By "cloud chamber photograph", is that a literal photograph (the capturing of light). Or is that a derived "image" like from an MRI (where the "I" in "MRI" stands for "image" but it's not a literally image made from light, it's a topography derived from detecting deviations in the magnetic field).
If it's a literal photograph that gives me a whole new perspective and respect for the accuracy of results from experiments like this.
That’s a real photograph. What you are seeing is not the actual positron itself, though, but a path of little bubbles that are released as a particle passes through the liquid.
It’s a photograph of condensation caused by the passing positron.