This circuit uses a diode as a radiation sensor. The operational ones are old because the publication is from the 80's, but modern low voltage equivalents can be tested.
This circuit was published in a 1981 magazine, but it can be easily assembled using a BC548 paraQ1...
This circuit is from a 1967 publication, but it can be implemented with any Triac of the TIC...
This circuit was found in an 80's EDN. The circuit uses a current common CMOS, the 4093 powering...