Disk source with particle gun

Dear all,
I need to create a disk source with a radius of 0.125 cm and electron Gaussian energy distribution (E_mean = 6MeV, sigma = 0.127MeV) using the ParticleGun. How can I do it? If you have an example code, please give me for reference.


Thank you so much :kissing_closed_eyes: :kissing_closed_eyes: :kissing_closed_eyes: