Scionix in The Netherlands has taken advantage of the recent development of miniature mesh-type dynode photomultiplier tubes to construct small-diameter scintillation probes. Scionix’s miniature probes incorporate one of those PMTs, a NaI(Tl) scintillation crystal, and a built-in dynode voltage divider. Connection to the probe is made through a miniature high-voltage locking coaxial connector. Finding a mating connector is the main
Many surplus scintillation probes have a single connector through which the PMT is fed with high voltage and the anode signal is output. However, this may require an external “Bias-T” (a high voltage / signal splitter) to connect the probe to a high-voltage power supply that is separate from the PMT amplifier/processor.
Simple d.i.y. Low-Pass Filter for Interfacing PMT Amplifier to PC Sound Card (Used with Free “Pulse Recorder and Analyser” Software MCA)
Figure 34 in the book shows the schematic diagram for our photomultiplier tube (PMT) signal processing circuit has an analog output that is suitable for use with a sound-card-based multichannel pulse-height analyzer (MCA). However, if you already have a commercial scintillation processor that you would like to use with PRA, then you will somehow need to
Last week I posted detailed construction information for my rubidium atomic clock frequency reference. Besides that unit, I also built a GPS-disciplined 10 MHz oscillator to serve as a secondary frequency reference, as well as a source of GPS NMEA data for my ham shack instruments that can use precise location and real-time-clock data (e.g. for
Transformers made for powering large neon signs are inexpensive and very reliable. Most commonly, the secondary is center-tapped, which prevents the use of its full peak-to-peak output in applications where one of the terminals needs to be grounded. In the power supply described in this post, I took out the high-voltage transformer out of its metallic
Efratom Model M-100 Rubidium Frequency Standard (RFS) oscillators are widely available in the surplus market. Units on eBay commonly sell in the $150 to $200 range. Despite their low surplus price, they were originally very expensive components, with superb performance. The M100 was designed to be used by the military as a master oscillator in high-performance
Experimental chemistry is not our forte, so we prefer to use professionally-manufactured quantum dots for the Schrödinger’s Wave Equation experiments we discuss in the book‘s Chapter 7. However, if you are interested in synthesizing your own quantum-dot nanoparticle suspensions, we recommend that you take a look at the detailed instructions prepared by Professor George Lisensky
Our two prior posts show how to build very high voltage power supplies using flybacks from old color TVs. The advantage of the method we use is that any flyback can be driven, regardless of how its primary is wired. This is because we wind our own primary using litz wire.
We use the flyback-driver circuit shown in our d.i.y. 250 kV DC power supply in many other of our setups, so we built a stand-alone universal resonant transformer driver.
High voltage DC power supplies are used by science enthusiasts for powering electron tubes and x-ray tubes, charging high-voltage capacitors, powering electrostatic “levitators”, etc. Many of these power supplies use a flyback transformer to produce high voltage at high frequency (AC), followed by a “Cockroft-Walton Multiplier” to rectify and dramatically increase the voltage. The Cockroft-Walton multiplier
I just posted at www.prutchi.com the construction of a simple, but very useful laser power meter. I used it to tune my 18 W CO2 laser, but the concept is applicable to any other high-power CW laser. Click here for a direct link to the blog post.
Military DT-590A/PDR-56 “x-ray” probes are widely available in the surplus market. They were meant to be used with the military Radiac Set AN/PDR-56, which is a portable scintillation-type instrument used for detection of plutonium-239 contamination. In addition to emitting 5.1 MeV alpha particles, Plutonium-239 also emits gamma rays in the energy range of 14 to 21
The military Radiac Set, AN/PDR-56 is a portable scintillation type instrument used for detection of alpha contamination. The system includes a large and small interchangeable probe with a probe extension. This system is being phased out by the US Air Force, so new probes are becoming widely available in the surplus market. The “x-ray” probe
An amateur-use open-source gamma spectrum analyzer is being developed by members of the GeigerCounterEnthusiast (GCE) Yahoo Group. This multichannel analyzer (MCA) is based on the STM32F103VBT6 microcontroller. It displays spectra on a color LCD. To access the design files (and hopefully to participate in the development) you will need to join the GammaSpectrometry Yahoo Group