Warmng up fusor IV for HEAS

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Richard Hull
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Warmng up fusor IV for HEAS

Post by Richard Hull »

As per my usual effort, I have been warming up and conditioning fusor IV over the last three days. Being a leaky fusor it takes a bit of conditioning to bring it on line. As it turns out, about a week is needed, but I am doing great for only 3 days into it.

I will update these figure via the edit function over the period before HEAS. This effort should allow those who are up to fusion eneergy with good D2 flow control to see what a leaky fusor can do if operated by an old hand.

Background 6.6 cpm on neutron counter, averaged over three nights.

Day one: 15 Sept 2015. Lousy startup 1.6 hours to pump to .5 microns with diff pump running.

Absolute best run after 3 hours of fiddling 41kv @ 11ma with 5.7microns of D2 - 51,000 n/s

16 Sept 2015. A good bit better and pumped down to 5X10e-5 torr in under 40 minutes.

Best run after 1.5 hours 36.8kv @ 9ma with 7 microns D2 - 131,600 n/s

17 Sept 2015. Fast pump down to 2X10e-5 torr 30 minutes

Best run after 1hour 39kv @ 11ma with 8 microns of D2 - 306,320 n/s

18 Sept 2015. Fast pump down to 4X10e-5 torr 30 minutes

Best run after 40 minutes 41.5kv @ 11.5ma with 8.5 microns of D2 - 517,880 n/s

20 Sept 2015 Very fast pump down in 20 minutes

Best run after only 15 minutes of operation 40kv @ 11.6ma with 10.3 microns of D2 - 731,680 n/s

24 Sept 2015 Fast pump down, but 4 day lapse caused operation to be hard to beat the 20th

Best run after half an hour 40.8 kv @ 11ma with 10.8 microns of D2 - 697,160 n/s

26 Sept 2015

Best run after 30 minutes 42kv @ 10.6ma with 11.7 microns of D2 - 882,020 n/s

Notice how the higher D2 pressures and higher currents at any voltage over the days shows more neutrons..
The takeaway here is that once you have the voltage, it is all about higher pressures and currents.


Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Jim Kovalchick
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Re: Warmng up fusor IV for HEAS

Post by Jim Kovalchick »

Richard,
I wonder if the biggest factor that helps you with increasing neutron numbers is the heat up that drives water off your chamber walls that also helps your ultimate pressure or is it just buildup of deuterium into the wall and grid surfaces. Given the coincidence of improving best vacuum numbers with improving neutron numbers I suspect that water and other contaminants can poison the plasma a little and once they are mostly gone the fusion is optimized. We have also seen changes in plasma color over time when the chamber is warmed up after long idle periods.

Jim Kovalchick
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Richard Hull
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Re: Warmng up fusor IV for HEAS

Post by Richard Hull »

Jim,

I have long ago assumed and stated all of this and have just pushed a new FAQ into the vacuum forum for the benefit of the newbies. This is nothing new to me as I tend to post these startup figures each September to push the notion home.

I am a firm believer in D implantation of fast neutrals into the shell walls/grid which tremendously aid successive runs of any and all fusors. Remember, all metals absolutely love to absorb hydrogen....Usually to their structural detrement over time. (I have long noted old grids are extremely brittle) Deuterons popping back out of the walls under electron bombardment are ideal in that they can undergo full potential acceleration. Another advantage includes driving water out of the walls via electron and D neutral bombardment heating. Thus, thermal kinetic energy loses in the system help to improve its operation provided runs are successive over a period of days. I worry that a lot of amateurs attempting fusion are disappointed at their first pass results and never see this benefit. Of couse, there is always the possibility of poor results due to poor operation or preparation of the system as well.

I have noticed a latency period for deuterium wall retention. While I have not studied temperature effects, the wall loading seems to last at least a week or so as I can leave the system alone for about that long and still get the system back to full operation easily within that period. However, at 1 month, it is a "start all over" situation.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Nick Peskosky
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Re: Warmng up fusor IV for HEAS

Post by Nick Peskosky »

Richard,

It would be interesting to see what would happen if you wrapped the chamber in heating tapes or utilized a halogen bulb mounted in the chamber to bake-out the system prior to your first "conditioning" run. I'd be curious to see if you neutron rates would be substantially higher than what you have posted in the past for the first few runs after the Fusor has laid dormant for weeks/months leading up to HEAS. If someone has a good source for MKS (or any other manufacturer for that matter) heater tapes/jackets I would definitely try this on my own 6" tee.
Nick Peskosky
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"The whole of science is nothing more than the refinement of everyday thinking." - Albert Einstein
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Richard Hull
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Re: Warmng up fusor IV for HEAS

Post by Richard Hull »

Nick,

I am sure it is a combination of both as I posted. The water is usually all chased out as vapor after the first very long run, as I noted. I feel that the wall loading continues to improve the numbers well afer the water situation is taken out of the equation. The neutron number just keep on climbing and climbing, day after day.

I added, (edited), in a few lines on my above original since you posted. I tend to post and read and amend about 5 or six times within a few minutes after each post. So you might re-read.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Richard Hull
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Re: Warmng up fusor IV for HEAS

Post by Richard Hull »

As added info, I have timed my leak over the past nights as I have added to the original post in this thread. Interestingly, the leak is real and constant and not virtual, at all.

As the neutron numbers has gone up the leak is nearly constant at the very end of each run. Here is what I do:

1. Run the fusor for however long it takes to get a new peak reading "each day".
2. When this is achieved and logged in my notebook, I shut the system down.
3. The very first thing I do is to get my stop watch ready and with all pumps still running full bore, I turn off the high voltage and shut the deuterium gas line valve.
4. The diff pump to fusor throttle valve is nearly shut due to throttling to obtain a usable differential, usable gas flow.
5. I throw this valve wide open, and naturally, the pressure plunges from the 10 micron running pressure back to about 5X10-5 torr that the fully pumping system can maintain.
6. Once the bottoming pressure is reached, (usually in under 5 seconds), I slam the fusor to diff pump valve to dead shut-off, completely isolating the fusor from any pumping action. I start the stop watch and watch the capacitive manometer gauge on the fusor and stop the stop watch when the chamber reaches 10 torr.

Here is the data

the 15th 115 seconds
16th 121 seconds
17th 128 seconds
18th 131 seconds
20th 130 seconds

Note the best fusor run was yesterday 750,000+ neutrons/second with the natural leak the same as many previous poorer run nights. Looking a bit more like wall loading to me, but still not conclusive beyond any doubt. I consider this a fast leak as I am sure, most dyed in the wool vacuum heads would agree. However, not so fast that a lot of decent fusion can't be done against a well delivered and throttled gas flow. It appears most of the water and volatiles were "cooked out" by the end of the long, torturous, first multi-hour run which resulted in rotten fusion numbers.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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