High power RF operations studies at TARLA facility

Karslı, Özlem; Aksoy, Avni; Kaya, Caglar; Koc, Burak; Doğan, Mustafa; Elçim, Omer; Bozdogan, Mehmet

doi:10.1139/cjp-2018-0778

Cited by 2 publications

(7 citation statements)

References 4 publications

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“…Achieving reduced phase variation in the transmitted RF power at high power levels is not a trivial process due to the electronics itself which also enforces incorporation of water cooling system to control temperature and pressure. Nevertheless, this reduction is of vital importance to increase the beam-power interaction and to reduce the emittance growth and energy spread [4,11] during beam transport.…”

Section: Resultsmentioning

confidence: 99%

“…Table 2 lists the basic technical specifications of 500 W RF amplifier to power the 1.3 GHz FB. The parameters listed in Table 2 are in accordance with the beam dynamics computation [4] and the qualifications are compatible with the FB.…”

Section: Rf Structure Of Tarlamentioning

confidence: 99%

“…Due to this compression process, these cavities are also called as bunch compressors. When the installation of the injector is completed, the TARLA injector line will deliver electrons with bunch length of ∼0.4-6 ps at the operation frequency of 1.3 GHz [4,5].…”

Section: Introductionmentioning

confidence: 99%

“…The phase drift on RF voltage (power signal) powering the accelerating RF cavities directly affects the beam quality parameters, such as emittance, beam energy spread, diffusion of beam transport and phase shift between the beam and RF voltage [4]. Irregular changes in amplitude and phase of RF signal at the output of the RF amplifier can occur due to different reasons such as amplifier gain variation, phase drift of components, etc.…”

Section: Introductionmentioning

confidence: 99%

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Long term stability of 1.3 GHz high power RF amplifier

Karslı¹,

Colak²

2021

Turk J Elec Eng & Comp Sci

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Turkish Accelerator and Radiation LAboratory (TARLA) is an accelerator based oscillator mode free electron laser (FEL) facility under construction. The acceleration beam-line includes a fundamental buncher (FB) in order to confine the electron beam into a compressed bunch. In this study, we demonstrate the commissioning tests of 500 W RF amplifier powering FB and present the phase stability dependence of the pressure and temperature of the water cooling line under long time run conditions. As the disturbing effects break down the synchronization between the particle and RF power during acceleration, the reasons disquieting the stability of the RF amplifier are investigated. One reason which disturbs the stability is the variation in the phase of the output power. Phase variation of the output power of the RF amplifier measured as ∼ 10 deg/ • C in average initially, which is beyond permitted variation levels by the controller electronics, namely the Low Level RF system (LLRF), is decreased to less than ∼ 0.45 deg/ • C by incorporating a phase shifter. In addition, this phase variation reduction is accompanied with a reflected power at the output of the RF amplifier decline from 4.3 W (36.33 dBm) down to 3 mW (4.7 dBm) by utilizing a circulator, which is also important and desirable in terms of protection of the electronics in the long term run. As ensuring phase stability in the output power is very important, this work may serve as a guide since the documentation regarding the output power dependence of the water cooling line for long term run is very limited.

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Section: Resultsmentioning

confidence: 99%

Section: Rf Structure Of Tarlamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Long term stability of 1.3 GHz high power RF amplifier

Karslı¹,

Colak²

2021

Turk J Elec Eng & Comp Sci

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“…TARLA injector line consists of an electron gun, subharmonic buncher (SHB) and fundamental buncher (FB) cavities, a macro-pulser, and solenoid and steering magnets, in basic. Electron gun is a thermionic type of DC gun and is composed of a tungsten dispenser cathode and a grid providing a ~600 ps pulsed electron beam in 13 MHz repetition rate [4]. Electron beam should be formed into bunches in the injector line, before entering the superconducting modules.…”

Section: Introductionmentioning

confidence: 99%

OPERATION TESTS of the 260 MHz 1500 W SOLID STATE RF AMPLIFIER at TARLA FACILITY

Karslı

Çolak

2019

Commun.Fac.Sci.Univ.Ank.Series A2-A3: Phys.Sci. and Eng.

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Turkish Accelerator and Radiation Laboratory (TARLA) will be the first accelerator-based user facility in Turkey. The facility is under construction at the Institute of Accelerator Technologies of Ankara University. Based on the state-of-art superconducting technology, TARLA accelerator offers a multi-experimental facility providing a variety of accelerator-based radiation sources for users coming from various fields like chemistry, physics, biology, material sciences, medicine and nanotechnology. TARLA consists of two acceleration lines: the first one is the injector that provides high current continuous wave (CW) electron beam at 250 keV energy, and the second one is the main accelerator that comprises of two superconducting (SC) cryomodules separated by a bunch compressor in order to accelerate the electron beam up to 40 MeV energy. Two normal conducting accelerators, so called subharmonic (SHB) and fundamental (FB) buncher cavities whose operation frequencies are 260 and 1300 MHz, respectively, are used to compress the electron bunches from ~600 ps to ~10 ps. SHB cavity is powered by a 1500 W Radio-frequency (RF) power amplifier. Currently, the electron gun training, and superconducting modules acceptance tests, personal safety system, and helium cryogenic system commissioning tests are performed simultaneously. In this study, we present the operation tests of the 1500 W RF amplifier in the scope of the commissioning tests of injector line which showed phase drift coefficents of ~0.5 deg/Co and ~0.67 deg/Co in repeated tests. Moreover, the importance of constancy of the water pressure in the water-cooling line for phase constancy of the delivered power has become evident as a result of current obervations.

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High power RF operations studies at TARLA facility

Cited by 2 publications

References 4 publications

Long term stability of 1.3 GHz high power RF amplifier

Long term stability of 1.3 GHz high power RF amplifier

OPERATION TESTS of the 260 MHz 1500 W SOLID STATE RF AMPLIFIER at TARLA FACILITY

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