Frequently Asked Questions

Hardware

Q: Does it work?

A: No, not yet. The files current posted (as of 14/09/15) are for our version 1 prototype which has a number of known bugs/issues:
including - readout speed issues with the Raspberry Pi (we're using interrupts that don't go fast enough under standard Raspian), an unintentional hard limit for the event detection rate of 1 Hz as a result of the way the high precision timing is implemented, and some issues with the ADC's - specifically they're not configured to caputre in the correct way and aren't pipelined. Finally, the rather neat Murata HV PSU we've integrated isn't sufficiently stable (too much noise) for use with our preference of Hammamatsu SiPMT. We're addressing all these issues (and more) for version 2!

Q: What can I do to get involved RIGHT NOW?

A: The best and easiest place for you to see our current status is on github, where the latest versions of our code are posted for your perusal [http://github.com/CosmicPi\]

Q: What about the detector medium?

A: Version 1 is based on using a pair of Hammamatsu SiPM's, a block of plastic scintillator and a wavelength shifting fibre. All these items are commercially available from people like Saint Gobain. Our version 1.1/1.2 is based on a square block of scintillator such as BC-408 with two directly coupled Avansid SiPM's, as this is a lot easier and cheaper to manufacture and assemble.

James Devine 14/09/15