Alpha Spark Detector
Contents
Why
Radiation is all around. And the Truely Mad Scientist's LVL1 Splinter Group wants to detect it all. For this build, the readiation being detected is alpha radiation. Alpha radiation consists of alpha particles ejected from a decaying atom. The particle consists of two protons and two neutrons. The particle is essentially a helium atom nuclei and carries a positive charge. The positive charge allows for its identification and detection.
The Build
The Bill of Materials:
- Thin Copper Wire
- Single Row Header Pins
- Stirring Straws
- Strip Board
- Acrylic Sheet (0.093, 0.22, 0.05 inches thicknesses)
- Copper Sheet
- 0.01 uf Ceramic Disc Capacitor 2kv rating (qty 2)
- 1N4007 Diode (qty 12)
- 1 watt 10 Mega Ohm Resistor
- Power Supply for CCFL Case MOD Lights
- Hardboard
- Wire
- Nuts and Bolts
- Super Glue
- Hot Glue
The Components:
- Sensor Assembly
- Voltage Multiplier
- Power Supply
- Housing
Assembly
Sensor Assembly
The Sensor Plate illustrated above is assembled in layers. The top layer consists of header pin spacers which are used to hold the sensor wires inplace. The sensor wires are wirewrapped to rows of header pin posts. Below the wires are straws which will tension the wire when assembled. This wire assembly is soldered onto a strip board with a square cut out of the center to allow the bottom elements to be adjusted in height and leveling. The bottom assembly begins with a Cover Plate designed to shield the Copper Plate's corner which collect charge and interfer with the operation. The Copper Plate is mounted on a Spacer with a through hole to allow the Negative Voltage Wire to be attached. The Leveling Plate also has an access hole for the Negative Voltage Wire and serves as the mounting for the bottom assembly. Finally, the Negative Voltage wire is soldered to the Copper Plate and the Ground Wire is soldered to the header pin posts. Not visible in the diagram are the four leveling screws through the Strip Board and fastened to the Leveling Plate with springs in between. A wire is also used to jumper/connect the two rows of header pin posts.
+Underside Stripboard woldered
This assembled diagram shows the straws, flattened by the wires, providing tension.
+ Lower Sensor Assembly
+Completed Sensor
Voltage Multiplier
This voltage multiplier has eight stages and generates Negative high voltage. The capacitors are 0.01uf ceramice rated at 2kv. The circuit uses pairs of diodes in series to represent a single diode in the diagram. The circuit is soldered wire-to-wire on perf-board.
+Voltage Multiplier
Power Supply
The power supply used is a common Cold Cathode Florescent (ccfl) Tube driver used in computer case mods. The output is rated as 600 volts ac and can drive two CCFL tubes.
+Power Supply
