The Regents Of The University Of California and Radiabeam Technologies, LLC | Date: 2016-10-19
A tapering enhanced stimulated superradiant amplification method and system which utilizes a strongly tapered undulator in reaching significant power outputs and conversion efficiencies. TESSA dramatically increases conversion/amplification efficiencies by violently (sharply) decelerating electrons and taking advantage of produced radiation to further drive interaction toward as it takes advantage of produced radiation to further drive interaction to increase overall radiation output. The system and method configures a strongly tapered undulator to operate in a new mode that is above normal input saturation levels to provide an amplified output with unexpectedly high efficiencies and power.
Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase II | Award Amount: 999.71K | Year: 2016
Metal photoinjector cathode development has shown recent promise with nano-patterning technology. However, in order to be competitive with semi-conductor cathodes, a further enhancement in efficiency is needed. TECHNICAL APPROACH Specific nano-patterning of sub-wavelength features to produce antennae provides coupling of incoming laser light with the surface of the metal cathode. Bowtie nano-antennae, in particular, have shown to increase the local field emission by up to an order of magnitude. Coupling novel nano-antennae in a high-current, superconducting injector shows promise to provide unprecedented efficiency as a robust metal cathode. PHASE II RESULTS The Phase II results demonstrated emission from a copper nano-patterned cathode that was 3000 times that of flat copper, with studies into pattern optimization, new materials like silver and niobium, and new geometries such as trenches and bowties. PHASE IIA PLANS In Phase IIa, emphasis will be place on the fabrication of bowtie nano-antennae for superior emission, and studies into patterning of niobium cathodes with planned testing in actual superconducting radio frequency photoinjectors. COMMERCIAL APPLICATIONS AND OTHER BENEFITS The results of the efforts will find immediate utility in present advanced accelerator and light source facilitates that employ high brightness photoinjectors which have direct impact on industrial, medical, defense and basic research applications.
Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase II | Award Amount: 999.61K | Year: 2016
Transmission electron microscopy (TEM) is one of the primary tools for biological and materials characterization and has many important research applications. There is an overarching need to improve the temporal resolution of TEMs. State-‐of-‐the-‐art single shot TEM only achieve 10 nanoseconds temporal resolution. Technical Approach UCLA and RadiaBeam Technologies propose to develop a single shot picosecond time resolved transmission electron microscope (SPTEM) with 10 ps temporal and 10 nm spatial resolution based on the use of MeV beams from an RF photoinjector aiming at improving the current state-‐of-‐the-‐art in temporal resolution in single shot electron microscopy by three orders of magnitude. Other key elements include the use of an x-‐band cavity linearizer to improve the source energy spread distribution, and an ultra-‐compact electron optical column based on strong permanent magnet quadrupoles (PMQs) to avoid the large costs and complexities associated with bulky relativistic electron lenses. Phase II Work Plans In Phase II, we will go forward in the realization of the first single shot picosecond transmission electron microscope (SPTEM) prototype based on the existing infrastructure at the UCLA Pegasus laboratory, completing the construction and commissioning of the x-‐band linearizer and introducing a second magnification stage to demonstrate 1000x magnification. The final goal of the project will be to test the instrument capabilities by performing a time-‐resolved study of motion of defects in a material. Commercial Applications and Other Benefits There are many exciting scientific challenges and commercial opportunities awaiting novel tools possessing very high combined spatial and temporal resolution, such as the proposed single-‐shot picosecond transmission electron microscope. These include conformational changes in protein, interface dynamics in battery and fuel cells, and phase transition and microstructure development in materials. The device would enable further breakthroughs in the understanding of ultrafast phenomena, stimulating new innovations in material science, chemistry, and biology.
Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase II | Award Amount: 999.55K | Year: 2016
Laser based advanced accelerators can achieve very high accelerating gradients, but their duty cycle is limited by the laser power availability and media recovery time. Inverse Free Electron Laser (IFEL) is a vacuum farfield laser accelerator scheme which does not rely on a medium (plasma) or a structure (metal or electric) and therefore is potentially capable of accelerating charged particles very efficiently and at very high duty cycles; however, it requires TWlaser power to reach GV/m gradients which still stands as the limiting factor for high average power applications. Technical approach In response to this opportunity, RadiaBeam is developing an active recirculated CO2 optical cavity to recover and recycle and reamplify the laser power after each IFEL interaction, enabling efficient laser driven acceleration of electron bunch trains at 20 MHz. Phase I Results: A conceptual design, initial engineering and thorough numerical simulations of the proposed intracavity IFEL has been carried out. A mock up optical cavity was assembled and tested to establish basic properties of the recirculated laser beam, and gain confidence in the ability to control the laser transverse profile and intensity over the duration of the pulse train. Phase II Plan: In Phase II, the subsystems will be fabricated and tested, and the full intracavity IFEL system will be integrated and commissioned at the Accelerator Test Facility at BNL. The goal of the project is the first ever demonstration of high gradient high energy gain laser acceleration of electron bunch trains at MHz frequencies. Commercial applications and other benefits: There are three commercialization thrusts: IFEL based Inverse Compton Scattering gamma ray source, IFEL based soft Xray FEL, and an IFEL decelerator light source (TESSA). The gamma ray source will target nuclear detection, safety and nuclear spectroscopy applications. IFEL driven FEL can offer a compact room size light source solution for universities and research laboratories; and TESSA will offer a high efficiency light source capability to multiple applications, including semiconductor industry. Key words Inverse Free Electron Laser, IFEL, CO2 laser, active optical cavity, gamma ray source, Inverse Compton Scattering, Free Electron Laser Summary for members of congress This project will develop an extremely bright, compact source of tunable gamma rays, which will uniquely enable detection of concealed nuclear materials at a stand off distances up to 1 km.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 999.91K | Year: 2015
Collinear wakefield accelerator approaches are limited to transformer ratios of less than two for symmetric drive profiles. Exceeding this limitation is necessary to establish dielectric wakefield acceleration as viable technology for future compact high-gradient accelerators. Novel methods are needed to generate asymmetric shaped drive beams ideal for enhanced transformer ratios. We propose to develop a longitudinal bunch shaper that is capable of generating nearly idealized triangular profiles using the beam self-wakefield interaction in a dielectric structure followed by a compact chicane. The shaped beam will serve as a driver for a second stage dielectric wakefield accelerator with enhanced transformer ratio. In Phase I, the system was conceptually designed and theoretically modeled with simulations for benchmarking. The system components were fabricated and assembled and installed for experimentation at the Brookhaven National Laboratory Accelerator Test Facility. The Phase I results experimentally demonstrated the generation of a beam with triangular profile consistent with theoretical modeling and simulations. In Phase II, we will build off the successful results and integrate a second stage structure to accelerate particles and measure the transformer ratio of the system. We will also explore alternate geometries and attempt higher-order shaping schemes. COMMERCIAL APPLICATIONS AND OTHER BENEFITS The benefits of dielectric wakefield accelerator structures include shaped bunches to extract energy, and access higher frequencies. It also provides high-added value in afterburner applications for existing facilities, allowing an increase in energy at negligible added footprint. The R&D has implications ranging from laser acceleration to high frequency components in communications. Finally, these structures serve as robust sources of terahertz radiation, (high peak power, narrow bandwidth) for material spectroscopy and pump-probe experiments.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 999.60K | Year: 2015
To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices (or so-called dirty bombs) DOE is planning to dramatically reduce the amount of radioactive material in use. Ir-192 is the most common isotope used for radiography and poses a higher risk of being diverted since it must constantly be replenished, and is found in small, portable devices that nevertheless contain dangerous amounts of material. The existing technology of RF linacs based on sophisticated multi-cup copper structures is too complicated and expensive to be compatible with massive replacement.RadiaBeam is developing an inexpensive, energy-tunable, portable linac based on easy-to-manufacture, structure to allow effective capture of tens of keV electron beam injected from an inexpensive electron gun and acceleration to a final energy up to 1 MeV. The structure design significantly simplifies brazing, eliminates time consuming tuning due to the high group velocity in common tube housing. The bremsstrahlung X-rays produced by the ~1 MeV electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical 200 Ci Ir-192 source.A two-section, hybrid Alumina-Copper, easy-to-fabricate, disk-and-ring-type structure has been designed. The novel design eliminates multi-cell brazing and expensive RF windows as combines them with the couplers. Assembling of the structure is as simple as stuffing of a pipe with the CNC-milled disks and ring. The simulations indicate attaining of a 1.2 MeV energy for a more than 10 mA current with low power ~100 kW X-band magnetron. Seven cells (~1/6th) of the structure have been fabricated at the cost of $180 per cell. Test mockup with the 7 cells driven by a 14 keV electron gun from L3 have been built with novel designs of vacuum port and alternating periodic permanent focusing. Up to 30 mA have been transported through the 7 cells at 50% transmission up to 30 Hz rep rate at better than 0.1 nbar pressure without indications of damage. In Phase II project we are going to design, fabricate and commission the X-ray source based on the novel type structure to match the penetration and dose rate of a typical 200 Ci Ir-192 source. In Phase II we demonstrate suitability of the system for mass production and feasibility of attaining 40 lbs weight of the system.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 925.15K | Year: 2016
Conventional thermionic RF guns can offer high average beam current, which is important for synchrotron light and THz radiation sources facilities, as well as for industrial accelerators. However, the thermionic RF guns are based on a decades old design, suffer from mechanical and thermal problems, and are generally due for a major upgrade and replacement. In response to this problem, RadiaBeam Systems proposes to design and build a new, more stable and reliable gun with optimized electromagnetic performance, improved thermal engineering and more robust cathode mounting technique. These tasks will be performed with cutting edge numerical modeling, multi-physics and beam dynamics simulation tools, and also using a proven design methodology developed by the company. This project is proposed as a Fast Track, since there is an immediate need to upgrade the thermionic injector at the Advanced Photon Source, where RadiaBeam and Argonne have jointly developed a tunable THz source. In the Phase I we will develop a prototype RF gun cavity with the improved RF contacts and exchangeable cathode back-plate, build the dummy cavity and RF stand to test the performance of the back-plate, frequency sensitivity, and tuning capability, using the available high power sources. In Phase II, a prototype thermionic RF injector will be fully engineered, fabricated, tested and integrated into the RadiaBeam/APS Terahertz radiation source. Synchrotron light facilities are critical part of the high impact scientific research infrastructure in the US. This project will provide a major upgrade for RF guns, which are used to drive this facilities, as well as emerging compact THz sources. Commercial Applications and Other Benefits: The goal of this project is to build an instrument that will be immediately used by Argonne National Laboratory in their work on improving stable and reliable operation of the Advanced Photon Source. This project also has an immediate impact on an existing joint APS-RadiaBeam THz radiator program, allowing increasing its power and frequency. In addition, a number of the light source facilities worldwide would be interested in replacing their thermionic RF injectors with an updated and improved version.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 999.91K | Year: 2016
The klystrons used to drive cryomodules at JLAB and other accelerator facilities are relatively inefficient and becoming obsolete, as the RF world has been progressively converting to solid state technology. The JLAB upgrade program requires a ~8 kW, 1497 MHz amplifier operating at 55-60% efficiency, and 8 kW CW power to replace the existing 340 klystrons. Capital and operational costs over the lifetime should be favorable vs. the klystron costs. These challenging requirements are beyond what is currently available on the market. B. Technical Approach This project will develop a solid state replacement based on high electron mobility GaN transistors in a Class-F amplifier with precise in-phase coaxial combiners and highly efficient step-down conversion based on an invertor with novel high voltage insulated-gate bipolar transistors. A water cooling system conformal to the dividing-combining architecture enables optimal performance conditions and long lifetime. High reliability and convenient maintenance of the architecture is provided by the so-called graceful degradation feature: failure or malfunction of one (or even more) transistors in the output array will not cause shutdown of the entire unit. C. Phase I Plan In Phase I, the 8 kW solid state amplifier will be designed and two key component mockups will be fabricated and tested: the F-Class high efficiency power amplifier and the multi-way divider. D. Commercial Applications and Other Benefits The applications include both superconducting and normal conducting accelerator facilities such as free electron lasers (FELs), industrial and medical accelerators, radars, mobile weapon systems, wireless communications, air traffic control and surveillance, wireless gadget charging, microwave chemical and plasmatron technological reactors.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 999.83K | Year: 2016
In order to produce short, intense pulses of x-ray light, current- and next-generation light source facilities must compress the electron bunches that feed the free-electron laser using a magnetic chicane. Such compression often results in a residual chirp, which has a detrimental effect on the lasing capabilities of the FEL, such as lowering the output power and widening the bandwidth of the resultant light. Methods exist for removing the chirp from the bunch, either through running RF accelerating cavities off-crest, or by employing wakefields in long sections of beam pipe; however, such techniques are not always available or economical, and they lack the flexibility to adequately attend to varying input conditions. Technical Approach In response to this problem, RadiaBeam proposes to create the first versatile commercial Dechirper system, based on an adjustable-gap corrugated insertion device, ruggedized for high- average-beam-power applications. Tuning the Dechirper by adjusting the gap between the corrugated plates applies a near-linear corrective wakefield of regulated strength across the length of the beam bunch and enables not only a removal of the undesired chirp, but also an unprecedented degree of control over the longitudinal phase space. Phase II progress to date A full-scale prototype Dechirper consisting of two 2-meter long modules was designed, fabricated, and installed in the beamline at the LCLS. The Dechirper system has been commissioned and has demonstrated the dechirping approach for the first time at an active multi-GeV light source. Phase IIB plans Building on the success first prototype’s experimental success, RadiaBeam Systems will design and manufacture a commercial-grade Dechirper system tailored to the demanding needs of superconducting XFELs such as the SLAC LCLS-II. The Dechirper Phase IIB prototype will be equipped with beam position monitoring diagnostics, cost-engineered, and ruggedized for high average current operations. Commercial Applications and Other Benefits The proposed Dechirper will improve XFEL performance by maximizing the achievable X-ray brightness and enabling the generation of longitudinally tailored X-ray beams for specific needs of the Users. The Dechirper system developed in this project will be delivered to the flagship US XFEL facility, LCLS-II, and, upon acceptance, will result in commercial sales of multiple units to this and other XFEL facilities worldwide.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 999.46K | Year: 2016
The future of high energy particle physics and Xray light sources for biological and material research require miniaturized linear accelerators that at present cannot be qualified using existing methods. Such miniaturized linear accelerates will be instrumental in managing the cost of future accelerator facilities. There is presently no suitable diagnostic for ensuring RF breakdowns are minimized during the commissioning stage of these miniaturized linacs. In response to this shortcoming, RadiaBeam proposes to develop and build an automated singleshot gratingbased spectrometer working in the terahertz regime of these new miniaturized linacs. Such a device will be capable of measuring the presence of an RF breakdown event and will be used as a feedback mechanism in the commissioning of these linacs. Such grating spectrometers exist in the visible and infrared regimes but recent advances in materials science and detector technology make this scheme extendable to the regime of interest on a costeffective basis. A proofofprinciple spectrometer was developed and tested with bench top sources. After calibration and bench testing, the spectrometer was used in the successful qualification of a terahertz linac at Facility for Advanced Accelerator Experimental Tests (FACET) beamline at SLAC. The shortcomings of the proofofconcept device and potential additions were identified. Building on the success of the prooforprinciple demonstration, RadiaBeam will design and deploy a narrow band and wideband spectrometer for general THz instrumentation and terahertz linac qualification. The resulting spectrometers will be full commercial devices and will be tested at the THz test stand at the advanced Photon Source, and as an advanced RFBD diagnostic at MIT during the commissioning of a nextgeneration terahertz linac. The proposed spectrometer will allow advancement of miniaturized terahertz linacs, allowing miniaturization of many future DOE accelerator facilities. In addition, the oneofakind single shot spectrometer developed here can be used in a wealth of complimentary fields, including terahertz instrumentation, bunch length diagnostics, drug discovery, and homeland security. Key Words THz, terahertz, mmwave, spectrometer, singleshot, Wband, linac. RadiaBeam Systems seeks to build a commercial quality THz spectrometer necessary to qualify the next generation of miniaturized particle accelerators. The spectrometer has additional applications in biology, drug discovery, security, and general instrumentation while serving the DOE mission of basic science.