- #1
eigenmax
- 58
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I am building a Cockcroft-Walton accelerator for a science fair project, so how does this design sound?
Starting from the top, there is a polished steel terminal, like a VDG terminal. Inside here is the proton source and power supply to the source (the source is a hydrogen discharge tube) . The top terminal is connected to the output (positive), of a Cockcroft-Walton voltage multiplier. From the top terminal comes the accelerator tube. It is a glass (probably borosilicate) pipe.
Three polished copper drift tubes are fitted within it. The highest tube is connected to the spherical terminal at the top. The middle tube is connected to the middle of a six-stage CW voltage multiplier. This is half the top terminal voltage (still positive). The bottom tube is connected to the start of the multiplier , ground. The proton beam enters a machined aluminium chamber and strikes a target. This creates gamma rays which can be detected. If lithium is struck with the beam, alpha particles are created which escape through a mica window in the target chamber and are detected by a end-window Geiger counter.
Should I place external corona needles connected to the drift tubes, outside the accelerator tube, to equalise potential over the tube, or is my current design fine? Should a seal the proton source with a mica window or us the design from http://info.ifpan.edu.pl/firststep/aw-works/fsII/alt/altineller.pdf. If I don't seal the source, won't the hydrogen just escape down the acceleration tube?
Please improve upon it and tell me what I'm doing wrong.
Thanks so much,
Max
Starting from the top, there is a polished steel terminal, like a VDG terminal. Inside here is the proton source and power supply to the source (the source is a hydrogen discharge tube) . The top terminal is connected to the output (positive), of a Cockcroft-Walton voltage multiplier. From the top terminal comes the accelerator tube. It is a glass (probably borosilicate) pipe.
Three polished copper drift tubes are fitted within it. The highest tube is connected to the spherical terminal at the top. The middle tube is connected to the middle of a six-stage CW voltage multiplier. This is half the top terminal voltage (still positive). The bottom tube is connected to the start of the multiplier , ground. The proton beam enters a machined aluminium chamber and strikes a target. This creates gamma rays which can be detected. If lithium is struck with the beam, alpha particles are created which escape through a mica window in the target chamber and are detected by a end-window Geiger counter.
Should I place external corona needles connected to the drift tubes, outside the accelerator tube, to equalise potential over the tube, or is my current design fine? Should a seal the proton source with a mica window or us the design from http://info.ifpan.edu.pl/firststep/aw-works/fsII/alt/altineller.pdf. If I don't seal the source, won't the hydrogen just escape down the acceleration tube?
Please improve upon it and tell me what I'm doing wrong.
Thanks so much,
Max
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