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Instapundit Links To: What Next For Polywell Fusion?
Instapundit Links To: What Next For Polywell Fusion?
Engineering is the art of making what you want from what you can get at a profit.
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Art Carlson
- Posts: 794
- Joined: Tue Jun 24, 2008 7:56 am
- Location: Munich, Germany
Time scale: Quasi-continuous is important. It doesn't have to be steady-state, but the basic parameters (magnetic field, plasma density) should be held constant on a time scale several times greater than the confinement time (or any other equilibration time that might be playing a role).
Size and field strength: This should be expressed in dimensionless parameters. For one, all gyroradii (ion as well as electron, at the maximum energy) should be substantially smaller than the device dimensions. I'd also worry a great deal about the ionization length of (cold) neutrals. This will depend on the field strength though the plasma density and should be much smaller than the physical dimensions.
That, coupled with good diagnostics, is what it takes to get a clean scaling and solid identification of physical processes. Straighten the physics out before you even start to think of power generation.
P.S. Can anybody tell me what these numbers are for current experiments?
Size and field strength: This should be expressed in dimensionless parameters. For one, all gyroradii (ion as well as electron, at the maximum energy) should be substantially smaller than the device dimensions. I'd also worry a great deal about the ionization length of (cold) neutrals. This will depend on the field strength though the plasma density and should be much smaller than the physical dimensions.
That, coupled with good diagnostics, is what it takes to get a clean scaling and solid identification of physical processes. Straighten the physics out before you even start to think of power generation.
P.S. Can anybody tell me what these numbers are for current experiments?
- pulse length / confinement time
- ion gyro radius at well depth energy / coil radius
- speed of cold ions * ionization time / coil radius
Good observations. Excellent questions. I'd like to see operation in the 1 to 2 second range.Art Carlson wrote:Time scale: Quasi-continuous is important. It doesn't have to be steady-state, but the basic parameters (magnetic field, plasma density) should be held constant on a time scale several times greater than the confinement time (or any other equilibration time that might be playing a role).
Size and field strength: This should be expressed in dimensionless parameters. For one, all gyroradii (ion as well as electron, at the maximum energy) should be substantially smaller than the device dimensions. I'd also worry a great deal about the ionization length of (cold) neutrals. This will depend on the field strength though the plasma density and should be much smaller than the physical dimensions.
That, coupled with good diagnostics, is what it takes to get a clean scaling and solid identification of physical processes. Straighten the physics out before you even start to think of power generation.
P.S. Can anybody tell me what these numbers are for current experiments?
- pulse length / confinement time
- ion gyro radius at well depth energy / coil radius
- speed of cold ions * ionization time / coil radius
Engineering is the art of making what you want from what you can get at a profit.
MSimon wrote: Good observations. Excellent questions. I'd like to see operation in the 1 to 2 second range.
Seems a physicist's definition of continuous is a tad different than an engineer's!In his 2006 Valencia paper, Dr. Bussard wrote:These should be tested best in an external vacuum system, with capacitor-driven power supply for the electron injection drive, and be driven to fusion conditions for a period of several tens of milliseconds.
Either way: you need a hell of a capacitor bank or a specially constructed generator that can put out high peak power. Or else some honking power supplies. Figure WB-6 at 1/4 mS vs 25 mS. That is 100 times as much capacitance. Might as well build power supplies.KitemanSA wrote:MSimon wrote: Good observations. Excellent questions. I'd like to see operation in the 1 to 2 second range.Seems a physicist's definition of continuous is a tad different than an engineer's!In his 2006 Valencia paper, Dr. Bussard wrote:These should be tested best in an external vacuum system, with capacitor-driven power supply for the electron injection drive, and be driven to fusion conditions for a period of several tens of milliseconds.
And I'm into stability testing. Very important to know if the reactors have to operate in the pulsed mode or can actually be continuous.
Engineering is the art of making what you want from what you can get at a profit.
There is, if they could manage to get use of it, the cap-bank the Navy created for its rail gun project.MSimon wrote:Either way: you need a hell of a capacitor bank or a specially constructed generator that can put out high peak power. Or else some honking power supplies. Figure WB-6 at 1/4 mS vs 25 mS. That is 100 times as much capacitance. Might as well build power supplies.
