ABSTRACT
The amplified spontaneous emission (ASE) dynamics in x-ray lasers with small-scale fluctuations of the dielectric permittivity https://www.w3.org/1998/Math/MathML"> ε ˜ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063032/9284f42f-003f-4795-89cd-da73f9068931/content/ieq0044.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is studied. The ASE scattering by https://www.w3.org/1998/Math/MathML"> ε ˜ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063032/9284f42f-003f-4795-89cd-da73f9068931/content/ieq0045.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is found to reduce the coherence degree and the coherent power. With an increase in laser length the coherence length tends to a constant value. At weak regular refraction the ASE scattering by https://www.w3.org/1998/Math/MathML"> ε ˜ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063032/9284f42f-003f-4795-89cd-da73f9068931/content/ieq0046.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> decreases the gain observed. At strong defocusing refraction the effect of https://www.w3.org/1998/Math/MathML"> ε ˜ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063032/9284f42f-003f-4795-89cd-da73f9068931/content/ieq0047.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on ASE has the “latent” character: an essential fall in the coherence degree is accompanied by a small decrease in the axial intensity and small broadening of the ASE beam as a whole.
