New the Design and Measurements of the Portable Cosmic Ray Muons Detector (CRMD) for an Observatory

Cosmic Rays (CR), which provide crucial

insights into the structure and evolution of the universe and

astronomical phenomena such as supernovae, hold

significant importance in the realms of physics and

astrophysics. Simultaneously, CRs pose a challenge in

astronomical observations due to their generation of hot

pixels, necessitating the need for their fluxes to be

accurately determined and eliminated from charge-coupled

device (CCD) images. To address this, it is essential to

measure the cosmic ray background at large observatories.

In response, we developed a cosmic-ray muon detector

utilizing scintillation technology, employing a plastic

scintillator and a photomultiplier tube. We utilized the

DRS4 Evaluation Board ver. 5.1 read-out system for signal

reception and processing. Our measurements were

conducted at the ATA50 Telescope on the Atatürk

University campus and at the site of Turkey’s largest

telescope, the Eastern Anatolia Observatory (DAG), using

our custom-designed cosmic ray muon detector (CRMD).

For the calculation of cosmic ray flux, we applied the Time

of Flight (TOF) method, which calculates the flight time of

cosmic rays passing through scintillators positioned

vertically on a shelf. Data analysis was conducted using our

Python code and ROOT programs. Cosmic ray-muon

measurements involved placing the detector at various

zenith angles. At the DAG site (elevation 3170 m), we

observed a cosmic ray flux of 0.0450 cm-2s-1sr-1.

Conversely, at the lower altitude ATA50 Telescope site

(elevation 1855 m), the flux was measured at 0.0235

cm-2s-1sr-1. Notably, a 1-meter thick concrete structure was

found to reduce cosmic muon measurements by 56%.

Furthermore, the flux values obtained at 30°, 45°, 60°, 75°

angles showed compatibility with theoretical predictions

and were compared with existing literature values. These

findings demonstrate the reliability, stability, and cost

effectiveness of our custom-designed detector.