Who has the audacity to do this?

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Steven Sesselmann
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Who has the audacity to do this?

Post by Steven Sesselmann » 27 Apr 2017, 18:39

Hi Guys,

I have been messing around with a method of remotely recording a gamma spectrum for post analysis, cool little project and just got it working. It's a raspberry-pi plugged into a small battery powered 4 port hub with a USB sound card connected. I then have a GS-1100A with detector connected to the sound card in the usual way. The raspberry pi has built in WIFI and provides the only connection to my network.

I turn on the GS-1100A and start recording a wav file on the Raspberry pi. A message told me that there was enough room on the disc for a 4 hour recording at 96 khz, and I am sure it's possible to delete some unwanted files to make more space if required. Once the recording completes I export it as a wav file and transfer it over the network to another computer and open it with PRA.

The method for opening a wav file in PRA is first obtain the pulse shape, then open the file from the File menu.

I bought the Raspberry Pi Zero W for the audacious price of £9.60 from thepiehut.com (it'r really tiny 65 x 35 mm) and could easily fit inside a detector housing. https://thepihut.com/collections/raspbe ... -pi-zero-w

I installed Raspian which is a debian version of Linux, on a 32 GB micro SD card.
Linux.png
Linux Desktop
Once Raspian was installed I installed Audacity which is an open source audio recording software. The installation is easy, just type the following into the command line, and the package installs itself.

pi@raspberrypi:~ $ sudo apt-get update
pi@raspberrypi:~ $ sudo apt-get install audacity
Audacity.png
Audacity Software
You then need a way to transfer the files to your computer so you need to install netatalk.

pi@raspberrypi:~ $ sudo apt-get install netatalk

this will allow you to open a file on the raspberry pi from another computer on the network with afp.

open afp://10.1.1.10 (your raspberrypi ip address)
cs-137-spect.png
60 second Spectrum opened from Wav File
As you can see this method is loss free and provides a way run a passive recording for post analysis. One of the neat things you can do with PRA is that you can analyse individual sections of the recording thereby isolating a single event in time.

Say for example you were recording a continuous wav file at some security check point, and someone walked through that check point with some Cobalt 60 in their pocket, if synchronised with a security video, you could identify from the spectrum who carried the source.
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | rephopper.com | beejewel.com.au |

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