Demonstration of ultra-low emittance beams in a kHz laser wakefield accelerator and application to electron diffraction

arXiv:2602.12765v1 Announce Type: new
Abstract: We present a compact, cost-effective method for measuring the emittance of kHz-repetition-rate laser-wakefield accelerated electron beams using a permanent solenoid. The measured normalized emittance, $epsilon_n = 124,mathrm{nm cdot rad}$ ($simeq 0.04 pi,mathrm{mm cdot mrad}$) at $2.7,$MeV, is comparable to that of ultra-low emittance radiofrequency guns used for electron diffraction. Leveraging this low emittance, we successfully applied the electron beam to electron diffraction. We demonstrate diffraction images obtained from a single crystal Silicon nano-membrane sample, clearly resolving diffraction peaks across multiple orders.