Cosmic Ray Environmental Sensing Online

We are in the preliminary stages of analyzing different options for how to modify the Cosmic Watch v2’s configuration and code to suit our purposes in detecting gamma rays. There are some assumption based methods like using the Cosmic Watch’s master-slave configuration and deducting the difference between them as the total amount of gamma rays. However, by working with the radiation detection group we are hoping to find ways to employ more exact methods in gamma ray detection.

While waiting for parts I began reading about scintillators and SiPMs being used to detect gamma rays and muons. Muons are have an average energy level of 4 GeV at sea level [1] while gamma rays have a much lower energy range typically defined as 100 KeV to 5 MeV [2]. The way the Cosmic Watch Muon detector works is when a muon hits the scintillator it emits light, the SiPM then sees this emission of light and converts it to a voltage pulse. The resulting pulse ranges from 10-100mV, which is too small to be read by the Arduino Nano, so the signal is amplified by 20-25 through an op-amp so it can be read by the Nano as an ADC voltage value.

One interesting thing I found was how one individual created a DIY gamma ray detector with a miniature solar cell [3]. This functioned similar to the Cosmic Watch in how a pulse was created from gamma rays and then amplified to be displayed. It may be worth looking into if this method of detection could be improved to suit our purposes.

Another thing I noticed when looking through the materials we are using for the Muon detector we have is that the scintillator we have, bc408, is not meant for gamma ray detection. However, the bc412 from the same manufacturer can detect gamma rays from 100 KeV to 5 MeV [4]. We will need to meet with the radiation detection group at OSU first before considering the use of bc412 material.

[1] “Muons.” [Online]. Available: https://cosmic.lbl.gov/SKliewer/Cosmic_Rays/Muons.htm. [Accessed: 24-Jan-2019].

[2] “Radioactivity : Gamma Rays in Matter.” [Online]. Available: http://www.radioactivity.eu.com/site/pages/Gamma_Matter.htm. [Accessed: 24-Jan-2019].

[3] “Alan Yates’ Laboratory - Photodiode Gamma Ray Detector.” [Online]. Available: http://www.vk2zay.net/article/265. [Accessed: 24-Jan-2019].

[4] “BC-408, BC-412, BC-416 | Products | Saint-Gobain Crystals.” [Online]. Available: https://www.crystals.saint-gobain.com/products/bc-408-bc-412-bc-416. [Accessed: 24-Jan-2019].