Numerical solution of the problem of shape recovery for a system of impedance surfaces

We consider the problem of shape determination of a system of surfaces with impedance properties, using the scattering pattern specified at a finite number of points. We use the method of artificial “embedding” of the given problem in a more general problem in which the impedance distribution at variable parts of the surface is also a desired parameter. This allows us to move to the nonlinear operator equation that permits efficient numerical solution. Calculated results are given. Novosibirsk State Architecture and Civil Engineering University. Novosibirsk, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 5, pp. 452–458, May 1999.     

Nanopowder Characterization: Challenges and Future Directions

This article summarizes the conclusions of a workshop organized at the National Institute of Standards and nobreak Technology (NIST), Gaithersburg, October 4–5, 2001. The workshop was focused on the strengths and limitations of the techniques currently used for creating stable dispersions of nanoparticles and measuring the size distribution of powders in the nanosize range. Several emerging and alternative techniques with potential for use in particle size measurement in the nanometer range were advanced. Future needs for procedural and instrumental techniques and standards were identified.     

Status and Future of Synchrotron Based Infrared Imaging

The Status and Future of Synchrotron Based Infrared Imaging Workshop convened at the Waisman Center at UW Madison on October 7, 2010. The goal of the workshop was to bring together imaging scientists from many disciplines, as well as data management and industry experts.     

Second User Workshop on High-Power Lasers at the Linac Coherent Light Source

The second international workshop on the physics enabled by the unique combination of high-power lasers with the world-class Linac Coherent Light Source (LCLS) free-electron X-ray laser beam was held in Stanford, CA, on October 7–8, 2014. The workshop was co-organized by UC Berkeley, Lawrence Berkeley, Lawrence Livermore, and SLAC National Accelerator Laboratories. More than 120 scientists, including 40 students and postdoctoral scientists who are working in high-intensity laser-matter interactions, fusion research, and dynamic high-pressure science came together from North America, Europe, and Asia. The focus of the second workshop was on scientific highlights and the lessons learned from 16 new experiments that were performed on the Matter in Extreme Conditions (MEC) instrument since the first workshop was held one year ago.     

The VEPP-2000 electron-positron collider: First experiments

In 2007, at the Institute of Nuclear Physics (Novosibirsk), the construction of the VEPP-2000 electron-positron collider was completed. The first electron beam was injected into the accelerator structure with turned-off solenoids of the final focus. This mode was used to tune all subsystems of the facility and to train the vacuum chamber using synchrotron radiation at electron currents of up to 150 mA. The VEPP-2000 structure with small beta functions and partially turned-on solenoids was used for the first testing of the “round beams” scheme at an energy of 508 MeV. Beam-beam effects were studied in strong-weak and strong-strong modes. Measurements of the beam sizes in both cases showed a dependence corresponding to model predictions for round colliding beams. Using a modernized SND (spherical neutral detector), the first energy calibration of the VEPP-2000 collider was performed by measuring the excitation curve of the phimeson resonance; the phi-meson mass is known with high accuracy from previous experiments at VEEP-2M. In October 2009, a KMD-3 (cryogenic magnetic detector) was installed at the VEPP-2000 facility, and the physics program with both the SND and LMD-3 particle detectors was started in the energy range of 1–1.9 GeV. This first experimental season was completed in summer 2010 with precision energy calibration by resonant depolarization.     

Preface

Dynamics and Structure of Critically Stable Quantum Few-Body Systems was held at Les Houches, France, on October 8–12, 2001. The idea of the workshop originates in the observation that almost all subfields of physics have interesting problems using very similar methods to study few-body problems at the edge of stability. The usual meetings do not often appeal to the interdisciplinary aspects of the common concepts and techniques. A similar workshop was held at Trento in February 1997. The present workshop stretched from nano-scales over quantum chemistry, atomic, molecular, and nuclear to mathematical physics. The main theme was the properties of weakly bound quantum states and resonances near threshold. Explicitly emphasized topics in the announcement were: 1. Electron and positron-molecular systems. 2. Halos in atomic, molecular, and nuclear physics. 3. Coulomb breakup above threshold. 4. The four-body problem. 5. Few-body correlations in N-body systems: nuclei or Bose condensates. 6. Complex rotations to study resonances. 7. The use of zero-range interactions. 8. Inequalities confining properties like binding energy and radius. 9. Two-dimensional systems. 10. Time-dependent problems near instability. The current interest was highlighted during the workshop when the Nobel prize in physics for 2001 was awarded for making Bose-Einstein condensates. The topics are rather practical although they at first sight may appear to be rather theoretical. This was confirmed during the workshop with abundant application on realistic examples and direct discussions of experimental results. Adequate representation of the many subfields and topics requires a minimum number of participants but on the other hand this number must be small enough to avoid fragmentation into subfields. We estimate that maximum information is exchanged with between 30 and 45 participants. Including the organizers there were 34 participants, all invited, from Brazil, USA, and 12 different European countries. Essentially all presented oral contributions on topics of their own choice within the main theme. This left the emphasis of the workshop to the latest interests of the participants. One page abstracts were available at the beginning of the workshop. We are indebted to a number of sponsors for their support: European Science Foundation (ESF), Conseil Régional de la Région Rh?ne-Alpes (for the Proceedings), Institut National de Physique Nucléaire et Physique des Particules (IN2P3), Commissariat à l’énergie Atomique (CEA), Université Joseph Fourier, Grenoble (UJF), Institut des Sciences Nucléaires Grenoble (ISN), Centre de Physique Théorique, CNRS, Marseille (CPT). We also acknowledge the help from the Les Houches organization. The intimate atmosphere, the modern accommodation, and the beautiful surroundings provided a perfect framework. We appraise the help by Anne-Marie Guglielmini for the secretariat and Jocelyne Riffault for the web pages, both from ISN, Grenoble. We want to thank the unusually enthusiastic participants. Their engagement made the workshop both very enjoyable and scientifically beneficial. We can recommend more of this type of cross disciplinary communication and collaboration. We greatly appreciate the privilege of having these proceedings published by Few-Body Systems, this providing a rapid and widespread diffusion. We thank Prof. W. Plessas and Mrs. S. Schilgerius for their efficient help. The Organizers: J. Carbonell, P. Duclos, A. S. Jensen, J.-M. Richard     

DMLS 2011: Fourth International Workshop on Diamonds for Modern Light Sources

The fourth in a series of workshops devoted to the use of diamonds at synchrotrons and free electron lasers (FELs) was held on May 5-6, 2011, at the Advanced Photon Source. The previous DMSL workshop was held in Japan in 2008. The workshop was supported in part by Argonne National Laboratory; Applied Diamond, Inc.; SINMAT, Inc.; and elementsix, Ltd. The scope was to assess : 1) the status, size, quality, and availability of synthetic type IIa diamonds; 2) the status of CVD diamonds; 3) applications for beamline optics; 4) applications for beam position monitors (BPMs) and detectors; 5) applications at FELs; and 6) novel applications, such as for an X-ray free electron laser oscillator (XFELO). On May 5, Linda Young (APS/XSD) gave the workshop welcome. There were three sessions on each of the two days. A website was created and will be kept live where the detailed age-nda and list of speakers will remain available (http://www.aps.anl.gov/News/Conferences/2011/DMLS). As part of the session on BPMs and detectors, there were several speakers from outside the light source community, which demonstrated that there is a larger science audience for these applications than just light sources. Highlights of the workshop include: 1) reports of supplier facilities for thinning and polishing; 2) reports on tests of supplier-provided bonds to CVD cooling manifolds; 3) a report of more than 99% reflectivity from diamond for hard X-rays, significant for XFELO feasibility, measured at the APS; 4) a report on thermal expansion measurements at low temperatures made at the APS (no negative thermal expansion, thermal expansion below 1e-9); 5) a report from Brookhaven National Laboratory on substantial progress in diamond beam flux monitors (BPMs), and fast detectors; 6) a presentation on plans for a self-seeding at LCLS with diamond crystals. A synopsis of each technical session follows below.     

Technical Report: UV and VUV Radiometry Programs at the Synchrotron Ultraviolet Radiation Facility (SURF III)

The fourth international workshop on Adaptive and Active X-ray &; XUV Optics (ACTOP11) was held on April 4–5, 2011, at Diamond Light Source in Oxfordshire, UK. This workshop follows on from earlier, successful active optic events at SOLEIL (2006), Elettra (2008), and Osaka (2009).     

Fourth Diffraction Limited Storage Ring (DLSR) Workshop

The Fourth Diffraction Limited Storage Ring (DLSR) Workshop was held at Argonne National Laboratory's Advanced Photon Source from November 19 to 21, 2014. The three-day meeting was attended by 120 participants from 22 different institutions. Local organizers of the workshop were Lahsen Assoufid, Herman Cease, Glenn Decker, Kathy Harkay, Dean Haeffner, Dennis Mills, Connie Vanni, and Diane Wilkinson (all Advanced Photon Source). The workshop website is http://dlsr-workshop-2014.aps.anl.gov/.     

Strangeness content and structure function of the nucleon in a statistical quark model

The strangeness content of the nucleon is determined from a statistical model using confined quark levels, and is shown to have a good agreement with the corresponding values extracted from experimental data. The quark levels are generated in a Dirac equation that uses a linear confining potential (scalar plus vector). With the requirement that the result for the Gottfried sum rule violation, given by the New Muon Collaboration (NMC), is well reproduced, we also obtain the difference between the structure functions of the proton and neutron, and the corresponding sea quark contributions. Received: 15 March 1999 / Revised version: 15 April 1999 / Published online: 14 October 1999     

Epitaxial growth of metals with high Ehrlich–Schwoebel barriers and the effect of surfactants

Interlayer diffusion in epitaxial systems with a high energy barrier at the atomic steps – the so-called Ehrlich–Schwoebel (ES) barrier – is strongly reduced. As a consequence of this, a continuous accumulation of roughness takes place during growth. This undesirable effect can be corrected by using surfactant agents. We have studied the influence of the ES barrier on the preparation of epitaxial films on Cu(111), and the surfactant effect of a monolayer of Pb. Received: 21 April 1999 / Accepted: 17 August 1999 / Published online: 6 October 1999     

Meeting Report: Vacuum Ultraviolet Radiometry

As part of the 2006 NSLS/CFN Users' Meeting, an all-day workshop on the topic of Vacuum Ultraviolet (VUV) Radiometry was held at Brookhaven National Laboratory on May 17 to address NSLS users with an interest in absolute photon rate measurements. For the purposes of this workshop, the VUV range was defined broadly as the range of photon energies requiring ring-contiguous vacuum (5–5000 eV). Also, both absolute (i.e. radiometry) and relative (e.g. reflectometry) instrumentation and results were discussed. The workshop included presenters from some of the world's most capable synchrotron-based radiometry facilities, including PTB at BESSY-2, ALS / CXRO, SURF-III at NIST, and both facility and Participating Research Team beamlines at NSLS. There were 8 speakers and roughly 45 total attendees. Speakers included Franz Weber (Livermore), Rob Vest (NIST), John Seely (NRL), Frank Scholze (PTB), Steve Hulbert (NSLS), Eric Gullikson (ALS), Tony Kuczewski (NSLS) and Jeff Keister (NSLS).     

Measurement and interpretation of fermion-pair production at LEP energies from 130 to 172 GeV

The data collected with the DELPHI detector at centre-of-mass energies between 130 and 172 GeV, during LEP operation in 1995 and 1996, have been used to determine the hadronic and leptonic cross-sections and leptonic forward–backward asymmetries. In addition, the cross-section ratios and forward–backward asymmetries for flavour-tagged samples of light (uds), c and b quarks have been measured. No significant deviations from the Standard Model expectations are found. The results are interpreted by performing S-matrix fits to these data and to the data collected previously at the energies near the resonance peak (88-93 GeV). The results are also interpreted in terms of physics beyond the Standard Model: contact interactions, R-parity violating SUSY particle exchange and of possible Z bosons. Received: 9 February 1999 / Published online: 14 October 1999     

Millimeter-Wave Radiometer for the Measurement of Stratospheric ClO Using a Superconductive (SIS) Receiver Installed in the Southern Hemisphere

A new sensitive radiometer for atmospheric minor constituents has been developed by Nagoya University and the National Institute for Environmental Studies (NIES). The instrument equipped low-noise superconducting (SIS) mixer with a system noise temperature of 200K (SSB) at 204GHz. The SIS mixer is operated in a single side band mode with a side band ratio grater than 10dB by adjusting the two tunable backshorts of the mixer. Since any additional SSB filters are not necessary, we can simplify the quasi-optical system and reduce the standing waves which makes difficult to achieve a flat spectral baseline. We installed the observation system at Las Campanas Observatory, Chile in December 1999, and started the test observation from 2000 October. We have detected significant ClO emission at 204.3 GHz with an actual observation time of only 4 hours. This is the first detection of the ClO at 40km altitude from the mid-latitude region of the southern hemisphere. The Nagoya-NIES system has enabled continuous monitoring of ClO in the stratosphere with a time resolution of 4 or 5 hours.     

Complex interferometry: Its principles and applications to fully automated on-line diagnostics

An interferometric technique which enables simultaneous recording of up to three sets of data into just one interferogram is discussed. The possibilities of the reconstruction of these data are studied. Three important particular cases allowing such a reconstruction are analyzed.Presented at the Iodine laser and applications workshop, 2–6 October 1989, Liblice Castle, Czechoslovakia.     

FOUNDATIONS OF PHYSICS LETTERS—List of Contents: Volume 12, Number 5, October 1999

Volume Contents

FOUNDATIONS OF PHYSICS LETTERS—List of Contents: Volume 12, Number 5, October 1999     

A high aperture beamline for vacuum ultraviolet circular dichroism on the srs

The three-day international workshop Actinide-XAS-2006 was held at Forschungszentrum Karlsruhe (FZK), Germany, from September 18–20, 2006. Actinide-XAS-2006 was the fourth workshop on speciation, techniques, and facilities for radioactive materials at synchrotron light sources. The Actinide-XAS series addresses the specialized field of the application of synchrotron techniques for investigating radioactive materials and is a forum for teaching and scientific discussion in this field, thereby strengthening existing and establishing new transnational cooperative scientific networks. The first and second workshops, Actinide-XAS-1998 and Actinide-XAS-2000, were held in Grenoble at the ESRF. The third and last workshop, Actinide-XAS-2004, was held at Lawrence Berkeley National Laboratory.     

Effects of boundary reflection on photoacoustic spectrum of porous silicon

Photoacoustic (PA) amplitude and phase spectra are studied on porous silicon (PS) samples. For the sample with a thinner PS layer and a rough interface observed by field-emission scanning electron microscope (FE-SEM), PA amplitude decays rapidly at short wavelengths but stays at a higher level above 650 nm compared with a sample with a thicker PS layer and a smooth interface. In this latter long-wavelength region, phase delay for the former sample is smaller. A model calculation for the two-layer model taking account of scattering of light in the porous media and interface reflection of light gives at least a qualitative explanation of these differences. Received: 30 June 1999 / Accepted: 11 October 1999 / Published online: 23 February 2000     

Catalysis Workshop at ANKA

“Shining Synchrotron Light on Catalysts at Work – Opportunities and Limitations” was the title of the workshop that took place on October 8, 2010, in Karlsruhe (Germany) as part of the ANKA/KNMF user meeting. More than 80 German and international guests met at this event. Tilo Baumbach (director of ANKA, Karlsruhe) outlined in his warm welcome speech that ANKA is more than only an open facility to future catalysis research — it really wants to act as “catalyst” for studying the structure of catalysts and properties in catalytic reactors. Jan-Dierk Grunwaldt, as one of the three organizers of this workshop, also welcomed the workshop participants from academia and industry and outlined the importance of studying catalysts under reaction conditions: More than 95% of all chemical products have “seen” a catalyst in course of their production. New catalysts are required in energy conversion, as well as more efficient and new catalysts in fine chemistry and environmental technology. Since the catalytic structure is mostly correlated to the structure on the atomic level, information about it is of profound importance. This was already demonstrated by Thorsten Ressler in his talk “Catalysis and Synchrotron Radiation” on the main ANKA/KMNF user meeting the day before. ANKA, with its mid-hard X-ray, soft X-ray, and infrared beamlines and embedded in the scientific environment of the KIT, is an excellent place for catalysis research as Stefan Mangold (ANKA) demonstrated in his short overview, and it is developing more and more toward this direction.     

User Workshop on High-Power Lasers at the Linac Coherent Light Source

A two-day international workshop on the physics and integration of high-power lasers with the Linac Coherent Light Source was held in Stanford, California, USA, on October 1–2, 2013. The workshop was co-organized by UC Berkeley, Lawrence Berkeley, Lawrence Livermore, and SLAC National Accelerator Laboratories. More than 150 scientists, including 30 students and postdocs who are working in high-intensity laser-matter interactions, fusion research, and dynamic high-pressure science, came together from North America, Europe, and Asia. The group discussed the most promising and important new physics experiments that will be enabled by the unique combination of high-power lasers and the world-class LCLS free-electron laser X-ray beam.