Figure 144 in the book shows the schematic diagram for our d.i.y. passively-quenched SPCM based on a Perkin-Elmer C30902S-DTC SPAD. In our circuit, the SPAD is reverse-biased through a 200kΩ resistor. This value is sufficiently large that an avalanche in the SPAD will be quenched by itself within less than a nanosecond. The pulses produced by
Our diy entangled-photon source, shown in the book’s Figure 142, uses two BBO crystals that support type I down-conversion that are mounted according to a design by Paul Kwiat and his colleagues at the Los Alamos National Laboratory. The nonlinear crystal in our photon entangler comprises two 5 mm x 5 mm x 0.1 mm BBO crystals mounted face-to-face at
This is the 405 nm pump laser used in the circuit shown in the book’s Figure 141. The laser is built from a Blu Ray disk burner laser diode. We drive the laser diode with 160 mA to produce around 100 mW of 405-nm polarized light. The laser diode is capable of producing 250 mW, but we
Figure 34 in the book shows the schematic diagram for the photomultiplier tube (PMT) signal processing circuit that amplifies the narrow pulses detected by the PMT probe. The discriminator stage removes small pulses produced by thermal noise in the tube. A pulse stretcher outputs pulses that can be heard on a speaker. In addition, the analog
The book’s Figure 32 shows the schematic diagram for a low-cost, variable-voltage PMT power supply based on a BXA-12579 inverter module that is originally designed as a power supply for cold-cathode fluorescent lamps. This under-$20 module produces 1,500VAC at around 30kHz from a 12VDC input. We are posting this picture to help you build your own power
This picture supplements Figure 148 in the book. The colors should help you visualize the paths of the beams in our entangled-photon source: Violet – 405 nm pump laser beam; Pink – 810 nm signal and idler entangled-photon beams. A detailed schematic diagram for the entangler is available in the book’s Figure 147. Figure 149 shows
This is the datasheet for the RCA 6655A PMT used in the probe shown in the book’s Figure 30: RCA_6655A_Datasheet This is the datasheet for Hamamatsu’s replacement of the RCA 6655A PMT: Hamamatsu replacement for RCA 6655A R2154-02 Schematic diagrams for the probe are in Figure 29.
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
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”
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
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
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).
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
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,
These two images supplement the book’s Figure 81. They were taken with the spectrometer of Figure 80.