The silicone grease I prefer to use is an ultra-clear 500,000 weight RC Differential Fluid made by Traxxas. A 20cc bottle sells for under $10. For a Burle / Photonis XP2902, I recommend using the approximate manufacture recommended string ratio using a 4.7 MegOhm as the base resistor value. All connections EXCEPT the following should be 4.7m, the rest should be as follows. K-D1=10m, D2-D3=6.8, D6-D7=2.2m. These values will total 56.6 MegOhm and have worked very well for me with most equipment.
Thanks! Not too many X-Rays are going to make it through the stainless steel, and no plastic is anywhere near the resolution and response of NaI(Tl). I do sell other scintillators, some with "windows" (including aluminized Mylar) and others are built with different housing materials, but these are built for economy. I sell these units for only $259.00 on eBay, and it's very hard to find any other comparable scintillator at that price. For Gamma counting, these perform VERY well.
WOW! What an interesting video! Three questions: Does the use of stainless steel have any bad effects with x-rays from gamma interactions? I use aluminium in my unit, partially for that reason. Secondly, is the plastic scintillator as efficient as NaI(Tl)? I have never messed with plastic. Lastly, have you considered adding a thin aluminium window to your units? It is amazing to watch them built! Thanks for posting this video!
On this particular build I was using a 2 inch diameter by 1-1/2 inch long BC-408 scintillator plastic. I now use a larger 2-1/4 inch long piece of BC-412 scintillator on my current build for even greater sensitivity to gamma and less sensitivity to beta.
I think I have a iRad gs-220, (I can only read iRad and -220) and it doesn't seem to react differently to samples I have. I'm trying to find information on it and I'm coming up empty. Perhaps you built it?
@greenhappens Wow! 259.00! I might need to think about one of these. I use a NaI(Tl) and I get about 6-8% resolution with it, but I will be in the market for a well detector in the near future. As long as I can interface it to my MCA correctly. Cheers!
When use a light spectrometer (visible light range) I see very sharp lines. I can distinguish two very narrow lines in a very short distance of their frequencies let's say a frequency distance of less than 0,01% . What is the resolution of a plastic BC-412 and/or a CsI(TI) detector ? What is the light frequency range of a plastic BC-412 detector ? Can I see little scintillation light sparks in a plastic BS-412 in complete darkness with my 1/2 hour in dark adpated eyes ?
A photomultiplier has a light amplification of approcs. one million. You try to couple the BC-408 plastic detector very close to the PMT surface. So you do not loose any of the emitted light. So let's say you win plus 20-50%. But the same you can do with increasing the amplification factor of the PMT by increasing the voltage at the PMT let's say from 1000 Volt-DC to 1010 Volt-DC
Adding the Mu-Metal or equivalent would just drive up the price and deliver no real benefit for most intended uses of this probe. Plastic scintillators are used for gross counting and not usually used for applications that are typically subject to interference. I do offer shielding (usually Ultraperm 80) as an option along with an internal lead collimator, different bulkhead connectors, thin aluminum windows, etc... Keeping the price affordable is my main objective on this probe. I sell others.
What you see in this video is the conclusion of hours of work preparing the different parts for final assembly. Finding the parts in quantity and at a profitable price takes the longest time and most effort. The Photomultipliers must be desoldered of their original circuitry and fitted with circuitry that works with standard meters. Cutting and polishing the crystals is also very tedious and time consuming. Product design also takes a lot of thought and time.
Good guide, thank you. It was very useful for building my first scintillation probe in 2015
The silicone grease I prefer to use is an ultra-clear 500,000 weight RC Differential Fluid made by Traxxas. A 20cc bottle sells for under $10. For a Burle / Photonis XP2902, I recommend using the approximate manufacture recommended string ratio using a 4.7 MegOhm as the base resistor value. All connections EXCEPT the following should be 4.7m, the rest should be as follows. K-D1=10m, D2-D3=6.8, D6-D7=2.2m. These values will total 56.6 MegOhm and have worked very well for me with most equipment.
@greenhappens Oh well. I still might just check you out for a replacement probe for my CD-v 700. Scintialltors are a scientist's best friend.
Cheers!
Thanks!
Not too many X-Rays are going to make it through the stainless steel, and no plastic is anywhere near the resolution and response of NaI(Tl). I do sell other scintillators, some with "windows" (including aluminized Mylar) and others are built with different housing materials, but these are built for economy. I sell these units for only $259.00 on eBay, and it's very hard to find any other comparable scintillator at that price. For Gamma counting, these perform VERY well.
Hey Tom would this probe work for Gamma spectroscopy?
Is there are reason why you don't have a milar window on the front instead of that thick stainless steel?
WOW! What an interesting video! Three questions: Does the use of stainless steel have any bad effects with x-rays from gamma interactions? I use aluminium in my unit, partially for that reason. Secondly, is the plastic scintillator as efficient as NaI(Tl)? I have never messed with plastic. Lastly, have you considered adding a thin aluminium window to your units?
It is amazing to watch them built!
Thanks for posting this video!
On this particular build I was using a 2 inch diameter by 1-1/2 inch long BC-408 scintillator plastic. I now use a larger 2-1/4 inch long piece of BC-412 scintillator on my current build for even greater sensitivity to gamma and less sensitivity to beta.
I think I have a iRad gs-220, (I can only read iRad and -220) and it doesn't seem to react differently to samples I have. I'm trying to find information on it and I'm coming up empty. Perhaps you built it?
@greenhappens Wow! 259.00! I might need to think about one of these. I use a NaI(Tl) and I get about 6-8% resolution with it, but I will be in the market for a well detector in the near future. As long as I can interface it to my MCA correctly.
Cheers!
When use a light spectrometer (visible light range) I see very sharp lines.
I can distinguish two very narrow lines in a very short distance of their frequencies
let's say a frequency distance of less than 0,01% .
What is the resolution of a plastic BC-412 and/or a CsI(TI) detector ?
What is the light frequency range of a plastic BC-412 detector ?
Can I see little scintillation light sparks in a plastic BS-412 in complete darkness with my 1/2 hour in dark adpated eyes ?
How we can meck tuob sintlator
What kind of plastic scintillator is this? Seems to be quite sensitive...
A photomultiplier has a light amplification of approcs. one million.
You try to couple the BC-408 plastic detector very close to the PMT surface.
So you do not loose any of the emitted light.
So let's say you win plus 20-50%.
But the same you can do with increasing the amplification factor of the PMT
by increasing the voltage at the PMT let's say from 1000 Volt-DC to 1010 Volt-DC
Adding the Mu-Metal or equivalent would just drive up the price and deliver no real benefit for most intended uses of this probe. Plastic scintillators are used for gross counting and not usually used for applications that are typically subject to interference. I do offer shielding (usually Ultraperm 80) as an option along with an internal lead collimator, different bulkhead connectors, thin aluminum windows, etc... Keeping the price affordable is my main objective on this probe. I sell others.
What you see in this video is the conclusion of hours of work preparing the different parts for final assembly. Finding the parts in quantity and at a profitable price takes the longest time and most effort. The Photomultipliers must be desoldered of their original circuitry and fitted with circuitry that works with standard meters. Cutting and polishing the crystals is also very tedious and time consuming. Product design also takes a lot of thought and time.
这个和y能谱仪是不是类似的原理
I do not recommend plastic scintillators for use with a MCA, and I don’t know anyone who makes a plastic well scintillator.
Sure thing, I have plenty of interesting scintillator project items for a beginner. You can reach me at iRadInc@att.net