X-Ray cameras - xiRay with 11 and 16 Mpix¶
Q: Are there any recommended x-ray sources, or any that won’t work?¶
A: The cameras can withstand energies up to 100 kV.
Microfocus x-ray sources (for micro-CT):
Q: What is the phosphor level provided ?¶
A: 22 micrometers. Phosphor composition is P43, Gd2O2S:Tb
Q: Are there measurements for Linearity ?¶
A: <2% (of full scale) to 95% of full scale
Q: According to description xiRAY is “direct phosphor imaging camera”, does it mean that the phosphor is included and is applied directly onto the sensor?¶
A: Yes, phosphor coating is included, and the camera architecture is that fiber optics plate (5mm thick) is coupled directly to the CCD die on one end and the other is coated with phosphor.
The sensor is located in a chamber with inert gas and the window we are using is transparent at 20KeV.
Q: The MTBF is specified as 100.000 hours. Is this one hundred hours or one hundred thousand hours?¶
A: MTBF was estimated to 100 thousand hours.
Q: Does the camera have any TDI type acquisition modes?¶
A: Our cameras do not support TDI acquisition modes. KAI-11002 sensor has 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 feasibility study and get back to you with an offer.
Q: Camera Gain is specified as 4e/count. What wavelength/energy X-rays is this for?¶
A: Camera acquisition gain figure is provided from the secondary electrons. Secondary electrons are generated by CCD from incident photons, which are emitted by phosphor activated by primary electrons or x-ray.
Q: The the readout time between frames is important to getting throughput. Does the camera allow readout of frame n while frame n+1 is being exposed?¶
A: Yes, our camera supports overlapped exposure and readout, so you can readout n-1’s frame while n’s frame is being exposed.
Q: How does partial readout affect readout time? Assuming readout time is 0.5s for the full frame at binning 1 (2.1fps), would this reduce the readout time to 0.1s per frame?¶
A: In case of horizontal ROI the readout time is reduced. There is a constant frame overhead time though.
Q: What is the effect of using HS readout mode? It is expected that it will increase the noise level in the image, if so, can you say how much?¶
A: HS readout, which effectively is the sensor overclocking (50MHz instead of 30Mhz), is used for focusing modes only.
For these modes SNR and image quality is not as important as for acquisition modes.
Recently manufactured cameras show 2..5 times higher noise, and there are other artifacts like gradients, reduce of acquisition gain, etc.
Q: What is the position of the scintillator with respect to the input window (in all three planes)? How far back from the front of the camera is it?¶
A: Attached is a sketch with position of the scintillator with respect to the reference plane.
It is centered in X-Y plane.