Red Pitaya's Role in Radiation Detection

The innovative experiments carried out by high school and junior high school students, as presented in the 38th International Cosmic Ray Conference (ICRC2023) and facilitated by Accel Kitchen LLC, involved the creation of advanced radiation detectors utilizing the Red Pitaya STEMlab board. These projects not only illustrate the application of theoretical physics, but also demonstrate the practical use of digital electronics and sensor technology in real-world scientific research. Let’s look into the specifics of these experiments, particularly focusing on the design and functionality of each type of detector.

Segmented Detector for Enhanced Particle Analysis                                    

The segmented detector was engineered to enhance the precision of particle detection, including the identification of different particle types, their energies, and trajectories. This detector employs a stack of plastic scintillators interlaid with Silicon Photomultipliers (SiPMs). The key to its operation lies in the Depth of Interaction (DOI) technique, which enables the detection of where within the scintillator stack a particle interaction occurs. As particles pass through the scintillators they emit light, which is attenuated and reflected differently based on the depth of interaction within the stack. By analyzing the ratio of output voltages from SiPMs placed on either side of the scintillator stack, the detector can deduce the position of the particle interaction. This method provides a more detailed picture of particle behavior, which is crucial for applications like PET scans in medical imaging.

Cherenkov Detector for Cosmic Ray Studies

The Cherenkov detector, designed by students from Toshimaoka Girls’ High School in Tokyo, Japan, represents an innovative application of Cherenkov radiation principles. This detector consists of an acrylic block, which has not undergone UV-cut treatment, attached to a SiPM. The detector was positioned perpendicular to the ground, with a plastic scintillator placed above it serving as a trigger mechanism. When cosmic rays pass through the acrylic block, they emit Cherenkov radiation, detected by the SiPM. The students observed a decrease in detection rates with an increase in the zenith angle, aligning with the expected distribution of cosmic-ray muons. Additionally, the effect of the acrylic block's length on the detection efficiency was studied, revealing insights into the optimization of Cherenkov detectors for cosmic ray studies.

Time-of-Flight Detector for Cosmic Ray Speed Measurement with Red Pitaya

The time-of-flight detector project showcases the exceptional capabilities of the Red Pitaya STEMlab board for precise measurements. By using scintillator detectors based on the Cosmic Watch design and a high-speed FPGA board (Red Pitaya), the students managed to measure the time it takes for cosmic rays to travel between two points with sub-nanosecond resolution. This high level of precision, achieved through cross-correlation analysis of the signals from the two detectors, allows for accurate speed measurements of cosmic rays over a short distance. The project exemplified how the integration of digital signal processing with traditional particle detection methods could lead to significant advances in scientific research, providing students with hands-on experience in cutting-edge technology.

The Red Pitaya board’s ability to carry out cross-correlation analysis was key to achieving a sub-nanosecond resolution, allowing for the precise measurement of cosmic ray speeds over a mere 30 cm distance between detectors. The experiment underscored the board’s exceptional performance in capturing and analyzing high-frequency data, facilitating a sophisticated analysis of cosmic rays with an estimated speed accuracy up to 3.03 ± 0.06 × 10^5 km/s, thus demonstrating sub-percent precision over a five-day measurement period.

Final Thoughts:

The use of a Red Pitaya STEMlab board in these high-school projects underscores the platform's adaptability, precision, and educational value in the context of scientific research. Through their work on segmented detectors, Cherenkov detectors, and time-of-flight measurement setups, the students not only contributed insights with regard to radiation detection, but also highlighted the practical application of Red Pitaya devices in scientific investigations. These initiatives exemplify the shift toward more interactive and practical learning in science education, with Red Pitaya leading the way in enabling students to engage deeply with technical subjects through direct experimentation.