FAQ - Make your own deuterium from heavy water!! The video

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Richard Hull
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Richard Hull »

We ran these calcs way back. We determined you get a lot more D2 via electrolyzation per unit dollar spent than tanked gas. A 50 liter tank can cost over $350 now with about $100 being the disposable, non-refillable tank. So in a large tank 100 liters might cost $500 in bulk. This is opposed to about $80-100 for D2O with similar gas capability and a lot of electrolyzation passes. The sole advantage to the tanked gas is you avoid a bit of a hassle every time you want to do fusion and have to be very mindful of not running out of D2 at a critical moment of operation. Obtaining some of those larger capacity storage cells for the electrolyzer would help obviate this though. I note Mark's process seems to warrant only pure D2 gets into his fusor. This is very important and demands evacuation of the lines which require a bit of forethought in construction design if you plan on getting your gas this way. This isn't present with tanked gas as you are constantly connecting and disconnecting you gas bottle, (syringe) if you electrolyze.

Mark seemed to do OK for his runs with just a 100ml syringe once he got his operation down to a routine.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Jim Kovalchick »

I have been using a 150 ml syringe, but I usually fill to 120. I have found that with my leaky 6 inch tee chamber running at 0.01 mbarr, and around 40 kV and 10 mA, I use about 60 ml before my chamber gets too hot to keep neutron numbers from falling. This is usually 15 minutes.

With regard to shuttling syringes and the resulting need vent and purge, I will be adding fittings and clamp valves to eliminate the need to separate the tubing.
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Frank Sanns »

Anybody know how the Hydrofill PEM unit gets the pressure in the Hydrostick canisters up to 400 psi? Whatever THAT is would solve all the problems for a reasonable compact storage reservoir.
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

Frank, hopefully Andrew Seltzman sees this post. After all the work he’s done on the little cylinders I’m fairly sure he has the answer.

Regarding the need for such a big reservoir I think we should ask ourselves a few questions…

How many folks build neutron capable fusors that go anything beyond “the big win”?

Out of that tiny fraction that do, how many get their systems efficient enough to begin activation work?

Out that smaller fraction, how many people add the necessary cooling to keep “activation capable” neutron output sustainable past 20-30 minutes?

In reality, we’re only talking about the rarest of rare occurrences. Being as such, it appears there are only three situations where a large reservoir would be needed:

1) a fusor capable of very long operational periods

2) a fledgling fusor builder who is still learning the ropes of gas handling and throttle efficiency. With certainty, I can say I wasted quite a bit of gas when I was getting my system off the ground. However, if I had a big reservoir, maybe I wouldn’t have focused as much as I have on gas use efficiency. Regarding that phase of learning, the occasional re-filling of the syringe was of no consequence.

3) a large chambered fusor

As discussed before, most if not all Fusors are as unique as a fingerprint. Gas effeciency will greatly depend on chamber size and the type of secondary pumping system one uses (not to mention smaller factors like needle valve types and such).

As long as ones system is small (cube fusor, 2.75” type, my cylinder system, etc) and cooled, making a 100mL syringe last a full hour at the mega n/s mark is attainable. As of now the best I’ve done is a bit over 45 minutes. My only limitation was a psu issue several months ago which has since been fixed. There was more than enough gas left in the syringe to take it home.

My main point of all this is of course directed to the newbies and rookies. For them, a PEM cell and syringe is all they need. It’s important to highlight, especially in a FAQ which is mostly frequented by the new folks.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Frank Sanns »

My chamber is one of the larger ones at over 22 liters. As such, outgassing is a big issue so it takes gas. Normally I run a heavy deuterium stream to keep the chamber flushed of any outgassing. The ruddy color disappears in an hour or so with a good deuterium stream. That is for those of us that are not running everyday or like me, opening it up often to run different geometries and shell configurations. .

The large chamber has way more surface area to dissipate the heat. So a big chamber is good and a big chamber is bad. Still, in 20 years, I am only on my second cylinder. In my area, cylinders are hard to come by to purchase. The local dealers want you to pay a monthly leasing fee. No go for me as it takes me a long time to use a bottle. Some out of state suppliers will sell then there is the hazardous shipping charges.

I have a couple of PEM cells and have wanted to use the deuterium from them as the flush gas and the gas to bring it up to higher pressure between runs. I just don't want to dawdle with it every time I want to flush. It would be great to get enough to be able to sparge with no mind to how much is being used. I may just run my high vacuum pump and pull down a container and back fill it with electrolyzed D2. Running at some pressure would be a win. Hopefully Andrew can shed light.

For the new people, more gas makes getting to neutrons a little faster, especially in a less refined chamber or with little experience.

Just some thoughts from another angle.
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We have to stop looking at the world through our physical eyes. The universe is NOT what we see. It is the quantum world that is real. The rest is just an electron illusion. ---FS
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Andrew Seltzman »

As far as the Hydrofill units go, I believe they just use back pressure from the fuel cell to achieve the high pressure. There are no active compressor components in the system, the H2 or D2 output of the cell goes through some sort of moisture separator, thorough a molecular sieve canister to trap any additional moisture and to the metal hydride cartridge fitting (in parallel with a pressure switch/sensor). The molecular sieve canister is regenerated by occasionally purging D2 from the metal hydride back through the sieve and out to the atmosphere. The fuel cell is backed by a hefty 1/2" thick aluminum backing to withstand the pressure.

I made two youtube videos on the Hydrofill units
https://www.youtube.com/watch?v=7tC-uMBQv4g
https://www.youtube.com/watch?v=N-WEIwiA3Co

I'm pretty sure the hydrofill units run a Pressure Swing Adsorption cycle for hydrogen purification:
https://www.peakscientific.com/discover ... n-methods/
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Richard Hull »

I find Mark's reasoning quite sound. The DIY in-it-to-win-it types are best served by syringe fed electrolizers. Those few long term fusioneers might wish to invest in either tanked gas, if they can obtain it, or try out the Hydrofill tanked system. Mark, once he got his operation down, notes that the 100cc syringe works great for him. Guys with Mastodon sized fusors are pretty much doomed to tanked systems that can supply large volumetric gas flow rates over sustained operational periods. Again, sustained operation periods it seems tend to demand active coolant systems. This is especially true for activation work on elements of the activation isotopes sought with half-lives on the order of many minutes to a few hours.

The fabulous advantage to tanked gas is that no matter what, you are ready to go at a moments notice for years into the future off of one tank!! (assuming intermittent use in low volume fusors) I am still using the same tank I installed in 2016! No fiddling with the PEM system. This being said, I am now fully equipped with a PEM cell system and 300ml of D20! (belt and suspenders)

Note: Tanked D2 can now be obtained easily without much hassle, if you have the money and desire from the suggested vendor in the trading post section on prime resources.

viewtopic.php?f=75&t=13889



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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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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

As a final installment to the PEM video series, I made an unboxing vid to compliment Richards recent post about the kit.

https://youtu.be/dGlxx4_Ov0g

Richard, maybe this is something you can add to the first post under the other videos. That way they’re all together for easy initial access.

Since this new cell is defined for long term storage, I elected to vacu-seal it. As stated in the video, Horizon used to have them vacu-sealed but it seems now they’re just kept in a ziplock. Kinda odd since Horizon originally recommended against unsealing the cells until ready for use. Being as such, I decided to lightly vacu-seal it. I avoided a hard vacuum as there was concern about damaging the membranes.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Frank Sanns »

Andrew and Mark.

High pressure coming from the blue PEM cells is not possible. They will blow out at very low pressures. The membranes are delicate and cannot take 4 psi let alone 400. Either the PEM cell is vastly different in the HYDROFILL unit to achieve the 400 psi or the adsorption of the hydrogen onto the metal hydride takes place at a very low pressure yet gives the volume of hydrogen (deuterium) that would be equivalent to an open cylinder at that pressure.

As for finding the original Horizon cells, yes there are far fewer of them but they have been replaced by this other ones, also from China, for around half the cost. I have no idea of their quality but at $30 a piece, it looks to be a good unit consider maybe. They are all over eBay.

Mark, It might be good to add all of your links to your original thread starter here so people do not have to read through all pages to find them.
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

Frank,
I’ve seen the Chinese versions before but elected not to get one due to the month long shipping times. But you’ve convinced me to give it a shot. Ordered this morning so it should be here by mid to late June. Total cost inc shipping was $34. It’ll be a worthwhile comparison for the community… especially if they work equally well!

I added the unboxing vid to the original post on page 1.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Richard Hull »

I have significantly reorganized the original post. I now feel that this first posting FAQ is a stand alone video, extravaganza of great and lasting value when the videos are viewed as I have edited them in sequential order. Much of the following replies are dealt with in this one original posting now. I struggled with erasing posts that were made superfluous in many following replies but demurred, wishing to leave things intact. Fabulous work on Mark's behalf in successive videos now organized for proper and complete perspective.

To Frank:
I think, rather than confuse folks, we will let the original reversible PEM cell presented in the original FAQ posting, now in a fine order of videos, to stand alone. For those who wish to follow the replies they will stumble onto the Electrolyzer only cell and the Chi-Com yet cheaper cells that you posted on. They can choose and experiment with the unknowns should they wish at their convenience. We really wish that very complete initial posting to be the complete exposition on the subject.

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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
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

Shipping on the Chinese PEM cell was surprisingly fast (10 days!). Tracking was accurate which provided updates every 2 days or so.

So here’s the initial report:

Unboxing
The packaging was the typical padded speedpak envelope. The cell within was contained in a Mylar type ziplock bag. No instructions, no extra parts, just the cell all by its lonesome. If anyone decides to go this route first, they will be required to purchase or fabricate the wiring, silicone tubing and plugs, and filler syringe.

Physical Comparison
Other than the shape of the plastic frame, the membrane cell itself appears to be the same size as the Horizon cell (pictured in blue). Close inspection of the membranes reveal some slight differences (texture, perforation size, etc) but nothing strikingly obvious.

3EDD1E2B-7D92-4B97-AF88-9A8EE1CBAB4A.jpeg

There’s no indication in English to identify which is the hydrogen side or the D2O fill side. However, the negative polarity side (black terminal) is typically the H output side. This was confirmed during operation.

Making Deuterium Gas
Operation appeared to be identical with the Horizon unit. However, D production really slowed down after 70mL or 15 minutes of operation. To get a full 100mL charge took roughly 30 minutes. That’s 15 minutes longer than the Horizon. During operation there was no hint of any wet or damp deuterium product. No condensation in the lines or within the negative polarity side of the cell.

4199D1D7-4CEC-4F06-B9DA-93DC993CBBC9.jpeg

Deuterium Performance
Operating the fusor did not reveal any remarkable differences with this deuterium product. Fusor operational settings which typically produce 1.5E+6 n/s TIER were the same with both cells.

Questions Remain
Providing it’s maintained properly, the Horizon cell has been proven to last years. Will this cell have similar longevity?

The slowing down of deuterium production after 15 minutes is concerning. Will this improve, get worse, stay the same?

Will the cell withstand back pressure as well as the Horizon unit does?

All these questions can only be answered after several months to a year or continual usage. Additionally, as others try these cells it may identify mine as a lemon, top performer, or just the average.

As of now, I would recommend for the new fusorist to buy a Horizon kit or one of their electrolyzer cells before considering one of these….at least right now.

Mark Rowley
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Re: FAQ - Make your own deuterium from heavy water!! The video

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Thanks for this report on the chi-com electrolyzer. The slow down, in my book, means "spend the long buck" go Horizon.
The content and value of this FAQ keeps on improving thanks to Mark's continuing effort.

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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
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by John Futter »

Mark
The difference could be that the chinese version uses Chafion not Nafion. Nafion is now out of patent protection but I think they have guarded their IP well so there could be quite major differences.
We have bought some @ work will report when measurements are done
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Arun Luthra »

What is the story behind the odd looking needle valves with transparent cylinders with green caps?

https://www.youtube.com/watch?v=hUxv6gB3SlA
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Richard Hull »

Let me guess...Clear, lucite, valve extension rods, (Adapted extensions?) with pretty green end cap plugs?? Mark will set us straight. I love to look and take a guess at what has been done.

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Progress may have been a good thing once, but it just went on too long. - Yogi Berra
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

Richard is spot on correct. Really no story, just lucite extensions to keep my sleeves away from the gear. Otherwise just standard Swagelok needle vavles (ss-ss4, etc) which almost everyone here uses.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Mark Rowley »

Today was the second test of the Chinese cell. Gas production was not only dismal but fairly wet. Took almost an hour to fill the syringe. Deuterium quality was awful resulting in just a few neuts.

John, hopefully you have better luck but as of now I can’t recommend these cells under any condition. When you conduct your tests try to look for output decay over the course of a few days.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Richard Hull »

I told ya'....Go Horizon or go baroque.

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Fusion is the energy of the future....and it always will be
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Joe Gayo »

I ordered this kit directly from Horizon:
DIY Fuel Cell Science Kit (RESK-02B-1) - https://www.horizoneducational.com/diy- ... -kit/p1457 - $59 + $15 Shipping
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Jim Kovalchick »

Some bad experience to share:

I thought I would save some steps by connecting my syringe, cell, and fusor supply together and use Mark's hemostat pinch idea to just keep the line I wanted open by changing the hemistat lication. Mistake. The syringe pull resistance is enough to cause a negative pressure sufficient to leak through the hemostat and pull on my cell. The result was breach of heavy water through the cell membrane. A tiny slug even made it into my variable leak valve. Once I get everything dry, I am back to disconnecting the syringe from the cell every time. This will require purging everything each time, but it is better than this disaster.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Bob Reite »

You can also use an over/under pressure protection system consisting of two small vials initially half filed with pump oil. For details, visit topic viewtopic.php?f=6&t=9435. This will also give you some deuterium storage sufficient for a five to ten minute run.
The more reactive the materials, the more spectacular the failures.
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Re: FAQ - Make your own deuterium from heavy water!! The video

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Great tips in a great FAQ. Assuming folks read this far in future. Too many go for the Quick rinse on the first page. Too bad.

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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Jim Kovalchick »

This little tidbit could belong other places, but just a note on the impact of moisture and in my case, a droplet, making its way into a variable leak valve like the one I use to control the flow of d into my system. The moisture will build up as a film in the sealing surfaces and turn the variability into an on or off control. The problem is fixable. A bakeout is required.
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Re: FAQ - Make your own deuterium from heavy water!! The video

Post by Emma Black »

Even though its been a year since this thread was commented on I shall add my experience of these Horizon Cells.

Jim I had the same fun of liquid D2O reaching my leak valve. Had an empty syringe connected to the cell and fusor via a T piece.

The issue was much worse in low temperatures, to the point where a plus of D2O condensation on the hydrogen side of the cell would block the output until it burped a droplet. Warming the cell slightly before use helped a lot, but for now I have also gone back to using a syringe with disconnect and purge before use.
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