Abstract
An X-ray energy spectrum from plasma electrons at high temperature is numerically studied on the basis of a relativistic-quantum theory. The relativistic emission cross section is significantly larger than the non-relativistic one, which is indicated by modification of Gaunt factor. The relativistic Maxwellian energy distribution function is formed toward the higher side than the non-relativistic one. The relativistic X-ray intensity, as a result, is stronger and decreases more slowly with the X-ray energy than the non-relativistic one. The total emitted power due to a bremsstrahlung in the relativistic case is 1.5 times as large as that in the non-relativistic case at the temperature of 200 keV.
