The HGammaCam application makes use of CMOS cameras to detect ionizing radiation (e.g. gamma rays).
Especially cameras that provide RAW images are well suited.
Cooled cameras like those used in astrophotography are able to achieve a comparably good sensitivity because of the much lower dark current and therefore noise.
HGammaCam is a free software to allow everybody with access to CMOS cameras to measure gamma radiation.
Features
- Support of numerous RAW formats like *.ARW, *.CR2, etc. (Tested Cameras: Canon 5D Mark II and Sony Alpha 7C)
- Support of *.fits files to be able to use astrophotography cameras
- Darke Frame Calibration to mitigate the impact of hot pixels and to calculate the detection threshold
- Offline Mode to analyze a batch of input images
- Live Mode analyzing images as soon as they appear in a supervised folder
- Selection of different detection modes:
- Detections: Number of detections per image (measurement interval)
- Energies: The sum of the detected energies in ADU (Analog to Digital Converter Units)
- MCA: Multi Channel Analyzer covering different energy ranges (Low, Mid and High) to get the energy distribution.
- CSV file export of the measured energies over all images
Radiation Measurement
- Prevent normal light from hitting the camera sensor (e.g. by using aluminium foil or the cameras cap)
- Make sure that the camera achieves a stable temperature, either by using a cooled camera or the build in temperature sensor (available in most astrophotography cameras). This is necessary because the dark current and therefore noise level is strongly temperature dependend.
When using a normal camera like a Sony Alpha 7C make sure that it runs for a time to reach a stable temperature. - Use the appropriate software for your camera to do tethered shooting directly transfering the images to the computer (e.g. SharpCap for astrophotography cameras)
It is of course also possible to take the images offline and analyze them later on. - Take at least 30 images without a radiation source in the vicinity at the same gain/ISO and exposure length of the subsequent radiation measurements to create the Dark Frames.
- For weak sources a 10s exposure time per image is a good initial choice
- Set the Gain/ISO as low as possible or in the case of dedicated astrophotography cameras at the level where the read-out noise drops
- Load the dark frames (File -> Open Darks).
The master dark frame creation and threshold calculation can take a bit of time depending on the RAW image size - Do the measurement by taking several images (e.g. 100 x 10s).
A siginificant number of images makes it easier to get statistical meaningful measurements. - Analyze the images either in live mode or offline mode:
- Live Mode: Load a single image from the folder that shall be observed. This will activate the “Live” button to be clicked to activate the continues measurement.
- Offline Mode: Load a batch of images (File -> Open Images) to be analyzed
- Save the measurement results as CSV file
The format is:
measurement interval number, comma separated list of detected energies
Download v0.1 (BETA)
HGammaCam is a free software but not yet open sourced.
Currently only Windows is supported but that may change in the future.
Installation
Just uncompress the ZIP file in a folder and launch the application.
There is no need to install anything.
Disclaimer
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Licenses used to develop the solution
MIT, BSD, Apache