We are posting this picture to help you construct the variable-output, low-ripple, high-stability, high-voltage power supply described in pages 38-40 of “Exploring Quantum Physics Through Hands-On Projects.” The schematic diagrams for this power supply are in the book’s Figure 31. Output voltage (up to 2 kV) and current (up to 1 mA) are monitored via two LCD panel meters. Continue reading
Compton Scattering Experiment Using Spectrum Techniques’ Equipment
Spectrum Techniques of Oak Ridge, TN – a top supplier of Exempt Quantity radioisotope sources and nuclear measurement instrumentation – released today our tutorial:
“Experiment Note: Exploring Compton Scattering Using the Spectrum Techniques Universal Computer Spectrometer” Continue reading
quTools quED Entanglement Demonstrator
- Image Credit: quTools
quTools of München, Germany is the maker of the quED quantum entangled state demonstrator system to generate and analyze polarization entangled photons. This system is a professionally-manufactured version of the type of entangled-photon generator used by many universities, and similar to the diy version described in Chapter 8 of our book (Figure 148).
quED employs a spontaneous parametric down conversion process (type I or type II; collinear or non-collinear) to generate polarization entangled photon pairs. Fiber-coupled single photon detectors in connection with polarizing filters are used to detect the photon pairs, analyze their polarizations and verify their non-classical correlations. Continue reading
ALPhA’s Single Photon Detector Group Order for Educational Institutions
ALPhA (Advanced Laboratory Physics Association) has worked out a deal with Excelitas to sell Single-Photon Counting Modules (SPCMs) to instructional labs. The detectors carry labels specifying that these units belong in the undergraduate instructional labs and not in research labs. These educational detectors have reduced specs, notably a higher background dark count rate, compared to other models from the company.
The set of four SPCMs can be purchased for $5,720 (instead of the usual ~$10k). Continue reading
Actively-Quenched SPAD SPCM Student Design Project

Image Credit: Oliver Jan and Phil Makotyn
In 2006, then-students Oliver Jan and Phil Makotyn from University of Illinois (at Professor Paul Kwiat’s lab) developed an actively-quenched Single-Photon Counting Module (SPCM) based on the Perkin-Elmer C30902S-DTC Single-Photon Avalanche Photodiode (SPAD). Continue reading
β-Particle Magnetic Deflection Experiment – Supplementary Pictures
The book’s Figure 65 shows our β-particle magnetic deflection setup. It consists of a 90Sr disc source of beta particles, two copper washers to collimate the beam, and GM tubes placed at 0º and 90º to the β-particle beam. A sufficiently strong magnetic field (around 800 Gauss = 0.08 Tesla) provided by a permanent magnet bends the beam so much that it is easily detected at a right angle (notice the meter needles in the pictures above).
Attenuation of Alpha, Beta and Gamma Radiation in Air
The attenuation of radiation as a function of distance can be measured using a radiation counter with a Geiger-Müller tube that is sensitive to α, β, and γ radiation. We used exempt plastic-disc sources containing Polonium 210 (210Po), Strontium 90 (90Sr), and Cobalt 60 (60Co) to experiment with the penetrating power of α, β, and γ radiation in air. Continue reading
Color Spectrograph Using Spectrometer of Figure 80
These two images supplement the book’s Figure 81. They were taken with the spectrometer of Figure 80.
Our New Photomultiplier :)
diy Measurement of the Charge-to-Mass Ratio of the Electron Using “Magic Eye” Tube – Supplementary Pictures
Figure 54 in the book shows our setup based on a 6AF6-G “magic eye” tuning tube to measure e/m. The pictures in this figure supplement the book’s Figure 54 to help you build your own system. In the 6AF6, electrons produced by a thermionic cathode cause fluorescence on the tube’s anode. Applying an external magnetic field curves the path of the electrons reaching the anode’s fluorescent coating. Knowing R and the voltage applied to the tube allows one to calculate e/m. Continue reading
d.i.y. Two-Channel Single-Photon and Coincidence Counter
This is an inside view of the two-channel photon and coincidence counter of the book‘s Figure 145. It is used in the photon entanglement experiments of Chapter 8. Continue reading
d.i.y. Measurement of Electron’s Charge-to-Mass Ratio Through Hoag’s Method – Supplemental Pictures
Figures 51 and 52 in the book show how to use an oscilloscope 2AP1 CRT to measure e/m using Hoag’s method. The pictures in this figure supplement the book’s, showing you how to construct the d.i.y. setup, as well as the way in which the electron beam fan is reduced to a point as the magnetic field fulfills the focusing equation. In this setup, an AC signal is placed across one set of plates of the CRT to produce a line on the screen. The solenoid is then energized until the line makes one complete helical turn. Continue reading
d.i.y. Maltese Cross Cathode Ray Tube – Supplementary Picture
This is a supplementary picture to the book’s Figure 43. It shows our d.i.y. “Maltese Cross” CRT connected to the vacuum system and high-voltage power supply. Please note that the HV power supply is configured to produce a negative output referenced to ground. The anode and target electrode are at ground potential. The cathode rod inside the glow-discharge electron gun is connected to -HV. Continue reading
d.i.y. Glow Discharge Tube Diagnostics – Supplementary Figure
This figure supplements the book’s Figure 42. The book’s figure describes the features that appear in the glow discharge. However, we felt that a color picture is required as a cross-check to help you correctly set up your own system. Continue reading
X-Band Gunnplexer Microwave Transceiver for Microwave Optics Experiments
This is an inside view of our X-Band Gunnplexer transceiver (book‘s Figure 12) that should help you build your own units if you follow the schematics shown in the book’s Figure 11 . It is used throughout Chapter 1 for experiments in microwave optics, in Chapter 6 to measure single-slit diffraction, and in Chapter 7 to experiment with Quantum Tunneling. Continue reading