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| MOPPC036 | Influence of Intense Beam in High Pressure Hydrogen Gas Filled RF Cavities | 208 |
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Funding: This work is supported by US DOE under contract DE-AC02-07CH11359. Breakdown plasma in a high-pressure hydrogen gas filled RF cavity has been studied from a time domain spectroscopic light analysis. The observed breakdown plasma temperature and density reached 21,000 K and 1020 cm-3, respectively. The electron recombination rate has been evaluated from the decay of plasma density in various gas pressures. The recombination mechanism in dense plasma will be discussed. Finally, the similarity and difference of the breakdown processes between the high-pressure hydrogen gas filled RF cavity and a vacuum RF one will be discussed. |
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| TUPPD010 | Helical Muon Beam Cooling Channel Engineering Design | 1425 |
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Funding: Supported in part by DOE STTR Grant DE-SC0006266 The Helical Cooling Channel (HCC), a novel technique for six-dimensional (6D) ionization cooling of muon beams, has shown considerable promise based on analytic and simulation studies. However, the implementation of this revolutionary method of muon cooling requires new techniques for the integration of hydrogen-pressurized, high-power RF cavities into the low-temperature superconducting magnets of the HCC. We present the progress toward a conceptual design for the integration of 805 MHz RF cavities into a 10 T Nb3Sn based HCC test section. We include discussions on the pressure and thermal barriers needed within the cryostat to maintain operation of the magnet at 4.2 K while operating the RF and energy absorber at a higher temperature. Additionally, we include progress on the Nb3Sn helical solenoid design |
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| TUPPD033 | Conceptual Design of a Positron-annihilation System for Generation of Quasi-monochromatic Gamma Rays | 1476 |
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| A conceptual design is presented for a system consisting of the following: an electron accelerator and production target to produce positrons, a dipole magnet and wedge to compress the positron momenta to be nearly monochromatic, a magnetic transport system to focus and direct the positrons to a converter, and a converter in which the positrons annihilate in flight to produce quasi-monochromatic gamma rays. The system represented is designed to produce ~10 MeV gammas, but it can also be designed for other energies. | ||
| WEPPC059 | A Two-stage Injection-locked Magnetron for Accelerators with Superconducting Cavities | 2348 |
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Funding: Supported in part by SBIR Grant 4743 11SC06261 A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept is based on a theoretical model that considers a magnetron as a forced oscillator; the model has been experimentally verified with a 2.5 MW pulsed magnetron. The two-stage CW magnetron can be used as a RF power source for Fermilab’s Project-X to feed separately each of the SC of the 8 GeV pulsed linac. For Project-X the 1.3 GHz two-stage magnetron with output power of 20-25 kW and expected output/input power ratio of about 35-40 dB would operate in a quasi-CW mode with a pulse duration ≤ 10 ms and repetition rate of 10 Hz. The magnetrons for both stages should be based on the commercial prototypes to decrease the cost of the system. An experimental model of the two-stage CW S-band magnetron with peak power of 1 kW, with pulse duration of 1-10 ms, has been developed and built for study. A description of the theoretical and experimental models, simulations, and experimental results are presented and discussed in this work. |
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| WEPPC060 | A High-power 650 MHz CW Magnetron Transmitter for Intensity Frontier Superconducting Accelerators | 2351 |
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| A concept of a 650 MHz CW magnetron transmitter with fast control in phase and power, based on two-stage injection-locked CW magnetrons, has been proposed to drive Superconducting Cavities (SC) for intensity-frontier accelerators. The concept is based on a theoretical model considering a magnetron as a forced oscillator and experimentally verified with a 2.5 MW pulsed magnetron. To fulfill fast control of phase and output power requirements of SC accelerators, both two-stage injection-locked CW magnetrons are combined with a 3-dB hybrid. Fast control in output power is achieved by varying the input phase of one of the magnetrons. For output power up to 250 kW we expect the output/input power ratio to be about 35 to 40 dB in CW or quasi-CW mode with long pulse duration. All magnetrons of the transmitter should be based on commercially available models to decrease the cost of the system. An experimental model using 1 kW, CW, S-band, injection-locked magnetrons with a 3-dB hybrid combiner has been developed and built for study. A description of the model, simulations, and experimental results are presented and discussed in this work. | ||
| THPPC032 | Conditioning and Future Plans for a Multi-purpose 805 MHz Pillbox Cavity for Muon Acceleration | 3353 |
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Funding: Supported in part by grant 4735 · 10 LANL and Dept. of Energy STTR grant DE-FG02-08ER86352. An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques for a Muon Collider or Neutrino Factory. The cavity can operate in vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity has been designed for easy assembly and disassembly with bolted construction using aluminum seals. To perform vacuum and high pressure breakdown studies of materials and geometries most suitable for the collider or factory, the surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. In this paper we present the vacuum conditioning results and discuss plans for testing in a 5-Tesla magnetic field. Additionally, we discuss the testing plan for beryllium (a material research has shown to be ideal for the collider or factory) end walls. |
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| THPPD041 | Evaluation and Implementation of High Performance Real-Time Signal Processing For Rayleigh Scattering Based Quench Detection for High Field Superconducting Magnets | 3602 |
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Funding: Supported in part by SBIR Grant 4747 · 11SC06251 YBCO coated conductors are one of the primary options for generating the high magnetic fields needed for future high energy physics devices. Due to slow quench propagation, quench detection remains one of the primary limitations to YBCO magnets. Fiber optic sensing, based upon Rayleigh scattering, has the potential for quench detection with high spatial resolution. This paper discusses the potential of multicore CPU's and FPGA’s to accelerate the signal processing demands associated with Rayleigh scattering based quench detection systems in a real-time environment. |
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| THPPD045 | High Temperature Superconducting Magnets for Efficient Low Energy Beam Transport Systems | 3614 |
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| Modern ion accelerators and ion implantation systems need very short, highly versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and continuous operation requires LEBT designs to be simple and robust. The energy efficiency of available high temperature superconductors (HTS), with efficient and simple cryocooler refrigeration, is an additional attraction. Innovative, compact LEBT systems based on solenoids designed and built with high-temperature superconductor will be developed using computer models and prototyped. The parameters will be chosen to make this type of LEBT useful in a variety of ion accelerators, ion implantation systems, cancer therapy synchrotrons, and research accelerators, including the ORNL SNS. The benefits of solenoids made with HTS will be evaluated with analytical and numerical calculations for a two-solenoid configuration, as will be used in the SNS prototype LEBT that will replace the electrostatic one at SNS, and a single solenoid configuration, as was proposed for the Fermilab proton driver that will be most applicable to ion implantation applications. | ||