I am currently working on a project to develop a fibre optic dosimetry system. The system uses an organic scintillator (BCF-60), which emits green light at 530 nm, with an active volume of 0.8 mm³.
I am in the process of designing a transimpedance amplifier (TIA) circuit using different photodetectors, which I selected based on their spectral response range (360 nm to 900 nm).
Could you please guide me on the key tests I should perform to help select the most reliable and suitable photodiode for my application?
I am planning to test the TIA response using different LEDs (blue, green, red, and IR). I would appreciate your suggestions on any additional quick and effective tests I could perform to further characterize the photodiodes for use in my dosimetry system.
@ha879 - pro tip: in the same time you spent taking the picture, you could have positioned the camera so that the camera angle was perpendicular to the page you scribbled that schematic on.
And how long would it take anyone to make a much prettier hand drawn schematic plus some equations and adding a few more details, what might keep us from having to wonder about things and ask?
Transimpedance amplifiers are quite old and hard to get these days. They are much beloved by makers of sound synthesisers for making voltage controlled oscillators and filters. The thing is that they use very large resistors and are in no way like a 741 op amp.
I wrote article about them way back in about 1983, I can dig that out if you want? but it is waste of time if you can't buy any.
Thanks for your reply..I plan to use the OPA657 op-amp, as the 741 op-amp has higher noise and is not suitable for this application.
Yes, please feel free to share it if possible. Also, if you don't mind, I would appreciate your guidance on how to characterize different photodiodes to help me select the most suitable one for my project.
I am having a bit of a problem finding this. I have the paper copies of the magazine but they are difficult to find. So far I have only found the diagrams on line but not the words, I will have a further look tomorrow.
Note you will have to do these measurements in a light tight box, painted matt black on the inside.
I am looking to calculate the voltage obtained from the TIA output for estimating radiation flux. If I use BCF-60 as the scintillating material instead of a green LED, I would like to confirm which parameters are critical for accurate estimation.
In the clinical setup, the field size is 10×10 cm², the dose rate is 600 MU/min, the dose delivered is 100 MU, and the fibre is placed at the centre of the radiation field. The detector configuration consists of 1 mm of BCF-60 scintillating fibre and 4.9 cm of non-scintillating fibre.
Could you kindly guide me on which parameters I should consider to accurately estimate the signal generated from the BCF-60 fibre in this configuration?
