Development and Testing of the ITER Divertor Monoblock Braze Design

Watson, R.D.; Hosking, F.M.; Smith, Mark F.; Croessmann, C.D.

doi:10.13182/fst91-a29603

Cited by 15 publications

(2 citation statements)

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“…Most notable, it has been explored for high gradient accelerators due to its ability to withstand large temperatures. [70] [2] Glidcop has also been used for high temperature joints in the ITER fusion reactor [72] [23]. In addition, Glidcop has been successfully used to construct electron gun anodes [13] and high power gyrotrons cavities [69].…”

Section: Methodsmentioning

confidence: 99%

Overmoded W-Band Traveling Wave Tube Amplifier

Temkin¹,

Kowalski²

2014

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Air Force Materiel Command REPORT DOCUMENTATION PAGEForm Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information We report on the design and test of an overmoded W-band TWT. The TWT was designed to operate in the rectangular TM31 cavity mode at 94 GHz. The unwanted lower order modes were suppressed using selectively placed AlN dielectric loading; simulations in 3-D CST Particle Studio confirmed the suppression. The 87-cavity TWT was designed to operate at 30 kV with 320 mA in a 2.5 kG solenoid magnet. The experiment was built in-house at MIT and operated with a 3 microsecond pulsed power supply. An initial beam test was implemented which confirmed operation at 31 kV with 306±6 mA of current detected at the collector and 88 % transmission. The TWT produced 21±2 dB system gain at 94.3 GHz and 27 W of saturated output power in zero-drive stable operation. The TWT had about 6 dB of additional loss due to the input and output coupling; taking that loss into account, the gain on the TWT circuit itself was 27±2 dB circuit gain. CST simulations for the experimental current and voltage predict 28 dB circuit gain, in good agreement with measurements. This experiment demonstrated the first successful operation of an overmoded TWT. The overmoded TWT is a promising approach to high power TWT operation at W-Band and to the extension of the TWT to terahertz frequencies. AbstractWe report on the design and test of an overmoded W-band TWT. The TWT was designed to operate in the rectangular TM31 cavity mode at 94 GHz. The unwanted lower order modes, TM11 and TM21, were suppressed using selectively placed Aluminum Nitride dielectric loading; simulations in 3-D CST Particle Studio confirmed the suppression. The TWT was designed to operate at 30 kV with 320 mA in a 2.5 kG solenoid magnet. Simulations in both 1-D Latte and 3-D CST predicted 31 dB of gain, 200 MHz bandwidth, and 300 W peak output power at 94 GHz. Test structures of 9-and 19-cavities were made via CNC direct machining. Cold test measurements showed suppression of the unwanted modes and transmission of the TM31 mode, which correlated well with HFSS simulations. Two final 87-cavity structures were built and cold tested.The experiment was designed and built in-house at MIT. It was operated with a 3 microsecond pulsed power supply. An initial beam test was implemented which confirmed operation of the TWT at 31 kV with 306±6 mA of current detected at the collector and 88 % transmission of current. Operation of the TWT with the first structure showed 8 dB of system gain and 10 W saturated output power at 95.5 GHz....

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Section: Methodsmentioning

confidence: 99%

Overmoded W-Band Traveling Wave Tube Amplifier

Temkin¹,

Kowalski²

2014

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“…30 x 30 x 4 mm) with a hole in the middle through which a copper alloy coolant pipe (approx. 10 mm diameter) is passed whereupon both parts are joined together (coined a 'monoblock') [54]. The difficulty in achieving this is that the copper alloy has a significantly greater coefficient of thermal expansion than that of the CFC.…”

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confidence: 99%