Radiation safety considerations for ultrafast lasers beyond laser machining

Area of Science:

• Physics
• Laser Science
• Radiation Safety

Background:

• Ultrafast laser interactions with matter can generate ionizing radiation.
• This has become a safety concern in laser material processing, leading to specific regulations.
• Current German legislation mandates notification for laser systems exceeding 1×10¹³W/cm².

Purpose of the Study:

• To assess the applicability of existing radiation safety studies to non-processing ultrafast laser applications.
• To determine if X-ray generation is a general hazard across all ultrafast laser uses.
• To evaluate the adequacy of current radiation protection legislation.

Main Methods:

• Experimental investigation of X-ray dose production.
• Testing ultrafast laser interactions with underdense gas targets.
• Testing ultrafast laser interactions with stationary solid targets.
• Assessing conditions relevant to non-processing laboratory environments.

Main Results:

• X-ray generation conditions are highly specific and primarily occur during material processing.
• Experimental results show negligible or no X-ray dose production under representative non-processing laboratory conditions.
• Conditions tested included laser interactions with gas and stationary solid targets.

Conclusions:

• Current radiation protection legislation overgeneralizes a processing-specific hazard.
• The legislation does not adequately reflect the physical conditions of non-processing ultrafast laser applications.
• A distinction should be made between material processing and other applications regarding radiation safety.