Hi dear

I would like to define a GPS source with following requirements

- Electron beam with energy spectrum given by Gaussian with mean energy of 5.90 MeV and sigma 0.051 MeV.
- Spot taken to be Gaussian with sigma in X of 0.6645 mm and sigma in Y of 0.7274 mm;
- beam divergence given by Gaussian with sigma of 1 mrad, mean 0.

I tried

```
/gps/source/intensity 1
/gps/particle electron
# shape
/gps/pos/type Plane
/gps/pos/shape Circle
/gps/pos/centre 0. 0. -5 mm
/gps/pos/radius 0.5 mm
/gps/pos/sigma_x 0.6645 mm
/gps/pos/sigma_y 0.7274 mm
# energy distribution
/gps/ene/type Gauss
/gps/ene/mono 5.90 MeV
/gps/ene/sigma 0.051 MeV
```

Can anyone help me to define a source with the third requirement?

Thank you in advance.