Rethinking muon detection: First steps in design and discovery

Beginning the detector design

I am David, a fifth-year pre-university student (5 vwo) from the Netherlands with a passion for physics and an interest in uncovering what normally passes right through us: cosmic particles. Over the coming year, I will be working on the development of a new type of muon detector for a public observatory in the Netherlands. The intended outcome is twofold, since the final design should not only be a new kind of detector that is capable of reliably detecting muons but also be suitable for use during lectures and educational events at the observatory.

The first phase begins with a prototype based on conventional plastic scintillators. To test the system in a controlled setting, I will use a small piece of radioactive material — a radium watch hand. These were in the early 20th century to make watch faces glow in the dark.

Once I have successfully built and tested the prototype, as I aim for by May 2025, I will begin designing a new type of detector that moves beyond the conventional used materials. This design may involve alternatives to traditional scintillators, whether organic or inorganic, or possibly entirely different materials and concepts. The goal is not to replicate existing detectors, but to improve upon them with and to increase resolution, enhance portability, and contribute something original to the field of particle detection.

Why the detector uses SiPMs

Throughout the project, I will use Silicon Photomultipliers (SiPMs) instead of traditional photomultiplier tubes. Traditional photomultiplier tubes (PMTs) are large cylindrical vacuum tubes often about the size of a water bottle, whereas SiPMs are small enough to fit on a fingertip, roughly the size of a coin or postage stamp. Photomultipliers detect the photons produced by tiny flashes of light when a muon interacts with a scintillating material. Inside each SiPM is an array of microscopic light-sensitive cells called avalanche photodiodes, which amplify those faint signals electronically. SiPMs offer several advantages as they are more compact, operate at lower voltages, and are generally more robust and portable.

PMT on the left and SiPM on the right

In this blog, I will document each stage of the development process, from early experiments to design choices and final implementation. I hope this journey will provide insight not only into how we detect particles from space, but also contribute, in some small way, to the design of new detectors that help us better understand the universe.