improved.

  8. Auger Recombination in III-Nitride Nanowires and Its Effect on Nanowire Light-Emitting Diode Characteristics

    KAUST Repository

    Guo, Wei; Zhang, Meng; Bhattacharya, Pallab; Heo, Junseok

    2011-01-01

    We have measured the Auger recombination coefficients in defect-free InGaN nanowires (NW) and InGaN/GaN dot-in-nanowire (DNW) samples grown on (001) silicon by plasma-assisted molecular beam epitaxy. The nanowires have a density of ∼1×1011 cm-2 and exhibit photoluminescence emission peak at λ ∼ 500 nm. The Auger coefficients as a function of excitation power have been derived from excitation dependent and time-resolved photoluminescence measurements over a wide range of optical excitation power density. The values of C0, defined as the Auger coefficient at low excitation, are 6.1 × 10-32 and 4.1×10-33 cm6·s-1 in the NW and DNW samples, respectively, which are in reasonably good agreement with theoretical predictions for InGaN alloy semiconductors. Light-emitting diodes made with the NW and DNW samples exhibit no efficiency droop up to an injection current density of 400 A/cm 2. © 2011 American Chemical Society.

  9. Auger Recombination in III-Nitride Nanowires and Its Effect on Nanowire Light-Emitting Diode Characteristics

    KAUST Repository

    Guo, Wei

    2011-04-13

    We have measured the Auger recombination coefficients in defect-free InGaN nanowires (NW) and InGaN/GaN dot-in-nanowire (DNW) samples grown on (001) silicon by plasma-assisted molecular beam epitaxy. The nanowires have a density of ∼1×1011 cm-2 and exhibit photoluminescence emission peak at λ ∼ 500 nm. The Auger coefficients as a function of excitation power have been derived from excitation dependent and time-resolved photoluminescence measurements over a wide range of optical excitation power density. The values of C0, defined as the Auger coefficient at low excitation, are 6.1 × 10-32 and 4.1×10-33 cm6·s-1 in the NW and DNW samples, respectively, which are in reasonably good agreement with theoretical predictions for InGaN alloy semiconductors. Light-emitting diodes made with the NW and DNW samples exhibit no efficiency droop up to an injection current density of 400 A/cm 2. © 2011 American Chemical Society.

  10. Shielding in ungated field emitter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J. R. [U.S. Navy Reserve, Navy Operational Support Center New Orleans, New Orleans, Louisiana 70143 (United States); Jensen, K. L. [Code 6854, Naval Research Laboratory, Washington, D.C. 20375 (United States); Shiffler, D. A. [Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, New Mexico 87117 (United States); Petillo, J. J. [Leidos, Billerica, Massachusetts 01821 (United States)

    2015-05-18

    Cathodes consisting of arrays of high aspect ratio field emitters are of great interest as sources of electron beams for vacuum electronic devices. The desire for high currents and current densities drives the cathode designer towards a denser array, but for ungated emitters, denser arrays also lead to increased shielding, in which the field enhancement factor β of each emitter is reduced due to the presence of the other emitters in the array. To facilitate the study of these arrays, we have developed a method for modeling high aspect ratio emitters using tapered dipole line charges. This method can be used to investigate proximity effects from similar emitters an arbitrary distance away and is much less computationally demanding than competing simulation approaches. Here, we introduce this method and use it to study shielding as a function of array geometry. Emitters with aspect ratios of 10{sup 2}–10{sup 4} are modeled, and the shielding-induced reduction in β is considered as a function of tip-to-tip spacing for emitter pairs and for large arrays with triangular and square unit cells. Shielding is found to be negligible when the emitter spacing is greater than the emitter height for the two-emitter array, or about 2.5 times the emitter height in the large arrays, in agreement with previously published results. Because the onset of shielding occurs at virtually the same emitter spacing in the square and triangular arrays, the triangular array is preferred for its higher emitter density at a given emitter spacing. The primary contribution to shielding in large arrays is found to come from emitters within a distance of three times the unit cell spacing for both square and triangular arrays.

  11. Auger electron spectroscopy for the advanced student laboratory

    International Nuclear Information System (INIS)

    Greczylo, Tomasz; Mazur, Piotr; Debowska, Ewa

    2009-01-01

    This paper presents Auger electron spectroscopy with a retarding field analyser designed for an advanced physics experiment carried out in 'Physics Laboratory II' at the Institute of Experimental Physics, University of Wroclaw, Poland. The authors discuss the process of setting up the experiment and the results of the measurement of Auger spectra. The advantages and disadvantages of the apparatus are discussed along with its implementation in the teaching process

  12. Relation between field energy and RMS emittance in intense particle beams

    International Nuclear Information System (INIS)

    Wangler, T.P.; Crandall, K.R.; Mills, R.S.; Reiser, M.

    1985-01-01

    An equation is presented for continuous beams with azimuthal symmetry and continuous linear focusing, which expresses a relationship between the rate of change for squared rms emittance and the rate of change for a quantity we call the nonlinear field energy. The nonlinear field energy depends on the shape of the charge distribution and corresponds to the residual field energy possessed by beams with nonuniform charge distributions. The equation can be integrated for the case of an rms matched beam to yield a formula for space-charge-induced emittance growth that we have tested numerically for a variety of initial distributions. The results provide a framework for discussing the scaling of rms emittance growth and an explanation for the well-established lower limit on output emittance. 15 refs., 4 figs

  13. Experimental studies of emittance growth and energy spread in a photocathode RF gun

    International Nuclear Information System (INIS)

    Yang, J.; Sakai, F.; Okada, Y.; Yorozu, M.; Yanagida, T.; Endo, A.

    2002-01-01

    In this paper we report on a low emittance electron source, based on a photocathode RF gun, a solenoid magnet and a subsequent linac. The dependencies of the beam transverse emittance and relative energy spread with respect to the laser injection phase of the radio-frequency (RF) gun, the RF phase of the linac and the bunch charge were investigated experimentally. It was found that a lower beam emittance is observed when the laser injection phase in the RF gun is low. The emittance increases almost linearly with the bunch charge under a constant solenoid magnetic field. The corrected relative energy spread of the beam is not strongly dependent on the bunch charge. Finally, an optimal normalized rms transverse emittance of 1.91±0.28 πmm mrad at a bunch charge of 0.6 nC was obtained when the RF gun was driven by a picosecond Nd:YAG laser. A corrected relative rms energy spread of 0.2-0.25% at a bunch charge of 0.3-2 nC was obtained after the beam was accelerated to 14 MeV by the subsequent linac

  14. Experimental studies of emittance growth and energy spread in a photocathode RF gun

    CERN Document Server

    Yang, J; Okada, Y; Yorozu, M; Yanagida, T; Endo, A

    2002-01-01

    In this paper we report on a low emittance electron source, based on a photocathode RF gun, a solenoid magnet and a subsequent linac. The dependencies of the beam transverse emittance and relative energy spread with respect to the laser injection phase of the radio-frequency (RF) gun, the RF phase of the linac and the bunch charge were investigated experimentally. It was found that a lower beam emittance is observed when the laser injection phase in the RF gun is low. The emittance increases almost linearly with the bunch charge under a constant solenoid magnetic field. The corrected relative energy spread of the beam is not strongly dependent on the bunch charge. Finally, an optimal normalized rms transverse emittance of 1.91+-0.28 pi mm mrad at a bunch charge of 0.6 nC was obtained when the RF gun was driven by a picosecond Nd:YAG laser. A corrected relative rms energy spread of 0.2-0.25% at a bunch charge of 0.3-2 nC was obtained after the beam was accelerated to 14 MeV by the subsequent linac.

  15. Manipulation of resonant Auger processes with strong optical fields

    Science.gov (United States)

    Picón, Antonio; Buth, Christian; Doumy, Gilles; Krässig, Bertold; Young, Linda; Southworth, Stephen

    2013-05-01

    We recently reported on the optical control of core-excited states of a resonant Auger process in neon. We have focused on the resonant excitation 1 s --> 1s-1 3 p , while a strong optical field may resonantly couple two core-excited states (1s-1 3 p and 1s-1 3 s) in the Rydberg manifold as well as dressing the continuum. There is a clear signature in the Auger electron spectrum of the inner-shell dynamics induced by the strong optical field: i) the Auger electron spectrum is modified by the rapid optical-induced population transfer from the 1s-1 3 p state to the 1s-1 3 s state during their decay. ii) The angular anisotropy parameter, defining the angular distribution of the Auger electron, is manifested in the envelope of the (angle-integrated) sidebands. This work is funded by the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy, under Contract No. DE-AC02-06CH11357.

  16. Movement of Irrigation Water in Soil from a Surface Emitter

    Directory of Open Access Journals (Sweden)

    Ibrahim Abbas Dawood

    2016-09-01

    Full Text Available rickle irrigation is one of the most conservative irrigation techniques since it implies supplying water directly on the soil through emitters. Emitters dissipate energy of water at the end of the trickle irrigation system and provide water at emission points. The area wetted by an emitter depends upon the discharge of emitter, soil texture, initial soil water content, and soil permeability. The objectives of this research were to predict water distribution profiles through different soils for different conditions and quantify the distribution profiles in terms of main characteristics of soil and emitter. The wetting patterns were simulated at the end of each hour for a total time of application of 12 hrs, emitter discharges of 0.5, 0.75, 1, 2, 3, 4, and 5 lph, and five initial volumetric soil water contents. Simulation of water flow from a single surface emitter was carried out by using the numerically-based software Hydrus-2D/3D, Version 2.04. Two approaches were used in developing formulas to predict the domains of the wetted pattern. In order to verify the results obtained by implementing the software Hydrus-2D/3D a field experiment was conducted to measure the wetted diameter and compare measured values with simulated ones. The results of the research showed that the developed formulas to express the wetted diameter and depth in terms of emitter discharge, time of application, and initial soil water content are very general and can be used with very good accuracy.

  17. Physical design of the positron induced auger electron spectrometer

    International Nuclear Information System (INIS)

    Qin Xiubo; Jiang Xiaopan; Wang Ping; Yu Runsheng; Wang Baoyi; Wei Long

    2009-01-01

    Positron Annihilation Induced Auger Electron Spectroscopy (PAES) has several advantages over those excited by X-rays, high energy electrons or neutrons, such as excellent surface selectivity, high signal-to-noise ratio, low radiation damage,etc. A physical design of time of flight PAES (TOF-PAES) apparatus based on the Beijing Intense Slow Positron Beam (BIPB) is described in this paper. The positrons and electrons are transported in a 4 x 10 -3 T uniform magnetic field, and the gradient of magnetic field is designed to pluralize the Auger electrons emitted with 2π angle. The Auger electron energy is adjusted by a Faraday cage to optimize the energy resolution,which can be better than 2 eV. (authors)

  18. Thermal integrity profiling for augered cast-in-place piles – implementation plan : summary.

    Science.gov (United States)

    2017-09-01

    Auger-cast-in-place (ACIP) piles are created when an auger the diameter and length of the desired pile is drilled into the ground. Concrete is pumped through the central axis of the auger as it is withdrawn, pulling up excavated soil as concrete fill...

  19. Enhanced radiative Auger emission from lithiumlike 20Ca17+

    International Nuclear Information System (INIS)

    Bernstein, E.M.; Clark, M.W.; Tanis, J.A.; Graham, W.G.; Morgan, T.J.; Stoeckli, M.P.; Berkner, K.H.; Schlachter, A.S.; Stearns, J.W.

    1991-01-01

    Radiative Auger emission (RAE) from lithiumlike 20 Ca 17+ projectiles excited in collisions with He has been measured. The intensity of RAE photons relative to K α X-ray emission is enhanced by a factor of 10-17 compared with theoretical calculations for ions with few electron vacancies. The enhancement of RAE for Ca 17+ is consistent with the results reported previously for lithiumlike 16 S 13+ and 23 V 20+ and indicates a systematic dependence on Z. Both the enhancement and the relative RAE transition rate increase with Z. (orig.)

  20. Measuring Beam Sizes and Ultra-Small Electron Emittances Using an X-ray Pinhole Camera.

    Science.gov (United States)

    Elleaume, P; Fortgang, C; Penel, C; Tarazona, E

    1995-09-01

    A very simple pinhole camera set-up has been built to diagnose the electron beam emittance of the ESRF. The pinhole is placed in the air next to an Al window. An image is obtained with a CCD camera imaging a fluorescent screen. The emittance is deduced from the size of the image. The relationship between the measured beam size and the electron beam emittance depends upon the lattice functions alpha, beta and eta, the screen resolution, pinhole size and photon beam divergence. The set-up is capable of measuring emittances as low as 5 pm rad and is presently routinely used as both an electron beam imaging device and an emittance diagnostic.

  1. Ne, Ar, Fe, and Cu Auger-electron production at National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Lee, D.H.; Johnson, B.M.; Jones, K.W.; Guardala, N.A.; Price, J.L.; Stumborg, M.F.; Glass, G.A.

    1992-01-01

    Energetic K and L Auger electrons produced by focussed, filtered, broad-band synchrotron radiation have been measured at the x-ray ring of the National Synchrotron Light Source (NSLS). The x-ray beam was used to study inner-shell photoionization of Ne and Ar gas and Fe and Cu solid film targets. The Auger electrons were analyzed by means of a semi-hemispherical electrostatic electron spectrometer at the energy resolution of ∼ 3 %. The electrons were detected at both 90 degree and 0 degree with respect to the photon beam direction. Broad distributions of the inner-shell photoelectrons were also observed, reflecting the incoming photon flux distribution. The Fe and Cu K Auger electron spectra were found to be very similar to the Ar K Auger electron spectra. This was expected, since deep inner-shell Auger processes are not affected by the outer valence electrons. Above 3 keV in electron energy, there have been few previous Auger electron measurements. 2 figs., 13 refs

  2. Positron annihilation induced Auger electron spectroscopic studies of oxide surfaces

    Science.gov (United States)

    Nadesalingam, Manori

    2005-03-01

    Defects on oxide surfaces are well known to play a key role in catalysis. TiO2, MgO, SiO2 surfaces were investigated using Time-Of-Flight Positron induced Auger Electron Spectroscopy (TOF-PAES). Previous work in bulk materials has demonstrated that positrons are particularly sensitive to charged defects. In PAES energetic electron emission results from Auger transitions initiated by annihilation of core electrons with positrons trapped in an image-potential well at the surface. Annealed samples in O2 environment show a strong Auger peak of Oxygen. The implication of these results will be discussed

  3. Angle and Spin Resolved Auger Emission Theory and Applications to Atoms and Molecules

    CERN Document Server

    Lohmann, Bernd

    2009-01-01

    The Auger effect must be interpreted as the radiationless counterpart of photoionization and is usually described within a two-step model. Angle and spin resolved Auger emission physics deals with the theoretical and numerical description, analysis and interpretation of such types of experiments on free atoms and molecules. This monograph derives the general theory applying the density matrix formalism and, in terms of irreducible tensorial sets, so called state multipoles and order parameters, for parameterizing the atomic and molecular systems, respectively. Propensity rules and non-linear dependencies between the angular distribution and spin polarization parameters are included in the discussion. The numerical approaches utilizing relativistic distorted wave (RDWA), multiconfigurational Dirac-Fock (MCDF), and Greens operator methods are described. These methods are discussed and applied to theoretical predictions, numerical results and experimental data for a variety of atomic systems, especially the rare...

  4. Angular Correlation between Photoelectrons and Auger Electrons from K-Shell Ionization of Neon

    International Nuclear Information System (INIS)

    Landers, A. L.; Robicheaux, F.; Bhandary, A.; Jahnke, T.; Schoeffler, M.; Titze, J.; Akoury, D.; Doerner, R.; Osipov, T.; Lee, S. Y.; Adaniya, H.; Hertlein, M.; Weber, Th.; Prior, M. H.; Belkacem, A.; Ranitovic, P.; Bocharova, I.; Cocke, C. L.

    2009-01-01

    We have used cold target recoil ion momentum spectroscopy to study the continuum correlation between the photoelectron of core-photoionized neon and the subsequent Auger electron. We observe a strong angular correlation between the two electrons. Classical trajectory Monte Carlo calculations agree quite well with the photoelectron energy distribution that is shifted due to the potential change associated with Auger decay. However, a striking discrepancy results in the distribution of the relative angle between Auger and photoelectron. The classical model predicts a shift in photoelectron flux away from the Auger emission direction, and the data strikingly reveal that the flux is lost rather than diverted, indicating that the two-step interpretation of photoionization followed by Auger emission is insufficient to fully describe the core-photoionization process.

  5. Experimental verification of the line-shape distortion in resonance Auger spectra

    International Nuclear Information System (INIS)

    Aksela, S.; Kukk, E.; Aksela, H.; Svensson, S.

    1995-01-01

    When the mean excitation energy and the width of a broad photon band are varied the Kr 3d 5/2 -1 5p→4p -2 5p resonance Auger electron lines show strong asymmetry and their average kinetic energies shift. Even extra peaks appear. Our results demonstrate experimentally, for the first time, that the incident photon energy distribution has very crucial importance on the resonance Auger line shape and thus on the reliable data analysis of complicated Auger spectra

  6. Ghost signals in Allison emittance scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Moehs, D.P.; Keller, R.; Welton, R.F.

    2004-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  7. Ghost Signals In Allison Emittance Scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R. F.

    2005-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  8. A coincidence study between photo- and Auger electrons

    International Nuclear Information System (INIS)

    Ricz, S.; Koever, A.; Varga, D.; Molnar, J.; Aksela, S.; Jurvansuu, M.

    2000-01-01

    Complete text of publication follows. The investigation of double differential cross sections of photon induced Auger electrons provides very sensitive method for studying the rearrangement process, especially when the angular correlation between photo- and Auger electrons is also studied. Such type of measurements could reveal a new aspect in studying the electron-electron, hole-electron and photoelectron - Auger electron interactions. It enables one to separate the overlapping Auger lines belonging to different initial holes. The traditional coincidence measurement is very time consuming and causes serious calibration problems. In order to overcome these experimental difficulties a new electron-spectrometer (ESA-22) was developed in ATOMKI, Debrecen in cooperation with the Electron spectroscopy group of University of Oulu, Finland. The analyzer consists of a spherical and a cylindrical part. It is very similar to the ESA-21 analyzer. The main differences is that the focal ring can be set different diameters thus either a series of channel detectors can be used to detect the electrons at different angles or a position sensitive channel plate can be applied for simultaneous angular recording of electrons. Furthermore the outer sphere and cylinder are cut into two parts so the spectrometer is capable to analyze two independent angularly resolved electron spectra (in the 0 deg - 180 deg region) at different energy regions, simultaneously. A special electronic control and data handling electronics and software was worked out to control the analyzer. The first results were presented in. In the last year the ESA-22 electron-spectrometer was transported to the I411 beam line of MAX-II synchrotron in Lund, Sweden. The advanced properties of the spectrometer was investigated by measuring coincidences between the photoelectrons originated from the Ar L 3 subshell and the Ar Auger electrons in the 203-207 eV energy region. Fig. 1 shows the single and the coincidence spectra

  9. The effect of Coster-Kronig transition on the Auger-photoelectron coincidence spectroscopy spectra of early 3d-transition metals

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2004-01-01

    The singles L23-M45M45 Auger-electron spectroscopy (AES) spectrum of early 3d-transition metal can be fitted by a weighted sum of the density of the single-hole states and that of the two-hole states, broadened by the initial L23-hole lifetime width, respectively (in the present paper we denote the atomic shells Lx, My, and Nz by LX, MY and NZ, respectively). With increasing occupancy of the 3d band the probability of creating the two-hole states by the L23-M45M45 Auger transition and the L2-L3M45 Coster-Kronig (CK) transition increases. However, the M45 hole created by the CK transition is delocalized and becomes decoupled (screened out) from the L3-hole decay so that the L3M45 two-hole state 'decays' to the single L3-hole state before the L3-hole decays. Thus the singles AES spectrum by the L2-L3-M45(M45) CK-transition preceded Auger transition and the singles one by the L3-M45(M45) Auger-transition overlap. We can study the M45-hole dynamics by Auger-photoelectron coincidence spectroscopy because the coincidence spectral lineshape depends on the dynamics of the M45 hole created by the CK transition

  10. Interaction of measles virus vectors with Auger electron emitting radioisotopes

    International Nuclear Information System (INIS)

    Dingli, David; Peng, K.-W.; Harvey, Mary E.; Vongpunsawad, Sompong; Bergert, Elizabeth R.; Kyle, Robert A.; Cattaneo, Roberto; Morris, John C.; Russell, Stephen J.

    2005-01-01

    A recombinant measles virus (MV) expressing the sodium iodide symporter (NIS) is being considered for therapy of advanced multiple myeloma. Auger electrons selectively damage cells in which the isotope decays. We hypothesized that the Auger electron emitting isotope 125 I can be used to control viral proliferation. MV was engineered to express both carcinoembryonic antigen and NIS (MV-NICE). Cells were infected with MV-NICE and exposed to 125 I with appropriate controls. MV-NICE replication in vitro is inhibited by the selective uptake of 125 I by cells expressing NIS. Auger electron damage is partly mediated by free radicals and abrogated by glutathione. In myeloma xenografts, control of MV-NICE with 125 I was not possible under the conditions of the experiment. MV-NICE does not replicate faster in the presence of radiation. Auger electron emitting isotopes effectively stop propagation of MV vectors expressing NIS in vitro. Additional work is necessary to translate these observations in vivo

  11. Education and public outreach of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, B.; /Natl. Tech. U., San Rafael; Snow, G.

    2005-08-01

    The Auger collaboration's broad mission in education, outreach and public relations is coordinated in a separate task. Its goals are to encourage and support a wide range of outreach efforts that link schools and the public with the Auger scientists and the science of cosmic rays, particle physics, and associated technologies. This report focuses on recent activities and future initiatives.

  12. Slow Auger Relaxation in HgTe Colloidal Quantum Dots.

    Science.gov (United States)

    Melnychuk, Christopher; Guyot-Sionnest, Philippe

    2018-05-03

    The biexciton lifetimes in HgTe colloidal quantum dots are measured as a function of particle size. Samples produced by two synthetic methods, leading to partially aggregated or well-dispersed particles, exhibit markedly different dynamics. The relaxation characteristics of partially aggregated HgTe inhibit reliable determinations of the Auger lifetime. In well-dispersed HgTe quantum dots, the biexciton lifetime increases approximately linearly with particle volume, confirming trends observed in other systems. The extracted Auger coefficient is three orders of magnitude smaller than that for bulk HgCdTe materials with similar energy gaps. We discuss these findings in the context of understanding Auger relaxation in quantum-confined systems and their relevance to mid-infrared optoelectronic devices based on HgTe colloidal quantum dots.

  13. Studies and calculations of transverse emittance growth in proton storage rings

    International Nuclear Information System (INIS)

    Mane, S.R.; Jackson, G.

    1989-01-01

    When high energy storage rings are used to collide beams of particles and antiparticles for high energy physics experiments, it is important to obtain as high an integrated luminosity as possible. Reduction of integrated luminosity can arise from several factors, in particular from growth of the transverse beam sizes (transverse emittances). We have studied the problem of transverse emittance growth in high energy storage rings caused by random dipole noise kicks to the beam. A theoretical formula for the emittance growth rate is derived, and agreement is obtained with experimental measurements where noise of known amplitude and power spectrum was deliberately injected into the Fermilab Tevatron, to kick the beam randomly. In the experiment, phase noise was introduced into the Tevatron rf system, and the measured dependence of horizontal emittance growth on phase noise amplitude is compared against the theoretically derived response. (orig.)

  14. The Pierre Auger Observatory Upgrade - Preliminary Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Aab, Alexander [Univ. Siegen (Germany); et al.

    2016-04-12

    The Pierre Auger Observatory has begun a major Upgrade of its already impressive capabilities, with an emphasis on improved mass composition determination using the surface detectors of the Observatory. Known as AugerPrime, the upgrade will include new 4 m2 plastic scintillator detectors on top of all 1660 water-Cherenkov detectors, updated and more flexible surface detector electronics, a large array of buried muon detectors, and an extended duty cycle for operations of the fluorescence detectors. This Preliminary Design Report was produced by the Collaboration in April 2015 as an internal document and information for funding agencies. It outlines the scientific and technical case for AugerPrime. We now release it to the public via the arXiv server. We invite you to review the large number of fundamental results already achieved by the Observatory and our plans for the future.

  15. Theoretical and experimental study of the double ionization by electron impact involving the Auger effect: processes and exchanges interferences; Etude theorique et experimentale de la double ionisation par impact electronique incluant l'effet auger: interferences d'echanges et de processus

    Energy Technology Data Exchange (ETDEWEB)

    Catoire, F

    2006-09-15

    In this work, double ionisation mechanisms of argon by electron impact in which the Auger effect is included have been studied as a function of the incident electron energy. Five and six fold differential cross sections in angle and in energy have been measured and analysed in a coplanar geometry. The efficiency of the apparatus has been improved by the use of a new toroidal analyser. For the first time, the six fold differential cross section in which the Auger electron and the ejected electron with identical kinetic energies (205 eV) are involved, was measured at an incident energy of 956 eV in the case of argon. In the theoretical models developed during this work, the triple continuum is represented by a manifold of coulomb waves describing the interaction of all electrons with the residual ion. Exchange effects between electrons were also included in the models. Comparison between experimental and theoretical results allows to study the relative contribution of the Auger process and the direct double ionisation on the angular dependence five fold differential cross section. In particular, the Auger process contribution seems to become increasingly important as the incident energy is increased.

  16. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing [Daly City, CA; Yang, Peidong [Kensington, CA; Kim, Woong [Seoul, KR; Fan, Rong [Pasadena, CA

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  17. Emittance control in linear colliders

    International Nuclear Information System (INIS)

    Ruth, R.D.

    1991-05-01

    In this paper, we discuss the generation and control of the emittance in a next-generation linear collider. The beams are extracted from a damping ring and compressed in length by the first bunch compressor. They are then accelerated in a preaccelerator linac up to an energy appropriate for injection into a high gradient linac. In many designs this pre-acceleration is followed by another bunch compression to reach a short bunch. After acceleration in the linac, the bunches are finally focused transversely to a small spot. The proposed vertical beam sizes at the interaction point are the order of a few nanometers while the horizontal sizes are about a factor of 100 larger. This cross-sectional area is about a factor of 10 4 smaller than the SLC. However, the main question is: what are the tolerances to achieve such a small size, and how do they compare to present techniques for alignment and stability? These tolerances are very design dependent. Alignment tolerances in the linac can vary from 1 μm to 100 μm depending upon the basic approach. In this paper we discuss techniques of emittance generation and control which move alignment tolerances to the 100 μm range

  18. Calibrating the Auger Engineering Radio Array at the Pierre Auger Observatory using an Octocopter

    Energy Technology Data Exchange (ETDEWEB)

    Briechle, Florian; Erdmann, Martin; Krause, Raphael [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    With the Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory radio emission of extensive air showers induced by ultra high energy cosmic rays is observed. Characteristics of the primary cosmic ray, e.g., arrival direction, mass or energy, can be measured this way. To produce high quality data, the detector needs to be well understood and calibrated. A useful tool for calibration campaigns is an octocopter. With it, a calibration source can be placed above the array, which makes this a very flexible method useful for different types of calibrations. Special focus is put on the position reconstruction and the position accuracy of the octocopter during the calibration flights. A new optical method using two cameras for these position reconstructions is presented. Results of a measurement campaign in spring 2015 are presented. In this campaign, the sensitivity of the AERA stations as well as timing characteristics were measured. The results of the sensitivity measurement are compared to simulations.

  19. Low-energy electron emitters for targeted radiotherapy of small tumours

    International Nuclear Information System (INIS)

    Bernhardt, Peter; Forssell-Aronsson, Eva; Jacobsson, Lars; Skarnemark, Gunnar

    2001-01-01

    The possibility of using electron emitters to cure a cancer with metastatic spread depends on the energy of the emitted electrons. Electrons with high energy will give a high, absorbed dose to large tumours, but the absorbed dose to small tumours or single tumour cells will be low, because the range of the electrons is too long. The fraction of energy absorbed within the tumour decreases with increasing electron energy and decreasing tumour size. For tumours smaller than 1 g, the tumour-to-normal-tissue mean absorbed dose-rate ratio, TND, will be low, e.g. for 131 I and 90 Y, because of the high energy of the emitted electrons. For radiotherapy of small tumours, radionuclides emitting charged particles with short ranges (a few m u m ) are required. A mathematical model was constructed to evaluate the relation between TND and electron energy, photon-to-electron energy ratio, p/e, and tumour size. Criteria for the selection of suitable radionuclides for the treatment of small tumours were defined based on the results of the TND model. In addition, the possibility of producing such radionuclides and their physical and chemical properties were evaluated. Based on the mathematical model, the energy of the emitted electrons should be = 40 keV for small tumours ( 58m Co, 103m Rh, 119 Sb, 161 Ho, and 189m Os. All of these nuclides by internal transition or electron capture, which yields conversion and Auger electrons, and it should be possible to produce most of them in therapeutic amounts. The five low-energy electron-emitting radionuclides identified may be relevant in the radiation treatment of small tumours, especially if bound to internalizing radiopharmaceuticals

  20. The Cosmic Ray Energy Spectrum and Related Measurements with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the cosmic ray energy spectrum above 10{sup 18} eV with the Pierre Auger Observatory; (2) The cosmic ray flux observed at zenith angles larger than 60 degrees with the Pierre Auger Observatory; (3) Energy calibration of data recorded with the surface detectors of the Pierre Auger Observatory; (4) Exposure of the Hybrid Detector of The Pierre Auger Observatory; and (5) Energy scale derived from Fluorescence Telescopes using Cherenkov Light and Shower Universality.

  1. Theoretical investigation of confocal microscopy using an elliptically polarized cylindrical vector laser beam: Visualization of quantum emitters near interfaces

    Science.gov (United States)

    Boichenko, Stepan

    2018-04-01

    We theoretically study laser-scanning confocal fluorescence microscopy using elliptically polarized cylindrical vector excitation light as a tool for visualization of arbitrarily oriented single quantum dipole emitters located (1) near planar surfaces enhancing fluorescence, (2) in a thin supported polymer film, (3) in a freestanding polymer film, and (4) in a dielectric planar microcavity. It is shown analytically that by using a tightly focused azimuthally polarized beam, it is possible to exclude completely the orientational dependence of the image intensity maximum of a quantum emitter that absorbs light as a pair of incoherent independent linear dipoles. For linear dipole quantum emitters, the orientational independence degree higher than 0.9 can normally be achieved (this quantity equal to 1 corresponds to completely excluded orientational dependence) if the collection efficiency of the microscope objective and the emitter's total quantum yield are not strongly orientationally dependent. Thus, the visualization of arbitrarily oriented single quantum emitters by means of the studied technique can be performed quite efficiently.

  2. Emittance simulation for a different electron bunch charges with upgraded PITZ setup

    Energy Technology Data Exchange (ETDEWEB)

    Vashchenko, Grygorii [DESY, Platanenallee 6, 15738 Zeuthen (Germany)

    2013-07-01

    The photo injector test facility at DESY, Zeuthen site (PITZ) was invented with an aim to develop, characterize and optimize the electron sources for linac driven free electron lasers like FLASH and European XFEL. As a prerequisite for a successful experimental emittance optimization, emittance dependencies on the majority of linac parameters have to be studied in simulations. Despite that the nominal electron bunch charge for the operation of FLASH and XFEL is 1nC, there is an interest of the community to operate with other bunch charges. Emittance dependencies on such machine parameters like laser spot size on the photo cathode, laser pulse length, gun launching phase, focusing solenoid current and first accelerating structure gradient are simulated for different electron bunch charges. Based on the simulations data the systematic errors caused by detuning of the different machine parameters from their optimum values are estimated.

  3. Superposition Principle in Auger Recombination of Charged and Neutral Multicarrier States in Semiconductor Quantum Dots.

    Science.gov (United States)

    Wu, Kaifeng; Lim, Jaehoon; Klimov, Victor I

    2017-08-22

    Application of colloidal semiconductor quantum dots (QDs) in optical and optoelectronic devices is often complicated by unintentional generation of extra charges, which opens fast nonradiative Auger recombination pathways whereby the recombination energy of an exciton is quickly transferred to the extra carrier(s) and ultimately dissipated as heat. Previous studies of Auger recombination have primarily focused on neutral and, more recently, negatively charged multicarrier states. Auger dynamics of positively charged species remains more poorly explored due to difficulties in creating, stabilizing, and detecting excess holes in the QDs. Here we apply photochemical doping to prepare both negatively and positively charged CdSe/CdS QDs with two distinct core/shell interfacial profiles ("sharp" versus "smooth"). Using neutral and charged QD samples we evaluate Auger lifetimes of biexcitons, negative and positive trions (an exciton with an extra electron or a hole, respectively), and multiply negatively charged excitons. Using these measurements, we demonstrate that Auger decay of both neutral and charged multicarrier states can be presented as a superposition of independent elementary three-particle Auger events. As one of the manifestations of the superposition principle, we observe that the biexciton Auger decay rate can be presented as a sum of the Auger rates for independent negative and positive trion pathways. By comparing the measurements on the QDs with the "sharp" versus "smooth" interfaces, we also find that while affecting the absolute values of Auger lifetimes, manipulation of the shape of the confinement potential does not lead to violation of the superposition principle, which still allows us to accurately predict the biexciton Auger lifetimes based on the measured negative and positive trion dynamics. These findings indicate considerable robustness of the superposition principle as applied to Auger decay of charged and neutral multicarrier states

  4. The cataphoretic emitter effect exhibited in high intensity discharge lamp electrodes

    Science.gov (United States)

    Mentel, Juergen

    2018-01-01

    A mono-layer of atoms, electropositive with respect to the substrate atoms, forms a dipole layer, reducing its work function. Such a layer is generated by diffusion of emitter material from the interior of the substrate, by vapour deposition or by deposition of emitter material onto arc electrodes by cataphoresis. This cataphoretic emitter effect is investigated within metal halide lamps with transparent YAG ceramic burners, and within model lamps. Within the YAG lamps, arcs are operated with switched-dc current between rod shaped tungsten electrodes in high pressure Hg vapour seeded with metal iodides. Within the model lamps, dc arcs are operated between rod-shaped tungsten electrodes—one doped—in atmospheric pressure Ar. Electrode temperatures are determined by 1λ -pyrometry, combined with simulation of the electrode heat balance. Plasma temperatures, atom and ion densities of emitter material are determined by emission and absorption spectroscopy. Phase resolved measurements in YAG lamps seeded with CeI3, CsI, DyI3, TmI3 and LaI3 show, within the cathodic half period, a reduction of the electrode temperature and an enhanced metal ion density in front of the electrode, and an opposite behavior after phase reversal. With increasing operating frequency, the state of the cathode overlaps onto the anodic phase—except for Cs, being low in adsorption energy. Generally, the phase averaged electrode tip temperature is reduced by seeding a lamp with emitter material; its height depends on admixtures. Measurements at tungsten electrodes doped with ThO2, La2O3 and Ce2O3 within the model lamp show that evaporated emitter material is redeposited by an emitter ion current onto the electrode surface. It reduces the work function of tungsten cathodes above the evaporation temperature of the emitter material, too; and also of cold anodes, indicating a field reversal in front of them. The formation of an emitter spot at low cathode temperature and high emitter material

  5. Triggers for the Pierre Auger Observatory, the current status and plans for the future

    CERN Document Server

    Szadkowski, Z

    2009-01-01

    The Pierre Auger Observatory is a multi-national organization for research on ultra-high energy cosmic rays. The Southern Auger Observatory (Auger-South) in the province of Mendoza, Argentina, has been completed in 2008. First results on the energy spectrum, mass composition and distribution of arrival directions on the southern sky are really impressive. The planned Northern Auger Observatory in Colorado, USA, (Auger-North) will open a new window into the universe and establish charged particle astronomy to determine the origin and nature of ultra-high energy cosmic rays. These cosmic particles carry information complementary to neutrinos and photons and to gravitational waves. They also provide an extremely energetic beam for the study of particle interactions at energies that thirty times higher than those reached in terrestrial accelerators. The Auger Observatory is a hybrid detector consisting of a Surface Detector (SD) and an atmospheric Fluorescence Detector (FD). The hybrid data set obtained when both...

  6. Distributed Computing for the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Chudoba, J.

    2015-01-01

    Pierre Auger Observatory operates the largest system of detectors for ultra-high energy cosmic ray measurements. Comparison of theoretical models of interactions with recorded data requires thousands of computing cores for Monte Carlo simulations. Since 2007 distributed resources connected via EGI grid are successfully used. The first and the second versions of production system based on bash scripts and MySQL database were able to submit jobs to all reliable sites supporting Virtual Organization auger. For many years VO auger belongs to top ten of EGI users based on the total used computing time. Migration of the production system to DIRAC interware started in 2014. Pilot jobs improve efficiency of computing jobs and eliminate problems with small and less reliable sites used for the bulk production. The new system has also possibility to use available resources in clouds. Dirac File Catalog replaced LFC for new files, which are organized in datasets defined via metadata. CVMFS is used for software distribution since 2014. In the presentation we give a comparison of the old and the new production system and report the experience on migrating to the new system. (paper)

  7. Distributed Computing for the Pierre Auger Observatory

    Science.gov (United States)

    Chudoba, J.

    2015-12-01

    Pierre Auger Observatory operates the largest system of detectors for ultra-high energy cosmic ray measurements. Comparison of theoretical models of interactions with recorded data requires thousands of computing cores for Monte Carlo simulations. Since 2007 distributed resources connected via EGI grid are successfully used. The first and the second versions of production system based on bash scripts and MySQL database were able to submit jobs to all reliable sites supporting Virtual Organization auger. For many years VO auger belongs to top ten of EGI users based on the total used computing time. Migration of the production system to DIRAC interware started in 2014. Pilot jobs improve efficiency of computing jobs and eliminate problems with small and less reliable sites used for the bulk production. The new system has also possibility to use available resources in clouds. Dirac File Catalog replaced LFC for new files, which are organized in datasets defined via metadata. CVMFS is used for software distribution since 2014. In the presentation we give a comparison of the old and the new production system and report the experience on migrating to the new system.

  8. FACET Emittance Growth

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, J; Hogan, M.J.; Nosochkov, Y.; Litos, M.D.; Raubenheimer, T.; /SLAC

    2011-04-05

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The FACET beamline consists of a chicane and final focus system to compress the 23 GeV, 3.2 nC electron bunches to {approx}20 {micro}m long and {approx}10 {micro}m wide. Simulations of the FACET beamline indicate the short-duration and large, 1.5% rms energy spread beams may suffer a factor of four emittance growth from a combination of chromaticity, incoherent synchrotron radiation (ISR), and coherent synchrotron radiation (CSR). Emittance growth is directly correlated to head erosion in plasma wakefield acceleration and is a limiting factor in single stage performance. Studies of the geometric, CSR, and ISR components are presented. Numerical calculation of the rms emittance can be overwhelmed by long tails in the simulated phase space distributions; more useful definitions of emittance are given. A complete simulation of the beamline is presented as well, which agrees with design specifications.

  9. FACET Emittance Growth

    International Nuclear Information System (INIS)

    Frederico, Joel

    2011-01-01

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The FACET beamline consists of a chicane and final focus system to compress the 23 GeV, 3.2 nC electron bunches to ∼20 (micro)m long and ∼10 (micro)m wide. Simulations of the FACET beamline indicate the short-duration and large, 1.5% rms energy spread beams may suffer a factor of four emittance growth from a combination of chromaticity, incoherent synchrotron radiation (ISR), and coherent synchrotron radiation (CSR). Emittance growth is directly correlated to head erosion in plasma wakefield acceleration and is a limiting factor in single stage performance. Studies of the geometric, CSR, and ISR components are presented. Numerical calculation of the rms emittance can be overwhelmed by long tails in the simulated phase space distributions; more useful definitions of emittance are given. A complete simulation of the beamline is presented as well, which agrees with design specifications.

  10. Positron Annihilation Induced Auger and Gamma Spectroscopy of Catalytically Important Surfaces

    Science.gov (United States)

    Weiss, A. H.; Nadesalingam, M. P.; Sundaramoorthy, R.; Mukherjee, S.; Fazleev, N. G.

    2006-10-01

    The annihilation of positrons with core electrons results in unique signatures in the spectra of Auger-electron and annihilation-gamma rays that can be used to make clear chemical identification of atoms at the surface. Because positrons implanted at low energies are trapped with high efficiency in the image-correlation well where they are localized just outside the surface it is possible to use annihilation induced Auger and Gamma signals to probe the surfaces of solids with single atomic layer depth resolution. In this talk we will report recent applications of Positron Annihilation Induced Auger Electron Spectroscopy (PAES) and Auger-Gamma Coincidence Spectroscopy (AGCS) to the study of surface structure and surface chemistry. Our research has demonstrated that PAES spectra can provide new information regarding the composition of the top-most atomic layer. Applications of PAES to the study of catalytically important surfaces of oxides and wide band-gap semiconductors including TiO2, SiO2,Cu2O, and SiC will be presented. We conclude with a discussion of the use of Auger-Gamma and Gamma-Gamma coincidence spectroscopy for the study of surfaces at pressures closer to those found in practical chemical reactors. Research supported by the Welch Foundation Grant Number Y-1100.

  11. A study of Al/Si interface by photoemission, Auger electron yield and Auger electron spectroscopies

    International Nuclear Information System (INIS)

    Kobayashi, K.L.I.; Barth, J.; Gerken, F.; Kunz, C.; Deutsches Elektronen-Synchrotron

    1980-06-01

    Photoemission, Auger electron yield and Auger electron spectra were observed for Al/Si(111) interfaces with various Al coverage prepared by successive deposition using a molecular beam source. The Al 3p derived states are introduced at around the top of the valence band by the Al coverage of less than one monolayer. The Al surface layer behaves as a 'metal' and the Fermi level is stabilized in the Al 3p derived states at about 0.3 eV above the top of the valence band of Si. The Schottky barrier height in this stage is about 0.8 eV and further increase in Al coverage does not change the barrier height. A covalent bonding model of the Al/Si interface based on the experimental results is proposed. The present result favors the on-top geometry of Al atoms on Si(111) surface among the geometries used in the pseudopotential calculation by Zhang and Schlueter. (orig.)

  12. Ultrafast and band-selective Auger recombination in InGaN quantum wells

    International Nuclear Information System (INIS)

    Williams, Kristopher W.; Monahan, Nicholas R.; Zhu, X.-Y.; Koleske, Daniel D.; Crawford, Mary H.

    2016-01-01

    In InGaN quantum well based light-emitting diodes, Auger recombination is believed to limit the quantum efficiency at high injection currents. Here, we report the direct observation of carrier loss from Auger recombination on a sub-picosecond timescale in a single InGaN quantum well using time-resolved photoemission. Selective excitations of different valence sub-bands reveal that the Auger rate constant decreases by two orders of magnitude as the effective hole mass decreases, confirming the critical role of momentum conservation.

  13. Low emittance photoinjectors

    International Nuclear Information System (INIS)

    Ferrario, Massimo

    2001-01-01

    Photon colliders require high charge polarized electron beams with very low normalized emittances, possibly lower than the actual damping rings design goals. Recent analytical and numerical efforts in understanding beam dynamics in RF photoinjectors have raised again the question as to whether the performances of an RF electron gun based injector could be competitive with respect to a damping ring. As a matter of discussion we report in this paper the most recent results concerning low emittance photoinjector designs: the production of polarized electron beams by DC and/or RF guns is illustrated together with space charge compensation techniques and thermal emittance effects. New ideas concerning multi-gun injection system and generation of flat beams by RF gun are also discussed

  14. Spin effects in the screening and Auger neutralization of He+ ions in a spin-polarized electron gas

    International Nuclear Information System (INIS)

    Alducin, M.; Diez Muino, R.; Juaristi, J.I.

    2005-01-01

    The screening of a He + ion embedded in a free electron gas is studied for different spin-polarizations of the medium. Density functional theory and the local spin density approximation are used to calculate the induced electronic density for each spin orientation, i.e. parallel or antiparallel to the spin of the electron bound to the ion. Since both the He + ion and the electron gas are spin-polarized, we analyze in detail the spin state of the screening cloud for the two different possibilities: the spin of the bound electron can be parallel to either the majority spin or the minority spin in the medium. Finally, the spin-dependent Kohn-Sham orbitals are used to calculate the Auger neutralization rate of the He + ion. The polarization of the Auger excited electron is influenced by the spin-polarization of the medium. The results are discussed in terms of the spin-dependent screening and the indistinguishability of electrons with the same spin state

  15. The Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Hojvat, C.

    1997-03-01

    The Pierre Auger Observatory is an international collaboration for the detailed study of the highest energy cosmic rays. It will operate at two similar sites, one in the northern hemisphere and one in the southern hemisphere. The Observatory is designed to collect a statistically significant data set of events with energies greater than 10 19 eV and with equal exposures for the northern and southern skies

  16. Extraction panel guidelines for high production underground auger mining in Australian conditions

    Energy Technology Data Exchange (ETDEWEB)

    Paul Buddery; David Hill [Strata Engineering (Australia)

    2004-09-15

    The project involved monitoring ground behaviour during augering, with the intention of monitoring several sites with varying geotechnical environments and developing guidelines from these to assist in future layout design. This approach is appropriate where the mining layout involves the complex interaction of several components that cannot be readily simplified to the extent necessary for numerical or physical models to play the primary role. Only one site was secured within the project time frame. Consequently, the project has utilised the results from a Southern Colliery augering trial, coupled to the outcomes of numerical and physical modelling tests. The auger mining operations themselves were carried out by a Joint Venture (Coal Recovery Australia Pty Ltd) between Cutting Edge Technology Pty Ltd and SBD Services Pty Ltd. The underground trial indicated that empirical design methodologies involving pillar strength equations coupled to abutment angle models can be used to design stable augering layouts. Although the designed hole configuration was not fully achieved, there is, a suggestion that a layout so determined will be conservative, holding out the possibility of future optimisation on the basis of actual performance. Monitoring and re-appraisal in the context of a formal strata management process are critical to the success of any such approach, particularly in terms of optimisation. The two-dimensional UDEC numerical modelling code was used to model augering webs, but seemed to underestimate the stability of an auger mining panel, while over -estimating the strength of individual auger webs. Physical tests appeared to give a realistic quantification of the size effect. The tests suggest that determining the strength of an hourglass web by increasing the strength of an equivalent rectangular web by 25% would be a justifiable step at this stage.

  17. Electron beam effects in auger electron spectroscopy and scanning electron microscopy

    International Nuclear Information System (INIS)

    Fontaine, J.M.; Duraud, J.P.; Le Gressus, C.

    1979-01-01

    Electron beam effects on Si(100) and 5% Fe/Cr alloy samples have been studied by measurements of the secondary electron yield delta, determination of the surface composition by Auger electron spectroscopy and imaging with scanning electron microscopy. Variations of delta as a function of the accelerating voltage Esub(p) (0.5 -9 Torr has no effect on technological samples covered with their reaction layers; the sensitivities to the beam depend rather on the earlier mechanical, thermal and chemical treatment of the surfaces. (author)

  18. Identifying clouds over the Pierre Auger Observatory using infrared satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Pedro; et al.,

    2013-12-01

    We describe a new method of identifying night-time clouds over the Pierre Auger Observatory using infrared data from the Imager instruments on the GOES-12 and GOES-13 satellites. We compare cloud identifications resulting from our method to those obtained by the Central Laser Facility of the Auger Observatory. Using our new method we can now develop cloud probability maps for the 3000 km^2 of the Pierre Auger Observatory twice per hour with a spatial resolution of ~2.4 km by ~5.5 km. Our method could also be applied to monitor cloud cover for other ground-based observatories and for space-based observatories.

  19. Non-exponential spontaneous emission dynamics for emitters in a time-dependent optical cavity

    NARCIS (Netherlands)

    Thyrrestrup Nielsen, Henri; Hartsuiker, A.; Gerard, J.M.; Vos, Willem L.

    2013-01-01

    We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a

  20. Wakefield dependent emittance growth in the SLAC [Stanford Linear Accelerator Center] linac

    International Nuclear Information System (INIS)

    Bane, K.L.F.

    1990-10-01

    In this note we describe the emittance growth we can expect at bunch populations of N = 3,4,5 x 10 10 in the SLC linac. We will discuss briefly the effects of injection jitter, injection drift, and coherent oscillations starting in the middle of the linac. Finally, we will discuss in a more thorough manner the effects of random misalignment errors throughout the linac

  1. Application of positron annihilation induced auger electron spectroscopy to the study of surface chemistry

    International Nuclear Information System (INIS)

    Weiss, A.H.; Yang, G.; Nangia, A.; Kim, J.H.; Fazleev, N.G.

    1996-01-01

    Positron annihilation induced Auger Electron Spectroscopy (PAES), makes use a beam of low energy positrons to excite Auger transitions by annihilating core electrons. This novel mechanism provides PAES with a number of unique features which distinguishes it from other methods of surface analysis. In PAES the very large collisionally induced secondary electron background which is present under the low energy Auger peaks using conventional techniques can be eliminated by using a positron beam whose energy is below the range of Auger electron energies. In addition, PAES is more surface selective than conventional Auger Spectroscopy because the PAES signal originates almost exclusively from the topmost atomic layer due to the fact that the positrons annihilating with the core electrons are trapped in an image correlation well just outside the surface. In this paper, recent applications of Positron Annihilation Induced Auger Electron Spectroscopy (PAES) to the study of surface structure and surface chemistry will be discussed including studies of the growth, alloying and inter-diffusion of ultrathin layers of metals, metals on semiconductors, and semiconductors on semiconductors. In addition, the possibilities for future application of PAES to the study of catalysis and surface chemistry will be outlined. (author)

  2. Photoionization cross sections and Auger rates calculated by many-body perturbation theory

    International Nuclear Information System (INIS)

    Kelly, H.P.

    1976-01-01

    Methods for applying the many body perturbation theory to atomic calculations are discussed with particular emphasis on calculation of photoionization cross sections and Auger rates. Topics covered include: Rayleigh--Schroedinger theory; many body perturbation theory; calculations of photoionization cross sections; and Auger rates

  3. Measurement of horizontal air showers with the Auger Engineering Radio Array

    Science.gov (United States)

    Kambeitz, Olga

    2017-03-01

    The Auger Engineering Radio Array (AERA), at the Pierre Auger Observatory in Argentina, measures the radio emission of extensive air showers in the 30-80 MHz frequency range. AERA consists of more than 150 antenna stations distributed over 17 km2. Together with the Auger surface detector, the fluorescence detector and the underground muon detector (AMIGA), AERA is able to measure cosmic rays with energies above 1017 eV in a hybrid detection mode. AERA is optimized for the detection of air showers up to 60° zenith angle, however, using the reconstruction of horizontal air showers with the Auger surface array, very inclined showers can also be measured. In this contribution an analysis of the AERA data in the zenith angle range from 62° to 80° will be presented. CoREAS simulations predict radio emission footprints of several km2 for horizontal air showers, which are now confirmed by AERA measurements. This can lead to radio-based composition measurements and energy determination of horizontal showers in the future and the radio detection of neutrino induced showers is possible.

  4. Radio detection of extensive air showers at the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Berat, C.

    2013-01-01

    The Pierre Auger Observatory explores the potential of radio-detection techniques to measure extensive air showers (EAS) induced by ultra-high energy cosmic rays. To study in detail the mechanisms responsible for radio emission in the MHz range, the Auger Engineering Radio Array has been installed at the Observatory. Presently consisting of 24 radio-detection stations, this number will grow to 150 units covering an area of almost 20 km 2 . Novel detection techniques based on the GHz emission from the EAS are currently being studied. AMBER (Air-shower Microwave Bremsstrahlung Experimental Radiometer) and MIDAS (Microwave Detection of Air Showers) are prototypes for a large imaging dish antenna. In EASIER (Extensive Air Shower Identification using Electron Radiometer), the microwave emission is detected by antenna horns located on each surface detector. MIDAS is a self-triggering system while AMBER and EASIER use the trigger from the Auger detectors to record the emission. The status of these radio-detection R and D efforts at the Pierre Auger Observatory will be reported

  5. Radio detection of extensive air showers at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Berat, C., E-mail: berat@lpsc.in2p3.fr [LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38000 Grenoble (France)

    2013-08-01

    The Pierre Auger Observatory explores the potential of radio-detection techniques to measure extensive air showers (EAS) induced by ultra-high energy cosmic rays. To study in detail the mechanisms responsible for radio emission in the MHz range, the Auger Engineering Radio Array has been installed at the Observatory. Presently consisting of 24 radio-detection stations, this number will grow to 150 units covering an area of almost 20 km{sup 2}. Novel detection techniques based on the GHz emission from the EAS are currently being studied. AMBER (Air-shower Microwave Bremsstrahlung Experimental Radiometer) and MIDAS (Microwave Detection of Air Showers) are prototypes for a large imaging dish antenna. In EASIER (Extensive Air Shower Identification using Electron Radiometer), the microwave emission is detected by antenna horns located on each surface detector. MIDAS is a self-triggering system while AMBER and EASIER use the trigger from the Auger detectors to record the emission. The status of these radio-detection R and D efforts at the Pierre Auger Observatory will be reported.

  6. High brightness fiber laser pump sources based on single emitters and multiple single emitters

    Science.gov (United States)

    Scheller, Torsten; Wagner, Lars; Wolf, Jürgen; Bonati, Guido; Dörfel, Falk; Gabler, Thomas

    2008-02-01

    Driven by the potential of the fiber laser market, the development of high brightness pump sources has been pushed during the last years. The main approaches to reach the targets of this market had been the direct coupling of single emitters (SE) on the one hand and the beam shaping of bars and stacks on the other hand, which often causes higher cost per watt. Meanwhile the power of single emitters with 100μm emitter size for direct coupling increased dramatically, which also pushed a new generation of wide stripe emitters or multi emitters (ME) of up to 1000μm emitter size respectively "minibars" with apertures of 3 to 5mm. The advantage of this emitter type compared to traditional bars is it's scalability to power levels of 40W to 60W combined with a small aperture which gives advantages when coupling into a fiber. We show concepts using this multiple single emitters for fiber coupled systems of 25W up to 40W out of a 100μm fiber NA 0.22 with a reasonable optical efficiency. Taking into account a further efficiency optimization and an increase in power of these devices in the near future, the EUR/W ratio pushed by the fiber laser manufacturer will further decrease. Results will be shown as well for higher power pump sources. Additional state of the art tapered fiber bundles for photonic crystal fibers are used to combine 7 (19) pump sources to output powers of 100W (370W) out of a 130μm (250μm) fiber NA 0.6 with nominal 20W per port. Improving those TFB's in the near future and utilizing 40W per pump leg, an output power of even 750W out of 250μm fiber NA 0.6 will be possible. Combined Counter- and Co-Propagated pumping of the fiber will then lead to the first 1kW fiber laser oscillator.

  7. Low emittance electron storage rings

    Science.gov (United States)

    Levichev, E. B.

    2018-01-01

    Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

  8. The Pierre Auger fluorescence detector. Cross-checking the absolute calibration using a drone

    Energy Technology Data Exchange (ETDEWEB)

    Tomankova, Lenka [Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The Pierre Auger Observatory combines the air shower fluorescence and surface array methods to study ultra-high energy cosmic rays. As the energy scale of the experiment is derived from calorimetric measurements by the fluorescence telescopes, their accurate calibration is of primary importance to all Auger data. We discuss a novel calibration method based on a remotely flown drone equipped with a specially designed light source that mimics a snapshot of an air shower traversing the atmosphere. Several drone measurement campaigns have been performed to study the properties of the Auger fluorescence telescopes and to derive an end-to-end calibration. We give an overview of the measurements and present the basic analysis chain as well as the first results of an independent cross-check of the Auger energy scale.

  9. Back-view Auger electron spectrometer-diffractometer

    International Nuclear Information System (INIS)

    Antipov, V.G.; Bol'shunov, I.B.; Romanov, S.S.

    1990-01-01

    Design of a device on the base of quasispherical four-grid energy analyzer for recording the Auger electron spectra (AES) and observation of the patterns of slow electron diffraction (SED) on the side of an electron gun, is described. A layout of a small-sized electron gun providing for diffraction pattern recording up to the electron energies E ≅ 20 eV, is presented. At E=100 eV the gun current is ≅ 0.8 muA at electron beam diameter on a sample ≤ 1 mm. In the AES regime the gun allows one to record Auger spectra at electron energy E ≤ 3 keV, current ≅ 5 muA and electron beam diameter on a sample ≤ 0.2 mm. The maximum gun current is ≅ 25 muA for an increased beam diameter. Exapmles illustrating the device operation in AES and SED regimes, are presented

  10. Electron capture Auger aftereffect of ammine cobalt complex

    International Nuclear Information System (INIS)

    Harada, Masayuki; Sano, Hirotoshi

    1976-01-01

    The study of ammine cobalt complex by luminescent Moessbauer spectrometry method was performed. The method was compared with hot atom chemistry method. The electron states in atoms are changed by the aftereffect on Auger emission following the electron capture process. The state of oxidation of disintegration products is usually higher than that of parent nuclei. However, sometimes, lower oxidation is seen in Fe-57, the daughter nuclei of Co-57. This phenomenon may be due to radiation chemistry process, and this effect can be observed by the luminescent Moessbauer spectrometry method. However, the range of the effect can not be seen by the Moessbauer method. Estimation showed that the Auger electrons stay within the surrounding area of the disintegration atom, and the effect does not reach to distant places. The yield of Fe-57 in the electron capture process of Co-57 in cobalt complex, the G-value, and the hot atom chemical yield were obtained. It is concluded that the aftereffect of the Auger process is the localized radiation chemistry effect. Good correlation was seen between the present method and the hot atom chemistry method. (Kato, T.)

  11. Mass sensitive observables of the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Unger M.

    2013-06-01

    Full Text Available In this article we will discuss measurements of the longitudinal development of air showers at the Pierre Auger Observatory. The longitudinal development of the electromagnetic component can be directly observed by the fluorescence telescopes of the Auger Observatory and we will present the results on the evolution of the average shower maximum and its fluctuations as a function of energy. Moreover, two observables from the surface detector, the asymmetry of the rise time of the station signals and the muon production depth, will be discussed and the measurements will be compared to predictions from air shower simulations for different primary particle types.

  12. An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

    International Nuclear Information System (INIS)

    Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

    2011-01-01

    An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

  13. Modified theoretical minimum emittance lattice for an electron storage ring with extreme-low emittance

    Directory of Open Access Journals (Sweden)

    Yi Jiao

    2011-05-01

    Full Text Available In the continuing efforts to reduce the beam emittance of an electron storage ring composed of theoretical minimum emittance (TME lattice, down to a level of several tens of picometers, nonlinear dynamics grows to be a great challenge to the performance of the storage ring because of the strong sextupoles needed to compensate for its large global natural chomaticities coupled with its small average dispersion function. To help in dealing with the challenge of nonlinear optimization, we propose a novel variation of theoretical minimum emittance (TME lattice, named as “modified-TME” lattice, with minimal emittance about 3 times of the exact theoretical minimum, while with more compact layout, lower phase advance per cell, smaller natural chromaticities, and more relaxed optical functions than that in a TME cell, by using horizontally defocusing quadrupole closer to the dipole or simply combined-function dipole with horizontally defocusing gradient. We present approximate scaling formulas to describe the relationships of the design parameters in a modified-TME cell. The applications of modified-TME lattice in the PEP-X storage ring design are illustrated and the proposed lattice appears a good candidate for synchrotron radiation light source with extremely low emittance.

  14. The K Auger spectrum of krypton from the 83Rb decay

    International Nuclear Information System (INIS)

    Kovalik, A.; Gorozhankin, V.M.; Novgorodov, A.F.

    1990-01-01

    The K Auger spectrum of krypton was analyzed at the instrumental resolution of 6.5 eV using the evaporated 83 Rb source. The energies and relative intensities of the KLL-, KLX-, and KMX- Auger transitions were determined as well as the natural energy widths some of them. The results were compared with the theoretical predictions. 31 refs.; 3 figs.; 6 tabs

  15. A device for electron gun emittance measurement

    International Nuclear Information System (INIS)

    Aune, B.; Corveller, P.; Jablonka, M.; Joly, J.M.

    1985-05-01

    In order to improve the final emittance of the beam delivered by the ALS electron linac a new gun is going to be installed. To measure its emittance and evaluate the contribution of different factors to emittance growth we have developed an emittance measurement device. We describe the experimental and mathematical procedure we have followed, and give some results of measurements

  16. X-ray induced production and yield kinetics of photo- and Auger Electrons in semiconductors

    International Nuclear Information System (INIS)

    Peregudov, V.I.; Pashaev, Eh.M.

    1991-01-01

    The paper is dedicated to theoretical and experimental analysis of the mechanism of indirect excitation of soft Auger-electrons due to atom electron ionization using Ge crystal exposed to MoK α radiation as an example. Process of generation of these Auger-electrons is considered in detail, solution of kinetic equation for electrons, as well as, experimental data proving crucial role of indirect processes in generation of soft Auger-electrons are given

  17. 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.)

  18. Auger vs resonance neutralization in low energy He+ ion scattering

    International Nuclear Information System (INIS)

    Woodruff, D.P.

    1983-01-01

    He + ions incident on a metal surface can neutralize either by an Auger or resonant charge exchange. While the Auger process has always been thought to be dominant, recent theoretical interest in the simpler one-electron resonance process has led to suggestions that this alone can account for the neutralization seen in low energy He + ion scattering. In this paper this assertion is analysed by looking at the wider information available on charge exchange processes for He + ion scattering through comparison with Li + ion scattering, the importance of multiple scattering in both these scattering experiments and the results of ion neutralization spectroscopy. These lead to the conclusion that while resonance neutralization to produce metastable He* may well occur at a substantial rate in He + ion scattering, the dominant process leading to loss of ions from the final scattered signal is Auger neutralization as originally proposed. (author)

  19. Auger heating of carriers in {GaAs}/{AlAs} heterostructures

    Science.gov (United States)

    Borri, P.; Ceccherini, S.; Gurioli, M.; Bogani, F.

    1997-07-01

    The photoluminescence of {GaAs}/{AlAs} multiple quantum wells structures under optical ps excitation is investigated for carrier densities in the range 10 18-4 × 10 19 cm -3 with frequency and time-resolved spectroscopic techniques. The measurements give a direct evidence of the occurrence in the sample of carrier heating. This energy up-conversion gives rise to photoluminescence from the states near the Fermi level whose intensity and time evolution depend on the carrier density in a strongly non-linear way. The observed behaviour can be explained introducing in the carrier dynamics an up-conversion mechanism due to Auger-like processes.

  20. Test beam results of a low-pressure micro-strip gas chamber with a secondary-electron emitter

    International Nuclear Information System (INIS)

    Kwan, S.; Anderson, D.F.; Zimmerman, J.; Sbarra, C.; Salomon, M.

    1994-10-01

    We present recent results, from a beam test, on the angular dependence of the efficiency and the distribution of the signals on the anode strips of a low-pressure microstrip gas chamber with a thick CsI layer as a secondary-electron emitter. New results of CVD diamond films as secondary-electron emitters are discussed

  1. Diamond-based single-photon emitters

    International Nuclear Information System (INIS)

    Aharonovich, I; Castelletto, S; Simpson, D A; Su, C-H; Greentree, A D; Prawer, S

    2011-01-01

    The exploitation of emerging quantum technologies requires efficient fabrication of key building blocks. Sources of single photons are extremely important across many applications as they can serve as vectors for quantum information-thereby allowing long-range (perhaps even global-scale) quantum states to be made and manipulated for tasks such as quantum communication or distributed quantum computation. At the single-emitter level, quantum sources also afford new possibilities in terms of nanoscopy and bio-marking. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, as they are a photostable solid-state source of single photons at room temperature. In this review, we discuss the state of the art of diamond-based single-photon emitters and highlight their fabrication methodologies. We present the experimental techniques used to characterize the quantum emitters and discuss their photophysical properties. We outline a number of applications including quantum key distribution, bio-marking and sub-diffraction imaging, where diamond-based single emitters are playing a crucial role. We conclude with a discussion of the main challenges and perspectives for employing diamond emitters in quantum information processing.

  2. Fluorescence and Auger Decay Properties of the Core-Excited F-Like Ions from Ne to Kr

    International Nuclear Information System (INIS)

    Wang Xiang-Li; Dong Chen-Zhong; Su Mao-Gen; Koike Fumihiro

    2012-01-01

    We systematically study the decay properties of the K-shell excited F-like ions with 10≤Z≤36 based on the multiconfiguration Dirac—Fock method. The Breit interaction, the QED corrections and the nuclear finite mass effects are also considered as perturbation. Auger transition rates, radiative, Auger and natural widths, as well as fluorescence and Auger yields for K-shell excited F-like ions are presented. It is shown by means of concrete figures that the decay properties change significantly with the increase of the atomic number Z; the Auger rate is overtaken at Z = 30 by the radiative decay rate. Several fitting formulae for the radiative and Auger widths and the fluorescence yields have been evaluated which is expected to be useful in plasma analysis and plasma modeling. (atomic and molecular physics)

  3. Scanning Auger microscopy study of lanthanum partitioning in sphene-based glass-ceramics

    International Nuclear Information System (INIS)

    Hocking, W.H.; Hayward, P.J.; Watson, D.G.; Allen, G.C.

    1984-01-01

    Glass-ceramics are being investigated as possible hosts for the radioactive wastes that would result from recycling irradiated nuclear fuels. The partitioning of lanthanum in sphene-based glass-ceramics has been studied by scanning Auger electron microscopy for lanthanum concentrations from 0.2 to 2.0 mol.%. Sphene crystals (CaTiSiO 5 ) were located in the silica-rich glass matrix by recording digital Auger images of the calcium and titanium distributions. The sphene crystals were typically 0.5 to 5 μm in size and occupied approximately 40% of the total specimen volume. Auger spot analyses revealed that lanthanum was strongly partitioned into the sphene phase of phosphorus-free glass-ceramics; however, when a small amount of phosphorus was included in the glass-ceramic composition as a crystal nucleating agent, the lanthanum was concentrated in a third minor phase which also contained calcium, phosphorus and oxygen. Chemical shift effects in the Auger spectra of silicon, titanium and phosphorus showed evidence for electron-stimulated desorption of oxygen. (author)

  4. Emittance compensation of CW DC-gun photoinjector

    International Nuclear Information System (INIS)

    Li Peng; Wu Dai; Xu Zhou; Li Ming; Yang Xingfan

    2011-01-01

    Emittance growth induced by space charge effect is very important, especially for CW DC-gun photoinjector. In this work, the linear space charge force and its effect on electron beam transverse emittance are studied, and the principle and properties of emittance compensation by solenoid are analyzed. The CAEP DC-gun photoinjector with a solenoid is also simulated by code Parmela. Simulated results indicate that the normalized transverse emittance of an 80 pC bunch at the 350 keV DC-gun ex-it is 5.14 mm · mrad. And after compensated by a solenoid, it becomes 1.27 mm · mrad. The emittance of beam is well compensated. (authors)

  5. Auger generation as an intrinsic limit to tunneling field-effect transistor performance

    International Nuclear Information System (INIS)

    Teherani, James T.; Agarwal, Sapan; Chern, Winston; Antoniadis, Dimitri A.; Solomon, Paul M.; Yablonovitch, Eli

    2016-01-01

    Many in the microelectronics field view tunneling field-effect transistors (TFETs) as society's best hope for achieving a >10× power reduction for electronic devices; however, despite a decade of considerable worldwide research, experimental TFET results have significantly underperformed simulations and conventional MOSFETs. To explain the discrepancy between TFET experiments and simulations, we investigate the parasitic leakage current due to Auger generation, an intrinsic mechanism that cannot be mitigated with improved material quality or better device processing. We expose the intrinsic link between the Auger and band-to-band tunneling rates, highlighting the difficulty of increasing one without the other. From this link, we show that Auger generation imposes a fundamental limit on ultimate TFET performance.

  6. Auger generation as an intrinsic limit to tunneling field-effect transistor performance

    Energy Technology Data Exchange (ETDEWEB)

    Teherani, James T., E-mail: j.teherani@columbia.edu [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Agarwal, Sapan [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Chern, Winston; Antoniadis, Dimitri A. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Solomon, Paul M. [IBM T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Yablonovitch, Eli [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States)

    2016-08-28

    Many in the microelectronics field view tunneling field-effect transistors (TFETs) as society's best hope for achieving a >10× power reduction for electronic devices; however, despite a decade of considerable worldwide research, experimental TFET results have significantly underperformed simulations and conventional MOSFETs. To explain the discrepancy between TFET experiments and simulations, we investigate the parasitic leakage current due to Auger generation, an intrinsic mechanism that cannot be mitigated with improved material quality or better device processing. We expose the intrinsic link between the Auger and band-to-band tunneling rates, highlighting the difficulty of increasing one without the other. From this link, we show that Auger generation imposes a fundamental limit on ultimate TFET performance.

  7. Normal spectral emittance of Inconel 718 aeronautical alloy coated with yttria stabilized zirconia films

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Fernandez, L. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Industria de Turbo Propulsores, S.A., Planta de Zamudio, Edificio 300, 48170 Zamudio, Bizkaia (Spain); Campo, L. del [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, R.B., E-mail: raul.perez@ehu.es [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Tello, M.J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Emittance of Inconel 718 coated with plasma sprayed yttria stabilized zirconia. Black-Right-Pointing-Pointer The coating is opaque for {lambda} > 9 {mu}m and semi-transparent for {lambda} < 9 {mu}m. Black-Right-Pointing-Pointer In the semi-transparent region the emittance decreases with coating thickness. Black-Right-Pointing-Pointer 300 {mu}m thick coatings are still semi-transparent. Black-Right-Pointing-Pointer In the opaque region the surface roughness determines the emittance level. - Abstract: Knowledge of the radiative behaviour of the yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) is needed to perform radiative heat transfer calculations in industrial applications. In this paper, normal spectral emittance experimental data of atmospheric plasma sprayed (PS) YSZ films layered on Inconel 718 substrates are shown. The spectral emittance was measured between 2.5 and 22 {mu}m on samples with film thicknesses ranging from 20 to 280 {mu}m. The samples were heated in a controlled environment, and the emittance was measured for several temperatures between 330 and 730 Degree-Sign C. The dependence of the spectral emittance with film thickness, surface roughness and temperature has been studied and compared with the available results for YSZ TBCs obtained by electron-beam physical vapour deposition. The PS-TBC samples show a Christiansen point at {lambda} = 12.8 {mu}m. The films are semi-transparent for {lambda} < 9 {mu}m, and opaque for {lambda} > 9 {mu}m. In the semi-transparent region, the contribution of the radiation emitted by the Inconel 718 substrate to the global emittance of the samples is analysed. In addition, the influence of the roughness in the emittance values in the opaque spectral region is discussed. Finally, the total normal emittance is obtained as a function of the TBC thickness.

  8. Radiation emitter-detector package

    International Nuclear Information System (INIS)

    O'Brien, J.T.; Limm, A.C.; Nyul, P.; Tassia, V.S. Jr.

    1978-01-01

    Mounted on the metallic base of a radiation emitter-detector is a mounting block is a first projection, and a second projection. A radiation detector is on the first projection and a semiconductor electroluminescent device, i.e., a radiation emitter, is on the second projection such that the plane of the recombination region of the electroluminescent device is perpendicular to the radiation incident surface of the radiation detector. The electroluminescent device has a primary emission and a secondary emission in a direction different from the primary emission. A radiation emitter-detector package as described is ideally suited to those applications wherein the secondary radiation of the electroluminescent device is fed into a feedback circuit regulating the biasing current of the electroluminescent device

  9. Emittance investigation of RF photo-injector

    CERN Document Server

    Yang Mao Rong; Li Zheng; Li Ming; Xu Zhou

    2002-01-01

    A high-power laser beam illuminates a photocathode surface placed on an end wall of an RF cavity. The emitted electrons are accelerated immediately to a relativistic energy by the strong RF find in the cavity. But space charge effect induces beam emittance growth especially near the cathode where the electrons are still nonrelativistic. The author analyzes the factors which lead the transverse emittance growth and method how to resolve this problem. After introducing solenoidal focusing near the photocathode, the beam emittance growth is suppressed dramatically. The beam emittance is given also after compensation and simulation results. The measurements show these results are coincident

  10. Evidence for a new class of many-electron Auger transitions in atoms

    International Nuclear Information System (INIS)

    Lee, I.; Wehlitz, R.; Becker, U.; Amusia, M.Ya.; Academy of Sciences, Saint Petersburg

    1993-01-01

    The possibility of the joint decay of two holes and one excited electron is discussed as one way many-electron Auger transitions can take place. It is shown that existing experimental decay spectra of resonantly excited states in krypton and xenon exhibit weak lines which may be associated with this new type of Auger process. (Author)

  11. Monte Carlo Transverse Emittance Study on Cs2Te

    CERN Document Server

    Banfi, F; Galimberti, P G; Giannetti, C; Pagliara, S; Parmigiani, F; Pedersoli, E

    2005-01-01

    A Monte Carlo study of electron transport in Cs2Te films is performed to investigate the transverse emittance epsilon at the cathode surface. We find the photoemitted electron angular distribution and explain the physical mechanism involved in the process, a mechanism hindered by the statistical nature of the Monte Carlo method. The effects of electron-phonon scattering are discussed. The transverse emittance is calculated for different radiation wavelengths and a laser spot size of 1.5*10(-3) m. For a laser radiation at 265 nm we find epsilon = 0.56 mm-mrad. The dependence of epsilon and the quantum yield on the electron affinity Ea is also investigated. The data shows the importance of aging/contamination on the material.

  12. Atmospheric aerosols at the Pierre Auger Observatory: characterization and effect on the energy estimation for ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    Louedec, K.

    2011-01-01

    The Pierre Auger Observatory, located in the Province of Mendoza in Argentina, is making good progress in understanding the nature and origin of the ultra-high energy cosmic rays. Using a hybrid detection technique, based on surface detectors and fluorescence telescopes, it provides large statistics, good mass and energy resolution, and solid control of systematic uncertainties. One of the main challenges for the fluorescence detection technique is the understanding of the atmosphere, used as a giant calorimeter. To minimize as much as possible the systematic uncertainties in fluorescence measurements, the Auger Collaboration has developed an extensive atmospheric monitoring program. The purpose of this work is to improve our knowledge of the atmospheric aerosols, and their effect on fluorescence light propagation. Using a modelling program computing air mass displacements, it has been shown that nights with low aerosol concentrations have air masses coming much more directly from the Pacific Ocean. For the first time, the effect of the aerosol size on the light propagation has been estimated. Indeed, according to the Ramsauer approach, large aerosols have the largest effect on the light scattering. Thus, the dependence on the aerosol size has been added to the light scattering parameterizations used by the Auger Collaboration. A systematic overestimation of the energy and of the maximum air shower development X max is observed. Finally, a method based on the very inclined laser shots fired by the Auger central laser has been developed to estimate the aerosol size. Large aerosol sizes ever estimated at the Pierre Auger Observatory can now be probed. First preliminary results using laser-shot data collected in the past have identified a population of large aerosols. (author)

  13. Field emitters with low turn on electric field based on carbon fibers

    International Nuclear Information System (INIS)

    Wang Qilong; Mu Hui; Zhang Xiaobing; Lei Wei; Wang Jinchan; Zhao Hongping

    2007-01-01

    Field emitters of vertical carbon fibers on a silicon substrate are fabricated by catalytic chemical vapor deposition. After an ageing process of 150 min, field emission measurement of the fibers is carried out in a vacuum chamber with a base pressure of 5.0 x 10 -4 Pa. The experimental results display that field emission performance of the carbon fibers depends strongly on the vacuum level during the experiments. After the field emission measurement, damage to the carbon fiber field emitters is observed from the scanning electron microscopic images

  14. Criteria for emittance compensation in high-brightness photoinjectors

    Directory of Open Access Journals (Sweden)

    Chun-xi Wang

    2007-10-01

    Full Text Available A critical process in high-brightness photoinjectors is emittance compensation, which brings under control the correlated transverse emittance growth due to the linear space-charge force. Although emittance compensation has been used and studied for almost two decades, the exact criteria to achieve emittance compensation is not as clear as it should be. In this paper, a perturbative analysis of slice envelopes and emittance evolution close to any reference envelope is developed, via which space-charge and chromatic effects are investigated. A new criterion for emittance compensation is found, which is complementary to the well-known matching condition for the invariant envelope and agrees very well with simulations.

  15. PAES: Positron annihilation induced Auger electron spectrometer

    OpenAIRE

    Hugenschmidt, Christoph

    2015-01-01

    Positron annihilation induced Auger electron spectroscopy (PAES) is a newly developed application for surface studies with high elemental selectivity and exceptional surface sensitivity. The instrument is operated by the Technische Universität München and is located at NEPOMUC.

  16. Ellog Auger Drilling -"3-in-one" method for hydrogeological data collection

    DEFF Research Database (Denmark)

    Sørensen, Kurt; Larsen, Flemming

    1999-01-01

    The Ellog auger drilling method is an integrated approach for hydrogeological data collection during auger drilling in unconsolidated sediments. The drill stem is a continuous flight, hollow-stem auger with integrated electrical and gamma logging tools. The geophysical logging is performed...... continuously while drilling. Data processing is carried out in the field, and recorded log features are displayed as drilling advances. A slotted section in the stem, above the cutting head, allows anaerobic water and soil-gas samples to be taken at depth intervals of approximately 0.2 m. The logging, water......, and gas sampling instrumentation in the drill stem is removable; therefore, when the drill stem is pulled back, piezometers can be installed through the hollow stem. Cores of sediments can subsequently be taken continuously using a technique in which the drill bit can be reinserted after each coring...

  17. The radiopharmaceuticals in nuclear medicine diagnostic procedures and the problem of radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Ftacnikova, S [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

    1996-12-31

    In this paper equivalent dose from Auger electron emitters was reevaluated. The presented approach represents a practical step toward the estimation of equivalent dose for incorporated Auger electron emitters, an aspects that has not been given adequate consideration so far. Given the widespread use of this class of radionuclides in nuclear medicine and in biomedical research, the formalism and practical calculation presented here may be of value to assessing the risk associated with this radionuclides (in diagnostic nuclear medicine procedures), as well as predicting their therapeutic efficiency. (J.K.) 2 tabs., 11 refs.

  18. Small horizontal emittance in the TESLA damping ring

    International Nuclear Information System (INIS)

    Decking, W.

    2001-01-01

    The present TESLA damping ring is designed for a normalized horizontal emittance of 8x10 -6 m. γ-γ collisions at the TESLA linear collider will benefit from a further decrease of the horizontal emittance. This paper reviews the processes which limit the horizontal emittance in the damping ring. Preliminary estimates on the smallest horizontal emittance for the present TESLA damping ring design as well as an ultimate limit of the emittance reachable with the TESLA damping ring concept will be given

  19. Determination of local absolute detection efficiency of a ceratron with 55Fe Auger electrons

    International Nuclear Information System (INIS)

    Mori, C.; Sugiyama, T.; Watanabe, T.

    1983-01-01

    The local absolute detection efficiency of a Ceratron (channel electron multiplier made of ceramics) was determined with collimated Mn K Auger electrons ( 5 keV) emitted from 55 Fe as a function of electron incident position and applied voltage. The local efficiency at the channel inlet did not depend so much on the applied voltage. The efficiency at the funnel increased with the applied voltage, while it was always lower than that at the channel inlet. (orig.)

  20. Beam diagnostics using an emittance measurement device

    International Nuclear Information System (INIS)

    Sarstedt, M.; Becker, R.; Klein, H.; Maaser, A.; Mueller, J.; Thomae, R.; Weber, M.

    1995-01-01

    For beam diagnostics aside from Faraday cups for current measurements and analysing magnets for the determination of beam composition and energy the most important tool is an emittance measurement device. With such a system the distribution of the beam particles in phase-space can be determined. This yields information not only on the position of the particles but also on their angle with respect to the beam axis. There are different kinds of emittance measurement devices using either circular holes or slits for separation of part of the beam. The second method (slit-slit measurement), though important for the determination of the rms-emittance, has the disadvantage of integrating over the y- and y'-coordinate (measurement in xx'-plane assumed). This leads to different emittance diagrams than point-point measurements, since in xx'-plane for each two corresponding points of rr'-plane there exists a connecting line. With regard to beam aberrations this makes xx'-emittances harder to interpret. In this paper the two kinds of emittance diagrams are discussed. Additionally the influence of the slit height on the xx'-emittance is considered. The analytical results are compared to experimental measurements in rr'-, rx'- and xx'-phase-space. (orig.)

  1. Energy analyzer for Auger electron spectroscopy and low-energy backscattering ion spectroscopy

    International Nuclear Information System (INIS)

    Volkov, S.S.; Gorelik, V.A.; Gutenko, V.T.; Protopopov, O.D.; Trubitsin, A.A.; Shuvalova, Z.A.; Yakushev, G.A.

    1988-01-01

    Energy analyzer for electron Auger spectroscopy and low-energy backscattering ion spectroscopy is described. Analyzer presents one-cascade variant of cylindrical mirror with second-order focusing. Energy relative resolution is continuously adjusted within 0.2-1.2% limits. Signal/noise relation by Cu Auger-line at 1 muA current of exciting beam changes upper limit of range 150-450

  2. PAES: Positron annihilation induced Auger electron spectrometer

    Directory of Open Access Journals (Sweden)

    Christoph Hugenschmidt

    2015-08-01

    Full Text Available Positron annihilation induced Auger electron spectroscopy (PAES is a newly developed application for surface studies with high elemental selectivity and exceptional surface sensitivity. The instrument is operated by the Technische Universität München and is located at NEPOMUC.

  3. Low emittance configuration for spear

    International Nuclear Information System (INIS)

    Blumberg, L.N.; Harris, J.; Stege, R.; Cerino, J.; Hettel, R.; Hofmann, A.; Liu, R.Z.; Wiedemann, H.; Winick, H.

    1985-01-01

    The quality of synchrotron radiation beams from SPEAR, in particular the brilliance of undulator radiation, can be improved significantly by reducing the emittance of the stored electron beam. A reduction of the horizontal emittance by a factor of 3.5 to a value of 130 nanometer-radians (nm-r) at 3 GeV has been achieved by using stronger focussing, mainly in the horizontal plane. The low emittance configuration also reduces the dispersion and vertical beta functions in the straight sections, making them more suitable for wigglers. The higher betatron tunes lead to a larger phase advance between the two kickers, which has to be corrected during injection by shunting current from some quadrupoles. The configuration was optimized within SPEAR hardware limitations and tested for dynamic aperture with the tracking program PATRICIA. After implementation of this scheme, beam was successfully injected and accumulated. The measured emittance of the stored beam was in agreement with calculations. Presently the configuration is being made operational

  4. Emittance measurements by variable quadrupole method

    International Nuclear Information System (INIS)

    Toprek, D.

    2005-01-01

    The beam emittance is a measure of both the beam size and beam divergence, we cannot directly measure its value. If the beam size is measured at different locations or under different focusing conditions such that different parts of the phase space ellipse will be probed by the beam size monitor, the beam emittance can be determined. An emittance measurement can be performed by different methods. Here we will consider the varying quadrupole setting method.

  5. MCDF calculations of Auger cascade processes

    Science.gov (United States)

    Beerwerth, Randolf; Fritzsche, Stephan

    2017-10-01

    We model the multiple ionization of near-neutral core-excited atoms where a cascade of Auger processes leads to the emission of several electrons. We utilize the multiconfiguration Dirac-Fock (MCDF) method to generate approximate wave functions for all fine-structure levels and to account for all decays between them. This approach allows to compute electron spectra, the population of final-states and ion yields, that are accessible in many experiments. Furthermore, our approach is based on the configuration interaction method. A careful treatment of correlation between electronic configurations enables one to model three-electron processes such as an Auger decay that is accompanied by an additional shake-up transition. Here, this model is applied to the triple ionization of atomic cadmium, where we show that the decay of inner-shell 4p holes to triply-charged final states is purely due to the shake-up transition of valence 5s electrons. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

  6. Emitter depletion studies on electrodes of 50 Hz mercury/noble gas discharge lamps during ignition

    International Nuclear Information System (INIS)

    Hoek, W.J. van den; Thijssen, T.L.G.; Heijden, A.J.H. van der; Buijsse, B.; Haverlag, M.

    2002-01-01

    The depletion of emitter from the oxide cathodes during the glow switch starting of the discharge in 50 Hz operated low-pressure mercury/noble gas discharge lamps (fluorescent lamps) has been studied. It follows from pulse ignition studies and computer-controlled ignition experiments that two plasma modes exist during ignition: a glow discharge and a vapour-arc discharge. The occurrence of these modes depends on the point of interruption with respect to the phase of the 50 Hz preheat current. The vapour arc appears to be the dominant mechanism of emitter depletion. The average emitter loss per vapour-arc pulse has been quantified by radioactive Ba tracer experiments. The nature of the vapour arc has been studied by fast photography and SEM. The vapour arc involves dielectric breakdown over the non-conducting oxide mass and gives rise to explosive emitter vapourization. (author)

  7. Radio detection of cosmic ray induced air showers at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Fliescher, Stefan, E-mail: fliescher@physik.rwth-aachen.de [3. Physikalisches Institut A, RWTH Aachen, University (Germany)

    2012-01-11

    AERA - the Auger Engineering Radio Array - is currently being set up at the southern site of the Pierre Auger Observatory. AERA will explore the potential of the radio-detection technique to cosmic ray induced air showers with respect to the next generation of large-scale surface detectors. As AERA is co-located with the low-energy enhancements of the Pierre Auger Observatory, the observation of air showers in coincidence with the Auger surface and fluorescence detector will allow to study the radio emission processes in detail and to calibrate the radio signal. Finally, the combined reconstruction of shower parameters with three independent techniques promises new insights into the nature of cosmic rays in the transition region from 10{sup 17} to 10{sup 19} eV. Besides the detection of coherent radiation in the MHz frequency range, the setups AMBER - Air-shower Microwave Bremsstrahlung Experimental Radiometer - and MIDAS - MIcrowave Detection of Air Showers - prepare to check the possibility to detect air showers due the emission of molecular bremsstrahlung in the GHz range at the Auger site. This article presents the status of the radio-detection setups and discusses their physics potential as well as experimental challenges. Special focus is laid on the first stage of AERA which is the startup to the construction of a 20 km{sup 2} radio array.

  8. 45-Day safety screening for Tank 241-B-102 auger samples, riser 1

    International Nuclear Information System (INIS)

    Bell, K.E.

    1994-01-01

    This is the 45-Day report for the fiscal year 1994 Tank 241-B-102 auger sampling characterization effort. Only one of the two planned auger samples was received by the 222-S Laboratory, however it was decided to begin the 45-day clock and issue a report based on receipt of the first auger sample. Included are copies of the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) scans as requested. Also included is a copy of any immediate notification documentation, chain of custody forms, the hot cell work plan, extruded segment [auger] description sheets, and total alpha data. The TGA percent moisture results are below the safety criteria limit of 17% in a subsample taken approximately five minutes after extrusion and a second subsample taken from the lower half of the auger. Verbal and written notifications were made as prescribed. The DSC analysis of all subsamples indicates the presence of fraction exotherms, however the results are a factor of two or more below the notification limit of 523 Joules/gram (J/g). Total alpha results are all below the detection limit. In some cases, the tank characterization plan (TCP) accuracy and precision criteria are not met. If a re-run was not performed when a TCP quality control limit was not met, then reasons for not performing the re-run are provided

  9. Multinozzle emitter arrays for ultrahigh-throughput nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Mao, Pan; Wang, Hung-Ta; Yang, Peidong

    2017-10-17

    The present invention provides for a structure comprising a plurality of emitters, wherein a first nozzle of a first emitter and a second nozzle of a second emitter emit in two directions that are not or essentially not in the same direction; wherein the walls of the nozzles and the emitters form a monolithic whole. The present invention also provides for a structure comprising an emitter with a sharpened end from which the emitter emits; wherein the emitters forms a monolithic whole. The present invention also provides for a fully integrated separation of proteins and small molecules on a silicon chip before the electrospray mass spectrometry analysis.

  10. The Pierre Auger Observatory status and the AugerPrime upgrade program

    Directory of Open Access Journals (Sweden)

    Martello Daniele

    2017-01-01

    Full Text Available The nature and the origin of ultra-high energy cosmic rays (UHECRs, above 1017 eV, are still unknown. The Pierre Auger Observatory with its huge exposure provides us with a large set of high quality data. The analysis of these data has led to major breakthroughs in the last decade, but a coherent interpretation is still missing. To answer the open questions the Observatory has started a major upgrade, with an emphasis on improved mass composition determination using the surface detectors. The latest results and the planned detector upgrade will be presented. The expected performance and the improved physics sensitivity of the Observatory will be discussed.

  11. Hybrid emitter all back contact solar cell

    Science.gov (United States)

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  12. 3D Auger quantitative depth profiling of individual nanoscaled III–V heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Hourani, W. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Gorbenko, V. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Univ. Grenoble Alpes, LTM, CNRS, F-38000 Grenoble (France); Barnes, J.-P.; Guedj, C. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Cipro, R.; Moeyaert, J.; David, S.; Bassani, F.; Baron, T. [Univ. Grenoble Alpes, LTM, CNRS, F-38000 Grenoble (France); Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2016-11-15

    Highlights: • The nanoscale chemical characterization of III–V heterostructures is performed using Auger depth profiling below decananometric spatial resolution. • Reliable indium quantification is achieved on planar structures for thicknesses down to 9 nm. • Quantitative 3D compositional depth profiles are obtained on patterned structures, with sufficient lateral resolution to analyze one single trench. • The Auger intrinsic spatial resolution is estimated around 150–200 nm using a comparison with HAADF-STEM. • Auger and SIMS provide reliable in-depth chemical analysis of such complex 3D heterostructures, in particular regarding indium quantification. - Abstract: The nanoscale chemical characterization of III–V heterostructures is performed using Auger depth profiling below decananometric spatial resolution. This technique is successfully applied to quantify the elemental composition of planar and patterned III–V heterostructures containing InGaAs quantum wells. Reliable indium quantification is achieved on planar structures for thicknesses down to 9 nm. Quantitative 3D compositional depth profiles are obtained on patterned structures, for trench widths down to 200 nm. The elemental distributions obtained in averaged and pointed mode are compared. For this last case, we show that Zalar rotation during sputtering is crucial for a reliable indium quantification. Results are confirmed by comparisons with secondary ion mass spectrometry, photoluminescence spectroscopy, transmission electron microscopy and electron dispersive X-ray spectroscopy. The Auger intrinsic spatial resolution is quantitatively measured using an original methodology based on the comparison with high angle annular dark field scanning transmission electron microscopy measurements at the nanometric scale.

  13. Hydraulic performance evaluation of pressure compensating (pc) emitters and micro-tubing for drip irrigation system

    International Nuclear Information System (INIS)

    Mangrio, A.G.; Asif, M.; Jahangir, I.

    2013-01-01

    Drip irrigation system is necessary for those areas, where the water scarcity issues are present. The present study was conducted at the field station of Climate Change, Alternate Energy and Water Resources Institute (CAEWRI), National Agricultural Research Center (NARC), Islamabad, during 2013, regarding drip irrigation system. Drip irrigation system depends on uniform emitter application flow. All the emitters were tested and replicated thrice at pressure head (34 to 207Kpa) with an increment of 34 Kpa. The minimum and maximum discharges were 1.32 - 3.52, 3.36 - 5.42, and 43.22 - 100.99 Lph, with an average of 2.42, 4.63 and 73.66 Lph, for Bow Smith, RIS and Micro-tubing, respectively. It indicates that more than 90% of emission uniformity (EU) and uniformity coefficient (CU) for all Emitters, which shows excellent water application with least standard deviation, ranging 0.12 to 2.37, throughout the operating pressure heads in all emitters. An average coefficient of variation (CV) of all emitters were behaving less than 0.07, indicating an excellent class at all operating pressure heads between 34 to 207 Kpa. Moreover, the relationship of discharge and pressure of emitters indicates that discharge increased with the increase of pressure head. The Q-H curve plays key role in the selection of emitters. (author)

  14. Emittance measurements of the CLIO electron beam

    Science.gov (United States)

    Chaput, R.; Devanz, G.; Joly, P.; Kergosien, B.; Lesrel, J.

    1997-02-01

    We have designed a setup to measure the transverse emittance at the CLIO accelerator exit, based on the "3 gradients" method. The beam transverse size is measured simply by scanning it with a steering coil across a fixed jaw and recording the transmitted current, at various quadrupole strengths. A code then performs a complete calculation of the emittance using the transfer matrix of the quadrupole instead of the usual classical lens approximation. We have studied the influence of various parameters on the emittance: Magnetic field on the e-gun and the peak current. We have also improved a little the emittance by replacing a mismatched pipe between the buncher and accelerating section to avoid wake-field effects; The resulting improvements of the emittance have led to an increase in the FEL emitted power.

  15. Resonant Ni and Fe KLL Auger spectra photoexcited from NiFe alloys

    International Nuclear Information System (INIS)

    Koever, L.; Cserny, I.; Berenyi, Z.; Egri, S.; Novak, M.

    2005-01-01

    Complete text of publication follows. KLL Auger spectra of 3d transition metal atoms in solid environment, measured using high energy resolution, give an insight into the details of the local electronic structure surrounding the particular atoms emitting the signal Auger electrons. Fine tuning the energy of the exciting monochromatic photons across the K-absorption edge, features characteristic to resonant phenomena can be identified in the spectra. The shapes of the resonantly photoexcited KLL Auger spectra induced from 3d transition metals and alloys are well interpreted by the single step model of the Auger process, based on the resonant scattering theory. The peak shapes are strongly influenced by the 4p partial density of unoccupied electronic states around the excited atom. High energy resolution studies of KLL Auger spectra of 3d transition metals using laboratory X-ray sources, however, request very demanding experiments and yield spectra of limited statistical quality making the evaluation of the fine details in the spectra difficult. The Tunable High Energy XPS (THE- XPS) instrument at BW2 offers optimum photon x and energy resolution for spectroscopy of deep core Auger transitions. For the present measurements high purity polycrystalline Ni and Fe sheets as well as NiFe alloy samples of different compositions (Ni 80 Fe 20 , Ni 50 Fe 50 , Ni 20 Fe 80 ) were used. The surfaces of the samples were cleaned by in-situ argon ion sputtering. The measurements of the Ni and Fe KL 23 L 23 Auger spectra of the metal and alloy samples were performed with the THE-XPS instrument using high electron energy resolution (0.2 eV). In Fig.1, the measured Fe KL 23 L 23 spectrum, photoexcited at the Fe K absorption edge from Fe metal, is compared with the respective spectrum excited from a Ni 50 Fe 50 alloy. A significant broadening of the 1 D 2 peak and an enhancement of the spectral intensity at the low energy loss part of this peak observed in the alloy sample, while the

  16. Correlation of the Auger electrons direction of movement with the internal electron conversion direction of movement

    International Nuclear Information System (INIS)

    Mitrokhovich, N.F.; Kupryashkin, V.T.; Sidorenko, L.P.

    2013-01-01

    On installation of coincidences of γ-quanta with electrons and with law energy electrons about zero area the spatial correlation of the direction emitting Auger-electrons and electron of internal conversion was investigated at the 152 Eu decay. Auger-electrons were registered on e 0 -electrons of the secondary electron emission (γ e IC e 0 -coincidences). It was established, that Auger-electrons of M-series, as well as electrons 'shake-off' at β-decay and internal conversion, are strongly correlated at the direction of movement with the direction of movement of basic particle (β -particle, conversion electron), moving together mainly in the forward hemisphere. The intensity of correlated M-Auger radiation in range energy 1000 - 1700 eV is equal to intensity of correlated radiation 'shake-off' electron from internal conversion in this range. The assumption, that the presence of spatial correlating Auger-electron and conversion electron caused by cur-rent components of electron-electron interaction of particles in the final state is made

  17. Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

    OpenAIRE

    Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I.F.M.; Allekotte, I.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muñiz, J.; Anastasi, G.A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.

    2017-01-01

    We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above $5 \\cdot 10^{18}$ eV, i.e.~the region of the all-particle spectrum above the so-called "ankle" feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism...

  18. 2-D emittance equation with acceleration and compression

    International Nuclear Information System (INIS)

    Hahn, K.D.; Smith, L.

    1988-10-01

    Since both acceleration and compression are required for an Inertial Fusion Driver, the understanding of their effect on the beam quality, emittance, is important. This report attempts to generalize the usual emittance formula for the drifting beam to include these effects. The derivation of the 2-D emittance equation is carried out and a comparison with the particle code results is given. The 2-D emittance at a given axial location is reasonable to consider for a long beam, particularly with velocity tilt; transverse emittance averaged over the entire bunch is not a useful quantity. 6 refs., 2 figs., 1 tab

  19. A practical trial to increase the coal recovery in highwall auger mining in Australia

    Energy Technology Data Exchange (ETDEWEB)

    K. Matsui; A. Yabuki; H. Shimada; T. Sasaoka; T. Ueda; T. Yuasa

    2003-07-01

    The basic concept of auger mining is to extract coal beyond the economic limits of surface mining technology by drilling holes of an appropriate diameter size into the exposed seam of the highwall as deep as is technically, economically and operationally feasible. This method of mining is used at the final highwall of typical surface mining operations. This paper describes the auger mining systems and discusses the methods to increase the coal recovery in auger mining from a field trial at Muswell Brook mine in Hunter Valley, NSW in Australia. 1 ref., 6 figs., 2 tabs.

  20. Emittance growth in rf linacs

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1979-01-01

    As the space-charge limit is approached, the current that can be accelerated in an rf linac and the output emittance that can be expected are discussed. The role of the envelope equations to estimate limits is outlined. The results of numerical experiments to explore general properties of emittance growth are given

  1. Production of alpha emitters for therapy

    International Nuclear Information System (INIS)

    Vucina, J.; Orlic, M.; Lukic, D.

    2006-01-01

    The basis for the introduction of alpha emitters into nuclear medical practice are their radiobiological properties. High LET values and short ranges in biological tissues are advantageous in comparison with nowadays most often used beta emitters, primarily 90 Y and 131 I. Given are the most important criteria for the introduction of a given radionuclide in the routine use. Shown are the procedures for the production of the most important alpha emitters 211 At, 212 Bi and 213 Bi. (author)

  2. Spectral calibration of the fluorescence telescopes of the Pierre Auger observatory

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Blažek, Jiří; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Juryšek, Jakub; Mandát, Dušan; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2017-01-01

    Roč. 95, Oct (2017), s. 44-56 ISSN 0927-6505 R&D Projects: GA MŠk LM2015038; GA MŠk LG15014; GA MŠk EF16_013/0001402 Grant - others:OP VVV - AUGER-CZ(XE) CZ.02.1.01/0.0/0.0/16_013/0001402 Institutional support: RVO:68378271 Keywords : Auger observatory * nitrogen fluorescence * extensive air shower * calibration Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 3.257, year: 2016

  3. The determination of carbon, nitrogen and oxygen in TiCsub(x)Nsub(y)Osub(z) with the Auger electron spectroscopy (AES)

    International Nuclear Information System (INIS)

    Schneider, H.; Nold, E.; Miller, H.T.

    1980-01-01

    The possibility of determining the carbon, nitrogen and oxygen contents in TiCsub(x)Nsub(y)Osub(z) with the Auger-electron-spectroscopy (AES) is discussed. As an example the concentration dependence over the cross section of 1 μm thick TiN-layers is presented. (orig.)

  4. Minimum emittance in TBA and MBA lattices

    Science.gov (United States)

    Xu, Gang; Peng, Yue-Mei

    2015-03-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

  5. Minimum emittance in TBA and MBA lattices

    International Nuclear Information System (INIS)

    Xu Gang; Peng Yuemei

    2015-01-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 3 1/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design. (authors)

  6. Many-electron effect in the Si K-LL resonant Auger-electron spectroscopy spectra of the Si delta layer in GaAs

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2006-01-01

    The Si K-LL resonant Auger-electron spectroscopy (RAES) spectra of silicon delta dopped layers in GaAs with very thin capping layers show both normal Auger decay and resonant Auger decay, when the core-level electron is excited to the conduction band. The resonant Auger peak kinetic energy (KE) shows no dispersion with photon energy, except when excited by the highest energy photons [M.D. Jackson, J.M.C. Thornton, D. Lewis, A. Robinson, M. Fahy, A. Aviary, P. Weightman, Phys. Rev. B71 (2005) 075313]. The RAES spectra are analyzed using a many-body theory. The presence of resonant Auger decay and no dispersion of resonant Auger peak KE with photon energy is explained in terms of the relaxation of a metastable excited core-hole state to a stable one on the time scale of core-hole decay. The excited electron in the conduction band either delocalizes rapidly leaving the ionized Si to decay by a normal Auger decay or drops to a state localized in the Si delta layer before the core-hole decays so that the RAES spectrum has both normal Auger decay and resonant Auger decay. As a result of the relaxation, the resonant Auger peak KE does not show any dispersion with photon energy. The variations with photon energy of the normal or resonant Auger peak intensity, KE, and width are explained in a consistent manner by a many-body theory

  7. Cancer from internal emitters

    International Nuclear Information System (INIS)

    Boecker, B.B.; Griffith, W.C. Jr.

    1995-01-01

    Irradiation from internal emitters, or internally deposited radionuclides, is an important component of radiation exposures encountered in the workplace, home, or general environment. Long-term studies of human populations exposed to various internal emitters by different routes of exposure are producing critical information for the protection of workers and members of the general public. The purpose of this report is to examine recent developments and discuss their potential importance for understanding lifetime cancer risks from internal emitters. The major populations of persons being studied for lifetime health effects from internally deposited radionuclides are well known: Lung cancer in underground miners who inhaled Rn progeny, liver cancer from persons injected with the Th-containing radiographic contrast medium Thorotrast, bone cancer from occupational or medical intakes of 226 Ra or medical injections of 224 Ra, and thyroid cancer from exposures to iodine radionuclides in the environment or for medical purposes

  8. A SiPM-based scintillator prototype for the upgrade of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Johannes; Bretz, Thomas; Hebbeker, Thomas; Kemp, Julian; Meissner, Rebecca; Middendorf, Lukas; Niggemann, Tim; Peters, Christine [III. Physikalisches Institut A, RWTH Aachen University (Germany); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    Plastic scintillator-based detectors are simple and yet powerful instruments, commonly used in particle physics experiments. These detectors are also planned to be installed at the Pierre Auger Observatory as part of the upgrade called AugerPrime. Here, a single detector module will consist of several large-sized scintillator bars. Embedded wavelength shifting fibres read out the scintillation light and are coupled to a single photo-sensitive device. We investigate the application of silicon photomultipliers (SiPMs) in this scope, which benefits from high photon detection efficiency and stability. We show the performance of a SiPM-based prototype device installed in the 2 m{sup 2} detector ASCII - an early prototype of the scintillating detector planned for AugerPrime. We focus on the electronics, the optical coupling and the in situ calibration. As ASCII has been operating with SiPMs for several months now, we also highlight first high-energy events seen in coincidence with the Surface Detector of the Pierre Auger Observatory.

  9. Extracting the emitter orientation in organic light-emitting diodes from external quantum efficiency measurements

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Tobias D., E-mail: Tobias.Schmidt@physik.uni-augsburg.de; Reichardt, Lukas J.; Wehrmeister, Sebastian; Scholz, Bert J.; Mayr, Christian; Brütting, Wolfgang, E-mail: Wolfgang.Bruetting@physik.uni-augsburg.de [Institute of Physics, University of Augsburg, 86135 Augsburg (Germany); Rausch, Andreas F.; Wehlus, Thomas; Reusch, Thilo C. G. [OSRAM OLED GmbH, Wernerwerkstrasse 2, 93049 Regensburg (Germany); Ciarnáin, Rossá Mac; Danz, Norbert [Fraunhofer Institute for Applied Optics and Precision Engineering, 07745 Jena (Germany)

    2014-07-28

    Emitter orientation will play a major role in future applications of organic light-emitting diodes due to its strong impact on the efficiency of the devices. Up to now, determining the orientation of transition dipole moments required elaborate angular-dependent measurements of the light emission pattern. In this paper, we present a simplified and straightforward method to extract the emitter orientation from external quantum efficiency measurements. We demonstrate the validity of the method on three different dye-doped emitting systems.

  10. Development of Emittance Analysis Software for Ion Beam Characterization

    International Nuclear Information System (INIS)

    Padilla, M.J.; Liu, Yuan

    2007-01-01

    Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a figure of merit frequently used to determine the quality of ion beams, the compatibility of an ion beam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally, a high-quality beam is characterized by a small emittance. In order to determine and improve the quality of ion beams used at the Holifield Radioactive Ion Beam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ion beams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profiles, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fitting are also incorporated into the software. The software will provide a simplified, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate

  11. DEVELOPMENT OF EMITTANCE ANALYSIS SOFTWARE FOR ION BEAM CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, M. J.; Liu, Y.

    2007-01-01

    Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a fi gure of merit frequently used to determine the quality of ion beams, the compatibility of an ion beam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally a high quality beam is characterized by a small emittance. In order to determine and improve the quality of ion beams used at the Holifi eld Radioactive Ion beam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ion beams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profi les, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fi tting are also incorporated into the software. The software will provide a simplifi ed, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate.

  12. Origin of Si(LMM) Auger Electron Emission from Silicon and Si-Alloys by keV Ar+ Ion Bombardment

    Science.gov (United States)

    Iwami, Motohiro; Kim, Su Chol; Kataoka, Yoshihide; Imura, Takeshi; Hiraki, Akio; Fujimoto, Fuminori

    1980-09-01

    Si(LMM) Auger electrons emitted from specimens of pure silicon and several Si-alloys (Ni-Si, Pd-Si and Cu-Si) under keV Ar+ ion bombardment, were examined. In the Auger spectra from all specimens studied there were four peaks at energies of 92, 86, 76 and 66 eV. The Auger signal intensity varied considerably with both the incident angle and the energy of the primary ion beam. It is proposed that the Auger electrons are emitted from silicon atoms (or ions) just beneath the specimen surface but free from the bulk network.

  13. Application of a digital data acquisition system for time of flight Positron annihilation-induced Auger Electron Spectroscopy

    Science.gov (United States)

    Gladen, R. W.; Chirayath, V. A.; McDonald, A. D.; Fairchild, A. J.; Chrysler, M. D.; Imam, S. K.; Koymen, A. R.; Weiss, A. H.

    We describe herein a digital data acquisition system for a time-of-flight Positron annihilation-induced Auger Electron Spectrometer. This data acquisition system consists of a high-speed digitizer collecting signals induced by Auger electrons and annihilation gammas in a multi-channel plate electron detector and a BaF2 gamma detector, respectively. The time intervals between these two signals is used to determine the times of flight of the Auger electrons, which are analyzed by algorithms based on traditional nuclear electronics methods. Ultimately, this digital data acquisition system will be expanded to incorporate the first coincidence measurements of Auger electron and annihilation gamma energies.

  14. Coincident Auger electron and recoil ion momentum spectroscopy for low-energy ion-atom collisions

    International Nuclear Information System (INIS)

    Laurent, G.; Tarisien, M.; Flechard, X.; Jardin, P.; Guillaume, L.; Sobocinski, P.; Adoui, L.; Bordenave-Montesquieu, A.; Bordenave-Montesquieu, D.; Chesnel, J.-Y.; Fremont, F.; Hennecart, D.; Lienard, E.; Maunoury, L.; Moretto-Capelle, P.; Cassimi, A.

    2003-01-01

    The recoil ion momentum spectroscopy (RIMS) method combined with the detection of Auger electrons has been used successfully to analyse double electron capture following O 6+ + He collisions at low impact velocities. Although RIMS and Auger spectroscopies are known to be efficient tools to obtain details on the primary processes occurring during the collision, the conjunction of both techniques provides new insights on the electron capture process. In the present experiment, triple coincidence detection of the scattered projectile, the target recoil ion and the Auger electron allows for a precise identification of the doubly excited states O 4+ (1s 2 nln ' l ' ) populated after double electron-capture events

  15. Quantum efficiency and thermal emittance of metal photocathodes

    Directory of Open Access Journals (Sweden)

    David H. Dowell

    2009-07-01

    Full Text Available Modern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths with major advances occurring since the invention of the photocathode gun and the realization of emittance compensation. These state-of-the-art electron beams are now becoming limited by the intrinsic thermal emittance of the cathode. In both dc and rf photocathode guns details of the cathode emission physics strongly influence the quantum efficiency and the thermal emittance. Therefore improving cathode performance is essential to increasing the brightness of beams. It is especially important to understand the fundamentals of cathode quantum efficiency and thermal emittance. This paper investigates the relationship between the quantum efficiency and the thermal emittance for metal cathodes using the Fermi-Dirac model for the electron distribution. We use a consistent theory to derive the quantum efficiency and thermal emittance, and compare our results to those of others.

  16. The AMIGA enhancement of the Pierre Auger Observatory

    Science.gov (United States)

    Maldera, S.

    2014-06-01

    The AMIGA (Auger Muons and Infill for the Ground Array) enhancement of the Auger Surface Detector consists of a 23.5 km2 infill area instrumented with water-Cherenkov detector stations accompanied by 30 m2 of scintillator counters, buried 2.3 m underground. The spacing of 750 m between the surface detectors extends the energy range as low as 3 × 1017 eV, thus allowing the study of the energy region where the transition between galactic and extra-galactic cosmic rays is expected to take place. We describe the reconstruction of the events observed with the infill water-Cherenkov detector array and the derived energy spectrum. We also discuss the basic properties of the muon detector modules obtained from measurements and tests during the construction phase and from the first data in the field.

  17. Interpretation of the depths of maximum of extensive air showers measured by the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Pedro; et al.

    2013-02-01

    To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.

  18. Muon counting using silicon photomultipliers in the AMIGA detector of the Pierre Auger observatory

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; Dallier, R.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; del Peral, L.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Diaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorofeev, A.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Garcia, B.; Garcia-Pinto, D.; Gate, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glas, D.; Glaser, C.; Glass, H.; Golup, G.; Gomez Berisso, M.; Gomez Vitale, P. F.; Gonzalez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Horandel, J. R.; Horvath, P.; Hrabovsky, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Mezek, G. Kukec; Kunka, N.; Awad, A. Kuotb; LaHurd, D.; Latronico, L.; Lauscher, M.; Lautridou, P.; Lebrun, P.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; Lopez, R.; Lopez Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Masias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Molina-Bueno, L.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafa, M.; Mueller, G.; Muller, M. A.; Mueller, S.; Naranjo, I.; Navas, S.; Nellen, L.; Neuser, J.; Nguyenu, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, H.; Nunez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pekala, J.; Pelayo, R.; Pena-Rodriguez, J.; Pereira, L. A. S.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollant, R.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Reinert, D.; Revenue, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Fernandez, G. Rodriguez; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Rogozin, D.; Rosado, J.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanabria Gomez, J. D.; Sanchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento-Cano, C.; Sato, R.; Scarso, C.; Schauer, M.; Scherini, V.; Schieler, H.; Schmidt, D.; Scholten, O.; Schovanek, P.; Schroeder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Smiaikowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanic, S.; Stasielak, J.; Strafella, F.; Suarez, F.; Suarez Duran, M.; Sudholz, T.; Suomijarvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Torri, M.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valbuena-Delgado, A.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Villasenor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczynski, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yang, L.; Yelos, D.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.; collaboration, Pierre Auger

    AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory designed to extend its energy range of detection and to directly measure the muon content of the cosmic ray primary particle showers. The array will be formed by an infill of surface water-Cherenkov

  19. Increase of intrinsic emittance induced by multiphoton photoemission from copper cathodes illuminated by femtosecond laser pulses

    Science.gov (United States)

    An, Chenjie; Zhu, Rui; Xu, Jun; Liu, Yaqi; Hu, Xiaopeng; Zhang, Jiasen; Yu, Dapeng

    2018-05-01

    Electron sources driven by femtosecond laser have important applications in many aspects, and the research about the intrinsic emittance is becoming more and more crucial. The intrinsic emittance of polycrystalline copper cathode, which was illuminated by femtosecond pulses (FWHM of the pulse duration was about 100 fs) with photon energies above and below the work function, was measured with an extremely low bunch charge (single-electron pulses) based on free expansion method. A minimum emittance was obtained at the photon energy very close to the effective work function of the cathode. When the photon energy decreased below the effective work function, emittance increased rather than decreased or flattened out to a constant. By investigating the dependence of photocurrent density on the incident laser intensity, we found the emission excited by pulsed photons with sub-work-function energies contained two-photon photoemission. In addition, the portion of two-photon photoemission current increased with the reduction of photon energy. We attributed the increase of emittance to the effect of two-photon photoemission. This work shows that conventional method of reducing the photon energy of excited light source to approach the room temperature limit of the intrinsic emittance may be infeasible for femtosecond laser. There would be an optimized photon energy value near the work function to obtain the lowest emittance for pulsed laser pumped photocathode.

  20. Drift compression experiments on MBE-4 and related emittance growth phenomena

    International Nuclear Information System (INIS)

    Eylon, S.; Faltens, A.; Fawley, W.; Garvey, T.; Hahn, K.; Henestroza, E.; Smith, L.

    1991-04-01

    We have recently conducted a series of experiments on the MBE-4 heavy ion accelerator in which a velocity tilt was placed on the beam in the first accelerating section beyond the injector, followed by drift compression over the remaining 11 meters. Depending upon the magnitude of the velocity tilt and the accompanying mismatch in the focusing lattice, emittance growth was observed, manifested by ''butterfly'' shapes in x - x' phase space. We discuss various analytical limits on ion beam compression and relate them to these experiments and also to a driver for a heavy ion fusion reactor. We also present numerical simulations which investigate various aspects of compression and consequent emittance growth. 2 refs., 3 figs., 1 tab

  1. Postcollision interactions in the Auger decay of the Ar L-shell

    Energy Technology Data Exchange (ETDEWEB)

    Samson, J.A.R.; Stolte, W.C.; He, Z.X. [Univ. of Nebraska, Lincoln, NE (United States)] [and others

    1997-04-01

    The photoionization cross sections for Ar{sup +} through Ar{sup 4+}, produced by the Auger decay of an inner shell 2p hole, have been measured between 242 eV and 253 eV on beamline 9.0.1 and 6.3.2. In this study the authors are interested in near threshold phenomenon involving postcollision interactions (PCI), which are related to the Auger decay of a vacancy in the Ar L-shell. During an Auger decay a postcollision interaction can occur causing the out-going photoelectron to be retarded thus losing a certain amount of energy. If the retardation is sufficiently large the photoelectron will not escape. This result produces a singly charged ion, which normally would not be present. Such evidence of electron capture by the PCI effect was first shown clearly by Eberhardt et al. and, with higher resolution, in the present work. However, capture of the photoelectron is expected to be 100% exactly at the L{sub 2,3} thresholds. Thus, from the authors results they would have expected the Ar{sup 2+} signal to be zero at threshold, but it was not? The authors can explain this anomoly on the basis that during the Auger decay the photoelectrons are captured into high lying excited states of Ar{sup +}, which subsequently decay through autoionization yielding Ar{sup 2+}. Future work in this area will seek experimental evidence to verify this prediction.

  2. Characterization of NiSi nanowires as field emitters and limitations of Fowler-Nordheim model at the nanoscale

    Science.gov (United States)

    Belkadi, Amina B.; Gale, E.; Isakovic, A. F.

    2015-03-01

    Nanoscale field emitters are of technological interest because of the anticipated faster turn-on time, better sustainability and compactness. This report focuses on NiSi nanowires as field emitters for two reasons: (a) possible enhancement of field emission in nanoscale field emitters over bulk, and (b) achieving the same field emission properties as in bulk, but at a lower energy cost. To this end, we have grown, fabricated and characterized NiSi nanowires as field emitters. Depending on the geometry of the NiSi nanowires (aspect ratio, shape etc.), the relevant major field emission parameters, such as (1) the turn-on field, (2) the work function, and (3) the field enhancement factor, can be comparable or even superior to other recently explored nanoscale field emitters, such as CdS and ZnO. We also report on a comparative performance of various nanoscale field emitters and on the difficulties in the performance comparison in the light of relatively poor applicability of the standard Folwer-Nordheim model for field emission analysis for the case of the nanoscale field emitters. Proposed modifications are discussed. This work is supported through SRC-ATIC Grant 2011-KJ-2190. We also acknoweldge BNL-CFN and Cornell CNF facilities and staff.

  3. Beam phase space and emittance

    International Nuclear Information System (INIS)

    Buon, J.

    1990-12-01

    The classical and elementary results for canonical phase space, the Liouville theorem and the beam emittance are reviewed. Then, the importance of phase portraits to obtain a geometrical description of motion is emphasized, with examples in accelerator physics. Finally, a statistical point of view is used to define beam emittance, to study its law of approximate conservation and to treat two particular examples

  4. Cooling mechanical motion via vacuum effect of an ensemble of quantum emitters.

    Science.gov (United States)

    Nie, Wenjie; Chen, Aixi; Lan, Yueheng

    2015-11-30

    We design a hybrid optomechanical setup, in which an ensemble of quantum emitters is coupled with a movable mirror through vacuum interaction. The optical cavity is driven along with the quantum emitters and therefore the coupling between the cavity field and the ensemble determines the dynamics of the coupled system. In particular, we investigated the influence of the vacuum coupling strength on the effective frequency and the effective damping rate of the movable mirror, which shows that the vacuum interaction enhances greatly the effective damping rate. Further, the cooling characteristics of the mechanical resonator is analyzed in detail by counting the effective phonon number in the mirror's motion. It is found that the ground-state cooling of the mechanical motion can be approached in the bad cavity limit when the vacuum coupling is included. The dependence of the cooling of the mechanical motion on the parameters of the cavity and the quantum emitter is investigated in detail numerically.

  5. Parametric emittance measurements of electron beams produced by a laser plasma accelerator

    Science.gov (United States)

    Barber, S. K.; van Tilborg, J.; Schroeder, C. B.; Lehe, R.; Tsai, H.-E.; Swanson, K. K.; Steinke, S.; Nakamura, K.; Geddes, C. G. R.; Benedetti, C.; Esarey, E.; Leemans, W. P.

    2018-05-01

    Laser plasma accelerators (LPA) offer an exciting possibility to deliver high energy, high brightness electrons beams in drastically smaller distance scales than is typical for conventional accelerators. As such, LPAs draw considerable attention as potential drivers for next generation light sources and for a compact linear collider. In order to asses the viability of an LPA source for a particular application, the brightness of the source should be properly characterized. In this paper, we present charge dependent transverse emittance measurements of LPA sources using both ionization injection and shock induced density down ramp injection, with the latter delivering smaller transverse emittances by a factor of two when controlling for charge density. The single shot emittance method is described in detail with a discussion on limitations related to second order transport effects. The direct role of space charge is explored through a series of simulations and found to be consistent with experimental observations.

  6. Low-energy electron microdosimetry of CS-137

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Wrenn, M.E.

    1980-09-01

    The mass of tissue irradiated by an internal emitter depends upon the distribution of the radionuclide within the organism and the type of radiation emitted. The range (95% absorption) of low-energy electron effectively defines the sensitive volume in which the energy of the emitted electron is deposited. Accordingly, in the case of Auger electron microdosimetry of internal emitters the correct definition of the sensitive volume is of paramount importance. The amount of energy delivered by the monoenergetic electrons emitted by the decay system 137 Cs → sup(137m)Ba to spherical volumes of water-like tissue media of radii equivalent to the estimated ranges of those electrons in water is calculated and discussed as far as the variations of the estimated ranges of electrons as a function of the initial energy of emission are concerned. Although there are still many uncertainties on the actual ranges of low-energy electrons, one can state confidently that the ranges of the Auger electrons of the decay system 137 Cs → 137 sup(m) Ba → 137 Ba can be considered to be in the same order of magnitude of the diameter of a cell. The energy deposition in spherical volumes of water-like tissue media, considered equivalent to the sensitive volumes for the Auger electrons of the decay system 137 Cs → 137 sub(m) Ba → 137 Ba, range for several orders of magnitude from 10 2 to about 10 10 times higher than the energy deposition in similar media by the internal conversion electrons of this decay system. If equivalent variations of energy deposition per unit mass occur when the masses considered are cellular, and subcellular structures, then the effects into the sensitive volume should be taken into biological consideration as far as the microdosimetry of low-energy electrons (approximately equal to 10 keV) is considered, whenever there is internal localization of Auger emitters. (Author) [pt

  7. Generalized superradiant assembly for nanophotonic thermal emitters

    Science.gov (United States)

    Mallawaarachchi, Sudaraka; Gunapala, Sarath D.; Stockman, Mark I.; Premaratne, Malin

    2018-03-01

    Superradiance explains the collective enhancement of emission, observed when nanophotonic emitters are arranged within subwavelength proximity and perfect symmetry. Thermal superradiant emitter assemblies with variable photon far-field coupling rates are known to be capable of outperforming their conventional, nonsuperradiant counterparts. However, due to the inability to account for assemblies comprising emitters with various materials and dimensional configurations, existing thermal superradiant models are inadequate and incongruent. In this paper, a generalized thermal superradiant assembly for nanophotonic emitters is developed from first principles. Spectral analysis shows that not only does the proposed model outperform existing models in power delivery, but also portrays unforeseen and startling characteristics during emission. These electromagnetically induced transparency like (EIT-like) and superscattering-like characteristics are reported here for a superradiant assembly, and the effects escalate as the emitters become increasingly disparate. The fact that the EIT-like characteristics are in close agreement with a recent experimental observation involving the superradiant decay of qubits strongly bolsters the validity of the proposed model.

  8. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.

    2013-03-01

    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  9. Internal emitter research and standard setting

    International Nuclear Information System (INIS)

    Stannard, J.N.

    1981-01-01

    The history of the use of data from internal emitter research in the derivation of safety standards is reviewed. At first, observed biological effects were correlated with body burdens or exposure levels. This direct approach is illustrated by detailed accounts of the cases of uranium and plutonium. In the 1950's, when it was decided to provide standards for over 200 isotopes, the direct approach was replaced by a system of calculations. This necessitated changes in internal emitter research programs to provide metabolic data, and the development of models such as Reference Man and the Lung and Gastrointestinal Tract models. The continuing contribution of internal emitter research to standard setting can be seen in the references quoted in the metabolic data section of the new ICRP report (ICRP Publication 30). Present trends suggest a possible return to the direct use of internal emitter effects data for obtaining risk estimates. (U.K.)

  10. Search for ultra high energy primary photons at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Colalillo Roberta

    2016-01-01

    Full Text Available The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture in the search for primary photons with energy above 1017 eV over a large portion of the southern sky. Such photons can be detected in principle via the air showers they initiate at such energies, using the complement of Auger Observatory detectors. We discuss the results obtained in diffuse and directional searches for primary photons in the EeV energy range.

  11. L-MM Auger electron production in 0.3-1.6 MeV Kr-Kr collisions

    International Nuclear Information System (INIS)

    DeGroot, P.; Zarcone, M.J.; Kessel, Q.C.; Connecticut Univ., Storrs

    1987-01-01

    Relative total cross sections for Kr L-Auger electron emission are presented and compared with the corresponding X-ray data of Woerlee and Shanker and coworkers. These data sets all show the same incident ion energy dependence, indicating a constant fluorescence yield for the collision conditions under consideration. These data are also in agreement with a rotational coupling calculation by shanker and coworkers that was carried out within the framework of the one-electron molecular orbital model of Fano and Lichten. (orig.)

  12. Measurement of the ultra high energy cosmic ray flux from data of very inclined showers at the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Dembinski, Hans Peter

    2009-01-01

    This work describes the derivation of the energy dependent flux of ultra-high energy cosmic rays from data of very inclined air showers observed with the Pierre Auger Observatory. It focuses on the event class of very inclined air showers with zenith angles larger than 60 . The lateral ground profile of these showers is muon dominated and not radially symmetric around the shower axis due to geomagnetic deflections and other effects. The dependency of this profile on the direction, energy and mass of the cosmic ray is discussed with a mixture of detailed Monte-Carlo simulations and a simplified analytical model of the air shower cascade. It is found in agreement with other studies that the normalized shape of the muon density profile is approximately universal over the range of cosmic ray energies and masses measured at the Pierre Auger Observatory, that the amplitude of the profile is almost proportional to the cosmic ray energy, and that its shower-to-shower fluctuations are sensitive to the mass composition of the cosmic rays. (orig.)

  13. Measurement of the ultra high energy cosmic ray flux from data of very inclined showers at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, Hans Peter

    2009-12-03

    This work describes the derivation of the energy dependent flux of ultra-high energy cosmic rays from data of very inclined air showers observed with the Pierre Auger Observatory. It focuses on the event class of very inclined air showers with zenith angles larger than 60 . The lateral ground profile of these showers is muon dominated and not radially symmetric around the shower axis due to geomagnetic deflections and other effects. The dependency of this profile on the direction, energy and mass of the cosmic ray is discussed with a mixture of detailed Monte-Carlo simulations and a simplified analytical model of the air shower cascade. It is found in agreement with other studies that the normalized shape of the muon density profile is approximately universal over the range of cosmic ray energies and masses measured at the Pierre Auger Observatory, that the amplitude of the profile is almost proportional to the cosmic ray energy, and that its shower-to-shower fluctuations are sensitive to the mass composition of the cosmic rays. (orig.)

  14. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    International Nuclear Information System (INIS)

    Hugenschmidt, Christoph; Legl, Stefan

    2006-01-01

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1 eV at high electron energies up to E≅1000 eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube

  15. Computer simulation of the emittance growth due to noise in large hadron colliders

    International Nuclear Information System (INIS)

    Lebedev, V.

    1993-03-01

    The problem of emittance growth due to random fluctuations of the magnetic field in a hadron collider is considered. The results of computer simulations are compared with the analytical theory developed earlier. A good agreement was found between the analytical theory predictions and the computer simulations for the collider tunes located far enough from high order betatron resonances. The dependencies of the emittance growth rate on noise spectral density, beam separation at the Interaction Point (IP) and value of beam separation at long range collisions are studied. The results are applicable to the Superconducting Super Collider (SSC)

  16. Coincident Auger electron and recoil ion momentum spectroscopy for low-energy ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, G. E-mail: glaurent@ganil.fr; Tarisien, M.; Flechard, X.; Jardin, P.; Guillaume, L.; Sobocinski, P.; Adoui, L.; Bordenave-Montesquieu, A.; Bordenave-Montesquieu, D.; Chesnel, J.-Y.; Fremont, F.; Hennecart, D.; Lienard, E.; Maunoury, L.; Moretto-Capelle, P.; Cassimi, A

    2003-05-01

    The recoil ion momentum spectroscopy (RIMS) method combined with the detection of Auger electrons has been used successfully to analyse double electron capture following O{sup 6+} + He collisions at low impact velocities. Although RIMS and Auger spectroscopies are known to be efficient tools to obtain details on the primary processes occurring during the collision, the conjunction of both techniques provides new insights on the electron capture process. In the present experiment, triple coincidence detection of the scattered projectile, the target recoil ion and the Auger electron allows for a precise identification of the doubly excited states O{sup 4+} (1s{sup 2}nln{sup '}l{sup '}) populated after double electron-capture events.

  17. Measurements of electron beam emittance in the Accelerator Test Facility damping ring operated in multibunch modes

    Directory of Open Access Journals (Sweden)

    Yosuke Honda

    2003-09-01

    Full Text Available We present the measurement results of electron beam emittance in the Accelerator Test Facility damping ring operated in multibunch modes. The measurements were carried out with an upgraded laser wire beam profile monitor. The monitor has now a vertical wire as well as a horizontal one and is able to make much faster measurements thanks to an increased effective laser power inside the cavity. The measured emittance shows no large bunch-to-bunch dependence in either the horizontal or vertical directions. The values of the vertical emittance are similar to those obtained in the single-bunch operation. The present results are an important step toward the realization of a high-energy linear collider.

  18. Chemical effects in materials studies using Auger analysis

    International Nuclear Information System (INIS)

    Rye, R.R.

    1985-01-01

    Core-valence-valence Auger spectra (AES) afford a unique local view of valence electron structure. The direct involvement in the Auger process of both core and valence states means that the transition matrix element will have a large value only for that portion of the valence electron density which covers the same spatial extent as the core wave function. Thus, the information content of AES is local to the atomic site containing the initial core hole. Our approach in understanding the local information content of AES has been mainly experimental through the intercomparison of model systems, both molecular and solid. The use of molecules in this regard is particularly useful since the vast array of molecular species of known geometric and electronic structures allows one to both vary these properties in a systematic fashion to observe trends and to choose a molecule to probe a specific chemical question

  19. Solid-state single-photon emitters

    Science.gov (United States)

    Aharonovich, Igor; Englund, Dirk; Toth, Milos

    2016-10-01

    Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

  20. A low emittance configuration for spear

    International Nuclear Information System (INIS)

    Blumberg, L.N.; Cerino, J.; Harris, J.; Hettel, R.; Hofmann, A.; Liu, R.Z.; Stego, R.; Wiedemann, H.; Winick, H.

    1985-01-01

    The quality of synchrotron radiation beams from SPEAR, in particular the brilliance of undulator radiation, can be improved significantly by reducing the emittance of the stored electron beam. A reduction of the horizontal emittance by a factor of 3.5 to a value of 130 nanometer-radians (nm-r) at 3 GeV has been achieved by using stronger focussing, mainly in the horizontal plane. The low emittance configuration also reduces the dispersion and vertical beta functions in the straight sections, making them more suitable for wigglers. The higher betatron tunes lead to a larger phase advance between the two kickers, which has to be corrected during injection by shunting current from some quadrupoles. The configuration was optimized within SPEAR hardware limitations and tested for dynamic aperture with the tracking program PATRICIA. After implementation of this scheme, beam was successfully injected and accumulated. The measured emittance of the stored beam was in agreement with calculations. Presently the configuration is being made operational

  1. Emittance variations in current-amplifying ion induction linacs

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1991-01-01

    Since 1985 the Heavy Ion Fusion Accelerator Research program at the Lawrence Berkeley Laboratory has been studying current amplification and emittance variations in MBE-4, a four-cesium-beam induction linac. This experiment models much of the accelerator physics of the electrostatically focused section of a fusion driver. Four space-charge dominated Cs + beams, initially about one meter in length at currents of 5-10 mA, are focused by electrostatic quadrupoles and accelerated in parallel from approximately 200 keV up to one MeV by 24 accelerating gaps. Final currents of 20-40 mA per beam are typical. Recent experiments with extremely low emittance beams (var-epsilon n =0.03 mm-mRad) have investigated variations of transverse and longitudinal normalized emittance for drifting and accelerating beams. These very strongly tune-depressed beams (σ 0 =72 degree, σ∼6 degree) are difficult to match to the accelerator so as to avoid emittance growth during acceleration. During transport strong emittance fluctuations are observed in good qualitative agreement with simulations. Warmer beams with less tune depression exhibit little to no emittance growth, show smaller emittance fluctuations, and are much easier to match. A summary of findings from the MBE-4 studies is presented

  2. Emittance variations in current-amplifying ion induction linacs

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1991-04-01

    Since 1985 the Heavy Ion Fusion Accelerator Research program at the Lawrence Berkeley Laboratory has been studying current amplification and emittance variations in MBE-4, a four-cesium-beam induction linac. This experiment models much of the accelerator physics of the electrostatically focused section of a fusion driver. Four space-charge dominated Cs + beams, initially about one meter in length at currents of 5--10 mA, are focused by electrostatic quadrupoles and accelerated in parallel from approximately 200 keV up to one MeV by 24 accelerating gaps. Final currents of 20--40 mA per beam are typical. Recent experiments with extremely low emittance beams (ε n = 0.03 mm-mRad) have investigated variations of transverse and longitudinal normalized emittance for drifting and accelerating beams. These very strongly tune-depressed beams (σ o = 72 degrees, σ∼6 degree) are difficult to match the accelerator so as to avoid emittance growth during acceleration. During transport strong emittance fluctuations are observed in good qualitative agreement with simulations. Warmer beams with less tune depression exhibit little to no emittance growth, show smaller emittance fluctuations, and are much easier to match. A summary of findings from the MBE-4 studies is presented. 12 refs., 8 figs

  3. Nanodiamond composite as a material for cold electron emitters

    International Nuclear Information System (INIS)

    Arkhipov, A V; Sominski, G G; Uvarov, A A; Gordeev, S K; Korchagina, S B

    2008-01-01

    Characteristics of field-induced electron emission were investigated for one of newly designed all-carbon materials - nanodiamond composite (NDC). The composite is comprised by 4-6 nm diamond grains covered with 0.2-1 nm-thick graphite-like shells that merge at grain junctions and determine such properties as mechanical strength and high electric conductivity. Large number of uniformly distributed sp 3 -sp 2 interfaces allowed to expect enhanced electron emission in electric field. Combination of these features makes NDC a promising material for cold electron emitters in various applications. Experimental testing confirmed high efficiency of electron emission from NDC. In comparison with previousely tested forms of nanocarbon, NDC emitters demonstrated better stabily and tolerance to performance conditions. Unusual activation scenarios and thermal dependencies of emission characteristics observed in experiments with NDC can add new background for explanation of facilitated electron emission from nanocarbons with relatively 'smooth' surface morphology

  4. Local radiolytic effectiveness of Auger electrons of iodine-125 in benzene-iodine solutions

    International Nuclear Information System (INIS)

    Uenak, P.; Uenak, T.

    1987-01-01

    High radiotoxicity of iodine-125 has been mainly attributed to the local radiolytic effects of Auger electrons on biological systems. In the present study, experimental and theoretical results are compared. The agreement between the experimental and theoretical results explains that the energy absorption of iodine aggregates has an important role in the radiolytic effectiveness of Auger electrons and iodine-125 in benzene-iodine solutions. (author) 18 refs.; 3 figs

  5. Gamma flux responsive self-powered detector with a tubular emitter

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Todt, W.H.

    1982-01-01

    A gamma-sensitive flux detector comprises tubular emitter, an insulating core within the emitter and an insulating layer about the emitter, and a tubular conductive collector electrode about the insulating layer. The emitter material may be platinum, lead, bismuth, tantalum, tungsten; platinum preferred

  6. Emittance Growth in the NLCTA First Chicane

    International Nuclear Information System (INIS)

    Sun, Yipeng

    2011-01-01

    In this paper, the emittance growth in the NLCTA (Next Linear Collider Test Accelerator) first chicane region is evaluated by simulation studies. It is demonstrated that the higher order fields of the chicane dipole magnet and the dipole corrector magnet (which is attached on the quadrupoles) are the main contributions for the emittance growth, especially for the case with a large initial emittance (γε 0 = 5 (micro)m for instance). These simulation results agree with the experimental observations.

  7. A combined emitter threat assessment method based on ICW-RCM

    Science.gov (United States)

    Zhang, Ying; Wang, Hongwei; Guo, Xiaotao; Wang, Yubing

    2017-08-01

    Considering that the tradition al emitter threat assessment methods are difficult to intuitively reflect the degree of target threaten and the deficiency of real-time and complexity, on the basis of radar chart method(RCM), an algorithm of emitter combined threat assessment based on ICW-RCM (improved combination weighting method, ICW) is proposed. The coarse sorting is integrated with fine sorting in emitter combined threat assessment, sequencing the emitter threat level roughly accordance to radar operation mode, and reducing task priority of the low-threat emitter; On the basis of ICW-RCM, sequencing the same radar operation mode emitter roughly, finally, obtain the results of emitter threat assessment through coarse and fine sorting. Simulation analyses show the correctness and effectiveness of this algorithm. Comparing with classical method of emitter threat assessment based on CW-RCM, the algorithm is visual in image and can work quickly with lower complexity.

  8. Mass composition studies of Ultra High Energy cosmic rays through the measurement of the Muon Production Depths at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Collica, Laura [Univ. of Milan (Italy); Paris Diderot Univ. (France)

    2014-01-01

    The Pierre Auger Observatory (Auger) in Argentina studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of cosmic rays at these energies (above 1018 eV) is very low (less than 100 particle/km2-year) and UHECR properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyond the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHE- CRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. Auger is the largest cosmic rays detector ever built and it provides high-quality data together with unprecedented statistics. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highest energies is of fundamental importance from the astrophysical point of view, since it could discriminate between different scenarios of origin and propagation of cosmic rays. Moreover, mass composition studies are of utmost importance for particle physics. As a matter of fact, knowing the composition helps in exploring the hadronic interactions at ultra-high energies, inaccessible to present accelerator experiments.

  9. Radiative Auger effect in ion-atom collisions

    International Nuclear Information System (INIS)

    Richard, P.; Oltjen, J.; Jamison, K.A.; Kauffman, R.L.; Woods, C.W.; Hall, J.M.

    1975-01-01

    The radiative Auger effect, RAE, is observed for Al and Si bombarded by 1-2MeV H + . This is the first observation of the RAE X-ray edge using ion excitation. The K-L 23 L 23 RAE edge energy and the relative intensity are in agreement with the previously reported electron and photon induced spectra. (Auth.)

  10. Auger decay mechanism in photon-stimulated desorption of ions from surfaces

    International Nuclear Information System (INIS)

    Parks, C.C.

    1983-11-01

    Photon-stimulated desorption (PSD) of positive ions was studied with synchrotron radiation using an angle-integrating time-of-flight mass spectrometer. Ion yields as functions of photon energy near core levels were measured from condensed gases, alkali fluorides, and other alkali and alkaline earth halides. These results are compared to bulk photoabsorption measurements with emphasis on understanding fundamental desorption mechanisms. The applicability of the Auger decay mechanism, in which ion desorption is strictly proportional to surface absorption, is discussed in detail. The Auger decay model is developed in detail to describe Na + and F + desorption from NaF following Na(1s) excitation. The major decay pathways of the Na(1s) hole leading to desorption are described and equations for the energetics of ion desorption are developed. Ion desorption spectra of H + , Li + , and F + are compared to bulk photoabsorption near the F(2s) and Li(1s) edges of LiF. A strong photon beam exposure dependence of ion yields from alkali fluorides is revealed, which may indicate the predominance of metal ion desorption from defect sites. The large role of indirect mechanisms in ion desorption condensed N 2 -O 2 multilayers is demonstrated and discussed. Ion desorption spectra from several alkali halides and alkaline earth halides are compared to bulk photoabsorption spectra. Relative ion yields from BaF 2 and a series of alkali halides are discussed in terms of desorption mechanisms

  11. AugerNext: innovative research studies for the next generation ground-based ultra-high energy cosmic ray experiment

    Directory of Open Access Journals (Sweden)

    Haungs Andreas

    2013-06-01

    Full Text Available The findings so far of the Pierre Auger Observatory and also of the Telescope Array define the requirements for a possible next generation experiment: it needs to be considerably increased in size, it needs a better sensitivity to composition, and it should cover the full sky. AugerNext aims to perform innovative research studies in order to prepare a proposal fulfilling these demands. Such R&D studies are primarily focused in the following areas iconsolidation of the detection of cosmic rays using MHz radio antennas; iiproof-of-principle of cosmic-ray microwave detection; iiitest of the large-scale application of a new generation photo-sensors; ivgeneralization of data communication techniques; vdevelopment of new ways of muon detection with surface arrays. These AugerNext studies on new innovative detection methods for a next generation cosmic-ray experiment are performed at the Pierre Auger Observatory. The AugerNext consortium consists presently of fourteen partner institutions from nine European countries supported by a network of European funding agencies and it is a principal element of the ASPERA/ApPEC strategic roadmaps.

  12. Measurements of Thermal Emittance for Cesium Telluride Photocathodes at PITZ

    CERN Document Server

    Miltchev, V; Grabosch, H J; Han, J H; Krasilnikov, M; Oppelt, A; Petrosian, B; Staykov, L; Stephan, F

    2005-01-01

    The thermal emittance determines the lower emittance limit and its measurement is of high importance to understand the ultimate injector performance. In this contribution we present results of thermal emittance measurements under rf operation conditions for various Cs2Te cathodes and different accelerating gradients. Measurements of thermal emittance scaling with the cathode laser spot size are presented and analysed. The significance of the Schottky effect in the emittance formation process is discussed.

  13. Oxygen adsorption on Cu-9 at. %Al(111) studied by low energy electron diffraction and Auger electron spectroscopy

    Science.gov (United States)

    Yoshitake, Michiko; Bera, Santanu; Yamauchi, Yasuhiro; Song, Weijie

    2003-07-01

    Cu-based alloys have been used for electric cables for long time. In the field of microelectronics, Al had been used for electrical wiring. However, it became clear that electromigration occurs in Al that causes breaking of wires in minute wirings. Due to this problem, Cu wiring is used in most advanced microprocessors. Cu metal is more corrosive than Al and Cu-based alloys with a small amount of Al is expected to solve problems both on electromigration and corrosion. The initial stage of corrosion is oxygen adsorption. We studied surface segregation of Al on Cu-9% Al(111) and oxygen adsorption on the surface with/without Al segregation in ultrahigh vacuum by low energy electron diffraction (LEED) and Auger electron spectroscopy. It was found that Al segregates on the surface to form (√3×√3)R30° structure and the structure vanishes above 595 K to give (1×1) structure while Al still segregates. The specimen was exposed to oxygen at different temperatures. The amount of oxygen uptake was not structure dependent but temperature dependent. Below 595 K, only a small amount of oxygen adsorbed. Between 595 and 870 K, oxygen adsorbed surface showed amorphous LEED pattern. The specimen was annealed at 1070 K after oxygen exposure. When the specimen was exposed oxygen below 870 K, the oxygen Auger intensity decreased significantly by annealing and the annealed surface showed (√3×√3)R30° structure at room temperature. When the specimen was exposed to oxygen at 870 K, diffused spots developed newly in LEED pattern but the pattern disappeared after 1070 K annealing while oxygen Auger intensity remained almost constant. Exposing the specimen to oxygen at 995 K resulted in clear spots in the LEED pattern, which were attributed to the (7/√3×7√3)R30° structure.

  14. Electron emitter pulsed-type cylindrical IEC

    International Nuclear Information System (INIS)

    Miley, G.H.; Gu, Y.; Stubbers, R.; Zich, R.; Anderl, R.; Hartwell, J.

    1997-01-01

    A cylindrical version of the single grid Inertial Electrostatic Confinement (IEC) device (termed the C-device) has been developed for use as a 2.5-MeV D-D fusion neutron source for neutron activation analysis. The C-device employs a hollow-tube type cathode with similar anodes backed up by ''reflector'' dishes. The resulting discharge differs from a conventional hollow cathode discharge, by creating an explicit ion beam which is ''pinched'' in the cathode region. Resulting fusion reactions generate ∼10 6 neutron/s. A pulsed version is under development for applications requiring higher fluxes. Several pulsing techniques are under study, including an electron emitter (e-emitter) assisted discharge in a thorated tungsten wire emitter located behind a slotted area in the reflector dishes. Pulsing is initiated after establishing a low power steady-state discharge by pulsing the e-emitter current using a capacitor switch type circuit. The resulting electron jet, coupled with the discharge by the biased slot array, creates a strong pulse in the pinched ion beam. The pulse length/repetition rate are controlled by the e-emitter pulse circuit. Typical parameters in present studies are ∼30micros, 10Hz and 1-amp ion current. Corresponding neutron measurements are an In-foil type activation counter for time averaged rates. Results for a wide variety of operating conditions are presented

  15. Emittance and beam size distortion due to linear coupling

    International Nuclear Information System (INIS)

    Parzen, G.

    1993-01-01

    At injection, the presence of linear coupling may result in an increased beam emittance and in increased beam dimensions. Results for the emittance in the presence of linear coupling will be found. These results for the emittance distortion show that the harmonics of the skew quadrupole field close to ν x + ν y are the important harmonics. Results will be found for the important driving terms for the emittance distortion. It will be shown that if these driving terms are corrected, then the total emittance is unchanged, var-epsilon x + var-epsilon y = var-epsilon 1 + var-epsilon 2 . Also, the increase in the beam dimensions will be limited to a factor which is less than 1.414. If the correction is good enough, see below for details, one can achieve var-epsilon 1 = var-epsilon x , var-epsilon 2 = var-epsilon where var-epsilon 1 , var-epsilon 2 are the emittances in the presence of coupling, and the beam dimensions are unchanged. Global correction of the emittance and beam size distortion appears possible

  16. Study of the Pierre Auger Observatory ground detectors: tests, simulation and calibration; Etude des detecteurs de surface de l'observatoire Pierre Auger: tests, simulation et etalonnage

    Energy Technology Data Exchange (ETDEWEB)

    Creusot, A

    2004-10-01

    The Pierre Auger Observatory is intended to the ultra high energy cosmic rays study. This study is realized through the particles showers coming from the interaction between the cosmic rays and the atmosphere. The ground detection of these showers requires a comprehensive understanding of the detectors. Several test tanks have been elaborated for this purpose, especially the Orsay one. The first chapter is dedicated to the presentation of the cosmic rays and of the Pierre Auger Observatory. The second one describes the detectors used for the Observatory surface array. The Orsay test tank is then presented and detailed. We study the results we have got with the Orsay test tank in the fourth chapter and compare these results with those of the Observatory detectors in the fifth chapter. The sixth chapter is dedicated to the validation of the results set through the simulation (GEANT4 software). Finally, the first detected particles showers are presented in the seventh chapter. The data acquisition has begun this year. The construction will be finished by end of 2005. From this moment, The Pierre Auger Observatory will allow us to contribute to solving the cosmic rays puzzle. (author)

  17. Compact Rare Earth Emitter Hollow Cathode

    Science.gov (United States)

    Watkins, Ronald; Goebel, Dan; Hofer, Richard

    2010-01-01

    configuration with possibly an even longer emitter life. This cathode is specifically designed to integrate on the centerline of a high-power Hall thruster, thus eliminating the asymmetries in the plasma discharge common to cathodes previously mounted externally to the thruster s magnetic circuit. An alternative configuration for the cathode uses an external propellant feed. This diverts a fraction of the total cathode flow to an external feed, which can improve the cathode coupling efficiency at lower total mass flow rates. This can improve the overall thruster efficiency, thereby decreasing the required propellant loads for different missions. Depending on the particular mission, reductions in propellant loads can lead to mission enabling capabilities by allowing launch vehicle step-down, greater payload capability, or by extending the life of a spacecraft.

  18. The Quantum Efficiency and Thermal Emittance of Metal Photocathodes

    International Nuclear Information System (INIS)

    Dowell, D.

    2009-01-01

    Modern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths, with the principle improvements occurring since the invention of the photocathode gun. The state-of-the-art normalized emittance electron beams are now becoming limited by the thermal emittance of the cathode. In both DC and RF photocathode guns, details of the cathode emission physics strongly influence the quantum efficiency and the thermal emittance. Therefore improving cathode performance is essential to increasing the brightness of beams. It is especially important to understand the fundamentals of cathode quantum efficiency and thermal emittance. This paper investigates the relationship between the quantum efficiency and the thermal emittance of metal cathodes using the Fermi-Dirac model for the electron distribution. We derive the thermal emittance and its relationship to the quantum efficiency, and compare our results to those of others

  19. Scanning Auger microscopy for high lateral and depth elemental sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E., E-mail: eugenie.martinez@cea.fr [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Yadav, P. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Bouttemy, M. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Renault, O.; Borowik, Ł.; Bertin, F. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Etcheberry, A. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Chabli, A. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2013-12-15

    Highlights: •SAM performances and limitations are illustrated on real practical cases such as the analysis of nanowires and nanodots. •High spatial elemental resolution is shown with the analysis of reference semiconducting Al{sub 0.7}Ga{sub 0.3}As/GaAs multilayers. •High in-depth elemental resolution is also illustrated. Auger depth profiling with low energy ion beams allows revealing ultra-thin layers (∼1 nm). •Analysis of cross-sectional samples is another effective approach to obtain in-depth elemental information. -- Abstract: Scanning Auger microscopy is currently gaining interest for investigating nanostructures or thin multilayers stacks developed for nanotechnologies. New generation Auger nanoprobes combine high lateral (∼10 nm), energy (0.1%) and depth (∼2 nm) resolutions thus offering the possibility to analyze the elemental composition as well as the chemical state, at the nanometre scale. We report here on the performances and limitations on practical examples from nanotechnology research. The spatial elemental sensitivity is illustrated with the analysis of Al{sub 0.7}Ga{sub 0.3}As/GaAs heterostructures, Si nanowires and SiC nanodots. Regarding the elemental in-depth composition, two effective approaches are presented: low energy depth profiling to reveal ultra-thin layers (∼1 nm) and analysis of cross-sectional samples.

  20. Origin of Si(LMM) Auger electron emission from silicon and Si-alloys by keV Ar/sup +/ ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Iwami, M; Kim, S; Kataoka, Y; Imura, T; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering

    1980-09-01

    Si(LMM) Auger electrons emitted from specimens of pure silicon and several Si-alloys (Ni-Si, Pd-Si and Cu-Si) under keV Ar/sup +/ ion bombardment, were examined. In the Auger spectra from all specimens studied there were four peaks at energies of 92, 86, 76 and 66 eV. The Auger signal intensity varied considerably with both the incident angle and the energy of the primary ion beam. It is proposed that the Auger electrons are emitted from silicon atoms (or ions) just beneath the specimen surface but free from the bulk network.

  1. Effect of phonon-bath dimensionality on the spectral tuning of single-photon emitters in the Purcell regime

    Science.gov (United States)

    Chassagneux, Yannick; Jeantet, Adrien; Claude, Théo; Voisin, Christophe

    2018-05-01

    We develop a theoretical frame to investigate the spectral dependence of the brightness of a single-photon source made of a solid-state nanoemitter embedded in a high-quality factor microcavity. This study encompasses the cases of localized excitons embedded in a one-, two-, or three-dimensional matrix. The population evolution is calculated based on a spin-boson model, using the noninteracting blip approximation. We find that the spectral dependence of the single-photon source brightness (hereafter called spectral efficiency) can be expressed analytically through the free-space emission and absorption spectra of the emitter, the vacuum Rabi splitting, and the loss rates of the system. In other words, the free-space spectrum of the emitter encodes all the relevant information on the interaction between the exciton and the phonon bath to obtain the dynamics of the cavity-coupled system. We compute numerically the spectral efficiency for several types of localized emitters differing by the phonon bath dimensionality. In particular, in low-dimensional systems where this interaction is enhanced, a pronounced asymmetric energy exchange between the emitter and the cavity on the phonon sidebands yields a considerable extension of the tuning range of the source through phonon-assisted cavity feeding, possibly surpassing that of a purely resonant system.

  2. Emittance Measurements For Future LHC Beams Using The PS Booster Measurement Line

    CERN Document Server

    Abelleira, Jose; Mikulec, Bettina; Di Giovanni, Gian Piero; CERN. Geneva. ATS Department

    2017-01-01

    The CERN PS Booster measurement line contains three pairs of SEM grids separated by drift space that measures the beam size in both planes. The combined analysis of these grids allows calculating a value for the transverse beam emittances. The precision of such a measurement depends on the ratio of RMS beam size and wire spacing. Within the LIU-PSB upgrade the extraction kinetic energy of the PSB will be increased from the current 1.4 GeV to 2.0 GeV. This will result in smaller transverse beam sizes for some of the future beams. The present layout of the transverse emittance measurement line is reviewed to verify if it will satisfy future requirements.

  3. Design and fabrication of spectrally selective emitter for thermophotovoltaic system by using nano-imprint lithography

    Science.gov (United States)

    Kim, Jong-Moo; Park, Keum-Hwan; Kim, Da-Som; Hwang, Bo-yeon; Kim, Sun-Kyung; Chae, Hee-Man; Ju, Byeong-Kwon; Kim, Young-Seok

    2018-01-01

    Thermophotovoltaic (TPV) systems have attracted attention as promising power generation systems that can directly convert the radiant energy produced by the combustion of fuel into electrical energy. However, there is a fundamental limit of their conversion efficiency due to the broadband distribution of the radiant spectrum. To overcome this problem, several spectrally selective thermal emitter technologies have been investigated, including the fabrication of photonic crystal (PhC) structures. In this paper, we present some design rules based on finite-a difference time-domain (FDTD) simulation results for tungsten (W) PhC emitter. The W 2D PhC was fabricated by a simple nano-imprint lithography (NIL) process, and inductive coupled plasma reactive ion etching (ICP-RIE) with an isotropic etching process, the benefits and parameters of which are presented. The fabricated W PhC emitter showed spectrally selective emission near the infrared wavelength range, and the optical properties varied depending on the size of the nano-patterns. The measured results of the fabricated prototype structure correspond well to the simulated values. Finally, compared with the performance of a flat W emitter, the total thermal emitter efficiency was almost 3.25 times better with the 2D W PhC structure.

  4. Measurement of the intensity ratio of Auger and conversion electrons for the electron capture decay of 125I

    Science.gov (United States)

    Alotiby, M.; Greguric, I.; Kibédi, T.; Lee, B. Q.; Roberts, M.; Stuchbery, A. E.; Tee, Pi; Tornyi, T.; Vos, M.

    2018-03-01

    Auger electrons emitted after nuclear decay have potential application in targeted cancer therapy. For this purpose it is important to know the Auger electron yield per nuclear decay. In this work we describe a measurement of the ratio of the number of conversion electrons (emitted as part of the nuclear decay process) to the number of Auger electrons (emitted as part of the atomic relaxation process after the nuclear decay) for the case of 125I. Results are compared with Monte-Carlo type simulations of the relaxation cascade using the BrIccEmis code. Our results indicate that for 125I the calculations based on rates from the Evaluated Atomic Data Library underestimate the K Auger yields by 20%.

  5. Measurement of the intensity ratio of Auger and conversion electrons for the electron capture decay of 125I.

    Science.gov (United States)

    Alotiby, M; Greguric, I; Kibédi, T; Lee, B Q; Roberts, M; Stuchbery, A E; Tee, Pi; Tornyi, T; Vos, M

    2018-03-21

    Auger electrons emitted after nuclear decay have potential application in targeted cancer therapy. For this purpose it is important to know the Auger electron yield per nuclear decay. In this work we describe a measurement of the ratio of the number of conversion electrons (emitted as part of the nuclear decay process) to the number of Auger electrons (emitted as part of the atomic relaxation process after the nuclear decay) for the case of 125 I. Results are compared with Monte-Carlo type simulations of the relaxation cascade using the BrIccEmis code. Our results indicate that for 125 I the calculations based on rates from the Evaluated Atomic Data Library underestimate the K Auger yields by 20%.

  6. The Pierre Auger Cosmic Ray Observatory

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Grygar, Jiří; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2015-01-01

    Roč. 798, Oct (2015), s. 172-213 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LG13007; GA MŠk(CZ) 7AMB14AR005; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : Pierre Auger Observatory * high energy cosmic rays * hybrid observatory * water Cherenkov detectors * air fluorescence detectors Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.200, year: 2015

  7. Improved limit to the diffuse flux of ultrahigh energy neutrinos from the Pierre Auger Observatory

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, A.; Blanco, M.; Buitink, S.; Docters, W.; Dorosti Hasankiadeh, Q.; Ferguson, A P.; Lu, L.; Messina, S.; Scholten, O.; van den Berg, A. M.

    2015-01-01

    Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable with the Surface Detector array (SD) of the Pierre Auger Observatory. We report here on searches through Auger data from 1 January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to the

  8. Emittance growth of bunched beams in bends

    International Nuclear Information System (INIS)

    Carlsten, B.E.; Raubenheimer, T.O.

    1995-01-01

    Talman [Phys. Rev. Lett. 56, 1429 (1986)] has proposed a novel relativistic effect that occurs when a charged particle beam is bent in the magnetic field from an external dipole. The consequence of this effect is that the space-charge forces from the particles do not exhibit the usual inverse-square energy dependence and some part of them are, in fact, independent of energy. This led to speculation that this effect could introduce significant emittance growth for a bending electron beam. Subsequently, it was shown that this effect's influence on the beam's transverse motion is canceled for a dc beam by a potential depression within the beam (to first order in the beam radius divided by the bend radius). In this paper, we extend the analysis to include short bunch lengths (as compared to the beam pipe dimensions) and find that there is no longer the cancellation for forces both transverse to and in the direction of motion. We provide an estimate for the emittance growth as a function of bend angle, beam radius, and current, and for magnetic compression of an electron bunch

  9. Diamondoid monolayers as electron emitters

    Science.gov (United States)

    Yang, Wanli [El Cerrito, CA; Fabbri, Jason D [San Francisco, CA; Melosh, Nicholas A [Menlo Park, CA; Hussain, Zahid [Orinda, CA; Shen, Zhi-Xun [Stanford, CA

    2012-04-10

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  10. Nanodiamond Emitters of Single Photons

    Directory of Open Access Journals (Sweden)

    Vlasov I.I.

    2015-01-01

    Full Text Available Luminescence properties of single color centers were studied in nanodiamonds of different origin. It was found that single photon emitters could be realized even in molecularsized diamond (less than 2 nm capable of housing stable luminescent center “silicon-vacancy.” First results on incorporation of single-photon emitters based on luminescent nanodiamonds in plasmonic nanoantennas to enhance the photon count rate and directionality, diminish the fluorescence decay time, and provide polarization selectivity are presented.

  11. Mass composition studies using the surface detector of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Wahlberg, Hernan

    2009-01-01

    The mass composition of ultra-high energy cosmic rays is a critical issue to understand their origin and nature. The Pierre Auger Observatory is a hybrid instrument which provides a powerful environment for the determination of the primary mass. The Surface Detector of the Pierre Auger Observatory alone allows the study of several shower parameters with high discriminating power between primary elements. Novel analysis techniques using different features of signals in the Cherenkov stations are discussed. These are the signal risetime, the azimuthal time asymmetry and the muon density of the showers.

  12. Tolerances for the vertical emittance in damping rings

    International Nuclear Information System (INIS)

    Raubenheimer, T.O.

    1991-11-01

    Future damping rings for linear colliders will need to have very small vertical emittances. In the limit of low beam current, the vertical emittance is primarily determined by the vertical dispersion and the betatron coupling. In this paper, the contributions to these effects from random misalignments are calculated and tolerances are derived to limit the vertical emittance with a 95% confidence level. 10 refs., 5 figs

  13. Nanodiamond composite as a material for cold electron emitters

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, A V; Sominski, G G; Uvarov, A A [St.Petersburg State Polytechnic University, 29 Politchnicheskaya, St.Petersburg, 195251 (Russian Federation); Gordeev, S K; Korchagina, S B [FSUE ' Central Research Institute for Materials' , 8 Paradnaya Street, St.Petersburg, 191014 (Russian Federation)], E-mail: arkhipov@rphf.spbstu.ru

    2008-03-15

    Characteristics of field-induced electron emission were investigated for one of newly designed all-carbon materials - nanodiamond composite (NDC). The composite is comprised by 4-6 nm diamond grains covered with 0.2-1 nm-thick graphite-like shells that merge at grain junctions and determine such properties as mechanical strength and high electric conductivity. Large number of uniformly distributed sp{sup 3}-sp{sup 2} interfaces allowed to expect enhanced electron emission in electric field. Combination of these features makes NDC a promising material for cold electron emitters in various applications. Experimental testing confirmed high efficiency of electron emission from NDC. In comparison with previousely tested forms of nanocarbon, NDC emitters demonstrated better stabily and tolerance to performance conditions. Unusual activation scenarios and thermal dependencies of emission characteristics observed in experiments with NDC can add new background for explanation of facilitated electron emission from nanocarbons with relatively 'smooth' surface morphology.

  14. Beam emittance measurements on multicusp ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Sarstedt, M.; Lee, Y.; Leung, K.N. [and others

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 {mu}m patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma.

  15. Beam emittance measurements on multicusp ion sources

    International Nuclear Information System (INIS)

    Sarstedt, M.; Lee, Y.; Leung, K.N.

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 μm patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma

  16. Transfer mechanisms between emitter molecules for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Steinbacher, Frank [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Chiu, Chien-Shu [Department of Electrical Engineering and Information Technology, Technical University of Braunschweig (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Krause, Ralf; Hunze, Arvid [Siemens AG, CT MM 1, Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany)

    2009-07-01

    Within the last few years white organic light emitting diodes based on small molecules have shown the potential to have a promising future in the field of lighting technology. Nevertheless there is still room for improvement of the overall efficiency and lifetime of white OLEDs. A deeper understanding of the energy transfer mechanisms between different matrix and emitter molecules used in the OLED stack concept can help to optimize the layout and reduce driving voltage thus increasing the power efficiency and color stability of the device. To simplify the complex interactions within a complete white OLED we start out with a basic model system only containing the molecules of interest. This enables us to predict the fundamental concepts causing the behavior of more intricate systems. Using photoluminescence, excitation spectra and time-resolved photoluminescence we investigated the exciton transfer between different dyes for a variety of emitter systems. Our results indicate a dependence of exciton transfer probability on the total concentrations and therefore the distance between the molecules involved.

  17. Rayleigh scattering in an emitter-nanofiber-coupling system

    Science.gov (United States)

    Tang, Shui-Jing; Gao, Fei; Xu, Da; Li, Yan; Gong, Qihuang; Xiao, Yun-Feng

    2017-04-01

    Scattering is a general process in both fundamental and applied physics. In this paper, we investigate Rayleigh scattering of a solid-state-emitter coupled to a nanofiber, by S -matrix-like theory in k -space description. Under this model, both Rayleigh scattering and dipole interaction are studied between a two-level artificial atom embedded in a nanocrystal and fiber modes (guided and radiation modes). It is found that Rayleigh scattering plays a critical role in the transport properties and quantum statistics of photons. On the one hand, Rayleigh scattering produces the transparency in the optical transmitted field of the nanofiber, accompanied by the change of atomic phase, population, and frequency shift. On the other hand, the interference between two kinds of scattering fields by Rayleigh scattering and dipole transition modifies the photon statistics (second-order autocorrelation function) of output fields, showing a strong wavelength dependence. This study provides guidance for the solid-state emitter acting as a single-photon source and can be extended to explore the scattering effect in many-body physics.

  18. Detailed investigation of neutron emitters in the transmutation of Minor Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Letourneau, A.; Bringer, O.; Dupont, E.; Panebianco, S.; Veyssiere, Ch. [CEA/Saclay/DSM/IRFU - Gif-sur-Yvette (France); Al Mahamid, I. [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Chartier, F. [CEA/Saclay/DEN/DPC/SECR - Gif-sur-Yvette (France); Mutti, P. [Institut Laue-Langevin, Grenoble (France); Oriol, L. [CEA/Cadarache/DEN/DER/SPEX - Saint-Paul-lez-Durances (France)

    2008-07-01

    The production of neutron emitters during the incineration process of minor actinides could be very penalizing for the reprocessing of the targets when transmuted in heterogeneous mode, either in dedicated systems (ADS) or in generation IV reactors. Therefore their production has to be carefully evaluated. The reliability of such evaluation really depends on nuclear data (capture and fission cross sections) and their accuracy. In this paper we present a work we have done to investigate the production of neutron emitters in the incineration of {sup 237}Np and {sup 241}Am targets in fast and thermal nuclear reactor concepts. The impact of nuclear data uncertainties on the production of those neutron-emitters was evaluated by sensitivity calculations. The reduction for some of these uncertainties in the thermal energy region was done by measuring more precisely the {sup 244}Cm(n,gamma){sup 245}Cm, {sup 245}Cm(n,f) and {sup 249}Cf(n,gamma){sup 250}Cf capture cross sections at the Laue-Langevin Institute (ILL). It amounts to (15.6+-2.4) b for the first one, (1923+-49) b for the second and (389+-10) b for the third one. (authors)

  19. Prolixe-prototype reprocessing unit for irradiating wastes contamined with alpha emitters

    International Nuclear Information System (INIS)

    Madic, C.; Sontag, R.

    1987-01-01

    A large number of hot cells are employed for research on nuclear fuel reprocessing and the production of isotope of transuranium elements. These activities generate solid wastes highly contaminated with alpha, beta, gamma emitters. The Prolixe hot cell was built in order to: 1/ reprocess the solid wastes contaminated with alpha, beta, gamma emitters produced in the Radiochemistry building: 2/ produce package wastes storable in shallow-ground disposal sites: 3/ develop a process sufficiently flexible to make it applicable to waste produced in other installations. The process is based on waste leaching after grinding. Depending on the type of wastes the leaching reactant will have a different composition 1/ nitric acid solution for cellulose waste: 2/ nitric solutions containing Ag(II) for other material. The complete process should achieve: 1/ a high waste volume reduction factor: 2/ the production of immobilized waste packages storage in shallow-ground disposal sites: 3/ the recycling of transuranium elements: 4/ the generation of a minimal volume of effluents. This process can be considered as an alternative process to incineration for the reprocessing of solid wastes highly contaminated with alpha, beta, gamma emitters

  20. Clean and contaminated TiD2 films: Fabrication and Auger spectra

    International Nuclear Information System (INIS)

    Malinowski, M.E.

    1978-01-01

    Clean and intentionally contaminated stoichiometric TiD 2 thin films have been formed under controlled conditions and the surface compositions of the films measured using Auger electron spectroscopy. The unique ultrahigh vacuum system used to fabricate the films is described in detail. In addition, the Auger spectra of clean and CO- and CO 2 -contaminated films, before and after deuteriding, are presented. The MVV and LMV peaks in the differential spectrum of TiD 2 are significantly different from the corresponding peaks in the Ti spectrum, presumably a result of the deuteride formation. Films intentionally contaminated with CO and CO 2 have Auger spectra with oxygen peaks and carbide-like carbon peaks. The C and O peak heights and shapes for Ti exposed to CO and CO 2 do not change upon formation of TiD 2 . In addition, for each of these gases, a definite ratio of C/O peak heights was observed: For CO, the C/O ratio was approx.1.3, while for CO 2 it was approx.0.58. Both ratios were independent of gas exposures up to approx.1 Torr s

  1. Test results on two thermionic converters with cermet emitters

    International Nuclear Information System (INIS)

    Saunders, M.; Danielson, L.; Huffman, F.

    1983-01-01

    An emitter made of a directionally solidified Mo-Al 2 O 3 , Cr 2 O 3 eutectic was provided by Eindhoven University of Technology in Eindhoven, The Netherlands. Although the high temperature braze cycle used in bonding this electrode to the emitter substrate destroyed its characteristic needle microstructure, the converter gave good performance. Apparently, chemical species evaporated from the emitter onto the collector provided a low collector work function. The resulting low barrier indices suggest that this surface is a promising emitter

  2. Results from and prospects for the Auger Engineering Radio Array

    Directory of Open Access Journals (Sweden)

    van den Berg A.M.

    2013-06-01

    Full Text Available The Auger Engineering Radio Array (AERA is one of the low-energy enhancements of the Pierre Auger Observatory. AERA is based on experience obtained with the LOPES and CODALEMA experiments in Europe and aims to study in the MHz region the details of the emission mechanism of radio signals from extensive air showers. The data from AERA will be used to assess the sensitivity of MHz radiation to the mass composition of cosmic rays. Because of its energy threshold at 2 × 1017 eV the dip region in the cosmic-ray flux spectrum can be studied in detail. We present first results of AERA and of its prototypes and we provide an outlook towards the future.

  3. The Slow Control System of the Auger Fluorescence Detectors

    Science.gov (United States)

    Barenthien, N.; Bethge, C.; Daumiller, K.; Gemmeke, H.; Kampert, K.-H.; Wiebusch, C.

    2003-07-01

    The fluorescence detector (FD) of the Pierre Auger experiment [1] comprises 24 telescopes that will be situated in 4 remote buildings in the Pampa Amarilla. It is planned to run the fluorescence detectors in absence of operators on site. Therefore, the main task of the Slow Control System (SCS) is to ensure a secure remote operation of the FD system. The Slow Control System works autonomously and continuously monitors those parameters which may disturb a secure operation. Commands from the data-acquisition system or the remote operator are accepted only if they do not violate safety rules that depend on the actual experimental conditions (e.g. high-voltage, wind-sp eed, light, etc.). In case of malfunctions (power failure, communication breakdown, ...) the SCS performs an orderly shutdown and subsequent startup of the fluorescence detector system. The concept and the implementation of the Slow Control System are presented.

  4. Transverse emittance growth in staged laser-wakefield acceleration

    Directory of Open Access Journals (Sweden)

    T. Mehrling

    2012-11-01

    Full Text Available We present a study on the emittance evolution of electron bunches, externally injected into laser-driven plasma waves using the three-dimensional particle-in-cell (PIC code OSIRIS. Results show order-of-magnitude transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This behavior is supported by analytic theory reproducing the simulation data to a percent level. The length over which the full emittance growth develops is found to be less than or comparable to the typical dimension of a single plasma module in current multistage designs. In addition, the analytic theory enables the quantitative prediction of emittance degradation in two consecutive accelerators coupled by free-drift sections, excluding this as a scheme for effective emittance-growth suppression, and thus suggests the necessity of beam-matching sections between acceleration stages with fundamental implications on the overall design of staged laser-wakefield accelerators.

  5. Emittance measurements in Grumman 1 MeV beamline

    International Nuclear Information System (INIS)

    Debiak, T.; Gammel, G.; Melnychuk, S.

    1992-01-01

    The emittance of a 30 keV H - beam has been measured with an Allison type electrostatic analyser at two positions separated by 85 cm along the Grumman 1 MeV beamline LEBT at low currents (about 4 mA, no Cs 2 O additive in the source) and at higher currents (10-15 mA, with Cs 2 O additive in the source). No emittance growth was observed between the two positions, but, at the higher current level, the emittance was about 60% higher than at the low current level (Σ n ,rms = .0045 π cm-mrad vs. 0070 π cm-mrad). Argon was then introduced up to a partial pressure of 4x10 -5 torr, and the emittance decreased back to a range corresponding to that found at the lower currents. However, beam noise was observed at the downstream position, and there is evidence for a small amount of emittance growth (<20%) between the two positions

  6. Study of the Pierre Auger Observatory ground detectors: tests, simulation and calibration; Etude des detecteurs de surface de l'observatoire Pierre Auger: tests, simulation et etalonnage

    Energy Technology Data Exchange (ETDEWEB)

    Creusot, A

    2004-10-01

    The Pierre Auger Observatory is intended to the ultra high energy cosmic rays study. This study is realized through the particles showers coming from the interaction between the cosmic rays and the atmosphere. The ground detection of these showers requires a comprehensive understanding of the detectors. Several test tanks have been elaborated for this purpose, especially the Orsay one. The first chapter is dedicated to the presentation of the cosmic rays and of the Pierre Auger Observatory. The second one describes the detectors used for the Observatory surface array. The Orsay test tank is then presented and detailed. We study the results we have got with the Orsay test tank in the fourth chapter and compare these results with those of the Observatory detectors in the fifth chapter. The sixth chapter is dedicated to the validation of the results set through the simulation (GEANT4 software). Finally, the first detected particles showers are presented in the seventh chapter. The data acquisition has begun this year. The construction will be finished by end of 2005. From this moment, The Pierre Auger Observatory will allow us to contribute to solving the cosmic rays puzzle. (author)

  7. Auger electron and X-ray spectroscopy of hollow atoms

    NARCIS (Netherlands)

    Morgenstern, R; Johnson, RL; Schmidtbocking, H; Sonntag, BF

    1997-01-01

    Hollow atoms as formed during collisions of multiply charged ions on metallic, semiconducting and insulating surfaces have in recent years successfully been investigated by various spectroscopic methods: low- and high-resolution X-ray spectroscopy as well as high resolution Auger electron

  8. Emittance Growth during Bunch Compression in the CTF-II

    Energy Technology Data Exchange (ETDEWEB)

    Raubenheimer, Tor O

    1999-02-26

    Measurements of the beam emittance during bunch compression in the CLIC Test Facility (CTF-II) are described. The measurements were made with different beam charges and different energy correlations versus the bunch compressor settings which were varied from no compression through the point of full compression and to over-compression. Significant increases in the beam emittance were observed with the maximum emittance occurring near the point of full (maximal) compression. Finally, evaluation of possible emittance dilution mechanisms indicate that coherent synchrotron radiation was the most likely cause.

  9. Recent results from the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Gouffon, Philippe

    2010-01-01

    Full text. The Pierre Auger Observatory has been designed to observe cosmic rays with energies above 1018 eV . The southern site, located in Malargue, Argentina, is now fully operational (since mid 2008) and has been collecting data continuously while being deployed. The northern site, which will give a full sky coverage, is under development in Lamar, Colorado, USA. The PAO uses two complementary techniques to measure the direction of arrival and the energy of the comic rays. In the southern site, its 1600 water Cerenkov tanks, spread over 3000 km 2 , sample the extended air shower front when it hits the ground, measuring time and energy deposited, while the 4 fluorescence detectors stations, each with 6 telescopes, collect the UV light emitted by the shower core, registering the time, intensity and angle of reception. Though the Pierre Auger collaboration will be taking data for the next two decades, several results have already been published based on data collected until 2009 and will be discussed briefly: the energy spectrum and its implications on the GZK cut off controversy, limits on photon and neutrino fluxes, anisotropy, point sources and mass composition. (author)

  10. Recent results from the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Gouffon, Philippe [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2010-07-01

    Full text. The Pierre Auger Observatory has been designed to observe cosmic rays with energies above 1018 eV . The southern site, located in Malargue, Argentina, is now fully operational (since mid 2008) and has been collecting data continuously while being deployed. The northern site, which will give a full sky coverage, is under development in Lamar, Colorado, USA. The PAO uses two complementary techniques to measure the direction of arrival and the energy of the comic rays. In the southern site, its 1600 water Cerenkov tanks, spread over 3000 km{sup 2}, sample the extended air shower front when it hits the ground, measuring time and energy deposited, while the 4 fluorescence detectors stations, each with 6 telescopes, collect the UV light emitted by the shower core, registering the time, intensity and angle of reception. Though the Pierre Auger collaboration will be taking data for the next two decades, several results have already been published based on data collected until 2009 and will be discussed briefly: the energy spectrum and its implications on the GZK cut off controversy, limits on photon and neutrino fluxes, anisotropy, point sources and mass composition. (author)

  11. Electrohydrodynamic emitters of ion beams

    International Nuclear Information System (INIS)

    Dudnikov, V.G.; Shabalin, A.L.

    1990-01-01

    Physical processes determining generation of ion beams with high emission current density in electrohydrodynamic emitters are considered. Electrohydrodynamic effects developing in ion emission features and kinetics of ion interaction in beams with high density are discussed. Factors determining the size of the emission zone, emission stability at high and low currents, cluster generation, increase of energy spread and decrease of brightness are analyzed. Problems on practical provision of stable EHD emitter functioning are considered. 94 refs.; 8 figs.; 1 tab

  12. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  13. X-ray photoelectron and x-ray-induced auger electron spectroscopic data, 2

    International Nuclear Information System (INIS)

    Baba, Yuji; Sasaki, Teikichi

    1984-04-01

    The intrinsic data of the X-ray photoelectron spectra (XPS) and X-ray-induced Auger electron spectra (XAES) for 4d transition-metals and related oxides were obtained by means of a spherical electron spectrometer. The metallic surfaces were cleaned by two different metheds : mechanical filing and Ar + ion etching. In the case of the Ar + io n bombarded Y, Zr, and Nb metals, the binding energies of the core-lines and the kinetic energies of the Auger lines shift from those for the mechanically filed surfaces. The energy shifts were interpreted in terms of the ion-induced lattice distortion of the metal surfaces. The oxides examined are typical compounds such as Y 2 O 3 , ZrO 2 , Nb 2 O 5 , MoO 3 and RuO 2 . The data consists of 4 wide scans, 33 core-line spectra, 10 valence-band spectra and 12 XAES spectra. The peak positions of the core-lines and the Auger lines were summarized in 6 tables together with their chemical shifts. (author)

  14. Transverse emittance measurement and preservation at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Maria

    2016-06-20

    The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation are discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constraints of various systems such as tune measurement precision and powering limitations of the LHC superconducting circuits into account. With sinusoidal k-modulation record low beta function measurement uncertainties in the LHC have been reached. 2015 LHC beta function and β*, which is the beta function at the collision point, measurements with k-modulation will be presented. Wire scanners and synchrotron light monitors are presently used in the LHC to measure the transverse beam size. Accuracy and limitations of the LHC transverse profile monitors are discussed. During the 2012 LHC proton run it was found that wire scanner photomultiplier saturation added significant uncertainty on all measurements. A large discrepancy between emittances from wire scanners and luminosity was discovered but not solved. During Long Shutdown 1 the wire scanner system was upgraded with new photomultipliers. A thorough study of LHC wire scanner measurement precision in 2015 is presented

  15. Improvements in emittance wake field optimization for the SLAC Linear Collider

    CERN Document Server

    Decker, Franz Josef

    2003-01-01

    The transverse emittances in the SLAC Linear Collider can be severely diluted by collective wakefield effects and dispersion. For the 1997/98 SLC/SLD run important changes were implemented in the way the emittance is optimized. Early in the linac, where the energy spread is large due to BNS damping, the emittance growth is dominated by dispersion. In this regime emittance tuning bumps may introduce additional wakefield tails and their use is now avoided. At the end of the linac the energy spread is minimal and the emittance measurement is most sensitive to wakefield emittance dilution. In previous years, the emittances were tuned on wire scanners located near but not at the end of the linac (after about 90% of its length). Simulations show that emittance growth of up to 100% can occur in the remaining 10%. In this run wire scanners at the entrance of the Final Focus, the last place where the emittances can be measured, were used for the optimization. Screens at the end of the linac allow additional real time ...

  16. Emittance calculations for the Stanford Linear Collider injector

    International Nuclear Information System (INIS)

    Sheppard, J.C.; Clendenin, J.E.; Helm, R.H.; Lee, M.J.; Miller, R.H.; Blocker, C.A.

    1983-03-01

    A series of measurements have been performed to determine the emittance of the high intensity, single bunch beam that is to be injected into the Stanford Linear Collider. On-line computer programs were used to control the Linac for the purpose of data acquisition and to fit the data to a model in order to deduce the beam emittance. This paper will describe the method of emittance calculation and present some of the measurement results

  17. Electrode system design for acceleration of ion beam of given initial emittance

    International Nuclear Information System (INIS)

    Dzmuran, R.; Kuzmiak, M.; Novy, F.

    1986-01-01

    A method is described for calculating beam optical equipment, proceeding from the fact that the motion of the ion beam is in fact a transmission of emittance in the direction of the motion. The calculation of the transmission of emittance is simplified when we assume the transmission in the form of erect phase ellipses. The calculation procedure was used to design a system of electrodes for ion beam acceleration, consisting of three thick electrostatic lenses: an extracting, an accomodating and an accelerating lens. A graphical representation is given of the transmission of the erect phase ellipse through the individual lenses and through the whole system, and tabulated are values of the beam divergence, both in dependence on the voltage ratio on the electrodes. (A.K.)

  18. Beam emittance measurement from CERN thermionic guns

    International Nuclear Information System (INIS)

    Kester, O.; Rao, R.; Rinolfi, L.

    1992-01-01

    In the LEP Injector Linacs (LIL) a thermionic gun provides electron beams with different peak intensities at an energy of 80 keV. The beam emittances were estimated from the EGUN programme. Since the gun is of triode type, the main contribution to the emittance comes from the grid. The simulation programme does not model the real geometry by assuming a cylindrical symmetry, while the grid does not have such symmetry. A Gun Test Facility (GTF), allowing emittance measurements, based on the 3-gradients-method was installed. The experimental results are presented. (author) 6 refs.; 6 figs

  19. Multi-dimensional beam emittance and β-functions

    International Nuclear Information System (INIS)

    Buon, J.

    1993-05-01

    The concept of r.m.s. emittance is extended to the case of several degrees of freedom that are coupled. That multi-dimensional emittance is lower than the product of the emittances attached to each degree of freedom, but is conserved in a linear motion. An envelope-hyperellipsoid is introduced to define the β-functions of the beam envelope. On the contrary of an one-degree of freedom motion, it is emphasized that these envelope functions differ from the amplitude functions of the normal modes of motion as a result of the difference between the Liouville and Lagrange invariants. (author) 4 refs

  20. Many-electron effect in the resonant Auger electron spectroscopy spectra of adsorbates

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2007-01-01

    It is shown by a many-body theory that a resonantly excited core hole state in a chemisorbed molecule such as CO/Ni, CO/Pd, and CO/Pt relaxes to a fully relaxed one, i.e., the ionized core hole state of the smallest binding energy observed by photoelectron spectroscopy, before the core hole decays so that the resonant Auger electron spectroscopy (RAES) spectrum shows the normal Auger decay spectrum. It is shown by a many-body theory that the Auger peaks on the higher kinetic energy (K.E.) side in the RAES or AES spectrum, i.e., so called back-bonding peaks, are the two-hole states consisting of a valence hole and a hole in the adsorbate-substrate hybrid states below the substrate Fermi level. The latter hole is the change in the density of the hybrid states occupied by the screening electron from the core hole state to the valence-hole state. The difference between the back-bonding peak energy and the single valence-hole energy provides an important information about the change in the density of the hybrid states occupied by the screening electron from the core hole state to the valence-hole state. The difference between the RAES spectrum measured at the resonance energy and the AES spectrum measured at far above the ionization limit shows the competition between relaxation and decay of shakeup satellites such as the charge transfer (CT) shakeup. The relaxation rate of the CT shakeup state can be determined by Auger-photoelectron coincidence spectroscopy (APECS)

  1. Ultra-high energy cosmic rays. Results and status of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Christine [III. Physikalisches Institut A, RWTH Aachen University (Germany); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The Pierre Auger Observatory is the world's largest experiment detecting extensive air showers initiated by cosmic rays at the highest energies. An area of 3000 km{sup 2} is instrumented by 1660 water Cherenkov detector stations, and 27 fluorescence telescopes overlook the atmosphere above the surface detector array. A hybrid detection principle is achieved by utilizing information of both detectors. A major upgrade of the experiment (AugerPrime) has been decided adding a third detector type, scintillator detector stations located on the water Cherenkov tanks. Thereby, the composition sensitivity of the Pierre Auger Observatory is extended by an improved determination of the muonic shower component. Additionally, underground muon detectors (AMIGA) are deployed. The experiment has been further extended by antennas measuring the emission of radio signals from air showers (AERA). An overview about recent results and the current status of the experiment are given in this talk. Highlights are updated results, e.g. on the energy spectrum, chemical composition or proton-air cross section.

  2. Auger Electron Therapy And Brachytherapy Tumor Treatment

    International Nuclear Information System (INIS)

    Laster, B.H.; Shani, G.

    2002-01-01

    Auger Electron Therapy (AET) is a binary approach for improving cancer radiotherapy. It involves the selective targeting of an atom to tumor cells using physiological pathway. The atom is then irradiated by a specific radiation that produces secondary radiation called Auger electrons. One of the problems associated with the clinical application of AET, is that the energy of the photons required for stimulating photoelectric absorption in most of the available high Z target atoms, is too low to achieve penetration through normal surrounding tissues to the depth of the tumor, when an external source is used. The solution is therefore the use of a brachytherapy technique. There are two other problems associated with the use of radiation as a cancer treatment. The first is the limitation on radiation dose to the normal tissue within the treatment volume. The second problem is the limitation imposed by the miniscule size of the critical target of the cell, namely the DNA (0.25% of the cell mass). The solution to the first problem can be achieved by using the brachytherapy technique. The second problem can be resolved by placing the radiation source in close position to the DNA. AET, as we apply it, provides the two solutions to the two problems. When a photon is absorbed by an electron in the K or L shell of an high Z atom, the electron is ejected from the atom, creating a vacancy in the shell. This vacancy is immediately filled with an electron from an upper shell. The energy difference between the two shells is sometimes emitted as an x-ray, however, frequently the energy is transferred to an outer shell electron that is emitted as an Auger electron. These electrons are emitted at energies of up to ∼30 keV and therefore have a very short range in the cell. They will deposit all their energy within 20-30 nm from the point of emission. i.e. all the energy is deposited in the DNA. In our work indium is used as the high Z atom

  3. Determining the field emitter temperature during laser irradiation in the pulsed laser atom probe

    International Nuclear Information System (INIS)

    Kellogg, G.L.

    1981-01-01

    Three methods are discussed for determining the field emitter temperature during laser irradiation in the recently developed Pulsed Laser Atom Probe. A procedure based on the reduction of the lattice evaporation field with increasing emitter temperature is found to be the most convenient and reliable method between 60 and 500 K. Calibration curves (plots of the evaporation field versus temperature) are presented for dc and pulsed field evaporation of W, Mo, and Rh. These results show directly the important influence of the evaporation rate on the temperature dependence of the evaporation field. The possibility of a temperature calibration based on the ionic charge state distribution of field evaporated lattice atoms is also discussed. The shift in the charge state distributions which occurs when the emitter temperature is increased and the applied field strength is decreased at a constant rate of evaporation is shown to be due to the changing field and not the changing temperature. Nevertheless, the emitter temperature can be deduced from the charge state distribution for a specified evaporation rate. Charge state distributions as a function of field strength and temperature are presented for the same three materials. Finally, a preliminary experiment is reported which shows that the emitter temperature can be determined from field ion microscope observations of single atom surface diffusion over low index crystal planes. This last calibration procedure is shown to be very useful at higher temperatures (>600 K) where the other two methods become unreliable

  4. Beam phase space and emittance

    International Nuclear Information System (INIS)

    Buon, J.

    1992-02-01

    The classical and elementary results for canonical phase space, the Liouville theorem and the beam emittance are reviewed. Then, the importance of phase portraits to obtain a geometrical description of motion is emphasized, with examples in accelerator physics. Finally, a statistical point of view is used to define beam emittance, to study its law of approximate conservation, with three particular examples, and to introduce a beam envelope-ellipse and the β-function, emphasing the statistical features of its properties. (author) 14 refs.; 11 figs

  5. Combustion powered thermophotovoltaic emitter system

    Energy Technology Data Exchange (ETDEWEB)

    McHenry, R.S. [Naval Academy, Annapolis, MD (United States). Naval Architecture, Ocean and Marine Engineering

    1995-07-01

    The US Naval Academy (USNA) has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the high temperature requirements necessary for high system efficiency. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design.

  6. Many-body effect in the resonant Ti L23-M23V Auger-electron spectroscopy spectra and Auger-photoelectron coincidence spectroscopy spectra of Ti oxides

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2007-01-01

    Recently Danger et al. [J. Danger, H. Magnan, D. Chandesris, P. Le Fevre, S. Bourgeois, J. Jupille, A. Verdini, R. Gotter, A. Morgante, Phys. Rev. B 64 (2001) 045110] and Le Fevre et al. [P. Le Fevre, J. Danger, H. Magnan, D. Chandesris, J. Jupille, S. Bourgeois, M.-A. Arrio, R. Gotter, A. Verdini, A. Morgante, Phys. Rev. B 69 (2004) 155421] showed the absence of resonant Raman scattering feature in the Ti L 23 -M 23 V resonant Auger-electron spectroscopy (RAES) spectra of Ti oxides measured across the Ti 2p edges. They attributed the absence to the covalent character of the Ti-O bond which allows an effective delocalization of 3d electrons. It is shown by a many-body theory that when the time scale of relaxation of the resonantly excited core-hole state to the fully relaxed core-hole state is much shorter than that of core-hole decay, any sizeable Raman scattering is absent in the RAES spectra measured across the Ti 2p edges. The relaxation width depends on the hybridization strength and the charge transfer (CT) energy between the two states. The L 2 -L 3 V Coster-Kronig (CK) decay widths of TiO 2 and TiO 2-x are determined from the L 23 -M 23 V Auger-photoelectron coincidence spectroscopy (APECS) spectra reported in the aforementioned papers. They are about 0.18 and 0.35 eV, respectively. The CK-decay width in the reduced Ti oxide increases compared to that of TiO 2 in rutile because of filling of the 3d states just below the Fermi level in the former

  7. Measurement of Auger electron energies and intensities from muonic transitions in silver

    International Nuclear Information System (INIS)

    Callies, R.; Daniel, H.; Egidy, T. von; Hagn, H.; Hartmann, F.J.; Neumann, W.

    1983-01-01

    There is now general agreement that Coulomb capture of mesonic particles and deexcitation of the formed exotic atom must be accompanied by Auger electron emission. Auger electrons from a thin silver foil were counted by Si-pn-junction detectors with an extraordinarily thin dead layer. Lines could be resolved and intensity ratios determined. Two types of experiments were performed simultaneously, (I) with the slow-muon telescope in coincidence with any e - detector of the array and (II) as above but with an additional Ag X-ray coincidence from a Ge(Li) detector placed close to the target. (Auth.)

  8. Coupling single emitters to quantum plasmonic circuits

    DEFF Research Database (Denmark)

    Huck, Alexander; Andersen, Ulrik Lund

    2016-01-01

    In recent years, the controlled coupling of single-photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic nonlinearity on a nanoscaled platform. In this article, we will review the recent progress on coupling single emitters...

  9. Auger processes in tracks of fast multicharged ions

    International Nuclear Information System (INIS)

    Katin, V.V.; Martynenko, Yu.V.; Yavlinskij, Yu.N.

    1992-01-01

    The fast multicharged ion spends about 40% of energy losses on vacancy creation in the inner electron shells. This energy is transferred to the kinetic energy of electrons due to the cascade of Auger processes during ∼ 10 -14 s whereas the primary excited electrons receive the energy in ∼10 -16 s. (author)

  10. Study of the Auger line shape of polyethylene and diamond

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M; Pepper, S V

    1984-03-01

    The KVV Auger electron line shapes of carbon in polyethylene and diamond have been studied. The spectra were obtained in derivative form by electron beam excitation. They were treated by background subtraction, integration and deconvolution to produce the intrinsic Auger line shape. Electron energy loss spectra provided the response function in the deconvolution procedure. The line shape from polyethylene is compared with spectra from linear alkanes and with a previous spectrum of Kelber et al. Both spectra are compared with the self-convolution of their full valence band densities of states and of their p-projected densities. The experimental spectra could not be understood in terms of existing theories. This is so even when correlation effects are qualitatively taken into account according to the theories of Cini and Sawatzky and Lenselink.

  11. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  12. Ultrahigh Energy Neutrinos at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    P. Abreu

    2013-01-01

    Full Text Available The observation of ultrahigh energy neutrinos (UHEνs has become a priority in experimental astroparticle physics. UHEνs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ν or in the Earth crust (Earth-skimming ν, producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere. In this work we review the procedure and criteria established to search for UHEνs in the data collected with the ground array of the Pierre Auger Observatory. This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEνs in the EeV range and above.

  13. Measurement of transverse emittance in the Fermilab booster

    Energy Technology Data Exchange (ETDEWEB)

    Graves, William Sproull [Wisconsin U., Madison

    1994-01-01

    A new beam profile monitor has been built and installed in the Fermilab Booster synchrotron. It nondestructively measures the beam's vertical density distribution on a fast turn-by-turn basis. This enables one to measure the beam's transverse emittance and to observe emittance growth as it occurs. For high intensities (>2 times 10^{12 } protons), the normalized 95% emittance was observed to grow from 6pi mm-mrad at injection to 16pi mm-mrad at extraction. The initial (<5 msec) emittance growth and beam losses are shown to be caused by the space charge tune shift onto integer and 1/2 integer resonance lines. The growth near injection accounts for approximately 40% of the observed emittance increase throughout the acceleration cycle. The remaining 60% is due to two factors: slow linear growth due to betatron-motion driven by noise in the rf system; and faster growth after the transition energy that is caused by coupling of the longitudinal beam motion into the transverse planes.

  14. James Cronin, CP Violation, and the Pierre Auger Observatory

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis James Cronin, CP Violation and the Pierre Auger Observatory matter over antimatter."1 "The experiment uncovered the CP [charge-parity] violation, or a with Additional Information Additional information about James Cronin and the charge-parity (CP

  15. A new route to nanoscale tomographic chemical analysis: Focused ion beam-induced auger electron spectrosocpy

    Science.gov (United States)

    Parvaneh, Hamed

    technique both spatially (x-y) and in depth (z) were also evaluated. For spatial resolution mainly the Monte Carlo simulations were utilized to estimate the area from which the excited target atoms with inner shell vacancies originate. Attention was paid to the relationship between the Auger electron infor-mation depth and the depth-dependency of various energy-loss mechanisms for the incoming ions. In particular, an area from which target atoms with energies higher than a threshold energy sputter off the surface, was concluded to be an estimate for lateral spatial resolution. Finally the effects of hardware parameters, in particular the solid angle of the detector and the transmission of the electron energy analyzer, on the collected signal were characterized and used to put together an estimate for the edge length of an information cube representing the minimum amount of material that has to be removed before a meaningful signal can be collected.

  16. Electromagnetic compatibility of implantable neurostimulators to RFID emitters.

    Science.gov (United States)

    Pantchenko, Oxana S; Seidman, Seth J; Guag, Joshua W; Witters, Donald M; Sponberg, Curt L

    2011-06-09

    The objective of this study is to investigate electromagnetic compatibility (EMC) of implantable neurostimulators with the emissions from radio frequency identification (RFID) emitters. Six active implantable neurostimulators with lead systems were tested for susceptibility to electromagnetic fields generated by 22 RFID emitters. These medical devices have been approved for marketing in the U.S. for a number of intended uses that include: epilepsy, depression, incontinence, Parkinsonian tremor and pain relief. Each RFID emitter had one of the following carrier frequencies: 125 kHz, 134 kHz, 13.56 MHz, 433 MHz, 915 MHz and 2.45 GHz. The test results showed the output of one of the implantable neurostimulators was inhibited by 134 kHz RFID emitter at separation distances of 10 cm or less. The output of the same implantable neurostimulator was also inhibited by another 134 kHz RFID emitter at separation distances of 10 cm or less and also showed inconsistent pulsing rate at a separation distance of 15 cm. Both effects occurred during and lasted through out the duration of the exposure. The clinical significance of the effects was assessed by a clinician at the U.S. Food and Drug Administration. The effects were determined to be clinically significant only if they occurred for extended period of time. There were no observed effects from the other 5 implantable neurostimulators or during exposures from other RFID emitters.

  17. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  18. Electronic excitation and Auger spectroscopy of hexamethyldissilane

    International Nuclear Information System (INIS)

    Souza, G.G.B. de; Azevedo e Souza, A.C. de; Martins, R.J.; Lucas, C.A.

    1988-01-01

    In this work, it is presented an spectroscopic study of Si 2 (CH 3 ) 6 which presents interesting characteristics in the Si - Si bond. Electron energy loss technique was used in the energy range of 500 - 200 eV for the electron beam. Electronic excitation spectra were obtained for the energy loss range from 5 to 30 eV, and also Auger spectra. (A.C.A.S.) [pt

  19. Photovoltaic investigation of minority carrier lifetime in the heavily-doped emitter layer of silicon junction solar cell

    Science.gov (United States)

    Ho, C.-T.

    1982-01-01

    The results of experiments on the recombination lifetime in a phosphorus diffused N(+) layer of a silicon solar cell are reported. The cells studied comprised three groups of Czochralski grown crystals: boron doped to one ohm-cm, boron doped to 6 ohm-cm, and aluminum doped to one ohm-cm, all with a shunt resistance exceeding 500 kilo-ohms. The characteristic bulk diffusion length of a cell sample was determined from the short circuit current response to light at a wavelength of one micron. The recombination rates were obtained by measurement of the open circuit voltage as a function of the photogeneration rate. The recombination rate was found to be dependent on the photoinjection level, and is positive-field controlled at low photoinjection, positive-field influence Auger recombination at a medium photoinjection level, and negative-field controlled Auger recombination at a high photoinjection level.

  20. Self-powered detectors with thulium emitter

    International Nuclear Information System (INIS)

    Haller, P.; Klar, E.

    1978-01-01

    In addition to fission chambers, prompt-indicating self-powered (SPN) detectors are used for measuring the neutron flux density in the core of power reactors. Although current SPN detectors with a cobalt emitter give satisfactora results, detectors with other emitter materials have been analyzed and tested. The author describes the properties and decay pattern of the nuclide thulium and presents the results of measurements made while testing thulium detectors. (orig.) [de

  1. Coherent single-photon absorption by single emitters coupled to one-dimensional nanophotonic waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yuntian; Wubs, Martijn; Moerk, Jesper [DTU Fotonik, Department of Photonics Engineering, Oersteds Plads, DK-2800 Kgs Lyngby (Denmark); Koenderink, A Femius, E-mail: yche@fotonik.dtu.dk [Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics (AMOLF), Science Park 104, 1098 XG Amsterdam (Netherlands)

    2011-10-15

    We study the dynamics of single-photon absorption by a single emitter coupled to a one-dimensional waveguide that simultaneously provides channels for spontaneous emission (SE) decay and a channel for the input photon. We have developed a time-dependent theory that allows us to specify any input single-photon wavepacket guided by the waveguide as the initial condition, and calculate the excitation probability of the emitter, as well as the time evolution of the transmitted and reflected fields. For single-photon wavepackets with a Gaussian spectrum and temporal shape, we obtain analytical solutions for the dynamics of absorption, with maximum atomic excitation {approx}40%. We furthermore propose a terminated waveguide to aid the single-photon absorption. We found that for an emitter placed at an optimal distance from the termination, the maximum atomic excitation due to an incident single-photon wavepacket can exceed 70%. This high value is a direct consequence of the high SE {beta}-factor for emission into the waveguide. Finally, we have also explored whether waveguide dispersion could aid single-photon absorption by pulse shaping. For a Gaussian input wavepacket, we found that the absorption efficiency can be improved by a further 4% by engineering the dispersion. Efficient single-photon absorption by a single emitter has potential applications in quantum communication and quantum computation. (paper)

  2. Study by Auger spectrometry and mass spectrometry of the chemisorption of carbon monoxide on polycrystalline molybdenum

    International Nuclear Information System (INIS)

    Gillet, E.; Chiarena, J.C.; Gillet, M.

    1976-01-01

    A combination of Auger spectrometry and mass spectrometry was employed to study CO chemisorption on polycrystalline Mo surfaces at room temperature. Five adsorption states were observed and the binding parameters (E,n 0 ,tau 0 ) were calculated for the three important states. The results obtained by the two methods are in accord but the occurence of electronic desorption in Auger experiments was pointed out. Contamination effects by C atoms in such studies were investigated by repeated cycles of adsorption-desorption and a characteristic evolution of flash desorption was observed. The results are discussed in this point of view enhancing the importance of a control of the adsorption surface cleanness by a method of great sensibility like Auger spectrometry. (Auth.)

  3. Localization of Narrowband Single Photon Emitters in Nanodiamonds.

    Science.gov (United States)

    Bray, Kerem; Sandstrom, Russell; Elbadawi, Christopher; Fischer, Martin; Schreck, Matthias; Shimoni, Olga; Lobo, Charlene; Toth, Milos; Aharonovich, Igor

    2016-03-23

    Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bioimaging. However, current understanding of the origin of these emitters is extremely limited. In this work, we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond and are directly relevant to fabrication of novel quantum optics devices and sensors.

  4. Innovative energy efficient low-voltage electron beam emitters

    International Nuclear Information System (INIS)

    Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

    2002-01-01

    Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates

  5. Innovative energy efficient low-voltage electron beam emitters

    Science.gov (United States)

    Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

    2002-03-01

    Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates.

  6. 30 CFR 941.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 941.819 Section 941.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE SOUTH DAKOTA...

  7. 30 CFR 921.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 921.819 Section 921.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE MASSACHUSETTS...

  8. 30 CFR 922.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 922.819 Section 922.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE MICHIGAN...

  9. 30 CFR 942.819 - Special performance standards-Auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-Auger mining. 942.819 Section 942.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE TENNESSEE...

  10. 30 CFR 905.819 - Special performance standards-Auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-Auger mining. 905.819 Section 905.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE CALIFORNIA...

  11. 30 CFR 933.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 933.819 Section 933.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE NORTH...

  12. 30 CFR 939.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 939.819 Section 939.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE RHODE ISLAND...

  13. 30 CFR 947.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 947.819 Section 947.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE WASHINGTON...

  14. Influence of emitter temperature on the energy deposition in a low-pressure plasma

    International Nuclear Information System (INIS)

    Levko, Dmitry; Raja, Laxminarayan L.

    2016-01-01

    The influence of emitter temperature on the energy deposition into low-pressure plasma is studied by the self-consistent one-dimensional Particle-in-Cell Monte Carlo Collisions model. Depending on the emitter temperature, different modes of discharge operation are obtained. The mode type depends on the plasma frequency and does not depend on the ratio between the densities of beam and plasma electrons. Namely, plasma is stable when the plasma frequency is small. For this plasma, the energy transfer from emitted electrons to plasma electrons is inefficient. The increase in the plasma frequency results first in the excitation of two-stream electron instability. However, since the thermal velocity of plasma electrons is smaller than the electrostatic wave velocity, the resonant wave-particle interaction is inefficient for the energy deposition into the plasma. Further increase in the plasma frequency leads to the distortion of beam of emitted electrons. Then, the electrostatic wave generated due to two-stream instability decays into multiple slower waves. Phase velocities of these waves are comparable with the thermal velocity of plasma electrons which makes possible the resonant wave-particle interaction. This results in the efficient energy deposition from emitted electrons into the plasma.

  15. Auger electron spectroscopy studies of boron carbide

    International Nuclear Information System (INIS)

    Madden, H.H.; Nelson, G.C.; Wallace, W.O.

    1986-01-01

    Auger electron spectroscopy has been used to probe the electronic structure of ion bombardment (IB) cleaned surfaces of B 9 C and B 4 C samples. The shapes of the B-KVV and C-KVV Auger lines were found to be relatively insensitive to the bulk stoichiometry of the samples. This indicates that the local chemical environments surrounding B and C atoms, respectively, on the surfaces of the IB cleaned samples do not change appreciably in going from B 9 C to B 4 C. Fracturing the sample in situ is a way of producing a clean representative internal surface to compare with the IB surfaces. Microbeam techniques have been used to study a fracture surface of the B 9 C material with greater spatial resolution than in our studies of IB surfaces. The B 9 C fracture surface was not homogeneous and contained both C-rich and B-rich regions. The C-KVV line for the C-rich regions was graphitic in shape. Much of the C-rich regions was found by IB to be less than 100 nm in thickness. The C-KVV line from the B-rich regions was carbidic and did not differ appreciably in shape from those recorded for the IB cleaned surfaces

  16. Theoretical studies of thermionic conversion of solar energy with graphene as emitter and collector

    Science.gov (United States)

    Olawole, Olukunle C.; De, Dilip Kumar

    2018-01-01

    Thermionic energy conversion (TEC) using nanomaterials is an emerging field of research. It is known that graphene can withstand temperatures as high as 4600 K in vacuum, and it has been shown that its work function can be engineered from a high value (for monolayer/bilayer) of 4.6 eV to as low as 0.7 eV. Such attractive electronic properties (e.g., good electrical conductivity and high dielectric constant) make engineered graphene a good candidate as an emitter and collector in a thermionic energy converter for harnessing solar energy efficiently. We have used a modified Richardson-Dushman equation and have adopted a model where the collector temperature could be controlled through heat extraction in a calculated amount and a magnet can be attached on the back surface of the collector for future control of the space-charge effect. Our work shows that the efficiency of solar energy conversion also depends on power density falling on the emitter surface, and that a power conversion efficiency of graphene-based solar TEC as high as 55% can be easily achieved (in the absence of the space-charge effect) through proper choice of work functions, collector temperature, and emissivity of emitter surfaces. Such solar energy conversion would reduce our dependence on silicon solar panels and offers great potential for future renewable energy utilization.

  17. Measurement of emittance of metal interface in molten salt

    International Nuclear Information System (INIS)

    Araki, N.; Makino, A.; Nakamura, Y.

    1995-01-01

    A new technique for measuring the total normal emittance of a metal in a semi-transparent liquid has been proposed and this technique has been applied to measure the emittance of stainless steel (SUS304), nickel, and gold in molten potassium nitrate KNO 3 . These emittance data are indispensable to analyzing the radiative heat transfer between a metal and a semitransparent liquid, such as a molten salt

  18. Boundary conditions on the plasma emitter surface in the presence of a particle counter flow: I. Ion emitter

    Energy Technology Data Exchange (ETDEWEB)

    Astrelin, V. T., E-mail: V.T.Astrelin@inp.nsk.su; Kotelnikov, I. A. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2017-02-15

    Emission of positively charged ions from a plasma emitter irradiated by a counterpropagating electron beam is studied theoretically. A bipolar diode with a plasma emitter in which the ion temperature is lower than the electron temperature and the counter electron flow is extracted from the ion collector is calculated in the one-dimensional model. An analog of Bohm’s criterion for ion emission in the presence of a counterpropagating electron beam is derived. The limiting density of the counterpropagating beam in a bipolar diode operating in the space-charge-limited-emission regime is calculated. The full set of boundary conditions on the plasma emitter surface that are required for operation of the high-current optics module in numerical codes used to simulate charged particle sources is formulated.

  19. X-ray photoelectron and x-ray-induced Auger electron spectroscopic data, 1

    International Nuclear Information System (INIS)

    Baba, Yuji; Sasaki, T.A.

    1984-02-01

    The intrinsic data of the X-ray photoelectron spectra (XPS) and X-ray-induced Auger electron spectra (XAES) for 3d transition-metals and related oxides were presented. The clean surfaces of the metals were obtained by two different methods ; mechanical filings and Ar + ion etchings. The oxides examined are typical compounds such as Sc 2 O 3 , TiO 2 , V 2 O 5 and NiO. The report consists of 4 wide scans, 26 core-line spectra, 10 valence-band spectra and 20 XAES spectra. The peak positions of the core-lines and the Auger lines were summarized in 8 tables together with their chemical shifts. (author)

  20. Electromagnetic compatibility of implantable neurostimulators to RFID emitters

    Directory of Open Access Journals (Sweden)

    Guag Joshua W

    2011-06-01

    Full Text Available Abstract Background The objective of this study is to investigate electromagnetic compatibility (EMC of implantable neurostimulators with the emissions from radio frequency identification (RFID emitters. Methods Six active implantable neurostimulators with lead systems were tested for susceptibility to electromagnetic fields generated by 22 RFID emitters. These medical devices have been approved for marketing in the U.S. for a number of intended uses that include: epilepsy, depression, incontinence, Parkinsonian tremor and pain relief. Each RFID emitter had one of the following carrier frequencies: 125 kHz, 134 kHz, 13.56 MHz, 433 MHz, 915 MHz and 2.45 GHz Results The test results showed the output of one of the implantable neurostimulators was inhibited by 134 kHz RFID emitter at separation distances of 10 cm or less. The output of the same implantable neurostimulator was also inhibited by another 134 kHz RFID emitter at separation distances of 10 cm or less and also showed inconsistent pulsing rate at a separation distance of 15 cm. Both effects occurred during and lasted through out the duration of the exposure. Conclusions The clinical significance of the effects was assessed by a clinician at the U.S. Food and Drug Administration. The effects were determined to be clinically significant only if they occurred for extended period of time. There were no observed effects from the other 5 implantable neurostimulators or during exposures from other RFID emitters.

  1. 30 CFR 903.819 - Special performance standards-Auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-Auger mining. 903.819 Section 903.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE ARIZONA § 903...

  2. 30 CFR 937.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 937.819 Section 937.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE OREGON § 937...

  3. 30 CFR 910.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 910.819 Section 910.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE GEORGIA § 910...

  4. 30 CFR 912.819 - Special performance standards-auger mining.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Special performance standards-auger mining. 912.819 Section 912.819 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE IDAHO § 912...

  5. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    Science.gov (United States)

    Pierre Auger Collaboration; Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; D\\'\\iaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garc\\'\\ia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agëra, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Mart\\'\\inez Bravo, O.; Martraire, D.; Mas\\'\\ias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodr\\'\\iguez-Fr\\'\\ias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiał kowski, A.; Šm\\'\\ida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2014-08-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  6. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    2014-01-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory

  7. Single-shot measurements of low emittance beams from laser-plasma accelerators comparing two triggered injection methods

    Science.gov (United States)

    van Tilborg, Jeroen

    2017-10-01

    The success of laser plasma accelerator (LPA) based applications, such as a compact x-ray free electron laser (FEL), relies on the ability to produce electron beams with excellent 6D brightness, where brightness is defined as the ratio of charge to the product of the three normalized emittances. As such, parametric studies of the emittance of LPA generated electron beams are essential. Profiting from a stable and tunable LPA setup, combined with a carefully designed single-shot energy-dispersed emittance diagnostic, we present a direct comparison of charge dependent emittance measurements of electron beams generated by two different injection mechanisms: ionization injection and shock-induced density down-ramp injection. Both injection mechanisms have gained in popularity in recent years due to their demonstrated stable LPA performance. For the down-ramp injection configuration, normalized emittances a factor of two lower were recorded: less than 1 micron at spectral charge densities up to 2 pC/MeV. For both injection mechanisms, a contributing correlation of space charge to the emittance was identified. This measurement technique in general, and these results specifically, are critical to the evaluation of LPA injection methods and development of high-quality LPA beam lines worldwide. This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231, by the U.S. DOE NNSA, DNN R&D (NA22), by the National Science Foundation under Grant No. PHY-1415596, and by the Gordon and Betty Moore Foundation under Grant ID GBMF4898.

  8. A polarization-insensitive plasmonic photoconductive terahertz emitter

    KAUST Repository

    Li, Xurong

    2017-11-16

    We present a polarization-insensitive plasmonic photoconductive terahertz emitter that uses a two-dimensional array of nanoscale cross-shaped apertures as the plasmonic contact electrodes. The geometry of the cross-shaped apertures is set to maximize optical pump absorption in close proximity to the contact electrodes. The two-dimensional symmetry of the cross-shaped apertures offers a polarization-insensitive interaction between the plasmonic contact electrodes and optical pump beam. We experimentally demonstrate a polarization-insensitive terahertz radiation from the presented emitter in response to a femtosecond optical pump beam and similar terahertz radiation powers compared to previously demonstrated polarization-sensitive photoconductive emitters with plasmonic contact electrode gratings at the optimum optical pump polarization.

  9. Emittance measurement for high-brightness electron guns

    International Nuclear Information System (INIS)

    Kobayashi, H.; Kurihara, T.; Sato, I.; Asami, A.; Yamazaki, Y.; Otani, S.; Ishizawa, Y.

    1992-01-01

    An emittance measurement system based on a high-precision pepper-pot technique has been developed for electron guns with low emittance of around πmm-mrad. Electron guns with a 1 mmφ cathode, the material of which is impregnated tungsten or single-crystal lanthanum hexaboride (La 1-x Ce x )B 6 , have been developed. The performance has been evaluated by putting stress on cathode roughness, which gives rise to an angular divergence, according to the precise emittance measurement system. A new type of cathode holder, which is a modified version of the so called Vogel type, was developed and the beam uniformity has been improved. (Author) 5 figs., tab., 9 refs

  10. Two and three electron Auger transitions in collisions of highly-charged ions with surfaces

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Andriamonje, S.; Andrae, H.J.

    1991-01-01

    The Auger electron spectra from Ar 9+ approaching at 265 eV a Si or metal surface in vacua of 10 -5 Pa or UHV are identical. Experiments on atomic physics in front of surfaces are thus possible in standard vacuum. N 7+ approaching a surface at 1000 eV penetrates with great probability into the bulk and gives rise to K 2 L 2 L double Auger lines, observed for the first time with low energy highly charged ions. (orig.)

  11. Interatomic Coulombic decay following the Auger decay: Experimental evidence in rare-gas dimers

    International Nuclear Information System (INIS)

    Ueda, K.; Fukuzawa, H.; Liu, X.-J.; Sakai, K.; Pruemper, G.; Morishita, Y.; Saito, N.; Suzuki, I.H.; Nagaya, K.; Iwayama, H.; Yao, M.; Kreidi, K.; Schoeffler, M.; Jahnke, T.; Schoessler, S.; Doerner, R.; Weber, Th.; Harries, J.; Tamenori, Y.

    2008-01-01

    Interatomic Coulombic decay (ICD) in Ar 2 , ArKr and Kr 2 following Ar 2p or Kr 3d Auger decay has been investigated by means of momentum-resolved electron-ion-ion coincidence spectroscopy. This sequential decay leads to Coulombic dissociation into dication and monocation. Simultaneously determining the kinetic energy of the ICD electron and the kinetic energy release between the two atomic ions, we have been able to unambiguously identify the ICD channels. We find that, in general, spin-conserved ICD, in which the singlet (triplet) dicationic state produced via the atomic Auger decay preferentially decays to the singlet (triplet) state, transferring the energy to the other atom, is faster than spin-flip ICD, in which the Auger final singlet (triplet) dicationic state decays to the triplet (singlet) state. However, spin-flip ICD may take place when spin-conserved ICD becomes energetically forbidden. Dipole-forbidden ICDs from Kr 2+ (4s -21 S)-B (B = Ar or Kr) to Kr 2+ (4p -21 D, 3 P)-B + are also observed

  12. Emittance formula for slits and pepper-pot measurement

    International Nuclear Information System (INIS)

    Zhang, M.

    1996-10-01

    In this note, a rigid formula for slits and pepper-pot emittance measurement is derived. The derivation is based on the one- dimensional slit measurement setup. A mathematical generalization of the slit emittance formula to the pepper-pot measurement is discussed

  13. MEV Energy Electrostatic Accelerator Ion Beam Emittance Measurement

    OpenAIRE

    I.G. Ignat’ev; M.I. Zakharets; S.V. Kolinko; D.P. Shulha

    2014-01-01

    The testing equipment was designed, manufactured and tried out permitting measurements of total current, current profile and emittance of an ion beam extracted from the ion beam. MeV energy electrostatic accelerator ion H + beam emittance measurement results are presented.

  14. Alpha-emitters for medical therapy workshop

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; McClure, J.J.

    1996-01-01

    A workshop on ''Alpha-Emitters for Medical Therapy'' was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference

  15. Alpha-emitters for medical therapy workshop

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E.; McClure, J.J.

    1996-12-31

    A workshop on ``Alpha-Emitters for Medical Therapy`` was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference.

  16. Design for a practical, low-emittance damping ring

    International Nuclear Information System (INIS)

    Krejcik, P.

    1988-01-01

    The luminosity requirements for future high-energy linear colliders calls for very low emittances in the two beams. These low emittances can be achieved with damping rings, but, in order to reach the design goal of a factor 10 improvement over present day machines, great care must be taken in their design. This paper emphasizes the need to address simultaneously all of the factors which limit the operational emittance in the ring. Particularly since in standard designs there is a conflict between different design parameters which makes it difficult to extrapolate such designs to very low emittances. The approach chosen here is to resolve such conflicts by separating their design solutions. Wigglers are used predominantly in zero-dispersion regions to achieve the desired damping rate, whereas in the arcs high dispersion insertions are made in regions of zero curvature to allow for easier chromaticity control

  17. Design of a minimum emittance nBA lattice

    Science.gov (United States)

    Lee, S. Y.

    1998-04-01

    An attempt to design a minimum emittance n-bend achromat (nBA) lattice has been made. One distinct feature is that dipoles with two different lengths were used. As a multiple bend achromat, five bend achromat lattices with six superperiod were designed. The obtained emittace is three times larger than the theoretical minimum. Tunes were chosen to avoid third order resonances. In order to correct first and second order chromaticities, eight family sextupoles were placed. The obtained emittance of five bend achromat lattices is almost equal to the minimum emittance of five bend achromat lattice consisting of dipoles with equal length.

  18. Remote detection of single emitters via optical waveguides

    Science.gov (United States)

    Then, Patrick; Razinskas, Gary; Feichtner, Thorsten; Haas, Philippe; Wild, Andreas; Bellini, Nicola; Osellame, Roberto; Cerullo, Giulio; Hecht, Bert

    2014-05-01

    The integration of lab-on-a-chip technologies with single-molecule detection techniques may enable new applications in analytical chemistry, biotechnology, and medicine. We describe a method based on the reciprocity theorem of electromagnetic theory to determine and optimize the detection efficiency of photons emitted by single quantum emitters through truncated dielectric waveguides of arbitrary shape positioned in their proximity. We demonstrate experimentally that detection of single quantum emitters via such waveguides is possible, confirming the predicted behavior of the detection efficiency. Our findings blaze the trail towards efficient lensless single-emitter detection compatible with large-scale optofluidic integration.

  19. ¹¹¹In-Bn-DTPA-nimotuzumab with/without modification with nuclear translocation sequence (NLS) peptides: an Auger electron-emitting radioimmunotherapeutic agent for EGFR-positive and trastuzumab (Herceptin)-resistant breast cancer.

    Science.gov (United States)

    Fasih, Aisha; Fonge, Humphrey; Cai, Zhongli; Leyton, Jeffrey V; Tikhomirov, Ilia; Done, Susan J; Reilly, Raymond M

    2012-08-01

    Increased expression of epidermal growth factor receptors (EGFR) in breast cancer (BC) is often associated with trastuzumab (Herceptin)-resistant forms of the disease and represents an attractive target for novel therapies. Nimotuzumab is a humanized IgG(1) monoclonal antibody that is in clinical trials for treatment of EGFR-overexpressing malignancies. We show here that nimotuzumab derivatized with benzylisothiocyanate diethylenetriaminepentaacetic acid for labelling with the subcellular range Auger electron-emitter, (111)In and modified with nuclear translocation sequence (NLS) peptides ((111)In-NLS-Bn-DTPA-nimotuzumab) was bound, internalized and transported to the nucleus of EGFR-positive BC cells. Emission of Auger electrons in close proximity to the nucleus caused multiple DNA double-strand breaks which diminished the clonogenic survival (CS) of MDA-MB-468 cells that have high EGFR density (2.4 × 10(6) receptors/cell) to less than 3 %. (111)In-Bn-DTPA-nimotuzumab without NLS peptide modification was sevenfold less effective for killing MDA-MB-468 cells. (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification were equivalently cytotoxic to MDA-MB-231 and TrR1 BC cells that have moderate EGFR density (5.4 × 10(5) or 4.2 × 10(5) receptors/cell, respectively) reducing their CS by twofold. MDA-MB-231 cells have intrinsic trastuzumab resistance due to low HER2 density, whereas TrR1 cells have acquired resistance despite HER2 overexpression. Biodistribution and microSPECT/CT imaging revealed that (111)In-NLS-Bn-DTPA-nimotuzumab exhibited more rapid elimination from the blood and lower tumour uptake than (111)In-Bn-DTPA-nimotuzumab. Tumour uptake of the radioimmunoconjugates in mice with MDA-MB-468 xenografts was high (8-16 % injected dose/g) and was blocked by administration of an excess of unlabelled nimotuzumab, demonstrating EGFR specificity. We conclude that (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification are promising Auger

  20. Design of a low emittance and high repetition rate S-band photoinjector

    Science.gov (United States)

    Han, Jang-Hui

    2014-09-01

    As an electron beam injector of X-ray free-electron lasers (FELs), photoinjectors have been developed for the past few decades. Such an injector starting with a photocathode RF gun provides high brightness beams and therefore it is being adopted as an injector of X-ray FELs. In this paper we show how to improve photoinjector performance in terms of emittance and repetition rates by means of injector components optimization, especially with the gun. Transverse emittance at the end of an injector is reduced by optimizing the gun design, gun solenoid position, and accelerating section position. The repetition rate of an injector mainly depends on the gun. It is discussed that a repetition rate of 1 kHz at a normal-conducting S-band photoinjector is feasible by adopting a coaxial RF coupler and improving cooling-water channels surrounding the gun.

  1. Jamming of Quantum Emitters by Active Coated Nanoparticles

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Ziolkowski, Richard W.

    2013-01-01

    to effectively cloak the emitters to a far-field observer is reported and explained through thorough near- and far-field investigations. This property offers an interesting route toward the jamming of quantum emitters/nanoantennas that might be of potential use, for instance, in biological fluorescence assays...

  2. Transverse Emittance Measurement and Preservation at the LHC

    CERN Document Server

    AUTHOR|(CDS)2082907

    The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation will be discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constra...

  3. Emittance increase caused by core depletion in collisions

    CERN Document Server

    Bruce, R

    2009-01-01

    A new effect is presented, which changes the emittance during colliding-beam operation in circular colliders. If the initial transverse distribution is Gaussian, the collision probability is much higher for particles in the core of the beam than in the tails. When small-amplitude particles are removed, the remaining ones therefore have a larger transverse emittance. This effect, called core depletion, may cause a decrease in luminosity. An approximate analytic model is developed to study the effect and benchmarked against a multiparticle tracking simulation. Finally, the time evolution of the intensity and emittances of a Pb bunch in the Large Hadron Collider (LHC) at CERN is calculated, taking into account also other processes than collisions. The results show that integrated luminosity drops by 3--4% if core depletion is taken into account. It is also found that core depletion causes the transverse emittance to be larger when more experiments are active. This observation could be checked against experimenta...

  4. Selective solar absorber emittance measurement at elevated temperature

    Science.gov (United States)

    Giraud, Philémon; Braillon, Julien; Raccurt, Olivier

    2017-06-01

    Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The characterization of a material in such condition is complicated and requires advanced apparatuses, and different measurement methods exist for the determination of the two quantities of relevance regarding an absorber, which are its emittance and its solar absorbance. The objective is to develop new optical equipment for measure the emittance of this solar absorber at elevated temperature. In this paper, we present an optical bench developed for emittance measurement on absorbers is conditions of use. Results will be shown, with a discussion of some factors of influence over this measurement and how to control them.

  5. Strong coupling of collection of emitters on hyperbolic meta-material

    Science.gov (United States)

    Biehs, Svend-Age; Xu, Chenran; Agarwal, Girish S.

    2018-04-01

    Recently, considerable effort has been devoted to the realization of a strong coupling regime of the radiation matter interaction in the context of an emitter at a meta surface. The strong interaction is well realized in cavity quantum electrodynamics, which also show that strong coupling is much easier to realize using a collection of emitters. Keeping this in mind, we study if emitters on a hyperbolic meta materials can yield a strong coupling regime. We show that strong coupling can be realized for densities of emitters exceeding a critical value. A way to detect strong coupling between emitters and hyperbolic metamaterials is to use the Kretschman-Raether configuration. The strong coupling appears as the splitting of the reflectivity dip. In the weak coupling regime, the dip position shifts. The shift and splitting can be used to sense active molecules at surfaces.

  6. Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; /Lisbon, IST; Aglietta, M.; /Turin U. /INFN, Turin; Ahlers, M.; /Wisconsin U., Madison; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Buenos Aires, CONICET; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Almela, A.; /Natl. Tech. U., San Nicolas /Buenos Aires, CONICET; Alvarez Castillo, J.; /Mexico U., ICN /Santiago de Compostela U.

    2012-01-01

    Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown.

  7. Measurement of the Auger decay after resonance excitation of Xe 4d and Kr 3d resonance lines

    International Nuclear Information System (INIS)

    Eberhardt, W.; Kalkoffen, G.; Kunz, C.

    1978-03-01

    The Nsub(4,5) 0sub(2,3) 0sub(2,3) Auger spectra from Xe and the Msub(4,5) Nsub(2,3) Nsub(2,3) Auger spectra from Kr are investigated for different photon energies around threshold of ionization. When exciting at the resonance line (4d 9 5s 2 5p 6 6p for Xe and 3d 9 4s 2 4p 6 5p for Kr) we observe the usual Auger multiplet structure to be shifted to higher kinetic energies. Additionally, new lines appear which can be assigned to shake-up processes int he Xe + and Kr + ions. (orig.) [de

  8. Radial arrays of nano-electrospray ionization emitters and methods of forming electrosprays

    Science.gov (United States)

    Kelly, Ryan T [West Richland, WA; Tang, Keqi [Richland, WA; Smith, Richard D [Richland, WA

    2010-10-19

    Electrospray ionization emitter arrays, as well as methods for forming electrosprays, are described. The arrays are characterized by a radial configuration of three or more nano-electrospray ionization emitters without an extractor electrode. The methods are characterized by distributing fluid flow of the liquid sample among three or more nano-electrospray ionization emitters, forming an electrospray at outlets of the emitters without utilizing an extractor electrode, and directing the electrosprays into an entrance to a mass spectrometry device. Each of the nano-electrospray ionization emitters can have a discrete channel for fluid flow. The nano-electrospray ionization emitters are circularly arranged such that each is shielded substantially equally from an electrospray-inducing electric field.

  9. Low emittance lattices for electron storage rings revisited

    International Nuclear Information System (INIS)

    Trbojevic, D.; Courant, E.

    1994-01-01

    Conditions for the lowest possible emittance of the lattice for electron storage rings are obtained by a simplified analytical approach. Examples of electron storage lattices with minimum emittances are presented. A simple graphical presentation in the normalized dispersion space (Floquet's transformation) is used to illustrate the conditions and results

  10. Auger decay of 1σg and 1σu hole states of the N2 molecule: Disentangling decay routes from coincidence measurements

    International Nuclear Information System (INIS)

    Semenov, S. K.; Schoeffler, M. S.; Titze, J.; Petridis, N.; Jahnke, T.; Cole, K.; Schmidt, L. Ph. H.; Czasch, A.; Jagutzki, O.; Schmidt-Boecking, H.; Doerner, R.; Akoury, D.; Williams, J. B.; Landers, A. L.; Osipov, T.; Lee, S.; Prior, M. H.; Belkacem, A.; Weber, Th.; Cherepkov, N. A.

    2010-01-01

    Results of the most sophisticated measurements in coincidence with the angular-resolved K-shell photoelectrons and Auger electrons and with two atomic ions produced by dissociation of N 2 molecule are analyzed. Detection of photoelectrons at certain angles makes it possible to separate the Auger decay processes of the 1σ g and 1σ u core-hole states. The Auger electron angular distributions for each of these hole states are measured as a function of the kinetic-energy release of two atomic ions and are compared with the corresponding theoretical angular distributions. From that comparison one can disentangle the contributions of different repulsive doubly charged molecular ion states to the Auger decay. Different kinetic-energy-release values are directly related to the different internuclear distances. In this way one can trace experimentally the behavior of the potential energy curves of dicationic final states inside the Frank-Condon region. Presentation of the Auger-electron angular distributions as a function of kinetic-energy release of two atomic ions opens a new dimension in the study of Auger decay.

  11. BEAM EMITTANCE MEASUREMENT TOOL FOR CEBAF OPERATIONS

    International Nuclear Information System (INIS)

    Chevtsov, Pavel; Tiefenback, Michael

    2008-01-01

    A new software tool was created at Jefferson Lab to measure the emittance of the CEBAF electron beams. The tool consists of device control and data analysis applications. The device control application handles the work of wire scanners and writes their measurement results as well as the information about accelerator settings during these measurements into wire scanner data files. The data analysis application reads these files and calculates the beam emittance on the basis of a wire scanner data processing model. Both applications are computer platform independent but are mostly used on LINUX PCs recently installed in the accelerator control room. The new tool significantly simplifies beam emittance measurement procedures for accelerator operations and contributes to a very high availability of the CEBAF machine for the nuclear physics program at Jefferson Lab.

  12. Achievement of ultralow emittance coupling in the Australian Synchrotron storage ring

    Directory of Open Access Journals (Sweden)

    R. Dowd

    2011-01-01

    Full Text Available Investigations into producing an electron beam with ultralow vertical emittance have been conducted using the Australian Synchrotron 3 GeV storage ring. A method of tuning the emittance coupling (ϵ_{y}/ϵ_{x} has been developed using a machine model calibrated through the linear optics from closed orbits method. Direct measurements of the beam emittance have not been possible due to diagnostic limitations, however two independent indirect measurements both indicate a vertical emittance of 1.2–1.3 pm rad (ϵ_{y}/ϵ_{x}=0.01%. Other indirect measurements support the validity of these results. This result is the smallest vertical emittance currently achieved in a storage ring.

  13. Measurements of Transverse Emittance for RF Photocathode Gun at the PAL

    CERN Document Server

    Park Jang Ho; Park, Sung-Ju; Soo Ko In; Wang, Xijie; Woon Parc, Yong; Xiang, Dao

    2005-01-01

    A BNL GUN-IV type RF photo-cathode gun is under fabrication for use in the FIR (Far Infra-Red) facility being built at the Pohang Accelerator Laboratory (PAL). Performance test of the gun will include the measurement of transverse emittance profile along the longitudinal direction. Successful measurement of the emittance profile will provide powerful tool for the commissioning of the 4GLS (4th generation light source) injectors based on the emittance compensation principle. We are going to achieve this withthe use of pepper-pot based emittance meters that can be moved along the longitudinal direction. In this article, we present design considerations on the emittance meter with the resolution of 1 mm mrad.

  14. Calculation of the detection efficiency in liquid scintillators. II. Single positron emitters

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia Torano, E.

    1982-01-01

    Counting efficiency as a function of the figure of merit for 30 positron emitters has been computed from the positron energy spectrum. Only the efficiency contribution of positrons has been taken into consideration. The contribution of the annihilation photons depending on the volume of the scintillator will be investigated in a near future. Efficiency vs figure of merit is plotted and tabulated. (Author) 19 refs

  15. Self-consistent Analysis of Three-dimensional Uniformly Charged Ellipsoid with Zero Emittance

    International Nuclear Information System (INIS)

    Batygin, Yuri K.

    2001-01-01

    A self-consistent treatment of a three-dimensional ellipsoid with negligible emittance in time-dependent external field is performed. Envelope equations describing the evolution of an ellipsoid boundary are discussed. For a complete model it is required that the initial particle momenta be a linear function of the coordinates. Numerical example and verification of the problem by a 3-dimensional particle-in-cell simulations are given

  16. Aluminum oxide film thickness and emittance

    International Nuclear Information System (INIS)

    Thomas, J.K.; Ondrejcin, R.S.

    1991-11-01

    Aluminum reactor components which are not actively cooled could be subjected to high temperatures due to gamma heating after the core coolant level dropped during the ECS phase of a hypothetical LOCA event. Radiative heat transfer is the dominant heat transfer process in this scenario and therefore the emittance of these components is of interest. Of particular interest are the safety rod thimbles and Mark 60B blanket assemblies; for the K Reactor, these components have been exposed to low temperature (< 55 degrees C) moderator for about a year. The average moderator temperature was assumed to be 30 degrees C. The Al oxide film thickness at this temperature, after one year of exposure, is predicted to be 6.4 μm ± 10%; insensitive to exposure time. Dehydration of the film during the gamma heating accident would result in a film thickness of 6.0 μm ± 11%. Total hemispherical emittance is predicted to be 0.69 at 96 degrees C, decreasing to 0.45 at 600 degrees C. Some phenomena which would tend to yield thicker oxide films in the reactor environment relative to those obtained under experimental conditions were neglected and the predicted film thickness values are therefore conservative. The emittance values predicted for a given film thickness are also conservative. The conservativisms inherent in the predicted emittance are particularly relevant for uncertainty analysis of temperatures generated using these values

  17. Transverse-to-longitudinal Emittance-exchange with an Energy Chirped Beam

    Energy Technology Data Exchange (ETDEWEB)

    Thangaraj, J.; Ruan, J.; Johnson, A.S.; Thurman-Keup, R.; Lumpkin, A.H.; Santucci, J.; Sun, Y.-E; Maxwell, T.; Edwards, H.; /Fermilab

    2012-05-01

    Emittance exchange has been proposed to increase the performance of free electron lasers by tailoring the phase space of an electron beam. The principle of emittance exchange - where the transverse phase space of the electron beam is exchanged with the longitudinal phase space - has been demonstrated recently at the A0 photoinjector. The experiment used a low charge bunch (250 pC) with no energy chirp. Theory predicts an improvement in the emittance exchange scheme when the incoming beam has an energy chirp imparted on it. The energy chirp helps to overcome the thick lens effect of the deflecting mode cavity and other second order effects that might lead to an incomplete emittance exchange at higher charges. In this work, we report experimental and simulation results from operating the emittance exchange beam line using an energy chirped beam with higher charge (500 pC) at different RF-chirp settings.

  18. Transverse beam emittance optimization for the injection into BESSY II

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Felix [Helmholtz Zentrum Berlin, Institut Beschleunigerphysik (Germany); Humboldt-Universitaet zu Berlin, Institut fuer Physik (Germany)

    2016-07-01

    For top up injection into the storage ring BESSY II an average injection efficiency of at least 90% is required. In low alpha mode the injection efficiency does not meet the requirements. Future BESSY II features will include shorter bunches in the storage ring (VSR) and user transparent injection with a non linear kicker. These will raise the demands on the quality of the injected beam even further. This work investigates the development of transverse emittance over the acceleration cycle in the synchrotron and the possibility of transverse emittance exchange by a sequence of skew quadrupoles in the transfer line. Results of emittance measurements and emittance exchange simulations will be given.

  19. Stability and dissociation dynamics of N{sub 2}{sup ++} ions following core ionization studied by an Auger-electron–photoion coincidence method

    Energy Technology Data Exchange (ETDEWEB)

    Iwayama, H.; Shigemasa, E. [UVSOR Facility, Institute for Molecular Science, Nishigonaka 38, Myodaiji, Okazaki 444-8585 (Japan); SOKENDAI, Nishigonaka 38, Myodaiji, Okazaki 444-8585 (Japan); Kaneyasu, T. [SAGA Light Source, Tosu 841-0005 (Japan); Hikosaka, Y. [Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan)

    2016-07-21

    An Auger-electron–photoion coincidence (AEPICO) method has been applied to study the stability and dissociation dynamics of dicationic states after the N K-shell photoionization of nitrogen molecules. From time-of-flight and kinetic energy analyses of the product ions, we have obtained coincident Auger spectra associated with metastable states of N{sub 2}{sup ++} ions and dissociative states leading to N{sub 2}{sup ++} → N{sup +} + N{sup +} and N{sup ++} + N. To investigate the production of dissociative states, we present two-dimensional AEPICO maps which reveal the correlations between the binding energies of the Auger final states and the ion kinetic energy release. These correlations have been used to determine the dissociation limits of individual Auger final states.

  20. Numerical evaluation of Auger recombination coefficients in relaxed and strained germanium

    Energy Technology Data Exchange (ETDEWEB)

    Dominici, Stefano [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary' s Street, Boston, Massachusetts 02215 (United States); Wen, Hanqing; Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary' s Street, Boston, Massachusetts 02215 (United States); Bertazzi, Francesco; Goano, Michele [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); IEIIT-CNR, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2016-05-23

    The potential applications of germanium and its alloys in infrared silicon-based photonics have led to a renewed interest in their optical properties. In this letter, we report on the numerical determination of Auger coefficients at T = 300 K for relaxed and biaxially strained germanium. We use a Green's function based model that takes into account all relevant direct and phonon-assisted processes and perform calculations up to a strain level corresponding to the transition from indirect to direct energy gap. We have considered excess carrier concentrations ranging from 10{sup 16} cm{sup −3} to 5 × 10{sup 19} cm{sup −3}. For use in device level simulations, we also provide fitting formulas for the calculated electron and hole Auger coefficients as functions of carrier density.

  1. Passivated emitters in silicon solar cells

    International Nuclear Information System (INIS)

    King, R.R.; Gruenbaum, P.E.; Sinton, R.A.; Swanson, R.M.

    1990-01-01

    In high-efficiency silicon solar cells with low metal contact coverage fractions and high bulk lifetimes, cell performance is often dominated by recombination in the oxide-passivated diffusions on the cell surface. Measurements of the emitter saturation current density, J o , of oxide-passivated, boron and phosphorus diffusions are presented, and from these measurements, the dependence of surface recombination velocity on dopant concentration was extracted. The lowest observed values of J o which are stable under UV light are given for both boron- and phosphorus-doped, oxide-passivated diffusions, for both textured and untextured surfaces. Contour plots which incorporate the above data have been applied to two types of backside-contact solar cells with large area (37.5 cm 2 ) and one-sun efficiencies up to 22.7%

  2. Alpha particle emitters in medicine

    International Nuclear Information System (INIS)

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ( 211 At) and natural bismuth-212 ( 212 Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ( 223 Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs

  3. Anisotropy analysis of the data measured by the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Golup, Geraldina

    2006-01-01

    This thesis is focused in the development of analysis methods of data measured by the Pierre Auger Observatory's surface array.The Auger Observatory is being built in Malargue, Mendoza and its objective is to detect ultra high energy cosmic rays (E > 10 1 8eV) in order to understand their origin, propagation and to be able to identify their sources.Chapter 1 is a summary of current cosmic rays' theory.It includes details about the energy spectrum of cosmic rays, acceleration sites, forms of acceleration, chemical composition of cosmic rays, the GZK cutoff, magnetic lensing and experiments.Following in Chapter 2 deflection as a function of energy, using the equation of small deflections to first or second order, is analyzed, and the energy range where is approximation is valid is determined.Then, the case of multiple images, which appear when a caustic crosses the position of a source, is studied.Two simulations of cosmic rays from point sources and propagating through a realistic model of the galactic magnetic field were used.Principal and secondary images were analyzed in order to extract information concerning their sources and the magnetic fields they passed through.In Chapter 3 the Minimal Spanning Tree method (MST) used for the detection of filamentary structures is studied.This method was adapted to the analysis of cosmic rays' arrival directions, considering that the detector only observes a part of the sky, with a non uniform exposure and that the density of events depends on exposure.Moreover, the correlation between energy and position is analyzed including now experimental errors in the simulations. Correlated events with experimental errors plus background are simulated and methods of extracting the correlated structure, identifying its source and deducing information about the magnetic field are determined.Finally, conclusions are made, highlighting the most relevant results [es

  4. A numerical study of emittance growths in RF guns

    CERN Document Server

    Masuda, K; Sobajima, M; Kitagaki, J; Ohnishi, M; Toku, H; Yoshikawa, K

    1999-01-01

    A beam with greatly reduced emittance is required for further improvements of FELs, in particular, for FELs of shorter wavelengths, and of narrower bandwidths. From this viewpoint, the BNL/SLAC/UCLA 1.6-cell S-band photocathode RF gun performance characteristics were calculated, first in order to evaluate what may contribute to the emittance growths in photocathode RF guns. We developed an RF gun to produce an electron beam with an extremely low emittance, by using a 2-D simulation code. It is found that, by optimizing the laser injection phase, the drive laser spot radius and the cavity shape around the laser spot, the beam emittance by the 1.6-cell RF gun can be greatly reduced to 2.1 pi mm mrad, from the previous 4.4 pi mm mrad of the original shape.

  5. Simulation studies of emittance growth in RMS mismatched beams

    International Nuclear Information System (INIS)

    Cucchetti, A.; Wangler, T.; Reiser, M.

    1991-01-01

    As shown in a separate paper, a charged-particle beam, whose rms size is not matched when injected into a transport channel or accelerator, has excess energy compared with that of a matched beam. If nonlinear space-charge forces are present and the mismatched beam transforms to a matched equilibrium state, rms-emittance growth will occur. The theory yields formulas for the possible rms-emittance growth, but not for the time it takes to achieve this growth. In this paper we present the results of systematic simulation studies for a mismatched 2-D round beam in an ideal transport channel with continuous linear focusing. Emittance growth rates obtained from the simulations for different amounts of mismatch and initial charge will be presented and the emittance growth will be compared with the theory. 6 refs., 7 figs

  6. Low Emittance Tuning Studies for SuperB

    Energy Technology Data Exchange (ETDEWEB)

    Liuzzo, Simone; /INFN, Pisa; Biagini, Maria; /INFN, Rome; Raimondi, Pantaleo; /INFN, Rome; Donald, Martin; /SLAC

    2012-07-06

    SuperB[1] is an international project for an asymmetric 2 rings collider at the B mesons cm energy to be built in the Rome area in Italy. The two rings will have very small beam sizes at the Interaction Point and very small emittances, similar to the Linear Collider Damping Rings ones. In particular, the ultra low vertical emittances, 7 pm in the LER and 4 pm in the HER, need a careful study of the misalignment errors effects on the machine performances. Studies on the closed orbit, vertical dispersion and coupling corrections have been carried out in order to specify the maximum allowed errors and to provide a procedure for emittance tuning. A new tool which combines MADX and Matlab routines has been developed, allowing for both corrections and tuning. Results of these studies are presented.

  7. Arc-textured metal surfaces for high thermal emittance space radiators

    International Nuclear Information System (INIS)

    Banks, B.A.; Rutledge, S.K.; Mirtich, M.J.; Behrend, T.; Hotes, D.; Kussmaul, M.; Barry, J.; Stidham, C.; Stueber, T.; DiFilippo, F.

    1994-01-01

    Carbon arc electrical discharges struck across the surfaces of metals such as Nb-1% Zr, alter the morphology to produce a high thermal emittance surface. Metal from the surface and carbon from the arc electrode vaporize during arcing, and then condense on the metal surface to produce a microscopically rough surface having a high thermal emittance. Quantitative spectral reflectance measurements from 0.33 to 15 μm were made on metal surfaces which were carbon arc treated in an inert gas environment. The resulting spectral reflectance data were then used to calculate thermal emittance as a function of temperature for various methods of arc treatment. The results of arc treatment on various metals are presented for both ac and dc arcs. Surface characterization data, including thermal emittance as a function of temperature, scanning electron microscopy, and atomic oxygen durability, are also presented. Ac arc texturing was found to increase the thermal emittance at 800 K from 0.05. to 0.70

  8. Impact of water temperature and structural parameters on the hydraulic labyrinth-channel emitter performance

    Directory of Open Access Journals (Sweden)

    Ahmed I. Al-Amoud

    2014-06-01

    Full Text Available The effects of water temperature and structural parameters of a labyrinth emitter on drip irrigation hydraulic performance were investigated. The inside structural parameters of the trapezoidal labyrinth emitter include path width (W and length (L, trapezoidal unit numbers (N, height (H, and spacing (S. Laboratory experiments were conducted using five different types of labyrinth-channel emitters (three non-pressure compensating and two pressure-compensating emitters commonly used for subsurface drip irrigation systems. The water temperature effect on the hydraulic characteristics at various operating pressures was recorded and a comparison was made to identify the most effective structural parameter on emitter performance. The pressure compensating emitter flow exponent (x average was 0.014, while non-pressure compensating emitter’s values average was 0.456, indicating that the sensitivity of non-pressure compensating emitters to pressure variation is an obvious characteristic (p<0.001 of this type of emitters. The effects of water temperature on emitter flow rate were insignificant (p>0.05 at various operating pressures, where the flow rate index values for emitters were around one. The effects of water temperature on manufacturer’s coefficient of variation (CV values for all emitters were insignificant (p>0.05. The CV values of the non-pressure compensating emitters were lower than those of pressure compensating emitters. This is typical for most compensating models because they are manufactured with more elements than non-compensating emitters are. The results of regression analysis indicate that N and H are the essential factors (p<0.001 to affect the hydraulic performance.

  9. Mean values of the LMM Auger transition in a KLM model

    Energy Technology Data Exchange (ETDEWEB)

    Malonda, A. Grau [Departamento Proyectos Estrategicos, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain)]. E-mail: agustin.grau@ciemat.es; Carles, A. Grau [Instituto de Matematicas y Fisica Fundamental (CSIC), Dcho. 211, C/Serrano, 113b, 28006 Madrid (Spain); Garcia, G. [Instituto de Matematicas y Fisica Fundamental (CSIC), Dcho. 211, C/Serrano, 113b, 28006 Madrid (Spain)

    2006-10-15

    The standardization of radionuclides decaying by electron capture can be carried out in LS counters by the CIEMAT/NIST method. The KLM model considers a simplified atomic rearrangement model in which all L- and M-subshells have been averaged. In this paper, instead of considering the 22 rearrangement pathways of the KLM model, we concentrate our analysis on the pathways corresponding to L-Auger electron transition. It is proved that the counting efficiency depends strongly on the energy E(LMM). Therefore, it is important to know the optimum value for E(LMM) and how to obtain it. To this end, the equations of the probabilities and the reduced energies for 3816 atomic rearrangement pathways have been derived. To average the equations, a computer program called MOYEN has been developed. The energy E(LMM) has been computed for {sup 55}Fe and {sup 125}I from different mean value definitions.

  10. Mean values of the LMM Auger transition in a KLM model

    International Nuclear Information System (INIS)

    Malonda, A. Grau; Carles, A. Grau; Garcia, G.

    2006-01-01

    The standardization of radionuclides decaying by electron capture can be carried out in LS counters by the CIEMAT/NIST method. The KLM model considers a simplified atomic rearrangement model in which all L- and M-subshells have been averaged. In this paper, instead of considering the 22 rearrangement pathways of the KLM model, we concentrate our analysis on the pathways corresponding to L-Auger electron transition. It is proved that the counting efficiency depends strongly on the energy E(LMM). Therefore, it is important to know the optimum value for E(LMM) and how to obtain it. To this end, the equations of the probabilities and the reduced energies for 3816 atomic rearrangement pathways have been derived. To average the equations, a computer program called MOYEN has been developed. The energy E(LMM) has been computed for 55 Fe and 125 I from different mean value definitions

  11. The effect of dimethyl sulfoxide on the induction of DNA strand breaks in plasmid DNA and colony formation of PC Cl3 mammalian cells by alpha-, beta-, and Auger electron emitters (223)Ra, (188)Re, and (99m)Tc.

    Science.gov (United States)

    Runge, Roswitha; Oehme, Liane; Kotzerke, Jörg; Freudenberg, Robert

    2016-12-01

    DNA damage occurs as a consequence of both direct and indirect effects of ionizing radiation. The severity of DNA damage depends on the physical characteristics of the radiation quality, e.g., the linear energy transfer (LET). There are still contrary findings regarding direct or indirect interactions of high-LET emitters with DNA. Our aim is to determine DNA damage and the effect on cellular survival induced by (223)Ra compared to (188)Re and (99m)Tc modulated by the radical scavenger dimethyl sulfoxide (DMSO). Radioactive solutions of (223)Ra, (188)Re, or (99m)Tc were added to either plasmid DNA or to PC Cl3 cells in the absence or presence of DMSO. Following irradiation, single strand breaks (SSB) and double strand breaks (DSB) in plasmid DNA were analyzed by gel electrophoresis. To determine the radiosensitivity of the rat thyroid cell line (PC Cl3), survival curves were performed using the colony formation assay. Exposure to 120 Gy of (223)Ra, (188)Re, or (99m)Tc leads to maximal yields of SSB (80 %) in plasmid DNA. Irradiation with 540 Gy (223)Ra and 500 Gy (188)Re or (99m)Tc induced 40, 28, and 64 % linear plasmid conformations, respectively. DMSO prevented the SSB and DSB in a similar way for all radionuclides. However, with the α-emitter (223)Ra, a low level of DSB could not be prevented by DMSO. Irradiation of PC Cl3 cells with (223)Ra, (188)Re, and (99m)Tc pre-incubated with DMSO revealed enhanced survival fractions (SF) in comparison to treatment without DMSO. Protection factors (PF) were calculated using the fitted survival curves. These factors are 1.23 ± 0.04, 1.20 ± 0.19, and 1.34 ± 0.05 for (223)Ra, (188)Re, and (99m)Tc, respectively. For (223)Ra, as well as for (188)Re and (99m)Tc, dose-dependent radiation effects were found applicable for plasmid DNA and PC Cl3 cells. The radioprotection by DMSO was in the same range for high- and low-LET emitter. Overall, the results indicate the contribution of mainly indirect radiation

  12. Large scale anisotropy studies with the Auger Observatory

    International Nuclear Information System (INIS)

    Santos, E.M.; Letessier-Selvon, A.

    2006-01-01

    With the increasing Auger surface array data sample of the highest energy cosmic rays, large scale anisotropy studies at this part of the spectrum become a promising path towards the understanding of the origin of ultra-high energy cosmic particles. We describe the methods underlying the search for distortions in the cosmic rays arrival directions over large angular scales, that is, bigger than those commonly employed in the search for correlations with point-like sources. The widely used tools, known as coverage maps, are described and some of the issues involved in their calculations are presented through Monte Carlo based studies. Coverage computation requires a deep knowledge on the local detection efficiency, including the influence of weather parameters like temperature and pressure. Particular attention is devoted to a new proposed method to extract the coverage, based upon the assumption of time factorization of an extensive air shower detector acceptance. We use Auger monitoring data to test the goodness of such a hypothesis. We finally show the necessity of using more than one coverage to extract any possible anisotropic pattern on the sky, by pointing to some of the biases present in commonly used methods based, for example, on the scrambling of the UTC arrival times for each event. (author)

  13. Many-electron effect in the resonant L23-M23V Auger-electron spectrum of Ti metal

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2006-01-01

    Above the L23 absorption edge the L 23 -M 23 V resonant Auger-electron spectroscopy (RAES) spectrum of Ti metal shows a normal L 23 -M 23 V Auger decay spectrum at a constant kinetic energy (K.E.). Here LX and MY are the atomic shells Lx and My, respectively. Apart from a weak spectral feature of the L2-M23V Auger transition appearing around the L2 edge, the RAES spectra of Ti meal show a very little difference between the L2 and L3 regions [P. Le Fevre, J. Danger, H. Magnan, D. Chandesris, J. Jupille, S. Bourgeois, M.-A. Arrio, R. Gotter, A. Verdini, A. Morgante, Phys. Rev. B69 (2004) 155421]. It is shown that the time scale of relaxation of the resonantly excited L23-hole state to the L23-electron ionized state is much shorter than that of the L23-hole decay so that the L 23 -M 23 V RAES spectrum of Ti metal resembles much the normal L 23 -M 23 V Auger decay spectrum. The relaxation of the resonantly excited L23-hole state to the fully relaxed L23-hole state before the L23-hole decays, explains the extra width which is the primary cause of the discrepancy between the experimental high resolution near edge X-ray absorption spectroscopy (XAS) spectrum of Ti metal and the one calculated by the particle-hole Green's function including the Coulomb exchange interaction between the 2p hole and the 3d electron. The time scale of relaxation of the L3V two-hole state created by the L2-L3V Coster-Kronig (CK) decay to the single L3-hole state is much shorter than that of the L3-hole decay so that the L2-L3V-L3-M23V CK preceded Auger decay spectrum resembles much the L3-M23V Auger decay one

  14. Transition from the radiationless resonant Raman scattering to the normal Auger decay in a charge transfer system

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2006-01-01

    The transition from the radiationless resonant Raman scattering to the normal Auger decay in resonant Auger-electron spectroscopy (RAES) spectra of charge transfer (CT) systems is discussed by treating the relaxation and the core-hole decay of the excited core-hole state on the same footing by a many-body theory. When the resonantly excited electron remains at the excited atomic site during the core-hole decay, the RAES spectrum shows the characteristic feature of the resonant Auger-Raman effect, whereas when the excited electron has been transferred from the atomic site before the core-hole decays, the RAES spectrum shows the normal Auger decay. The present theory supports the interpretation of the variation with photon energy of the intensity ratio of the latter spectrum to the former one in the RAES spectrum by the Ar 2p → 4s resonance of Ar atoms adsorbed on Ru(0 0 1) surface reported by Keller et al. [C. Keller, M. Stichler, G. Comelli, F. Esch, S. Lizzit, D. Menzel, W. Wurth, Phys. Rev. B 57 (1998) 11951]. The transition from the radiationless resonant Raman scattering to the normal Auger decay in the RAES spectrum of CuO reported by Finazzi et al. [M. Finazzi, G. Ghiringhell, O. Tjernberg, Ph. Ohresser, N.B. Brookes, Phys. Rev. B 61 (2000) 4629] is discussed in terms of the relaxation of the resonantly excited core-hole state to the core-electron ionized main-line state by the hole-particle excitations. The merging of the resonant Raman-Auger-electron kinetic energy into the normal one about 2 eV above the absorption maximum in Cu 2 O reported by Finazzi et al. [M. Finazzi, G. Ghiringhell, O. Tjernberg, Ph. Ohresser, N.B. Brookes, Phys. Rev. B 61 (2000) 4629] is explained in terms of the change in the characteristics of the screening electron in the two-hole final state. The Ti L 23 -M 23 V RAES spectra of TiO 2 and TiO 2-x are also analyzed

  15. Untersuchungen zur Radiotoxizität von Tc-99m-markierten Radiotracern in vitro an FRTL-5- und A431-Zellen

    OpenAIRE

    Maucksch, Ute

    2016-01-01

    Einleitung/ Zielstellung Zusätzlich zur Gammastrahlung emittiert 99mTc ca. 5 niederenergetische Auger-Elektronen mit Reichweiten von wenigen Nanometern im Gewebe. Diese haben für die nuklear-medizinische Diagnostik keine Bedeutung. Es wird jedoch über eine therapeutische Nutzung diskutiert, wofür eine Anreicherung der Auger-Elektronen-Emitter in einem strahlensensitiven Zellkompartiment erforderlich ist. Ziel der Arbeit war es, verschiedene [99mTc]Tc-Radiopharmaka hinsichtlich ihres U...

  16. Xenon spectator and diagram L3-M4,5M4,5 Auger intensities near the L3 threshold

    International Nuclear Information System (INIS)

    Armen, G.B.; Levin, J.C.; Southworth, S.H.; LeBrun, T.; Arp, U.; MacDonald, M.A.

    1997-01-01

    Calculations based on the theory of radiationless resonant Raman scattering are employed in the interpretation of new XeL 3 -M 4,5 M 4,5 Auger spectra recorded using synchrotron radiation tuned to energies across the L 3 edge. Fits of theoretical line shapes to the spectra are employed in separating intensities due to nd spectator (resonant) and diagram Auger processes. Near-threshold Auger intensity, previously attributed to diagram decay, is found to be due to the large-n spectator lines that result from postcollision-interaction endash induced open-quotes recaptureclose quotes of threshold photoelectrons to nd orbitals. copyright 1997 The American Physical Society

  17. On the design guideline for the low emittance synchrotron radiation source

    International Nuclear Information System (INIS)

    Kamiya, Y.; Kihara, M.

    1983-09-01

    In this note we will describe how the emittance of the electron storage ring is determined by the orbit parameters of the storage ring and show the lowest value of emittance which is achieved theoretically. Implication of this note with regard to the design of the low emittance storage ring will be discussed. (author)

  18. Homogeneous Gaussian Profile P+-Type Emitters: Updated Parameters and Metal-Grid Optimization

    Directory of Open Access Journals (Sweden)

    M. Cid

    2002-10-01

    Full Text Available P+-type emitters were optimized keeping the base parameters constant. Updated internal parameters were considered. The surface recombination velocity was considered variable with the surface doping level. Passivated homogeneous emitters were found to have low emitter recombination density and high collection efficiency. A complete structure p+nn+ was analyzed, taking into account optimized shadowing and metal-contacted factors for laboratory cells as function of the surface doping level and the emitter thickness. The base parameters were kept constant to make the emitter characteristics evident. The most efficient P+-type passivated homogeneous emitters, provide efficiencies around 21% for a wide range of emitter sheet resistivity (50 -- 500 omega/ with the surface doping levels Ns=1×10(19 cm-3 and 5×10(19 cm-3. The output electrical parameters were evaluated considering the recently proposed value n i=9.65×10(9 (cm-3. A non-significant increase of 0.1% in the efficiency was obtained, validating all the conclusions obtained in this work, considering n i=1×10(10 cm-3.

  19. K-shell auger decay of atomic oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, W.C.; Lu, Y.; Samson, J.A.R. [Univ. of Nebraska, Lincoln, NE (United States)] [and others

    1997-04-01

    The aim of the present research is to understand the interaction between the ejected photoelectron and Auger electron produced by the Auger decay of a 1s hole in atomic oxygen, and to understand the influence this interaction has on the shape of the ionization cross sections. To accomplish this the authors have measured the relative ion yields (ion/photon) in the vicinity of the oxygen K-shell (525 - 533 eV) for O{sup +} and O{sup 2+}. The measurements were performed at the ALS on beamline, 6.3.2. The atomic oxygen was produced by passing molecular oxygen through a microwave-driven discharge. A Rydberg analysis of the two series leading to the [1s]2s{sup 2}2p{sup 4}({sup 4}P) and [1s]2s{sup 2}2p{sup 4}({sup 2}P) limits were obtained. This analysis shows some differences to the recently published results by Menzel et al. The energy position of the main 1s{sup 1}2s{sup 2}2p{sup 5}({sup 3}P) resonance differs by approximately 1 eV from the authors value, all members of the ({sup 2}P)np series differ by 0.3 eV, but the members of the ({sup 4}P)np series agree. The molecular resonance at 530.5 eV and those between 539 eV and 543 eV, measured with the microwave discharge off show identical results in both experiments.

  20. Minimum emittance of three-bend achromats

    International Nuclear Information System (INIS)

    Li Xiaoyu; Xu Gang

    2012-01-01

    The calculation of the minimum emittance of three-bend achromats (TBAs) made by Mathematical software can ignore the actual magnets lattice in the matching condition of dispersion function in phase space. The minimum scaling factors of two kinds of widely used TBA lattices are obtained. Then the relationship between the lengths and the radii of the three dipoles in TBA is obtained and so is the minimum scaling factor, when the TBA lattice achieves its minimum emittance. The procedure of analysis and the results can be widely used in achromats lattices, because the calculation is not restricted by the actual lattice. (authors)

  1. Thermal integrity profiling for augered cast-in-place piles - implementation plan.

    Science.gov (United States)

    2017-08-01

    This study was the second in a two-part research program focused on assessing the feasibility of using thermal integrity profiling (TIP) as a quality assurance tool for Augered Cast-In-Place (ACIP) piles. This was made possible by coordinating with t...

  2. Auger-electron spectroscopy investigation of thin Ag-As-S-Se films

    International Nuclear Information System (INIS)

    Todorov, R; Spasov, G; Petkov, K; Tasseva, J

    2010-01-01

    The photoinduced changes in the refractive index and optical band-gap of thin As 32 S 34 Se 34 films photodoped with silver were studied using spectrophotometric methods. The compositional profile of the films was revealed by means of Auger-electron spectroscopy.

  3. Study of ultra-energetic cosmic rays at the Pierre Auger Observatory from particle detection to anisotropy measurement

    International Nuclear Information System (INIS)

    Aublin, J.

    2006-09-01

    The Pierre Auger Observatory, still under construction in Argentina, is designed to study the cosmic rays with energies above a few EeV. The experiment combines two complementary techniques: the fluorescence light detection and the sampling of the shower with an array of detectors at ground, covering a surface of 3000 square kilometers. The calculation of the acceptance of the detector, which is of utmost importance to establish the energy spectrum, has been achieved. The method of computation of the acceptance is simple and reliable. The detection efficiency depends on the nature of primary cosmic rays, allowing to study the cosmic rays composition with the surface detector. The calculation of the cosmic rays energy spectrum has been performed, using different methods to estimate the energy of the events. A cross calibration between the fluorescence and the surface detector provides an estimation of the energy almost independent of hadronic interaction models. The study of large scale anisotropies in the cosmic rays angular distribution provides useful informations about the cosmic rays sources and the conditions of propagation. A new analysis method is presented, allowing to estimate the parameters of an underlying dipolar and quadrupolar anisotropy in the data. The method is applied to a preliminary Auger data set. (author)

  4. High emittance black nickel coating on copper substrate for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, Soniya, E-mail: jrf0013@isac.gov.in; Pillai, Anju M., E-mail: anjum@isac.gov.in; Rajendra, A., E-mail: rajendra@isac.gov.in; Sharma, A.K., E-mail: aks@isac.gov.in

    2015-09-15

    Highlights: • High emittance black nickel coating is obtained on copper substrate. • The effect of various process parameters on IR emittance is studied systematically. • Process parameters are optimized to develop a high emittance black nickel coating. • Coating obtained using the finalized parameters exhibited an emittance of 0.83. • SEM and EDAX are used for coating characterization. - Abstract: Black nickel, an alloy coating of zinc and nickel, is obtained on copper substrate by pulse electrodeposition from a modified Fishlock bath containing nickel sulphate, nickel ammonium sulphate, zinc sulphate and ammonium thiocyanate. A nickel undercoat of 4–5 μm thickness is obtained using Watts bath to increase the corrosion resistance and adhesion of the black nickel coating. The effect of bath composition, temperature, solution pH, current density and plating time on the coating appearance and corresponding infra-red emittance of the coating is investigated systematically. Process parameters are optimized to develop a high emittance space worthy black nickel coating to improve the heat radiation characteristics. The effect of the chemistry of the plating bath on the coating composition was studied using energy dispersive X-ray analysis (EDAX) of the coatings. The 5–6 μm thick uniform jet black zinc–nickel alloy coating obtained with optimized process exhibited an emittance of 0.83 and an absorbance of 0.92. The zinc to nickel ratio of black nickel coatings showing high emittance and appealing appearance was found to be in the range 2.3–2.4.

  5. A correction for emittance-measurement errors caused by finite slit and collector widths

    International Nuclear Information System (INIS)

    Connolly, R.C.

    1992-01-01

    One method of measuring the transverse phase-space distribution of a particle beam is to intercept the beam with a slit and measure the angular distribution of the beam passing through the slit using a parallel-strip collector. Together the finite widths of the slit and each collector strip form an acceptance window in phase space whose size and orientation are determined by the slit width, the strip width, and the slit-collector distance. If a beam is measured using a detector with a finite-size phase-space window, the measured distribution is different from the true distribution. The calculated emittance is larger than the true emittance, and the error depends both on the dimensions of the detector and on the Courant-Snyder parameters of the beam. Specifically, the error gets larger as the beam drifts farther from a waist. This can be important for measurements made on high-brightness beams, since power density considerations require that the beam be intercepted far from a waist. In this paper we calculate the measurement error and we show how the calculated emittance and Courant-Snyder parameters can be corrected for the effects of finite sizes of slit and collector. (Author) 5 figs., 3 refs

  6. Emittance measuring unit for 100% duty factor linac injector beams

    Energy Technology Data Exchange (ETDEWEB)

    Shubaly, M R; Pachner, J Jr; Ormrod, J H; Ungrin, J; Schriber, S O [ed.

    1976-11-01

    A description is given of a system to measure the emittance of a 750 keV 100 mA dc proton beam suitable for injection into a 100% duty factor linear accelerator. A relatively slowly pulsed 45/sup 0/ magnet switches the beam to a beam dump inside the emittance measuring unit for approx. 10 s. A fast pulsed 5/sup 0/ magnet then deflects the beam to a multiple aperture ''pepper-pot'' plate for 300 ..mu..s. Beamlets passing through the plate travel 520 mm and produce a pattern on a scintillator screen. A photograph of the pattern is analyzed to determine beam emittance. Preliminary results on low current beams show a gross increase in the emittance in the horizontal plane.

  7. An Online Multisensor Data Fusion Framework for Radar Emitter Classification

    Directory of Open Access Journals (Sweden)

    Dongqing Zhou

    2016-01-01

    Full Text Available Radar emitter classification is a special application of data clustering for classifying unknown radar emitters in airborne electronic support system. In this paper, a novel online multisensor data fusion framework is proposed for radar emitter classification under the background of network centric warfare. The framework is composed of local processing and multisensor fusion processing, from which the rough and precise classification results are obtained, respectively. What is more, the proposed algorithm does not need prior knowledge and training process; it can dynamically update the number of the clusters and the cluster centers when new pulses arrive. At last, the experimental results show that the proposed framework is an efficacious way to solve radar emitter classification problem in networked warfare.

  8. Transverse emittance dilution due to coupler kicks in linear accelerators

    Directory of Open Access Journals (Sweden)

    Brandon Buckley

    2007-11-01

    Full Text Available One of the main concerns in the design of low emittance linear accelerators (linacs is the preservation of beam emittance. Here we discuss one possible source of emittance dilution, the coupler kick, due to transverse electromagnetic fields in the accelerating cavities of the linac caused by the power coupler geometry. In addition to emittance growth, the coupler kick also produces orbit distortions. It is common wisdom that emittance growth from coupler kicks can be strongly reduced by using two couplers per cavity mounted opposite each other or by having the couplers of successive cavities alternate from above to below the beam pipe so as to cancel each individual kick. While this is correct, including two couplers per cavity or alternating the coupler location requires large technical changes and increased cost for superconducting cryomodules where cryogenic pipes are arranged parallel to a string of several cavities. We therefore analyze consequences of alternate coupler placements. We show here that alternating the coupler location from above to below compensates the emittance growth as well as the orbit distortions. For sufficiently large Q values, alternating the coupler location from before to after the cavity leads to a cancellation of the orbit distortion but not of the emittance growth, whereas alternating the coupler location from before and above to behind and below the cavity cancels the emittance growth but not the orbit distortion. We show that cancellations hold for sufficiently large Q values. These compensations hold even when each cavity is individually detuned, e.g., by microphonics. Another effective method for reducing coupler kicks that is studied is the optimization of the phase of the coupler kick so as to minimize the effects on emittance from each coupler. This technique is independent of the coupler geometry but relies on operating on crest. A final technique studied is symmetrization of the cavity geometry in the

  9. Emittance and trajectory control in the main linacs of the NLC

    International Nuclear Information System (INIS)

    Assmann, R.; Adolphsen, C.; Bane, K.; Raubenheimer, T.O.; Thompson, K.

    1996-09-01

    The main linacs of the next generation of linear colliders need to accelerate the particle beams to energies of up to 750 GeV while maintaining very small emittances. This paper describes the main mechanisms of static emittance growth in the main linacs of the Next Linear Collider (NLC). The authors present detailed simulations of the trajectory and emittance control algorithms that are foreseen for the NLC. They show that the emittance growth in the main linacs can be corrected down to about 110%. That number is significantly better than required for the NLC design luminosity

  10. Recent Results from the Pierre Auger observatory

    International Nuclear Information System (INIS)

    Kampert, Karl-Heinz

    2010-01-01

    The Pierre Auger observatory is a hybrid air shower experiment which uses multiple detection techniques to investigate the origin, spectrum, and composition of ultrahigh energy cosmic rays. We present recent results on these topics and discuss their implications to the understanding the origin of the most energetic particles in nature as well as for physics beyond the Standard Model, such as violation of Lorentz invariance and 'top-down' models of cosmic ray production. Future plans, including enhancements underway at the southern site in Argentina will be presented. (author)

  11. Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Aab, A. [Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen (Netherlands); Abreu, P.; Andringa, S. [Laboratório de Instrumentação e Física Experimental de Partículas—LIP and Instituto Superior Técnico—IST, Universidade de Lisboa—UL (Portugal); Aglietta, M. [Osservatorio Astrofisico di Torino (INAF), Torino (Italy); Samarai, I. Al [Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3 (France); Albuquerque, I.F.M. [Universidade de São Paulo, Inst. de Física, São Paulo (Brazil); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET) (Argentina); Almela, A.; Andrada, B. [Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica (Argentina); Castillo, J. Alvarez [Universidad Nacional Autónoma de México, México (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela (Spain); Anastasi, G.A. [Gran Sasso Science Institute (INFN), L' Aquila (Italy); Anchordoqui, L., E-mail: auger_spokespersons@fnal.gov [Department of Physics and Astronomy, Lehman College, City University of New York (United States); and others

    2017-04-01

    We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 ⋅ 10{sup 18} eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.

  12. Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Aab, A.; Buchholz, P.; Erfani, M.; Froehlich, U.; Heimann, P.; Niechciol, M.; Ochilo, L.; Risse, M.; Tepe, A.; Yushkov, A.; Ziolkowski, M.; Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Diogo, F.; Espadanal, J.; Goncalves, P.; Oliveira, M.; Pimenta, M.; Santo, C.E.; Sarmento, R.; Tome, B.; Aglietta, M.; Bertaina, M.E.; Bonino, R.; Castellina, A.; Chiavassa, A.; Gorgi, A.; Latronico, L.; Maldera, S.; Morello, C.; Navarra, G.; Ahn, E.J.; Fazzini, N.; Glass, H.; Hojvat, C.; Kasper, P.; Lebrun, P.; Mantsch, P.; Mazur, P.O.; Al Samarai, I.; Deligny, O.; Lhenry-Yvon, I.; Martraire, D.; Salamida, F.; Suomijaervi, T.; Albuquerque, I.F.M.; Gouffon, P.; Santos, E.M.; Allekotte, I.; Asorey, H.; Bertou, X.; Berisso, M.G.; Harari, D.; Mollerach, S.; Purrello, V.; Roulet, E.; Sidelnik, I.; Taborda, O.A.; Allen, J.; Awal, N.; Farrar, G.; Zaw, I.; Allison, P.; Beatty, J.J.; Gordon, J.; Griffith, N.; Stapleton, J.; Sutherland, M.S.; Almela, A.; Etchegoyen, A.; Wainberg, O.; Castillo, J.A.; D'Olivo, J.C.; Medina-Tanco, G.; Nellen, L.; Galicia, J.F.V.; Vargas Cardenas, B.; Alvarez-Muniz, J.; Ave, M.; Roca, S.T.G.; Agueera, A.L.; Parente, G.; Parra, A.; Carvalho, W.R. de; Cabo, I.R.; Elipe, G.T.; Tueros, M.; Valino, I.; Vazquez, R.A.; Zas, E.; Batista, R.A.; Schiffer, P.; Sigl, G.; Vliet, A. van; Ambrosio, M.; Aramo, C.; Buscemi, M.; Cilmo, M.; Colalillo, R.; Guarino, F.; Valore, L.; Aminaei, A.; Buitink, S.; Schulz, J.; Aar, G. van; Velzen, S. van; Wykes, S.; Anchordoqui, L.; Aranda, V.M.; Arqueros, F.; Garcia-Pinto, D.; Minaya, I.A.; Rosado, J.; Vazquez, J.R.; Aublin, J.; Billoir, P.; Blanco, M.; Caccianiga, L.; Gaior, R.; Ghia, P.L.; Letessier-Selvon, A.; Muenchmeyer, M.; Settimo, M.; Avenier, M.; Berat, C.; Le Coz, S.; Lebrun, D.; Louedec, K.; Montanet, F.; Stutz, A.; Tartare, M.; Avila, G.; Vitale, P.F.G.; Badescu, A.M.; Fratu, O.; Barber, K.B.; Bellido, J.A.; Blaess, S.; Clay, R.W.; Cooper, M.J.; Dawson, B.R.; Grubb, T.D.; Harrison, T.A.; Hill, G.C.; Malacari, M.; Nguyen, P.; Saffi, S.J.; Sorokin, J.; Bodegom, P. van; Baeuml, J.; Baus, C.; Fuchs, B.; Gonzalez, J.G.; Huber, D.; Kambeitz, O.; Katkov, I.; Link, K.; Ludwig, M.; Maurel, D.; Melissas, M.; Palmieri, N.; Werner, F.; Becker, K.H.; Homola, P.; Jandt, I.; Kaeaepae, A.; Kampert, K.H.; Krohm, N.; Kruppke-Hansen, D.; Mathys, S.; Neuser, J.; Niemietz, L.; Papenbreer, P.; Querchfeld, S.; Rautenberg, J.; Sarkar, B.; Winchen, T.; Wittkowski, D.; Biermann, P.L.; Caramete, L.; Curutiu, A.; Bleve, C.; Cataldi, G.; Cocciolo, G.; Coluccia, M.R.; De Mitri, I.; Marsella, G.; Martello, D.; Perrone, L.; Scherini, V.

    2015-01-01

    Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with E ≥ 6 x 10 19 eV by analyzing cosmic rays with energies above E ≥ 5 x 10 18 eVarriving within an angular separation of approximately 15 circle . We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources. (orig.)

  13. Modular low-voltage electron emitters

    International Nuclear Information System (INIS)

    Berejka, Anthony J.

    2005-01-01

    Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates

  14. Modular low-voltage electron emitters

    Science.gov (United States)

    Berejka, Anthony J.

    2005-12-01

    Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates.

  15. Resonant Auger electron-photoion coincidence study of the fragmentation dynamics of an acrylonitrile molecule

    Energy Technology Data Exchange (ETDEWEB)

    Kooser, K; Ha, D T; Granroth, S; Itaelae, E; Nommiste, E; Kukk, E [Department of Physics, University of Turku, FIN-20014 Turku (Finland); Partanen, L; Aksela, H, E-mail: kunkoo@utu.f [Department of Physics, University of Oulu, Box 3000, FIN-90014 Oulu (Finland)

    2010-12-14

    Monochromatic synchrotron radiation was used to promote K-shell electrons of nitrogen and carbon from the cyano group (C {identical_to} N) of gaseous acrylonitrile (C{sub 2}H{sub 3}-CN) to the unoccupied antibonding {pi}*{sub C} {sub {identical_to} N} orbital. Photofragmentation of acrylonitrile molecules following selective resonant core excitations of carbon and nitrogen core electrons to the {pi}*{sub C} {sub {identical_to} N} orbital was investigated using the electron-energy-resolved photoelecton-photoion coincidence technique. The fragment ion mass spectra were recorded in coincidence with the resonant Auger electrons, emitted in the decay process of the core-excited states. Singly and triply deuterated samples were used for fragment identification. The results showed the initial core-hole localization to be of minor importance in determining the dissociation pattern of the molecular cation. The participator and spectator Auger transitions produce entirely different fragmentation patterns and the latter indicates that complex nuclear rearrangements take place. It is suggested that the calculated kinetic energy releases are caused by the existence of metastable states, which appear with the opening of the spectator Auger channels.

  16. Auger-electron spectroscopy investigation of thin Ag-As-S-Se films

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, R; Spasov, G; Petkov, K; Tasseva, J, E-mail: jordanka@clf.bas.b [Acad. J. Malinowski Central Laboratory of Photoprocesses, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 109, 1113 Sofia (Bulgaria)

    2010-04-01

    The photoinduced changes in the refractive index and optical band-gap of thin As{sub 32}S{sub 34}Se{sub 34} films photodoped with silver were studied using spectrophotometric methods. The compositional profile of the films was revealed by means of Auger-electron spectroscopy.

  17. Beam dynamics in rf guns and emittance correction techniques

    International Nuclear Information System (INIS)

    Serafini, L.

    1994-01-01

    In this paper we present a general review of beam dynamics in a laser-driven rf gun. The peculiarity of such an accelerating structure versus other conventional multi-cell linac structures is underlined on the basis of the Panofsky-Wenzel theorem, which is found to give a theoretical background for the well known Kim's model. A basic explanation for some proposed methods to correct rf induced emittance growth is also derived from the theorem. We also present three emittance correction techniques for the recovery of space-charge induced emittance growth, namely the optimum distributed disk-like bunch technique, the use of rf spatial harmonics to correct spherical aberration induced by space charge forces and the technique of emittance filtering by clipping the electron beam. The expected performances regarding the beam quality achievable with different techniques, as predicted by scaling laws and simulations, are analyzed, and, where available, compared to experimental results. (orig.)

  18. Transverse emittance measurement at REGAE via a solenoid scan

    Energy Technology Data Exchange (ETDEWEB)

    Hachmann, Max

    2012-12-15

    The linear accelerator REGAE at DESY produces short and low charged electron bunches, on the one hand to resolve the excitation transitions of atoms temporally by pump probe electron diffraction experiments and on the other hand to investigate principal mechanisms of laser plasma acceleration. For both cases a high quality electron beam is required. A quantity to rate the beam quality is the beam emittance. In the course of this thesis transverse emittance measurements by a solenoid scan could be realized and beyond that an improved theoretical description of a solenoid was successful. The foundation of emittance measurements are constituted by theoretical models which describe the envelope of a beam. Two different models were derived. The first is an often used model to determine the transverse beam emittance without considering space charge effects. More interesting and challenging was the development of an envelope model taking space charge effects into account. It is introduced and cross checked with measurements and simulations.

  19. Laser-assisted electron emission from gated field-emitters

    CERN Document Server

    Ishizuka, H; Yokoo, K; Mimura, H; Shimawaki, H; Hosono, A

    2002-01-01

    Enhancement of electron emission by illumination of gated field-emitters was studied using a 100 mW cw YAG laser at a wavelength of 532 nm, intensities up to 10 sup 7 W/m sup 2 and mechanically chopped with a rise time of 4 mu s. When shining an array of 640 silicon emitters, the emission current responded quickly to on-off of the laser. The increase of the emission current was proportional to the basic emission current at low gate voltages, but it was saturated at approx 3 mu A as the basic current approached 100 mu A with the increase of gate voltage. The emission increase was proportional to the square root of laser power at low gate voltages and to the laser power at elevated gate voltages. For 1- and 3-tip silicon emitters, the rise and fall of the current due to on-off of the laser showed a significant time lag. The magnitude of emission increase was independent of the position of laser spot on the emitter base and reached 2 mu A at a basic current of 5 mu A without showing signs of saturation. The mech...

  20. Coupling of Quantum Emitters in Nanodiamonds to Plasmonic Structures

    DEFF Research Database (Denmark)

    Kumar, Shailesh

    This PhD thesis describes work towards the enhancement and efficient channeling of photons emitted from a single photon emitter. The emitter used is a defect center, the Nitrogen-Vacancy (NV) center, in diamond. The NV-center has many unique properties, such as long coherence time of its electron...

  1. Emittance growth due to dipole ripple and sextupole

    International Nuclear Information System (INIS)

    Shih, H.J.; Ellison, J.A.; Syphers, M.J.; Newberger, B.S.

    1993-05-01

    Ripple in the power supplies for storage ring magnets can have adverse effects on the circulating beams: orbit distortion and emittance growth from dipole ripple, tune modulation and dynamic aperture reduction from quadrupole ripple, etc. In this paper, we study the effects of ripple in the horizontal bending field of the SSC in the presence of nonlinearity, in particular, the growth in beam emittance

  2. Multibunch emittance growth and its corrections in S-Band linear collider

    International Nuclear Information System (INIS)

    Gao, J.

    1994-11-01

    Multibunch emittance growths caused by long range wake fields with the misalignments of accelerating structures and quadrupoles in S-Band linear collider are studied. Tolerances for the misalignment errors of accelerating structures and quadrupoles are given corresponding to different detuned+damped structures. At the end of main linac, emittance corrector (EC) is proposed to be used to reduce further the multibunch emittance. Numerical simulations show that the effect of EC is obvious (multibunch emittance can be reduced about one order of magnitude), and it is believed that this kind of EC will be necessary for future linear colliders. (author). 16 refs., 21 figs., 4 tabs

  3. Emittance Measurements from a Laser Driven Electron Injector

    Energy Technology Data Exchange (ETDEWEB)

    Reis, David A

    2003-07-28

    The Gun Test Facility (GTF) at the Stanford Linear Accelerator Center was constructed to develop an appropriate electron beam suitable for driving a short wavelength free electron laser (FEL) such as the proposed Linac Coherent Light Source (LCLS). For operation at a wavelength of 1.5 {angstrom}, the LCLS requires an electron injector that can produce an electron beam with approximately 1 {pi} mm-mrad normalized rms emittance with at least 1 nC of charge in a 10 ps or shorter bunch. The GTF consists of a photocathode rf gun, emittance-compensation solenoid, 3 m linear accelerator (linac), drive laser, and diagnostics to measure the beam. The rf gun is a symmetrized 1.6 cell, s-band high gradient, room temperature, photocathode structure. Simulations show that this gun when driven by a temporally and spatially shaped drive laser, appropriately focused with the solenoid, and further accelerated in linac can produce a beam that meets the LCLS requirements. This thesis describes the initial characterization of the laser and electron beam at the GTF. A convolved measurement of the relative timing between the laser and the rf phase in the gun shows that the jitter is less than 2.5 ps rms. Emittance measurements of the electron beam at 35 MeV are reported as a function of the (Gaussian) pulse length and transverse profile of the laser as well as the charge of the electron beam at constant phase and gradient in both the gun and linac. At 1 nC the emittance was found to be {approx} 13 {pi} mm-mrad for 5 ps and 8 ps long laser pulses. At 0.5 nC the measured emittance decreased approximately 20% in the 5 ps case and 40% in the 8 ps case. These measurements are between 40-80% higher than simulations for similar experimental conditions. In addition, the thermal emittance of the electron beam was measured to be 0.5 {pi} mm-mrad.

  4. Auger electron spectroscopy of alloys

    International Nuclear Information System (INIS)

    Kuijers, F.J.

    1978-01-01

    This thesis describes how the surface compositions of some alloys can be determined by Auger Electron Spectroscopy (AES). The motivation for this research and the reasons for the choice of alloy systems studied are formulated. The theoretical background of AES is briefly discussed and the apparatus used and the experimental procedures applied are described. Four alloy systems have been investigated in this thesis - Ni-Cu and Pd - Ag (consisting of a component active in most cataytic reactions - Ni and Pd; and a component which is almost inactive for a number of reactions - Cu and Ag) and Pt - Pd and Pt-Ir (consisting of two active components). Knowledge of the surface composition of the various alloy systems is shown to be essential for the interpretation of catalytic results. (Auth./C.F.)

  5. Quadrupole Transfer Function for Emittance Measurement

    CERN Document Server

    Cameron, Peter; Jansson, Andreas; Tan, Cheng-Yang

    2008-01-01

    Historically the use of the quadrupole moment measurement has been impeded by the requirement for large dynamic range, as well as measurement sensitivity to beam position. We investigate the use of the transfer function technique [1-3] in combination with the sensitivity and 160dB revolution line rejection of the direct diode detection analog front end [4] to open the possibility of an emittance diagnostic that may be implemented without operational complication, quasi- parasitic to the operation of existing tune measurement systems. Such a diagnostic would be particularly useful as an emittance monitor during acceleration ramp development in machines like RHIC and the LHC.

  6. Emitter/absorber interface of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Tao, E-mail: tsong241@gmail.com; Sites, James R. [Physics Department, Colorado State University, Fort Collins, Colorado 80523 (United States); Kanevce, Ana [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2016-06-21

    The performance of CdTe solar cells can be very sensitive to the emitter/absorber interface, especially for high-efficiency cells with high bulk lifetime. Performance losses from acceptor-type interface defects can be significant when interface defect states are located near mid-gap energies. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e., defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV ≤ ΔE{sub C} ≤ 0.3 eV) can help maintain good cell efficiency in spite of high interface defect density, much like with Cu(In,Ga)Se{sub 2} (CIGS) cells. The basic principle is that positive ΔE{sub C}, often referred to as a “spike,” creates an absorber inversion and hence a large hole barrier adjacent to the interface. As a result, the electron-hole recombination is suppressed due to an insufficient hole supply at the interface. A large spike (ΔE{sub C} ≥ 0.4 eV), however, can impede electron transport and lead to a reduction of photocurrent and fill-factor. In contrast to the spike, a “cliff” (ΔE{sub C} < 0 eV) allows high hole concentration in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. Another way to mitigate performance losses due to interface defects is to use a thin and highly doped emitter, which can invert the absorber and form a large hole barrier at the interface. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. The ΔE{sub C} of other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ΔE{sub C}. These

  7. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    NARCIS (Netherlands)

    Pierre Auger Collaboration, [No Value; Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; D\\'\\iaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garc\\'\\ia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agëra, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Mart\\'\\inez Bravo, O.; Martraire, D.; Mas\\'\\ias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodr\\'\\iguez-Fr\\'\\ias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiał kowski, A.; Šm\\'\\ida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2014-01-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade

  8. Ion concentration in micro and nanoscale electrospray emitters.

    Science.gov (United States)

    Yuill, Elizabeth M; Baker, Lane A

    2018-06-01

    Solution-phase ion transport during electrospray has been characterized for nanopipettes, or glass capillaries pulled to nanoscale tip dimensions, and micron-sized electrospray ionization emitters. Direct visualization of charged fluorophores during the electrospray process is used to evaluate impacts of emitter size, ionic strength, analyte size, and pressure-driven flow on heterogeneous ion transport during electrospray. Mass spectrometric measurements of positively- and negatively-charged proteins were taken for micron-sized and nanopipette emitters under low ionic strength conditions to further illustrate a discrepancy in solution-driven transport of charged analytes. A fundamental understanding of analyte electromigration during electrospray, which is not always considered, is expected to provide control over selective analyte depletion and enrichment, and can be harnessed for sample cleanup. Graphical abstract Fluorescence micrographs of ion migration in nanoscale pipettes while solution is electrosprayed.

  9. Auger transitions in singly and multiply ionized atoms

    International Nuclear Information System (INIS)

    Mehlhorn, W.

    1978-01-01

    Some recent progress in Auger and autoionizing electron spectrometry of free metal atoms and of multiply ionized atoms is reviewed. The differences which arise between the spectra of atoms in the gaseous and the solid state are due to solid state effects. This will be shown for Cd as an example. The super Coster-Kronig transitions 3p-3d 2 (hole notation) and Coster-Kronig transitions 3p-3d 4s have been measured and compared with free-atom calculations for free Zn atoms. The experimental width GAMMA(3p)=(2.1+-0.2)eV found for the free atom agrees with the value obtained for solid Zn but is considerably smaller than the theoretical value for the free atom. Autoionizing spectra of Na following an L-shell excitation or ionization by different particles are compared and discussed. The nonisotropic angular distribution of electrons from the transition 2p 5 3s 2 2 Psub(3/2)→2p 6 +e - is compared with theoretical calculations. Two examples for Auger spectrometry of multiply ionized atoms are given: (1) excitation of neon target atoms by light and heavy ions, and (2) excitation of projectile ions Be + and B + in single gas collisions with CH 4 . A strong alignment of the excited atoms has also been found here

  10. Emittance of a finite scattering medium with refractive index greater than unity

    International Nuclear Information System (INIS)

    Crosbie, A.L.

    1980-01-01

    Refractive index and scattering can significantly influence the transfer of radiation in a semitransparent medium such as water, glass, plastics, or ceramics. In a recent article (1979), the author presented exact numerical results for the emittance of a semiinfinite scattering medium with a refractive index greater than unity. The present investigation extends the analysis to a finite medium. The physical situation consists of a finite planar layer. The isothermal layer emits, absorbs, and isotropically scatters thermal radiation. It is characterized by single scattering albedo, optical thickness, refractive index, and temperature. A formula for the directional emittance is derived, the directional emittance being the emittance of the medium multiplied by the interface transmittance. The ratio of hemispherical to normal emittance is tabulated and discussed

  11. MD2065: Emittance exchange with linear coupling

    CERN Document Server

    Carver, Lee Robert; Persson, Tobias Hakan Bjorn; Amorim, David; Levens, Tom; Pesah, Arthur Chalom; CERN. Geneva. ATS Department

    2018-01-01

    In order to better understand the luminosity imbalance between ATLAS and CMS that was observed in 2016, it was proposed to perform a test whereby the horizontal and vertical emittances are exchanged by crossing the tunes in the presence of linear coupling. The luminosity before and after the exchange could be compared to see if the imbalance stems purely from the uneven emittances or if there is an additional mechanism in play. However, due to limited machine availability only tests at injection were able to performed.

  12. Prototype of a subsurface drip irrigation emitter: Manufacturing, hydraulic evaluation and experimental analyses

    Science.gov (United States)

    Souza, Wanderley De Jesus; Rodrigues Sinobas, Leonor; Sánchez, Raúl; Arriel Botrel, Tarlei; Duarte Coelho, Rubens

    2013-04-01

    Root and soil intrusion into the conventional emitters is one of the major disadvantages to obtain a good uniformity of water application in subsurface drip irrigation (SDI). In the last years, there have been different approaches to reduce these problems such as the impregnation of emitters with herbicide, and the search for an emitter geometry impairing the intrusion of small roots. Within the last this study, has developed and evaluated an emitter model which geometry shows specific physical features to prevent emitter clogging. This work was developed at the Biosystems Engineering Department at ESALQ-USP/Brazil, and it is a part of a research in which an innovated emitteŕs model for SDI has been developed to prevent root and soil particles intrusion. An emitter with a mechanical-hydraulic mechanism (opening and closing the water outlet) for SDI was developed and manufactured using a mechanical lathe process. It was composed by a silicon elastic membrane a polyethylene tube and a Vnyl Polychloride membrane protector system. In this study the performance of the developed prototype was assessed in the laboratory and in the field conditions. In the laboratory, uniformity of water application was calculated by the water emission uniformity coefficient (CUE), and the manufacturer's coefficient of variation (CVm). In addition, variation in the membrane diameter submitted to internal pressures; head losses along the membrane, using the energy equation; and, precision and accuracy of the equation model, analyzed by Pearson's correlation coefficient (r), and by Willmott's concordance index (d) were also calculated with samples of the developed emitters. In the field, the emitters were installed in pots with and without sugar cane culture from October 2010 to January 2012. During this time, flow rate in 20 emitters were measured periodically, and the aspects of them about clogging at the end of the experiment. Emitters flow rates were measured quarterly to calculate

  13. Numerical studies of emittance exchange in 2-D charged-particle beams

    International Nuclear Information System (INIS)

    Guy, F.W.

    1986-01-01

    We describe results obtained from a two-dimensional particle-following computer code that simulates a continuous, nonrelativistic, elliptical charged-particle beam with linear continuous focusing. Emittances and focusing strengths can be different in the two transverse directions. The results can be applied, for example, for a quadrupole transport system in a smooth approximation to a real beam with unequal emittances in the two planes. The code was used to study emittance changes caused by kinetic-energy exchange between transverse directions and by shifts in charge distributions. Simulation results for space-charge-dominated beams agree well with analytic formulas. From simulation results, an empirical formula was developed for a ''partition parameter'' (the ratio of kinetic energies in the two directions) as a function of initial conditions and beamline length. Quantitative emittance changes for each transverse direction can be predicted by using this parameter. Simulation results also agree with Hofmann's generalized differential equation relating emittance and field energy

  14. Growth rate of non-thermodynamic emittance of intense electron beams

    International Nuclear Information System (INIS)

    Carlsten, B.E.

    1998-01-01

    The nonlinear free-energy concept has been particularly useful in estimating the emittance growth resulting from any excess energy of electron beams in periodic and uniform channels. However, additional emittance growth, that is geometrical rather than thermodynamic in origin, is induced if the particles have different kinetic energies and axial velocities, which is common for mildly relativistic, very intense electron beams. This effect is especially strong if particles lose or gain significant kinetic energy due to the beam's potential depression, as the beam converges and diverges. In this paper we analyze these geometric emittance growth mechanisms for a uniform, continuous, intense electron beam in a focusing transport channel consisting of discrete solenoidal magnets, over distances short enough that the beam does not reach equilibrium. These emittance growth mechanisms are based on the effects of (1) energy variations leading to nonlinearities in the space-charge force even if the current density is uniform, (2) an axial velocity shear radially along the beam due to the beam's azimuthal motion in the solenoids, and (3) an energy redistribution of the beam as the beam compresses or expands. The geometric emittance growth is compared in magnitude with that resulting from the nonlinear free energy, for the case of a mismatched beam in a uniform channel, and is shown to dominate for certain experimental conditions. Rules for minimizing the emittance along a beamline are outlined. copyright 1998 The American Physical Society

  15. Measurement of the transverse emittance for the NSC Pelletron

    International Nuclear Information System (INIS)

    Rodriques, G.; Mandal, A.; Chopra, S.; Joshi, R.; Datta, S.K.; Roy, A.

    1998-01-01

    The knowledge of the emittance (transverse and longitudinal) of the NSC pelletron is essential for matching the acceptance of the LINAC which is to be installed to augment the pelletron beam energies. The transverse emittance of NSC pelletron has been measured by employing a focussing element and a down-stream beam profile monitor

  16. WE-E-BRE-08: Impact of IUdR in Rat 9L Glioma Cell Survival for 25–35 KeV Photo-Activated Auger Electron Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, D; Hogstrom, K [Louisiana State University, Baton Rouge, LA (United States); Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Brown, T; Dugas, J; Varnes, M [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Matthews, K [Louisiana State University, Baton Rouge, LA (United States)

    2014-06-15

    Purpose: To determine the biological effect from Auger electrons with 9% and 18% iododeoxyuridine (IUdR) incorporated into the DNA of rat 9L glioma cells at photon energies above and below the K-edge of iodine (33.2 keV). Methods: Rat 9L glioma cell survival versus dose curves with 0%, 9%, and 18% thymidine replacement with IUdR were measured using four irradiation energies (4 MV x-rays; monochromatic 35, 30, and 25 keV synchrotron photons). For each of 11 conditions (Energy, %IUdR) survival curves were fit to the data (826 cell cultures) using the linear-quadratic model. The ratio of doses resulting in 10% survival gave sensitization enhancement ratios (SER10) from which contributions due to linear-energy transfer (LET), radiosensitization (RS), and Auger effect (AE) were extracted. Results: At 35, 30, and 25 keV, SER10,LET values were 1.08±0.03, 1.22±0.02, and 1.37±0.02, respectively. At 4 MV SER10,RS values for 9% and 18% IUdR were 1.28±0.02 and 1.40±0.02, respectively. Assuming LET effects are independent of %IUdR and radiosensitization effects are independent of energy, SER10,AE values for 18% IUdR at 35, 30, and 25 keV were 1.35±0.05, 1.06±0.03, and 0.98±0.03, respectively; values for 9% IUdR at 35 and 25 keV were 1.01±0.04 and 0.82±0.02, respectively. Conclusion: For 18% IUdR the radiosensitization effect of 1.40 and the Auger effect of 1.35 at 35 keV are equally important to the combined effect of 1.90. No measureable Auger effect was observed for energies below the K-edge at 20 and 25 keV, as expected. The insignificant Auger effect at 9% IUdR was not expected. Additional data (40–70 keV) and radiobiological modeling are being acquired to better understand the energy dependence of Auger electron therapy with IUdR. Funding support in part by the National Science Foundation Graduate Research Fellowship Program and in part by Contract No. W81XWH-10-1-0005 awarded by the U.S. Army Research Acquisition Activity. This paper does not necessarily

  17. Low Cost Constant – Head Drip Irrigation Emitter for Climate ...

    African Journals Online (AJOL)

    Low Cost Constant – Head Drip Irrigation Emitter for Climate Change Adaptation in Nigeria: Engineering Design and Calibration. ... The drip system comprises of abarrel, sub-main line, lateral lines, tubes and emitters, it can irrigate140 crop ...

  18. Experimental studies on coherent synchrotron radiation at an emittance exchange beam line

    Science.gov (United States)

    Thangaraj, J. C. T.; Thurman-Keup, R.; Ruan, J.; Johnson, A. S.; Lumpkin, A. H.; Santucci, J.

    2012-11-01

    One of the goals of the Fermilab A0 photoinjector is to investigate experimentally the transverse to longitudinal emittance exchange (EEX) principle. Coherent synchrotron radiation in the emittance exchange line could limit the performance of the emittance exchanger at short bunch lengths. In this paper, we present experimental and simulation studies of the coherent synchrotron radiation (CSR) in the emittance exchange line at the A0 photoinjector. We report on time-resolved CSR studies using a skew-quadrupole technique. We also demonstrate the advantages of running the EEX with an energy-chirped beam.

  19. The camera of the Pierre Auger Observatory Fluorescence Detector

    CERN Document Server

    Ambrosio, M; Bracci, F; Facal, P; Fonte, R; Gallo, G; Kemp, E; Matthiae, Giorgio; Nicotra, D; Privitera, P; Raia, G; Tusi, E; Vitali, G

    2002-01-01

    The Fluorescence Detector of the Pierre Auger Observatory is a set of telescopes which measure the fluorescence light emitted by atmospheric nitrogen stimulated by the cosmic-ray showers. The Camera is an array of photomultipliers positioned on the telescope focal surface. We describe the main features of the camera: the hexagonal pixels geometry on the spherical focal surface; the light collectors which complement the photomultipliers; the photomultipliers test.

  20. The camera of the Pierre Auger Observatory Fluorescence Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, M.; Aramo, C.; Bracci, F.; Facal, P.; Fonte, R.; Gallo, G.; Kemp, E. E-mail: kemp@roma2.infn.it; Matthiae, G.; Nicotra, D.; Privitera, P.; Raia, G.; Tusi, E.; Vitali, G

    2002-02-01

    The Fluorescence Detector of the Pierre Auger Observatory is a set of telescopes which measure the fluorescence light emitted by atmospheric nitrogen stimulated by the cosmic-ray showers. The Camera is an array of photomultipliers positioned on the telescope focal surface. We describe the main features of the camera: the hexagonal pixels geometry on the spherical focal surface; the light collectors which complement the photomultipliers; the photomultipliers test.