Monthly Archives: January 2013

DECO: Cobalt-60 Tests (Quick Update)

Hey all,

Here is our set-up for running the aforementioned Cobalt-60 tests with the DECO App:

Testing the DECO app with Cobalt-60 (emmiting gamma rays) and a HTC Wildfire.

Testing the DECO app with Cobalt-60 (emmiting gamma rays) and a HTC Wildfire.

We will run with this set-up (source is 10cm away from the phone) until we get 1,000 events.

DECO: Update 1 (01.09.13)

Hey all,

One of our projects, DECO, has made a lot of progress since our last post in April. For those of you who don’t know what DECO (Distributed Electronic Cosmic-ray Observatory) is, the quick and dirty summary of the project involves the use of Android phones to detect cosmic rays–byproducts of supernovae, black holes, and other high-energy astronomical phenomena–using a CCD in the phones’ camera.

Over the summer, Veronica Hoyo, an undergrad at Haverford College, tested the application used to detect and collect data while placing the phones at various angles. Her results varied based on the angle. The scientific poster can be found here and the raw data here. Because of these results, we have been testing to see if there is a direct correlation between tilt angle and frequency.

We have found that there is a connection between cos^2θ and frequency. There is some constant the effects the frequency of events. To solve for this constant, work in the next coming weeks will involve using a Cobalt-60 gamma-ray emitter to create “fake” events to speed up testing.

Justin Vandenbroucke, a post-doctoral at Stanford University, has also done tests as of late underground (-16meters), in Italy (+800ft), and on an airplane with a cruising altitude of 36,000ft. Below are his results concerning event rate:

1) underground: 2.07 +/- 0.39
2) 800 feet altitude: 7.34 +/ 1.60
3) ~36,000 feet altitude (combining the two flights): 51.4 +/- 10.3
This is great because there should be a higher concentration of cosmic rays closer to space.

Until next time…

-The DECO Team