SCAPA NEWS
New Record of Shot Number
During a recent radioisotope production campaign, the laser demonstrated sustained operation for over 8 hours per day at a 1 Hz repetition rate, delivering more than 25,000 shots daily.
The electron beam pointing was continuously monitored online throughout the campaign, while the electron energy spectrum was measured hourly using 200 shots per measurement. The results demonstrated excellent electron beam stability, with consistent performance in both pointing direction and energy.
This demonstrated the excellent stability and reliability of the laser system, with the capability to operate for even longer periods and deliver more shots when required.
350TW Laser Contrast Ratio Improvement
Some pre-pulses were detected approximately 10 ps before the main pulse. An inspection of the laser frontend identified several potential sources of these pre-pulses, including beam splitters and wave plates. The optical setup was subsequently redesigned to eliminate these components. Following these modifications, the pre-pulses were no longer observed.
The laser system now achieves a contrast ratio of 10¹⁰:1 at 300 ps, 10⁸:1 at 30 ps, and 10⁴:1 at 2 ps ahead of the main pulse.
Gaia Pump Laser Upgraded
All pump modules in the Gaia Nd:YAG pump laser have been upgraded to the latest design. The previous version had several design limitations that affected long-term reliability. In particular, the plastic material used for the flashlamp holders degraded with age after years of operation, while the flashlamp high-voltage connectors were too short, occasionally leading to overheating and burning.
The new design addresses these issues, significantly improving the long-term reliability and operational stability of the Gaia laser and reducing the risk of component failure during extended operation.
In addition, an online beam diagnostic system was installed as part of the upgrade. It provides real-time monitoring of the Gaia laser beams, including pulse energy, near-field and far-field beam profiles. This enables continuous monitoring of laser performance and facilitates early detection of any potential issues.
New Deformable Mirror in A3 beam line
A new deformable mirror (DM) has been installed in the A3 beamline, further enhancing the wavefront correction capability across the facility. We now have four DMs in operation: one in the 350 TW laser system for wavefront flattening before the compressor, and one each in the A2, A3 and Bunker B beamlines.
These DMs enable active wavefront correction, helping to optimise the beam quality and achieve high-quality focal spots in each beamline.
First Proton Beam in BunkerB
