DoseNet returns to San Francisco at the Exploratorium After Dark event on Radioactivity. With a headlining talk, Full-Spectrum Science: Radioactivity given by Ron Hipschman, the theme of the night was set, and patrons eagerly flooded the building as the setting sun cast its last rays over the city’s skyline.
The inside of the Exploratorium was well lit, with a tall ceiling and dark walls that felt like staring into space whenever your head would tilt above the horizon. Scattered about the floorplan after the entrance were hundreds of exhibits to captivate the mind. Each exhibit helped explain or demonstrate some scientific concepts or phenomena, and they were grouped by section based upon which larger idea they belonged to; there were sections dedicated to perception, toying with your eyes and mind, colors and lights to confuse and amaze. The physics section had a particularly wide array of demonstrations, and next to each was a plaque that described what was going on that made it worth showcasing in the Exploratorium. Near the theater, however, next to all the audio exhibits, was one of the booths occupied by scientists and academics alike for UC Berkeley’s radiation public outreach and education: DoseNet!
Patron’s approached, some were there for the night, and some showed up particularly for the night’s focus on radioactivity. With smiling and eager faces behind the demonstration, all who neared DoseNet’s table were pulled in, like electrons whizzing by nuclei. Many stood for moments observing the table: laid out atop the tablecloth were bags holding a variety of radioactive samples, piles of differing shielding material, two Geiger counters and two DoseNet touchscreen devices. Behind us was a large screen swapping between a readout from our portable High Purity Germanium detector (HPGe) and the RadWatch website, with all its various data and maps that struck an air of curiosity on those that observed it.
Some came to us with questions that eagerly followed our spiel, but others were more awestruck and interested in hearing what we had to say and show, seeing what they could learn. Showcasing our DoseNet devices and all its circuitry and sensors was an excellent starting point for a conversation about radiation; radiation is emitted naturally by some prevalent elements in our crust, just as much a part of the environment as the weather and the water cycle. The various environmental sensors on our device had digital touch screen outputs that graphed in real-time pressure/temperature/humidity, CO2 concentration, air quality, and of utmost interest: radiation!
Moving to our radiation detector, attached to its custom 3D printed casing is a cesium iodide crystal scintillator: radiation travels through and can interact with a crystal in the detector, creating light and generating voltage that gets read out into a radiation spectrum, updating and changing as demonstration sources were placed onto or away from the detector. The particularly inquisitive could pick up the probe of a Geiger counter and hold it over the various rocks on display, double bagged for everyone’s safety. Upon holding the probe –the right way down– onto an active source, the characteristic beeps would increase in frequency, the radioactive decay of a uranium-or-thorium containing rock or our uranium-glazed Fiestaware ionizing the gas inside and creating a shower of electrons turned to voltage readings based on the intensity of radiation.
While fun to move around, there was yet still more to learn. One person could control the probe while another placed various shielding materials between the sources and the detector, creating a tangible relationship between the density of the shielding and the amount of ionizing radiation. What followed, by most, were pleasant exchanges of thanks for shared time well spent and the learning all around. Some few memorable visitors loved it so much, they stuck around for up to an hour asking questions and engaging in detailed discussion with our team.
An excellent and memorable time all around, it’s always a joy to share what we love with the public. Knowledge of the world around us benefits us when we know how to properly risk assess, and when it’s safe to indulge in the beauty of nature’s creation. The world around us glows with invisible energy, and we have harnessed it for what still seems like limitless capabilities in power, propulsion, environmental imaging, and revolutionary medical applications. Understanding it is just the beginning, we hope to be back soon!