Post on 05-Jul-2020
J-H. Jin1, S-H. Jung2, J-H. Moon2, J-G. Park2 1GammaTech Inc. 2Korea Atomic Energy Research Institute
Gamma Column Scan
Manual Gamma Scanning
Gamma Scanning using Winches
Difficult to install
- 4 guide cables
- Radiation exposure
Difficult to scan
- Long work time
- At least 3 persons
Not accurate positions
- Poor leveling
- Poor reproducibility
Problems in using manual or winch type scanner
Auto
matic G
am
ma C
olu
mn S
canner
• Simplification of cables (7 2 cables)
– By employing tensioning tools Removed the 4 guide cables
– By using signal cable in holding the detector and
– by employing an encoder Removed the measuring tape
• Computer controlled operation (3~5 0~1 person)
– By employing step motor – encoder system
– By incorporating a radiation counter in the scanner
– By logging position-counts data automatically
Main Idea for the Development of Automatic Gamma Column Scanner
• Easy and quick installation
• Only observation during scanning
Graphic results of the scan
Movement of S&D
• Accurate control of S&D positions
Reproducibility and Reliability
Very easy to repeat scanning
• Less radiation exposure
Advantage of the Automation
Improvements of the 4th Automatic Column Scanner
Hardware
- BGO detector, MCA
- Encoder calibration tool
- Simplified operators
- 2 control boxes, LAN
Software program
- LabView
- Encoder calibration method
- Graphic display with a drawing
- Smooth start and stop
- Emergency stops
- Gamma energy spectrum
Radiation detection system
• Scintillation detector
– 1”x1” BGO
• Electric circuit in Detector holder
– High voltage generator
– Counter
– Multichannel analyzer (MCA)
– Communication
• Coaxial wire cable
– Power supply (5 volt)
– Data communication
Smooth movement of source & detector
Installation of Automatic Gamma Column Scanner
① 1 person clime up on top and Lower a rope
② 1 person on the ground connects the rope to a pulley
Installation of Automatic Gamma Column Scanner
③ Raise the pulley to the top
④ Connect the puller to a rod and Fix the rod to the column
Installation of Automatic Gamma Column Scanner
⑤ Repeat ~ with the other side
⑥ Move up source and detector to a leveled position
⑦ Attach tensioners to source and detector
Encoder calibration
MCA
Auto Scan