Talk-Polywell.org

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http://en.wikipedia.org/wiki/Plasma_oscillation

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The natural frequency of a cold plasma is 8.976 Hz * sqrt(electrons/cu m) in a neutral plasma.

If the density is around 1E-6 torr and fully ionized the frequency is 9 GHz.

If we're really going to get 10^4 ion density improvements like this claims,

http://adsabs.harvard.edu/abs/2004APS..DPPNI2005P

then we could see some huge Q values in the near future.

I wonder if they're doing any POPS work on WB-7.

TallDave wrote:If we're really going to get 10^4 ion density improvements like this claims,

http://adsabs.harvard.edu/abs/2004APS..DPPNI2005P

then we could see some huge Q values in the near future.

I wonder if they're doing any POPS work on WB-7.

BTW, there's a slightly more beefy POPS write-up here:

http://www.lanl.gov/p/rh_pp_park.shtml

TallDave wrote:If we're really going to get 10^4 ion density improvements like this claims,

http://adsabs.harvard.edu/abs/2004APS..DPPNI2005P

then we could see some huge Q values in the near future.

I wonder if they're doing any POPS work on WB-7.

The current experimenters, Park and Nebel, are the original POPS people. If POPS will help, I'm sure it is in their plans.

Yeah, I just wonder if they're only trying to validate WB-6 or actually extending it with POPS.

TallDave wrote:Yeah, I just wonder if they're only trying to validate WB-6 or actually extending it with POPS.

Given that they are doing pulsed experiments, I think POPS would be difficult with WB-7. WB-7x (liquid cooled .45 T magnets, 80 KV continuous duty power supplies) or equivalent is the way to go to try POPS.

Seconds of operation is probably a minimum requirement - minutes better.

MSimon wrote:[Seconds of operation is probably a minimum requirement - minutes better.

What makes you say that? The data table in the LANL page linked above showed tests only 5ms long. Sure, they were using a small device, but the scaling shouldn't require minutes!

Solo wrote:

MSimon wrote:[Seconds of operation is probably a minimum requirement - minutes better.

What makes you say that? The data table in the LANL page linked above showed tests only 5ms long. Sure, they were using a small device, but the scaling shouldn't require minutes!

I'd like minutes so a series of tests could be run. Swept frequency tests can be most enlightening.

Plus, stability criteria are going to be a requirement for a production reactor. You don't get that (easily) from pulsed devices.

So does anyone know whether the current experiment being conducted is using a cap bank for HV power supply, or do they have steady-state source? IIRC, the HV supply was the limiting factor; if it weren't, what kind of limit would be placed by the temperature of the copper wires in the magrid?

Solo wrote:So does anyone know whether the current experiment being conducted is using a cap bank for HV power supply, or do they have steady-state source? IIRC, the HV supply was the limiting factor; if it weren't, what kind of limit would be placed by the temperature of the copper wires in the magrid?

I think they are using capacitor banks.

A steady state system with its attendant cost of power supplies is not useful with uncooled coils.

Coil temperature with really good high temp insulation might run 150 C to 200 C max.

MSimon wrote:Seconds of operation is probably a minimum requirement - minutes better.

How fast is the projected POPS frequency compared with test run time?

hanelyp wrote:

MSimon wrote:Seconds of operation is probably a minimum requirement - minutes better.

How fast is the projected POPS frequency compared with test run time?

For WB-6/7 type machines about 1 to 4 MHz.

With 250 uSec of pulsed operation that is 250 to 1,000 cycles. It might be enough time to learn something. It does not give you much time to tune around to characterize the process.

Wow, mission creep in action.

I'm all for figuring out the oscillation physics of POPS--sounds like a moderately promising avenue. But surely the first to do with WB-7 is to characterize electron losses, bremmstrahlung losses and ion thermalization. Either WB-7 drives a stake through Rider's heart or Rider drives a stake through IEC's heart in general. It sure would be nice to know which is which, ASAP.

TheRadicalModerate wrote:Wow, mission creep in action.

I'm all for figuring out the oscillation physics of POPS--sounds like a moderately promising avenue. But surely the first to do with WB-7 is to characterize electron losses, bremmstrahlung losses and ion thermalization. Either WB-7 drives a stake through Rider's heart or Rider drives a stake through IEC's heart in general. It sure would be nice to know which is which, ASAP.

I'm not sure WB-7 can drive a stake through Rider to anyone's satisfaction.

About the most it can show us is if fusion production and electron losses match theory.

Ruling out Rider will require a net power machine. IMO.

MSimon wrote:I'm not sure WB-7 can drive a stake through Rider to anyone's satisfaction.

About the most it can show us is if fusion production and electron losses match theory.

Ruling out Rider will require a net power machine. IMO.

Yes. Absolutely true. At best, WB-7 could maybe show Nevins was wrong about the impossibility of Q>.2.

POPS is yet another issue, one that won't be decided (let alone worked on) by WB-7.