Demonstration of stable long-term operation of a kilohertz laser-plasma accelerator oleh L. Rovige, J. Huijts, I. Andriyash, A. Vernier, V. Tomkus, V. Girdauskas, G. Raciukaitis, J. Dudutis, V. Stankevic, P. Gecys, M. Ouille, Z. Cheng, R. Lopez-Martens, J. Faure