Thursday 27 March 2025
Scientists have been working on developing a new type of particle detector that can withstand the harsh conditions found in high-energy collisions. These detectors are crucial for understanding the fundamental nature of matter and the universe.
The device, called MALTA2, is a depleted monolithic active pixel sensor (DMAPS) designed to meet the demanding requirements of future collider experiments. It’s essentially a tiny chip that captures the tracks left behind by subatomic particles as they zoom through the detector at incredible speeds.
To test its performance, researchers used a technique called grazing angle measurement, where they rotated the detector relative to the particle beam and measured how well it detected different types of particles. This allowed them to see how the detector’s efficiency varied depending on the angle of incidence.
The results showed that before being exposed to radiation, the MALTA2 sensor performed exceptionally well, with detection efficiencies above 98.5% at various angles. However, after being irradiated with a fluence equivalent to about 100 Mrad (a measure of radiation exposure), the detector’s performance took a hit.
At first glance, it seems like the radiation damaged the detector irreparably. But that’s not entirely true. By adjusting the voltage applied to the sensor, researchers were able to recover some of the lost performance. At higher voltages, the detection efficiency improved significantly, eventually reaching levels comparable to those before irradiation.
This is because the voltage controls the strength of the electric field within the detector. When the voltage is low, the electric field is weaker, allowing charge carriers (like electrons) to diffuse and lose their energy more easily. This reduces the sensor’s ability to detect particles accurately.
By increasing the voltage, researchers can strengthen the electric field, which helps to focus the charge carriers and improve detection efficiency. However, there are limits to how much voltage can be applied before other issues arise.
The study also estimated the active depth of the detector – essentially the distance within which the sensor is capable of detecting particles. This was done by analyzing the cluster size (a measure of particle energy) as a function of grazing angle.
The results suggested that at higher voltages, the active depth increases to around 40 micrometers. This is an important finding, as it provides insights into how the detector responds to different types of radiation and how it can be optimized for future experiments.
MALTA2 represents a significant step forward in the development of particle detectors.
Cite this article: “Radiation-Resilient Particle Detector Shows Promise for Future Collider Experiments”, The Science Archive, 2025.
Particle Detector, Malta2, Dmaps, Radiation Detection, Collider Experiment, Subatomic Particles, Grazing Angle Measurement, Depleted Monolithic Active Pixel Sensor, Charge Carriers, Electric Field, Particle Energy.
