Developments in pulse power supply applications at Daresbury laboratory

Physicists at the Daresbury Laboratory in the UK have received £2m from the government to carry out studies on a new type of accelerator technology designed to produce extremely intense and short-lived bunches of radiation. The Energy Recovery Linac Prototype (ERLP), due to begin operating in the spring of next year, will serve as a test-bed for a much larger facility known as the Fourth Generation Light Source (4GLS). If it is approved, 4GLS will combine both conventional synchrotron and freeelectron laser radiation for a wide range of research, from nanotechnology to medical science.

The bending magnet beam line 1.2 low-energy toroidal grating monochromator of the synchrotron radiation source (SRS) at Daresbury Laboratory, was designed1 to deliver moderately high fluxes (∼ 5 × 1011 photons s−1), of linearly polarized, medium resolution (∼0.2 eV) radiation in the energy range 5–85 eV. The colinear optical system utilizes platinum-coated silicon-carbide mirrors to focus the broad-band radiation emergent from the SRS at the entrance slits of the three grating monochromator. A single ellipsoidal mirror is then used to doubly focus the desired narrow-band radiation at the sample position. The colinear arrangement of the optical elements ensures that the radiation at the sample point is strongly horizontally plane polarized (estimated to be of order 90%). The entire system has been the subject of detailed analyses using the raytracing program shadow,2 and standard optical theory. These calculations have been compared with experimental determinations of photon flux outputs and resolution measurements.

Recently, pulsed power technologies, including pulsed electric fields (PEFs) and time-modulated plasmas, are starting to be applied actively in agriculture and food processing. In the applications, compact pulsed power generators with moderate peak power and repetitive operation are developed for controlling discharge plasmas and electric field distribution. These applications are mainly based on the biological effects of a spatially distributed electric field and the chemically active species in the plasma. The PEFs are caused by applying pulse voltage between the electrodes and contribute to form pores on the cell membrane or to change conformation of protein. When the applied voltage exceeds the discharge onset criterion, plasmas are generated through the avalanche process of electron accelerated with intense electric field in a gas or liquids medium. The plasmas produce chemically active species, UV radiation, an intense electric field in the vicinity of discharge channel and shock waves, which also have different biological effects. The agricultural applications of pulsed power can be categorized as two phases: pre-harvest and post-harvest phases. The pre-harvest phase consists of seed germination, seedling growth, plant growth and growth mode change from vegetative to reproductive. Pulsed power technologies are used to promotion of seed germination, plant growth enhancement through direct stimulation or indirect effect such as inactivation of bacteria in soil and liquid hydroponic media, and promotion of mushroom fruit body formation. The post-harvest phase consists of harvesting the agricultural produce, storing the products, transporting the products to consumers and food processing such as drying, pasteurization (sterilization of bacteria), permeabilization and fermentation. The pulsed power technologies are also used to keep freshness of agricultural produce through decontaminating airborne, inactivating bacteria and decomposition of plant hormone in the storage containers. The poration of cell membrane by PEF contributes improvement of extraction of juice, nutritional agents, and antioxidant metabolites such as polyphenols from agricultural products. In this review, at first, a basis of pulsed power system for agricultural applications and bio-effect by high-electric field exposure is outlined. After that, pre-harvest and post-harvest agricultural applications are described. The utilization of pulsed power technologies to contribute efficient food processing and improve food safety and quality is also described.

A project is currently underway to automate the protein crystallography beamlines on the Synchrotron Radiation Source (SRS) at Daresbury Laboratory. Included in this project is the development of an automatic sample changer to allow remote mounting and dismounting of frozen protein crystals and the upgrade of all of the experimental equipment on the station in order that all required movements can be controlled from

When an instructor creates an educational content with narration on Microsoft PowerPoint, it is the easiest method that he/she uses one's built-in feature of recording narration because there is no need to install any other software. We constructed the content authoring system for e-Learning, named Kumamoto Universal and Multipurpose Authoring (KUMA) system, which is based on cloud computing. Using the system, an instructor only has to upload the slide with narration created on PowerPoint to the system, and then he/she can publish a Windows Media streaming video and a PDF slide. The application of the system is the website of streaming video lectures contributed by researchers in the field of pulsed power, which we call "Streaming Book on Pulsed Power Engineering". Another application of it is the website of video lectures for graduate students as a part of blended learning. To deliver streaming videos to more than 100 students simultaneously, we need to configure quality of encoding streaming videos and estimate the amount of transferring data and the network traffic load. The purpose of this study is to examine the traffic load for streaming e-Learning content in applications of KUMA system. In this work, we use Windows Media Load Simulator to simulate the connections from more than 100 students.

Introduction: The demand for new rapid methods for development of medicines for health care is becoming more relevant. Detailed knowledge of the spatial structure of viral proteins and their complexes formed when the organism is infected with viruses is important for effective development of vaccines and antiviral drugs. Timely selection of sensitive animal models and the study of the pathogenesis of an infectious disease on them are important for quality testing of biological preparations. The synchrotron radiation source is a new powerful biological research tool. Objective: To analyze the potential of existing sources of synchrotron radiation for conducting virology research, from macroorganisms to individual viral proteins. Materials and methods: We searched for literary sources published in 1996–2022 and devoted to the use of synchrotron radiation in virology and its importance for public health in the future using relevant keywords in the PubMed and PDB databases. Fifty-one full-text publications were found eligible for inclusion in the review. Results: Currently, there are over 70 different synchrotron radiation sources worldwide and many of them are used for diverse biological studies of living systems. Phase-contrast X-ray imaging makes it possible to visualize soft tissues in vivo with resolution up to 1 µm in the absence of contrast agents. Synchrotron radiation allows real-time 3D-histology without the necessity to prepare ultra-thin slices. Obtaining the structure of viral proteins in solution and protein crystallography realized with synchrotron radiation sources has been actively used in antiviral drug development and the study of fundamental properties of viruses since 2000. Conclusion: The X-ray techniques realized in synchrotron radiation sources discussed in this review constitute the fundamental basis of many virology studies and have a promising future for ensuring biological safety of Russia. Keywords: synchrotron radiation, virology, animal microtomography, histology, protein crystallography.

We propose a Photon Storage Ring (PhSR), which is a novel free-electron laser (FEL) composed of a compact synchrotron radiation (SR) source and a cylindrical mirror surrounding the electron orbit. The SR source is an exactly circular type and the mirror is concentric to the electron orbit. In this scheme SR is reflected back tangentially to the electron orbit by the cylindrical mirror and interacts with the electrons, leading to the laser oscillation. The PhSR posesses many ideal features: since SR is confined by the mirror then all the radiations emitted at an angle to the electron orbit exibit good coherency; since the interaction occurs continiously along the electron orbit, a large gain is expected; and since all radiations are extracted through a simple opening, an extraction efficiency is fairly high. Compared with a conventional FEL, PhSR is capable of generating a high laser power by using a relatively small accelerator with a small electron beam current.

New orbit correction method uniting global and local orbit corrections

X-ray powder diffraction measurements using synchrotron radiation are currently being carried out on three experimental stations on the SRS at Daresbury Laboratory. Station 9.1 contains a general purpose powder diffractometer for angular dispersive measurements. The instrument is sited on the wiggler beamline, which provides radiation with a critical energy of 12 keV. A Si(111) water-cooled, channel-cut monochromator gives useful flux over an energy range from 6 to 30 keV. A cryostat and furnace are available for experiments requiring special environments, while a curved position sensitive detector can be used for time-resolved measurements. The wiggler white beam is employed on Station 9.7 for energy dispersive powder diffraction experiments. Various sample stages for kinetic experiments are in use on this station, and examples are shown of recent high-pressure work. A new high resolution powder diffractometer has been built and commissioned on Station 8.3, using bending magnet radiation. The diffractometer is based on the Parrish and Hart design, in which long, parallel foils are used to define the angular divergence accepted by the detector. In this way, large synchrotron beam cross sections can be employed while maintaining high angular resolution.

The discipline of pulsed power hydrodynamics is a new application of low-impedance, pulsed power technology, developed to study implosion hydrodynamics, instabilities, turbulence, and material properties in a highly precise, controllable environment at the extremes of pressure and material velocity. The discipline of pulsed power hydrodynamics arose in response to the need for economical, high-precision data to validate sophisticated numerical models used in current numerical simulations and to motivate the development of new models for future simulations. The international capability in pulsed power technology that has evolved over several decades in response to numerous other programmatic needs played a pivotal role in the development of the new discipline by enabling demonstrations of the techniques and production of introductory data long before a dedicated facility could be conceived, planned, and built. The high-precision, cylindrically imploding liner is the tool most frequently used to convert electromagnetic energy into the hydrodynamic (particle kinetic) energy needed to drive strong shocks, quasi-isentropic compression, or large volume adiabatic compression for the experiments. At typical parameters, a 30-gr, 1-mm- thick liner with an initial radius of 5 cm, driven by a current of 20 MA, can be accelerated to 7.5 km/sec producing mega-bar shocks in medium density targets. Velocities up to 20 km/sec and pressures >20 Mbar in high density targets are possible. The Atlas facility, designed and built by Los Alamos, houses the world's first laboratory pulsed power system designed specifically to explore this relatively new family of pulsed power applications. Constructed in the year 2000 and commissioned in August 2001, Atlas is a 24-MJ, high-performance capacitor bank delivering currents up to 30 Megamperes with a rise time of 5 to 6 musec. The first Atlas liner implosion experiments were conducted in September 2001, and 16 experiments were conducted in the first year of operation before Atlas was disassembled to be moved to the Nevada Test Site, where experiments began again in July 2005. Applications of pulsed power hydrodynamics techniques currently include material property topics such as: exploration of material strength at high rates of strain; material failure including fracture, damage, and spall; and interfacial dynamics at high relative velocities and high interfacial pressures. Implosion dynamics and a variety of complex hydrodynamic geometries have been explored and experiments to explore perturbation growth and transition to turbulence are under consideration. Longer term applications include the study of the behavior and properties of strongly coupled plasmas and the equation of state of metals and non-metals at pressures above 10 Mbar. This paper will provide an overview of the programmatic evolution that led to the birth of the discipline of pulsed power hydrodynamics.

The synchrotron radiation source at the Daresbury Laboratory, Science and Engineering Research Council, has been used to obtain white X-radiation topographs of high-quality single crystals of ice with exposure times of about 20 s. Sequences of topographs show the motion of individual dislocations under stress in the very early stages of plastic deformation at temperatures from −10 to −35°C. Glide on the basal plane appears to be limited by a Peierls barrier in the screw and 60° orientations. Edge, but not screw, dislocations on non-basal planes glide faster than dislocations on the basal plane and act as sources of dislocation multiplication. The velocities of both basal and non-basal dislocations are found to be linear functions of stress. Much recovery occurs on the time scale of previous experiments to measure dislocation velocities. The implications of the observations for theories of dislocation mobility are discussed.

A high-temperature furnace with an induction heater coil and a cryogenic system based on closed-cycle refrigeration have been assembled to enhance the non-ambient powder diffraction facilities at the Synchrotron Radiation Source, Daresbury Laboratory. The commissioning of the high- and low-temperature devices on the high-resolution powder diffractometer of Station 2.3 is described. The combined temperature range provided by the furnace/cryostat is 10-1500 K. Results from Fe and NH(4)Br powder samples are presented to demonstrate the operation of the apparatus. The developments presented in this paper are applicable to a wide range of other experiments and diffraction geometries.

Recently there has been much interest in the development and use of soft x-ray microscopy, as other contributions to this volume show. In the United Kingdom, a soft x-ray microscopy program is being carried out on the Synchrotron Radiation Source at the Daresbury Laboratory [12.1]. Although it is intended ultimately to develop a scanning microscope, the initial stages of the program have concentrated on the construction of high-resolution optical components for use in a prototype imaging microscope. For this purpose a lithographic technique using a Vacuum Generators HB5 scanning transmission electron microscope (STEM) is being used. This technique is capable of drawing accurate patterns, with linewidths much less than 50 nm, over small areas. It is therefore suitable for the manufacture of soft x-ray diffractive optics, in particular zone plates. This is discussed in this paper, as are the effects of possible manufacturing inaccuracies on the zone plate imaging properties. Deliberate modifications to the Fresnel zone plate are also considered.KeywordsScanning Transmission Electron MicroscopePrimary FieldZone PlateStrehl RatioFresnel Zone PlateThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Small-angle scattering studies of meso-scopic structures with synchrotron X-rays

At the Synchrotron Radiation Source (SRS) of the Science and Engineering Research Council’s (SERC) Daresbury Laboratory, England, the U5 undulator beamline has been built as a tunable source of soft (200–2000eV) x-rays appropriate for a scanning transmission x-ray microscope (STXM). Here we discuss the motivation, concept, design, and experimental program for the STXM with particular attention given to those features which are peculiar to this instrument. Finally, we take a look at the future of scanning x-ray microscopy.