| Paper | Title | Page |
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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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| 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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| TUPPD078 | A Novel Design of a High Brightness Superconducting RF Photoinjector Gun Cavity | 1581 |
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Funding: Work supported under U.S. DOE Grant Application Number 98802B12-I Next generation electron accelerators for research, medical, defense or industrial use are in need of electron sources operating at high repetition rates of 1 MHz and beyond, with normalized emittance of 1 mm-mrad or less and bunch charges as much as one nC or more. A conceptual layout of a novel superconducting RF photoinjector gun cavity (SRF gun) is proposed, which can provide unprecedented flexibility to vary beam pulse patterns in the MHz regime and beyond at average currents around 1 mA. It does not require an opening in the center of the back wall and avoids the complex cathode exchange system, but still allows an exchange or refurbishment of the cathode. The demountable back plate has the major benefit to clean the cavity cells independently from the back wall carrying a superconductive photocathode. This mitigates risks of cavity contamination and eases fabrication and chemical post-processing to achieve high accelerating fields, a key parameter to guarantee high brightness beams. |
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