Аннотация:Efficient laser-plasma line X-ray source was developed. X-ray generation was optimized by the laser pulseduration alteration and using the local helium blowing into the microplasma region on a copper target located in atmospheric conditions. Measured Kα x-ray flux of 2· 10^7 ph/pulse/2π sr and conversion efficiency of 10^(−5) wereachieved correspondingly.