04/12/2018
We had a great time at the USA Science and Engineering festival. We have some wonderful photos including the one attached. Thanks to everyone for helping make this happen. The Lowell students were a great addition to the effort. I think they learned a lot about engaging the public in regard to radiation. They helped out all day Saturday and Sunday.
The kids enjoyed looking for radiation with a pancake probe (coleman lantern mantles under paper) and talking about being radioactive. I mentioned that we could identify space aliens by their lack of radioactive K-40 in their bodies (unless of course they have been here long enough to reach equilibrium – so it is not 100%). If there were any space aliens, fortunately they appeared in human form, so they were not distracting. We went over Avogadro’s number and determined about how many radioactive K-40 atoms they had in their bodies. The guys from Lowell drew up a chart of how many banana’s worth of radioactivity you had by body weight.
We did get to observe an interesting radiological phenomenon during the event. We were doing 1 minute counts all day of background starting around 9:30am with a 2X2 NaI detector and comparing it to a 250g can of NuSalt (we got about 1100 counts above background from the Nusalt). The attached photo of our measured background on Friday shows (as an observant 12-year-old told me) that the background was going up all day (noticed at 12:59). Right around 13:45 the background dropped to what it was earlier in the morning. Just before that same time, it cooled off in the building as it was getting hot all day with all the attendees and you could feel the air from the ducts above. So I think it was the ventilation that changed the background. We kept this data posted so we could talk about it for the rest of the event. How the background fluctuated by 30%! We also marked the time of each count from that point forward. We talked about geometry (so that is why we take that class??) with the NuSalt and took some measurements lengthwise and across the center. We talked about how radiation emission is isotropic, but only the photons that entered the detector could be counted. We had a background of 3500+ cpm in a small detector. How many photons were striking each of us every minute seeing that we are much larger?
In the following days, the background didn’t repeat that pattern as the event was in full swing and the ventilation was going the whole time it seemed.
I like to say that you never know what you will find walking around with a radiation detector. This was another example of what you might find.
One thing I observed for future events. People would walk by and look at the posters in the back that indicated who we were. We should have something that has “How Radioactive Are You?” to catch their interest. The general public is not particularly interested in Health Physics Societies and whatnot. So having something that tells an interesting story is good.
Thanks again to everyone who helped put this together, especially Cathy who arranged the HPS Booth volunteers. The HPS, my company, and the ANS were right together. One aisle away was a group of “Young Nuclear Professionals”. The festival people are very accommodating. We could perhaps have a fairly large pavilion that has a number of entities talking about radiation protection, uses of radiation, and radiation in the environment. Having a pavilion would give a lot more space to do more things in, such as setting up a CA and dressing out and frisking out, or whatever. Kids like to put on the Anti-C clothing and it is a great photo-op. I brought my two kids and they had a blast going through the absolutely HUGE event. There were jet fighters and helicopters in the facility. There were several virtual reality trainers you could get into. And then there were those cool people with the radiation stuff!! So maybe next time we can get more of our colleagues from around the country to help out and have a mini science vacation. Each booth costs around $1250 for non-profits, $1700 for regular companies. The next one is in two years!!
Yours,
Rob
Robert J. Gunter, MSc, CHP
CHP Consultants/CHP Dosimetry
P.O. Box 4126
Oak Ridge, TN 37831
www.chpconsultants.com – Consulting and Nuclear Instrumentation
www.chpdosimetry.com – Radiation Dosimetry Services
https://counts.pro/ - Transform you radiation meter to a mobile laboratory
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