diy Physics Blog

Monthly Archives: January 2012

ALPhA’s Single Photon Detector Group Order for Educational Institutions

Posted on by Posted in Chapter 8 - Entanglement, Entanglement, Single-Photon Counting Modules (SPCMs), Single-Photon Experiments

Excelitas Perkin-Elmer Single Photon Counting ModuleALPhA (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

Posted on by Posted in Chapter 8 - Entanglement, Photon/Coincidence Counter, Single-Photon Counting Modules (SPCMs), Single-Photon Experiments
diy Single-Photon Counting Module designed by students at University of Illinois

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

Posted on by Posted in CDV700 Pro Geiger-Müller Counter, Chapter 3 - Atoms and Radioactvity, Ionizing Radiation Detection, β-Particle Magnetic Deflection

β-Particle Magnetic Deflection Experiment

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).

  Continue reading→

Attenuation of Alpha, Beta and Gamma Radiation in Air

Posted on by Posted in Attenuation of Radiation, CDV700 Pro Geiger-Müller Counter, Chapter 3 - Atoms and Radioactvity, Ionizing Radiation Detection

 Measurement of alpha, beta, and gamma radiation by air as a function of distance

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→

diy Measurement of the Charge-to-Mass Ratio of the Electron Using “Magic Eye” Tube – Supplementary Pictures

Posted on by Posted in Chapter 3 - Atoms and Radioactvity, e/m Measurement, Electron-Beam Tube

diy setup for measuring e/m using a 6AF6-G magic eye tube

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. Measurement of Electron’s Charge-to-Mass Ratio Through Hoag’s Method – Supplemental Pictures

Posted on by Posted in Chapter 3 - Atoms and Radioactvity, e/m Measurement, Electron-Beam Tube

d.i.y. Measurement of Electron's Charge-to-Mass Ratio Through Hoag's Method

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

Posted on by Posted in Chapter 3 - Atoms and Radioactvity, Electron-Beam Tube, Maltese Cross CRT

diy Maltese Cross Cathode Ray Tube

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

Posted on by Posted in Chapter 3 - Atoms and Radioactvity, Chapter 4 - The Priciple of Quantum Physics, Emission Spectrometry, Glow Discharge, Vacuum System

Glow discharge tube diagnostics as a function of pressure. Glow discharge vacuum gauge

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

Posted on by Posted in Chapter 1 - Light as a Wave, Chapter 6 - The Uncertainty Principle, Chapter 7 - Schrödinger's Wave Equation, Doppler Effect, Gunnplexer Transceiver, Quantum Tunneling, Single-Slit Diffraction, Two-Slit Interference

X-Band Gunnplexer 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→

MX-10160 Gen III Image Intensifier Tube

Posted on by Posted in Chapter 5 - Wave-Particle Duality, Chapter 7 - Schrödinger's Wave Equation, Mach-Zehnder Interferometer, Single-Photon Experiments, Single-Photon Imaging, Two-Slit Interference

MX-10160 Gen III intensifier tube used in the helmet-mounted AN/AVS-6 “ANVIS” aviation night vision imaging system

Gen III image intensifier tube used in diy single-photon camera

This is the surplus Gen III image intensifier tube (an MX-10160 Gen III intensifier tube used in the helmet-mounted AN/AVS-6 “ANVIS” aviation night vision imaging system, which we purchased on eBay®) that we used to build our setup to image interference patterns from our single-photon two-slit setup (book‘s Figure 93).  The tube is supplied by 3VDC from two AA cells.  We used the same camera to record interference patterns from a single-photon Mach-Zehnder interferometry setup (book‘s Figure 132). Continue reading→

Pictorial Instructions for Modifying ENI CD V700 into CDV700 Pro

Posted on by Posted in CDV700 Pro Geiger-Müller Counter, Chapter 3 - Atoms and Radioactvity, Ionizing Radiation Detection, Scintillation Detector 2 Comments

David Prutchi's CDV700 Pro Geiger Muller Counter

We modified a surplus Civil Defense V-700 radiation survey meter made by Electro Neutronics Inc. (Model 6-b) into a very capable radiation counter capable of working with both Geiger-Müller and PMT scintillation probes. We modified the front panel to accommodate the new switches, connectors, and panel light. In addition, we placed a Veeder-Root count totalizer module on the side of the box. The new electronic components, including a Zener diode stack and a PMT preamplifier are wired directly to the original printed circuit board. Continue reading→