# XTC

## Function

calculate on-axis brilliance tuning curves for an ideal undulator insertion device (regular planar device or a helical device).

The effect of the particle beam emittance and the beam energy spread is taken into account.

## Documentation

- application doc

- input parameters

- tc doc

## Technical aspects

- Calculations are done using a Fortran program tc.f

- Limitations:

- The program uses the Bessel function approximation which is valid for an ideal device, e.g., no magnetic field errors.

- Electron energy spread is not taken into account (for the moment).