Summary

Safran Electronic & Defense is developing a next-generation digital Low-Level RF (LLRF) system to upgrade the ALBA Synchrotron Light Source’s accelerator control infrastructure in Barcelona. Designed to ALBA’s technical specifications and integrated with its existing firmware, the system leverages direct sampling data acquisition, a Zynq UltraScale+ FPGA, and high-precision ADC/DAC components to deliver exceptional amplitude stability (down to 0.026%) and phase precision (as low as 0.03°) with ultra-low jitter performance (170 fs added). Fully compatible with EPICS/TANGO control and White Rabbit timing, the 500 MHz version will undergo on-site testing by late 2024, followed by a 1.5 GHz third harmonic version in early 2025, enabling enhanced beam stability, reliability, and operational efficiency for high-energy physics experiments.

Background

The ALBA Synchrotron Light Source in Barcelona requires highly stable control of electric fields within its accelerator cavities to maintain beam quality. The existing LLRF infrastructure must be upgraded to meet evolving performance demands, particularly in amplitude and phase stability.

Solution

Safran Electronic & Defense is developing a fully digital LLRF system aligned with ALBA’s technical specifications and firmware. The design uses a Zynq UltraScale+ FPGA with high-speed ADCs/DACs, extensive GPIO, integrated timing (White Rabbit compatible), and EPICS/TANGO control compatibility. Direct sampling data acquisition ensures precision and low jitter.

Key Features

• 5× dual-channel 16-bit ADCs at 250 MSPS
• 2× 16-bit DACs
• 32 GPIO ports, 8GB DDR4, temperature sensors
• uTCA MMC architecture with Ethernet and SFP ports
• RF input/output paths with amplification and filtering
• Jitter performance: 125 fs (reference), 210 fs (output), 170 fs added jitter
• Precision amplitude: 0.026%–0.047%; Precision phase: 0.03°–0.05°

Products Used

• LLRF (Low-Level Radio Frequency): the developed product includes a 500 MHz version that has already been tested and validated on-site, and a 1.5 GHz version that is currently in the validation phase (Q4 2025).

Results

Enhanced beam stability and operational reliability through ultra-precise amplitude and phase control, improved monitoring, and seamless integration into ALBA’s control ecosystem.