[0zelot]

The circuit used in the blog article is a very much simplified version of the Maxim one. And probably not so much worse in terms of signal to noise ratio: https://github.com/ozel/DIY_particle_detector/

The ion chambers are impressive because even lower-cost. But they also detect the presence of people, touches and what not. :) My favourite aspect of silicon sensors like those PIN diodes is that you get the absorbed particle energy as well. In particular with alpha particles that gets quite interesting when measuring for example old ceramics painted with uranium glaze ('Fiestaware').