The International Fusion Materials Irradiation Facility (IFMIF) is an international project to study and qualify candidate materials for the construction of a future fusion reactor. One of the objectives of the IFMIF-Engineering Validation and Engineering Design Activity Project is to build a linear prototype accelerator (LIPAc) to validate the final IFMIF accelerator concept. LIPAc, which is currently under construction in Rokkasho (Japan), will generate a 9-MeV deuteron beam of 125-mA current with 100% duty cycle. CIEMAT (Spain) is in charge of providing the RF power system, including the low-level radio frequency (LLRF) system. Most of the developed LLRF systems are not completely digital, as they use analog front ends for intermediate frequency conversion before or after digitalization. However, the LIPAc LLRF system is a fully digital system: no analog frequency conversion is performed, the radio frequency (RF) signals are directly digitally synthesized and sampled by means of high-speed digital-to-analog converters and analog-to-digital converters. This is a clear advantage in terms of flexibility, reliability, reconfigurability, cost, and response time, as all the signal processing is performed in the digital domain. The other main advantages and novelties are the use of White Rabbit (WR) for timing synchronization and master oscillator distribution (distributed RF over WR). The LIPAc LLRF system is the first LLRF based on WR, and it has been designed and fabricated using the most advanced technology. This paper presents the detailed description of the LIPAc LLRF system and its advantages, performance evaluation, and verification.

Fully Digital and White Rabbit-Synchronized Low-Level RF System for LIPAc

The Superconducting Super Collider Laboratory (SSCL) and the Los Alamos National Laboratory (LANL) entered into a joint venture to design and develop a 600 kW amplifier and its low-level controls for use in the Radio-Frequency Quadrupole (RFQ) accelerating cavity of the SSC. The design and development work has been completed. After being tested separately, the high power amplifier and low level RF control system were integrated and tested on a test cavity. Results of that test are given. Tests were then carried out on the actual RFQ with and without the presence of the accelerated beam. Results of these tests are also given, along with the phase and amplitude information.<<ETX>>

Design and Results of the Radio Frequency Quadrupole RF System at the Superconducting Super Collider Laboratory

The Superconducting Super Collider Laboratory (SSCL) and the Los Alamos National Laboratory (LANL) entered into a joint venture to design and develop a 600 kW amplifier and its low-level controls for use in the Radio-Frequency Quadrupole (RFQ) accelerating cavity of the SSC. The design and development work has been completed. After being tested separately, the high power amplifier and low level RF control system were integrated and tested on a test cavity. Results of that test are given. Tests were then carried out on the actual RFQ with and without the presence of the accelerated beam. Results of these tests are also given, along with the phase and amplitude information. >

Design and results of the Radio Frequency Quadrupole RF system at the Superconducting Super Collider laboratory

This paper describes the RF system being used to provide RF power and to control the cavity field used for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system that uses a tetrode as a high-power amplifier (HPA) as part of its plant to deliver up to 300 kW of peak power to the RFQ at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5{degrees} in phase in the presence of beam-induced instabilities. This paper describes the identified components and presents measured performance data. The user interface with the systems is described, and cavity field measurements are included.

D. Ziomek

Papers

Rf system description for the ground test accelerator radio-frequency quadrupole