Fast Calculation of Integration of Bremsstrahlung Radiation from Electrons with Power-law Distribution

Since the SSW (Solar Soft Ware) has been developed to the version 2, in comparison with the version 1 the performance of the integration calculation of the Bremsstrahlung radiation caused by high-energy electrons is improved. On the basis of the version 2 of SSW, we have made further improvement on the integration calculation. The comparison between a few schemes of Bremsstrahlung integration shows that our final scheme is faster than the version 2 for 2∼5 times. Compared with the version 1 and version 2 of SSW, the integration accuracy has been also improved a lot, even under the default control accuracy there will be no spikes appearing in photon spectra. In addition, the time consumption of integration is no longer sensitive to the upper limit of the integration. The improvement of the integration performance enables the accurate Bremsstrahlung cross-section be used to calculate the Bremsstrahlung integration. Compared with the result of approximate Bremsstrahlung cross-section, the result of accurate Bremsstrahlung cross-section gives a little smaller photon flux (≤4%), and the integration time increases about 30%.