X-Ray cameras with 11 and 16 Mpix¶
Q: Are there any recommended x-ray sources or any that will not work?¶
A: The cameras can withstand energies from around 5 up to 100 kV.
Microfocus x-ray sources (for micro-CT) that could be an option:
Q: What is the provided phosphor level?¶
A: It is 22 micrometres.
Phosphor composition is P43, Gd2O2S:Tb
Q: Are there measurements for the Linearity?¶
A: It is <2% of full scale to 95% of full scale
Q: Does “direct phosphor imaging camera” mean the phosphor is applied directly onto the sensor?¶
A: Yes, the phosphor coating is included and the camera architecture looks the following way:
The Fiber optics plate (5mm thick) is coupled directly to the CCD die on one end and coated with phosphor scintillator on the other. The field of view of the scintillator is 36x24 mm.
The sensor is located in a chamber with inert gas and the window that is used is transparent at 20KeV.
Q: What is the specified MTBF?¶
A: The MTBF was estimated at 100 thousand hours.
Q: Does the camera have any TDI type acquisition modes?¶
A: XIMEA cameras do not support TDI acquisition modes.
KAI-11002 sensor has an interline transfer structure, and it is possible to implement some sort of TDI.
Let us know whether you want to get a quotation for that, so we will perform a feasibility study and get back to you with an offer.
Q: What temperature conditions or values are important to keep in mind?¶
A: Threshold temperature value(on camera housing) to start the cooling is 36C.
The additional cooling of the camera would be provided by the fan.
Q: If camera Gain is specified as 4e/count to which wavelength/energy of X-rays does it refer to?¶
A: Overall Gain range is from 0 dB up to 36 dB.
The camera acquisition gain figure is provided from the secondary electrons.
Secondary electrons are generated by CCD from incident photons, which are emitted by phosphor that is activated by primary electrons or x-ray.
Q: What ADC options do X-RAY cameras provide?¶
A: The X-RAY camera models from XIMEA offer two ADC modes with 12 bits per pixel and 14 bits per pixel.
Saturation(maximum) value of pixel in case of 14 bits is 16383, minimum 512.
Q: How does partial readout affect readout time?¶
A: Assuming readout time is 0.5s for the full frame at binning 1 (2.1fps) and in case of horizontal ROI the readout time is reduced to 0.1s per frame.
There is a constant frame overhead time though.
Q: What is the effect of using HS readout mode?¶
A: HS readout, which effectively is the sensor overclocking (50MHz instead of 30Mhz), is used for focusing modes only.
It is expected that HS will increase the noise level in the image.
For these modes, SNR and image quality is not as important as for acquisition modes.
Recently manufactured cameras show that noise can be 2-5 times higher with HS and there are other artefacts like gradients, reduce of acquisition gain, etc.
Q: Does the camera allow readout of frame n while frame n+1 is being exposed?¶
A: Yes, the readout time between frames is important to getting throughput.
XIMEA camera supports overlapped exposure and readout, so you can readout n-1’s frame while n’s frame is being exposed.
Note: Feasible Exposure time ranges from 20 microseconds up to 30 minutes.
Q: What is the position of the scintillator with respect to the input window in all three planes?¶
A: Position and how far back from the front of the camera the scintillator is can be seen in the following sketch:
It is centred in X-Y plane