These units are quite efficient. The documentation on mine states you get about 2000 hours of operation on 2 D-Cells. I have two of these, and haven't had to replace the batteries yet!
There is a theory of "excess heat" released in old lithium ion batteries. They release more thermal energy than is predicted. The theory is that electron positron annihilation releases gamma rays because the surface of the lithium becomes nanoetched in a geometry that causes positrons to live longer. I want to observe the gamma rays. I also want to roll the lithium into a cassette tape and observe the magnetic flux.
Mark - One thing about the voltage setting on the Model 3, which has a relatively high threshold setting (fixed at about 35mV). You may need to up the HV to overcome the high threshold on energies below 100keV. If you are having problems seeing Am241 for instance, just up the HV to 950 or 1000 volts and you should be able to see those pulses. The pulses are there at 800 volts, but just not able to overcome the inherent high threshold in a Model 3 without a boost in HV.
Don't go directly to Ludlum, go through a distributer. If they happen to take your order they simply pass the order off to the nearest distributor to you. You can get replacement battery terminals from them. I've repaired damaged cases by removing circuit board & immersing the case so all corroded damaged areas are immersed in vinegar for several hours. Check occasionally wire brushing loose debris. Rinse. Now remove the battery terminals. I had to get the tool to remove the metal terminal - basically a spanner wrench. Brush on primer designed for aluminum. Color match some enamel & brush it on.
Hi Mark, I have just got one of these scintillator kits from IRad. Did not have to do any polishing on the BC412. However, some of the dynode wires were oxidised and had to be cleaned up. All working as it should now. Getting about 3000cpm background on an RM5/1 @ 900V. The scintillator " end stops" the RM5 with a cs137 source.
Yes i recall i had issues with the dynode wires, i think it's because they are not tinned copper but some kind of weird alloy that can form a vacuum tight seal with the glass. One of the reasons tubes always get plugged into a socket.
hey dear sir it was really great information about scintillation detector, but still what i have is about not understanding the pins in tube can you please guide me regarding to the same
All the layers, and the heat shrink tubing are probably more than enough to block all the light, but one thing I've found is that most common kinds of black electrical tape are semi-transparent in near-IR, even when in several layers. I was mocking up a DIY night vision scope with a 1980's British Electric Valve Co. Gen 1 cascade tube to get the focal length on the primary lens right, had it all sealed up with black electrical tape, and I could see light from my workshop coming into the tube when I expected it to be completely dark. The photomultiplier you're using for the scintillator is obviously different, and it may not even respond to NIR light, but if you're ever at just the "tape wrap" stage in such a build, and you're getting high anomalous readings until your final enclosure for the scintillator is complete, that might be why.
I've purchased a similar PMT from iRad and I'm planning to couple it with a nice Russian 3" NaI(Tl) scintillator crystal that I will use for gamma spectroscopy. Nice video!!
I've a Gamma spectacular GS1100-PRO and a quality external sound blaster. The system is supplied by an external low ripple DC power supply (I'm not using the one from the PC) and a custom built power supply splitter with LCL filter that further reduce the background noise. I'm quite satisfied about my current set-up. Next step is the 3" scintillation probe.
Hey Mark, could you please explain, how you found out , which of the wires from the PMT is cathode,Anode and Dynodes . Because after 7:47´ on your video the cleaned circuit board has numbers for Dynode 1,Dynode 2 etc.!, I have this Problem with my PMT R1307 ,but did not find out this assignment so far. Data sheet did not help.
Hi! I am trying to construct a detector from a scintillator and a photodiode. What kind of gel do you recommend me to attach the scintillator to the photodiode? And from where could I purchase some? Thanks!
I am confused. How does the PMT work with only 2 lines (red and yellow) out? Most PMTs need at least 2 connectors, one for HV/-HV, another for signal(Dynode or Anode).
+Xiao-Peng Zhang In a 2-wire setup the detection is made by monitoring the small voltage changes in the supply voltage when the avalanche progresses through the dynode chain. This is same procedure as using a Geiger Muller tube where a detection causes a negative going pulse on the supply. This is why meters like the Ludlum can operate both GM tubes and Scintillation probes using PMTs with only adjustments to the supply voltage.
Have you tried to see the scintillation? If you are in complete darkness and bring a source to that piece of plastic, can you see the scintillation with the naked eye? I would imagine the eye is at least as good as the photo multiplier tube, providing it emits visible light (a teacher told us that the eye can detect even one photon).
No i have not actually, of course i can't take my probe apart now but i do have another piece of scintillation plastic around somewhere, i'll look at trying something.
Nick F - I was not able to “see” the scintillation. I suspect the duration of the light pulses to be too fast for the dark adapted human eye. Photomultipliers are incredibly sensitive with electron gains from the photocathode of well over 1 million. PMT’s can also have nanosecond response times.
Thank you! I honestly don't know how the two scintillators compare. Given the one in the camera is looking directly at a xray beam it might not need to be particularly sensitive but i am only guessing.
I have never really found a definitive answer on it, but my gut instinct says it will degrade the photocathode so i always store mine wrapped in aluminium foil
![[UNCUT] The Loyal Pin ปิ่นภักดิ์ EP.8 (1/4)](http://i.ytimg.com/vi/7OwUsMs0M5s/mqdefault.jpg)
These units are quite efficient. The documentation on mine states you get about 2000 hours of operation on 2 D-Cells. I have two of these, and haven't had to replace the batteries yet!
There is a theory of "excess heat" released in old lithium ion batteries. They release more thermal energy than is predicted. The theory is that electron positron annihilation releases gamma rays because the surface of the lithium becomes nanoetched in a geometry that causes positrons to live longer. I want to observe the gamma rays. I also want to roll the lithium into a cassette tape and observe the magnetic flux.
Mark - One thing about the voltage setting on the Model 3, which has a relatively high threshold setting (fixed at about 35mV). You may need to up the HV to overcome the high threshold on energies below 100keV. If you are having problems seeing Am241 for instance, just up the HV to 950 or 1000 volts and you should be able to see those pulses. The pulses are there at 800 volts, but just not able to overcome the inherent high threshold in a Model 3 without a boost in HV.
Don't go directly to Ludlum, go through a distributer. If they happen to take your order they simply pass the order off to the nearest distributor to you. You can get replacement battery terminals from them. I've repaired damaged cases by removing circuit board & immersing the case so all corroded damaged areas are immersed in vinegar for several hours. Check occasionally wire brushing loose debris. Rinse. Now remove the battery terminals. I had to get the tool to remove the metal terminal - basically a spanner wrench. Brush on primer designed for aluminum. Color match some enamel & brush it on.
Hi Mark,
I have just got one of these scintillator kits from IRad. Did not have to do any polishing on the BC412. However, some of the dynode wires were oxidised and had to be cleaned up. All working as it should now. Getting about 3000cpm background on an RM5/1 @ 900V. The scintillator " end stops" the RM5 with a cs137 source.
Yes i recall i had issues with the dynode wires, i think it's because they are not tinned copper but some kind of weird alloy that can form a vacuum tight seal with the glass. One of the reasons tubes always get plugged into a socket.
hey dear sir it was really great information about scintillation detector, but still what i have is about not understanding the pins in tube can you please guide me regarding to the same
All the layers, and the heat shrink tubing are probably more than enough to block all the light, but one thing I've found is that most common kinds of black electrical tape are semi-transparent in near-IR, even when in several layers. I was mocking up a DIY night vision scope with a 1980's British Electric Valve Co. Gen 1 cascade tube to get the focal length on the primary lens right, had it all sealed up with black electrical tape, and I could see light from my workshop coming into the tube when I expected it to be completely dark.
The photomultiplier you're using for the scintillator is obviously different, and it may not even respond to NIR light, but if you're ever at just the "tape wrap" stage in such a build, and you're getting high anomalous readings until your final enclosure for the scintillator is complete, that might be why.
i think sometimes with electrical tape the glue is transparent and acts as a light guide
Good work. I want to get few hundreds of PM Tubes for school projects.
Thanks for this video, it was really helpful.
I've purchased a similar PMT from iRad and I'm planning to couple it with a nice Russian 3" NaI(Tl) scintillator crystal that I will use for gamma spectroscopy.
Nice video!!
Sounds like a nice crystal, hope the construction goes smoothly. How are you interfacing to a computer?
I've a Gamma spectacular GS1100-PRO and a quality external sound blaster. The system is supplied by an external low ripple DC power supply (I'm not using the one from the PC) and a custom built power supply splitter with LCL filter that further reduce the background noise. I'm quite satisfied about my current set-up.
Next step is the 3" scintillation probe.
hi friend one doubt, tell me list of the NaI(Tl) scintillator crystal application. and my email Id: sbalan.s8@gmail.com
We can supply scintillator like if you need, www.epic-crystal.com/products/
Any request please contact: petershu0920@gmail.com
Weher do I can buy scintillator screens ?
Very nice video .... Thank you
Hey Mark, could you please explain, how you found out , which of the wires from the PMT is cathode,Anode and Dynodes . Because after 7:47´ on your video the cleaned circuit board has numbers for Dynode 1,Dynode 2 etc.!,
I have this Problem with my PMT R1307 ,but did not find out this assignment so far. Data sheet did not help.
Looks like the pin assignment is on page 4: www.hamamatsu.com/resources/pdf/etd/R1307_TPMH1214E.pdf
Hi! I am trying to construct a detector from a scintillator and a photodiode. What kind of gel do you recommend me to attach the scintillator to the photodiode? And from where could I purchase some? Thanks!
It's normally Silicone Grease. You should be able to buy it very easily online. en.m.wikipedia.org/wiki/Silicone_grease
I am confused. How does the PMT work with only 2 lines (red and yellow) out? Most PMTs need at least 2 connectors, one for HV/-HV, another for signal(Dynode or Anode).
+Xiao-Peng Zhang In a 2-wire setup the detection is made by monitoring the small voltage changes in the supply voltage when the avalanche progresses through the dynode chain. This is same procedure as using a Geiger Muller tube where a detection causes a negative going pulse on the supply. This is why meters like the Ludlum can operate both GM tubes and Scintillation probes using PMTs with only adjustments to the supply voltage.
I see. Really a new idea to me. Thanks for the explanation :)
hi very nice video thank you
Are those resistors really 70MOhms?
Have you tried to see the scintillation? If you are in complete darkness and bring a source to that piece of plastic, can you see the scintillation with the naked eye? I would imagine the eye is at least as good as the photo multiplier tube, providing it emits visible light (a teacher told us that the eye can detect even one photon).
No i have not actually, of course i can't take my probe apart now but i do have another piece of scintillation plastic around somewhere, i'll look at trying something.
Nick F - I was not able to “see” the scintillation. I suspect the duration of the light pulses to be too fast for the dark adapted human eye. Photomultipliers are incredibly sensitive with electron gains from the photocathode of well over 1 million. PMT’s can also have nanosecond response times.
How does the sensitivity of the plastic scintillator compare to a similar size nal(ti) scintillator? Thanks and love your content
Thank you! I honestly don't know how the two scintillators compare. Given the one in the camera is looking directly at a xray beam it might not need to be particularly sensitive but i am only guessing.
We can supply scintillator like if you need, www.epic-crystal.com/products/
Any request please contact: petershu0920@gmail.com
Is direct sunlight harmful to the Photomultiplier if it's not in operation?
I have never really found a definitive answer on it, but my gut instinct says it will degrade the photocathode so i always store mine wrapped in aluminium foil
Great video 👍 where did you get the barium sample?
I took apart a scintillation analyser ages ago, it used the barium sample as a test/calibration source
We can supply scintillator like if you need, www.epic-crystal.com/products/
Any request please contact: petershu0920@gmail.com
@@petershu5601 how much for a 2X2 Na(Tl) crystal?
@@chemistryscuriosities www.epic-scintillator.com/NaI-crystal-scintillator/NaI-scintillator-2inchx2inch
Would this same voltage divider circuit work for a 10 pin PMT ?
We can supply scintillator like if you need, www.epic-crystal.com/products/
Any request please contact: petershu0920@gmail.com