Dudnikov V.,Muons, Inc.
Review of Scientific Instruments | Year: 2012
Features of the semiplanotron surface plasma sources (SPS) with cesiation used for high efficient negative ion beam production from first development to modern condition are considered. Design features of semiplanotrons SPS with cylindrical and spherical geometric focusing and the features of the negative ion production in the semiplanotrons are reviewed. Several versions of semiplanotrons with efficiency up to 0.1 A of H- per kW of discharge power are discussed. Modifications of the semiplanotrons for dc operation and for heavy negative ion production are reviewed. © 2012 American Institute of Physics. Source
Dudnikov V.,Muons, Inc.
Review of Scientific Instruments | Year: 2012
The cesiation effect, a significant enhancement of negative ion emission from a gas discharge with decrease of co-extracted electron current below negative ion current, was observed for the first time on July 1, 1971 by placing into the discharge a compound with 1 mg of cesium. Subsequent developments of surface plasma sources (SPS) for highly efficient negative ion production caused by the interaction of plasma particles with electrodes on which the adsorbed cesium reduced the surface work function are described. In the last 40 years, the intensity of negative ion beams has increased by cesiation up to 10 4 times from 3 mA to tens of amperes. Here, the main attention is concentrated on earlier SPS developments because recent results are well known and widely available. © 2012 American Institute of Physics. Source
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2015
Battery-powered compact, portable sources of gamma rays with energies between 1 MeV and 6 MeV and with variable duty cycles are needed for a variety of applications, from homeland security to a broad range of industrial and medical applications. Radioactive sources, although compact, are not tunable and are hazardous even when not being used. Typical industrial electron accelerators that provide gamma rays of the required energy are not compact or portable, nor can they operate on batteries. We propose a novel temperature-stabilized solid-state permanent-magnet microtron electron accelerator to provide a lightweight gamma-ray source with outstanding performance parameters and flexibility. The electrons are accelerated by a small RF cavity powered by a highly-efficient magnetron power source. Compactness and portability are achieved by using a magnet that does not need coils, power, or cooling, and using an efficient accelerating system that minimizes the need for RF power and cooling. The classical microtron design that we propose has a built-in vacuum chamber that eliminates a reliability issue seen in betatron gamma ray sources. A prototype portable microtron will be produced in Phase II. In Phase I, computations and simulations will be done to demonstrate accelerator performance and to verify that all requirements can be met. In addition, a complete conceptual design of a prototype unit will be produced, including the electrical, electronic, mechanical, and magnetic components. The design will utilize commercially available components from the US. Commercial applications of compact gamma ray sources include detection of fissile materials, observation of flaws in industrial components, discovery of flaws and weaknesses in bridges and other construction structures, medical scanning, oil exploration and others.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2014
High field magnets are needed for frontier accelerator facilities and have many applications beyond high-energy physics. Of particular interest are 30-40T class (LTS/HTS hybrid) solenoids required for the final beam cooling stages of a muon collider facility. The successful design of such magnets using Bi2212 conductor depends critically on the conductor processing, stress management in the coil, and quench protection. These are the challenges we will address in the proposal. This is the overall objective of the combined Phase I and Phase II projects. Bi2212 round wire conductor will be evaluated for accelerator use by concentrating on the design of a solenoid magnet that will be the enabling technology for realizing the final stages of muon beam cooling and thus a high luminosity muon collider. We will perform a full mechanical characterization of a test coil made from overpressure-processed conductor with engineering current density JE in the range of & gt;600 A/mm2 at 20-30 T. The data from the test coil will serve as input to a 30+ T magnet that will be designed, built, and tested to demonstrate the suitability of overpressure-processed Bi2212 for solenoids for final muon cooling and 6D cooling channels. Short lengths and coils wound from up to 100 m length conductor will be overpressure processed. Characterization of an overpressure processed Bi2212 round-wire based solenoid will be performed at 4.2 K in a background field of up to 14 T. The characterization will include mechanical, thermal, and quench properties. The data will be used as input to a 30+ T coil design that has suitable stress management and quench protection, to be built and tested in Phase II. Commercial Applications and Other Benefits: The technology developed by this work will benefit high-energy physics applications. The knowledge and expertise gained from this project will enable the development of very high-field solenoids, dipoles, and quadrupoles using Bi2212 cable at low temperature for applications in future particle accelerators. The technology will also extend the range available to Nuclear Magnetic Resonance Spectroscopy, an important technique used to understand molecular structures of proteins and other materials.
Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase I | Award Amount: 100.00K | Year: 2011
Current and future synchrotron radiation light sources and free electron laser facilities are in need of improvements in Electron Gun Technology, especially regarding the cost and efficiency of photoinjectors. Novel electron gun features are needed to enhance the intensity and reduce the emittances of electron bunches produced at a high repetition rate using laser excitation. The generation of Surface Acoustical Waves (SAW) on piezoelectric substrates is known to produce strong piezoelectric fields that propagate on the surface of the material. These fields significantly reduce the recombination probability of electrons and holes, increasing their radiative lifetime by orders of magnitude, which can result in enhanced quantum efficiency of photoemission. This project is developing the use of Surface Acoustic Waves on photocathodes to improve their efficiency, so that lower-power lasers can generate more intense electron beams having smaller emittances. Theory and simulations will be developed for the effect of SAW on photocathode efficiency for high-current conditions. We will perform modeling of a photoemission process in the presence of a moving super lattice generated by a surface sound wave propagating in piezoelectric substrates and evaluate changes in quantum efficiency caused by SAW Commercial Applications and Other Benefits: We propose to enhance the performance of electron guns with a new feature, surface acoustical waves. High-current, low-emittance electron guns are needed for development of high-brightness coherent light sources and for basic research with electron beams. Photoemission enhancement techniques will be developed that may also be used for production of more efficient photovoltaic materials.