X-ray, Gamma BTI bubble detector
Posted: Tue Aug 29, 2006 11:20 am
I recently returned from a Teslathon in New York. While there, I had a discussion with a well known fellow, who shall remain nameless. He was positive that gamma rays and neutrons were emitted from running Tesla devices and large powerful air discharges.
I told him that I might allow for x-rays as I had heard of their detection in lightning strikes, though I had my doubts about a tesla coil having the snort to do this. I told him that I was pretty sure that neutrons would definitely not be found in an arc discharge.
I noted to him that the intense and variable electrical fields and electromagnetic impulses in such discharges created so much noise that any electronic detection devices would probably not be of any use in his quest. I noted that there were neutron bubble detectors and that these were noise immune and might be used in the neutron part of his effort.
He disappeared to his car and reported back to me, in short order with three brand new BTI bubble detectors for which he had just paid over $1000.00 !!! The guy was serious............
One was the standard 100BDR unit like we use. Another was the $750.00 "defender" which is capable of 1500bubbles/mrem!!
The last detector I could not believe........It was marked X-ray/Gamma ray!!! Being very familiar with all of BTI's products, I told him that I had never seen this item. He told me it was incredibly sensitive. My interest was certainly peaked.
I was selling some of my four corners U-rock at the flea market that day and he purged the gamma detector of bubbles and we set the item next to a piece of rock I had that was rated at 35kcpm and within seconds, a bubble appeared. Over the next minute, there were 7 bubbles showing!!! I was stunned.
Later in the day, he placed this X-ray detector inside a toroidal valley plane of a large 6KW coil and had the person run it producing 8 foot white hot streamers for about 4 minutes of varied operation. At the end of the run there were about twenty bubbles. Again, I was stunned.
He was going to put the neutron bubble detector in next. I told him it was useless, but that experiment would confirm my prediction. Sure enough, zero bubbles after 2 different 5 minute plus runs. He was very sad at this last result having hoped to prove me wrong.
From all of this, I was determined to investigate this BTI, x-ray/gamma detector when I got back home. I called the head engineer at BTI, Rob Noulty. He confirmed that they do, indeed, make a gamma/xray INDICATOR, (he would not use the word detector). It is designed to indicate or sense the presence of both gamma and x-radiation. When I asked why it was not in their catalog, he noted that the device was not calibratable, nor could it discriminate between x and gamma. Futhermore, it was unstable. Thus, the bubbles are for indication only and bears no bubble/dose relationship to the shortwave EM radiation actually passing through the device. The instability, Rob claimed, comes from temperature variability with use and age. He noted to me that at about 80-85 deg F and above the device would spontaneously produce bubbles, but at 75 degrees was totally usable as a reliable gamma/x-ray INDICATOR.
Thinking back, the outside temp in Rochester was about 78 degrees that day, so the test of my U-rock out of doors was viable. However, the tesla coils were setup in a large metal building which was shut up most of the time for photo ops during coil running sessions. The sun hitting the metal kept it about 10 or more degrees warmer inside. Add to this the fact that the arcs off a tesla coil naturally dissapate many KW in the immediate air surrounding the coil, and you have a combination that could easily create false readings in the particular instance of test performed last Saturday.
So we are back to ....did the coil truly produce x-rays or did the high building temperature coupled with the local air temperature rise at the discharge terminal, while running, cause spontaneous bubbles?
The question remains unanswered, but now we also know that such a device as a noise immune gamma/X-ray detector exists provided it is used in a lower temperature environment.
The device costs only $80.00 and is one of BTIs cheapest bubble detectors. With BTI's $250.00 minimum, the next big order we gather together might include this item for those doing noisy environment gamma/x-ray testing.
Apparently it is just embarrasingly unstable enough and lacking any link to intensity indication that they refuse to list it as a sales item in their catalog.
Richard Hull
I told him that I might allow for x-rays as I had heard of their detection in lightning strikes, though I had my doubts about a tesla coil having the snort to do this. I told him that I was pretty sure that neutrons would definitely not be found in an arc discharge.
I noted to him that the intense and variable electrical fields and electromagnetic impulses in such discharges created so much noise that any electronic detection devices would probably not be of any use in his quest. I noted that there were neutron bubble detectors and that these were noise immune and might be used in the neutron part of his effort.
He disappeared to his car and reported back to me, in short order with three brand new BTI bubble detectors for which he had just paid over $1000.00 !!! The guy was serious............
One was the standard 100BDR unit like we use. Another was the $750.00 "defender" which is capable of 1500bubbles/mrem!!
The last detector I could not believe........It was marked X-ray/Gamma ray!!! Being very familiar with all of BTI's products, I told him that I had never seen this item. He told me it was incredibly sensitive. My interest was certainly peaked.
I was selling some of my four corners U-rock at the flea market that day and he purged the gamma detector of bubbles and we set the item next to a piece of rock I had that was rated at 35kcpm and within seconds, a bubble appeared. Over the next minute, there were 7 bubbles showing!!! I was stunned.
Later in the day, he placed this X-ray detector inside a toroidal valley plane of a large 6KW coil and had the person run it producing 8 foot white hot streamers for about 4 minutes of varied operation. At the end of the run there were about twenty bubbles. Again, I was stunned.
He was going to put the neutron bubble detector in next. I told him it was useless, but that experiment would confirm my prediction. Sure enough, zero bubbles after 2 different 5 minute plus runs. He was very sad at this last result having hoped to prove me wrong.
From all of this, I was determined to investigate this BTI, x-ray/gamma detector when I got back home. I called the head engineer at BTI, Rob Noulty. He confirmed that they do, indeed, make a gamma/xray INDICATOR, (he would not use the word detector). It is designed to indicate or sense the presence of both gamma and x-radiation. When I asked why it was not in their catalog, he noted that the device was not calibratable, nor could it discriminate between x and gamma. Futhermore, it was unstable. Thus, the bubbles are for indication only and bears no bubble/dose relationship to the shortwave EM radiation actually passing through the device. The instability, Rob claimed, comes from temperature variability with use and age. He noted to me that at about 80-85 deg F and above the device would spontaneously produce bubbles, but at 75 degrees was totally usable as a reliable gamma/x-ray INDICATOR.
Thinking back, the outside temp in Rochester was about 78 degrees that day, so the test of my U-rock out of doors was viable. However, the tesla coils were setup in a large metal building which was shut up most of the time for photo ops during coil running sessions. The sun hitting the metal kept it about 10 or more degrees warmer inside. Add to this the fact that the arcs off a tesla coil naturally dissapate many KW in the immediate air surrounding the coil, and you have a combination that could easily create false readings in the particular instance of test performed last Saturday.
So we are back to ....did the coil truly produce x-rays or did the high building temperature coupled with the local air temperature rise at the discharge terminal, while running, cause spontaneous bubbles?
The question remains unanswered, but now we also know that such a device as a noise immune gamma/X-ray detector exists provided it is used in a lower temperature environment.
The device costs only $80.00 and is one of BTIs cheapest bubble detectors. With BTI's $250.00 minimum, the next big order we gather together might include this item for those doing noisy environment gamma/x-ray testing.
Apparently it is just embarrasingly unstable enough and lacking any link to intensity indication that they refuse to list it as a sales item in their catalog.
Richard Hull