"Hardware Hacking" is a term referring to either the modification, cannibalization or combination of new and/or old technologies to create something different, in order to solve a problem, make more affordable, convey an idea, art, experiment, tinker or just for the fun.
This cosmic ray detector works by detecting muons which are a by-product of cosmic rays hitting our atmosphere. It detects these muons using Geiger Muller tubes - the very same type of detector used in a Geiger counter to measure radiation. However, this detector uses 18 Geiger Muller tubes that are arranged in an XY array of 9 tubes oriented on an X-axis and 9 tubes on a Y-axis.

This project was an experiment to see if a multilayered array of Geiger–Müller Tubes (GMT) could track ionizing particles as they pass through. The result is an interesting display demonstrating how cosmic rays travel down through the atmosphere at different angles.

January in Australia is summer, and it is then we have our summer holidays. In Adelaide where I live it is also the hottest time of the year, sometimes reaching temperatures of 45 Degrees Centigrade (113F) with clear blue skies and weeks without rain.
Ideal weather for solar experiments with the kids, as they tend to become a little crazy staying inside out of the sun.

Using a neutron detector to measure cosmic rays may sound odd, but this has been a common way to measure the level of cosmic ray levels since 1948. This is because if the primary cosmic ray that starts a cascade has an energy well over 500 MeV, and so many of its secondary by-products will be neutrons that will reach ground where they can be detected. These systems are commonly called Neutron Monitors

Recently some Russian Boron Coated Cathode Corona Pulse Neutron Tubes (SI-19N) became available on ebay at low cost and so I thought I'd see if I could also make one these guys.
This Geiger–Müller Array (or Geiger tube telescope) exploits an effect called Electromagnetic Cascade as a means of significantly increasing the effective aperture of the detector while reducing other issues I've identified in experiments with cosmic ray detection.

In a 1964 publication Bruno Rossi first described an experiment where cosmic rays could penetrate dense materials. Finding that cosmic radiation at sea level could penetrate over 1m of lead. In these same experiments he was also surprised to record a higher rate of detection as the thickness of lead increased peaking at 1.5cm and then falling slowly.
This detector is to be used as test unit, to measure the performance of my other project using Fluorescent Tubes against in order to clarify and identify any issues, also to better understand and to also demonstrate the principles of a cosmic ray telescope.