Experimental demonstration of an electromagnetic pulse mitigation concept for a laser driven proton source

Area of Science:

• Plasma Physics
• Laser-driven particle acceleration
• Electromagnetic Pulse (EMP) mitigation

Background:

• High-intensity lasers interacting with targets generate significant electromagnetic pulses (EMPs).
• These EMPs are an undesired byproduct that can interfere with experiments and equipment.

Purpose of the Study:

• To develop and test a novel concept, the "birdhouse," for mitigating EMPs.
• To evaluate the effectiveness of the "birdhouse" in reducing EMP intensity and its impact on proton beams.

Main Methods:

• A prototype "birdhouse" device was designed to confine and dissipate EMP energy using an electric resistor.
• The prototype was tested at a 10 TW, 50 fs laser facility.
• EMP mitigation ratios were measured across a frequency range of 100 MHz to 6 GHz.
• Proton emission intensity was measured along the laser propagation direction and at the edge of the proton beam.

Main Results:

• An average EMP mitigation ratio of approximately 20 was achieved from 100 MHz to 6 GHz.
• The "birdhouse" demonstrated a higher mitigation ratio of 50 in the 1-2 GHz range, where microwave emission is maximal.
• Proton beam intensity increased twofold in the center and decreased twofold at the edge.
• No significant modification of the proton beam's normalized spectrum was observed.

Conclusions:

• The "birdhouse" concept is effective in mitigating electromagnetic pulses generated by high-intensity laser-target interactions.
• The device shows potential for controlling EMPs without negatively impacting the proton beam spectrum.
• Further research may explore optimization for enhanced EMP reduction and beam shaping.