# XPOWER

## Function

calculate the transmission in terms of flux or spectral power as a function of photon energy for a set of up to five attenuators and mirrors.

The integral of the spectral power gives the total power of the beam.

Therefore this application can be used for calculating the power absorbed and/or transmitted by the optical elements.

Produced results:

- Local transmission and absorption of individual optical elements

- Apply the transmitivity/reflectivity of elements on the source spectrum (cumulated properties).

## Documentation

- application doc

- input parameters

- See also: X-ray Optics

## Technical aspects

- Limitations:

- The calculations made by XPOWDER concern only intensities. Therefore, all effects related to the beam divergence, size, etc. are neglected. In other words, it performs calculations in a one-dimensional phase space (intensity). For more accurate calculation, a multidimensional phase space has to be taken into account. For that, a full ray-tracing can be done using the ShadowVUI extension.

- The calculation of the attenuators use the total photon-atom cross section. This means that every photon that interacts with matter (attenuator) is removed from the beam. In real cases, one should consider that coherently scattered photons, as well as inelastically scattered photons may contribute to the transmitted beam intensity. These effects are neglected here.

- XPOWER does not include crystals. However, the effect of the monochromator crystals can be easily calculated as described in: Manuel Sanchez del Rio and Olivier Mathon (2004) "A simple formula to calculate the x-ray flux after a double-crystal monochromator" SPIE Proceedings 5536 pp.157-164