Longview. which would be your choice for temperature < 1200C ? The choices would be
- Graphite -> high temperature, but low strength
- Stainless Steel -> 1400C, I need to check the strength as a function of temperature
- SiC
- Al2O3
- copper tungsten
- Titanium
- TUNGSTEN CARBIDE
They are all pretty easy to obtain.
HEXOLOY SINTERED ALPHA SILICON CARBIDE CERAMIC TUBE
I wonder how well they would handle a high internal pressure. Other than that, this is attractive.
@WishfulThinking.null
A few ways to measure the temperatures, but an easy one is to use a monochrome camera to image the tube(s) with a diffraction grating in the optical path. this will give you a coarse spectra which can give you a very good temperature estimate. Calibration (Qe response of the camera to wavelength) can be done using sunlight (which is very very well calibrated) or other well known hot sources.
In the 1000 to 1200C temperature range, the slope of the spectra between 700 nm and 1000 nm would be an accurate measurement.
@wishfulThinking, how about have two tubes at the same time and check if there is any difference of temperature for the dummy and active ? Maybe the magnetron heating has some un-evenness which would prevent using a simple differential test ?
What are the dimensions of the heating area in your setup, I was thinking that a simple oven going at 1000C +. could be a good way to get multiple reactors going at the same time to do some comparison of active/inactive mixes.
any good suggestion for radiation detector? I am thinking of using http://www.vernier.com/product…diation-monitors/vrm-btd/
I could not find LiAlH4 on ebay either. some Li-deuterium, yes ! http://www.ebay.com/itm/2H-Lithium-Aluminum-Deuteride-/221666221735?pt=LH_DefaultDomain_0&hash=item339c561ea7
Going to do some microphoto of my nickel power next, I will post here.
Thank you all for the input. I would think that at this point, no lithium in the reaction will be my first step and ramp up the temperature and pressure up to the limit of the test setup. Then in the future, Lithium and maybe other excitation mechanisms (magnetic and/or RF).
I am second guessing my initial choice of using a quartz/silica tube, I did underestimate the potential pressure and also do now think that at temperatures sufficient for a potential reaction, the emission of the silica tube will anyway hide the reaction itself, so maybe back to stainless steel or similar ?
Is there a good estimate of the real world pressure reached in the current experiments, Alumina tubes do not seem to have that much tensile strength from what I do read (at least compared to stainless steel).
Any comment on atomic hydrogen vs. H2 molecule. I remember reading that high voltage discharges were the standard way to dissociate hydrogen. Is temperature (~1000C) enough for at least a small number of dissociation or is the critical temperature a steep cliff?
Perfect I am in California if you do want to mention
I can be public Peter. this experiment is so outside of my normal work that I do not have any issue with it.
I guess I better have some radiation monitoring added up the setup, do you have a reference to the Piantelli paper?
If I do get a negative result, I will add Li-6, but that's way down the road.
-- benoti
Sure Peter.
-- benoit
yes, it will need two seals, but then the tubes will be arbitrarily longer than the active area, which means that the plug+electrode section could be 5 inches on both side for a 1 inch active area.
Yes, going slowly, I do not have a good idea of the actual pressure this will produce and a big sand bag is a good advice (also keeping distance from the experiment).
The titanium hydride is, I think nice, since it is stable to water and air below 500F, way less worrisome that the LiAlH4
-- benoit
for the sealing, I do plan to use :
Mcmaster
http://www.mcmaster.com/#high-temperature-glue/=vt7x1p
They do have a single part glue which can hold to 4000F (!) in the High-Temperature Adhesives.
Polycarbonate is 0.5 inch thickness, this is basically just a safety box if I overpressure.
The quartz tubing
http://www.technicalglass.com/…/fused_quartz_tubing.html
Electrode are still a question. They do need to be a very good conductor obviously so that most of the restive heating takes place in the Ni.
Copper is tempting but is borderline for these temperatures, I do need to check how the resistance of different metal will change with temperature.
Astronomy -> yes, astronomers are good at figuring out the temperature and other aspects of a physical process as long as they can get the photons strait from the reaction, not hidden under layers of heating elements and other insulation.
I am pretty quickly putting together the pieces to do a simple replication. I would like the feedback from this forum on roadblocks, dangers, suggestions.
Design is:
- Multiple quartz/silica tubes with in ID of 2 mm, OD or 5 mm.
2 tubes are filled with pure nickel (3 micron power).
2 tubes are filled with a mix of TiH3 (titanium Hydride) and Ni 3 microns.
The tubes are sealed with a high temperature (2000 F maximum temperature).
The heating is done by direct joule heating of the power by providing direct current with two electrodes reaching across the seal. (think arc furnace).
The tubes can run in parallel and share the power source.
The temperature is measured with 3 cmos monochrome cameras with 3 bandpass filters to fit a black body.
The entire setup is in a polycarbonate enclosure.
So questions for the group:
Did anybody consider microwave heating ? simple and consistent for differential tests.
Any opinion on the need for Lithium ? I do plan for the simplest initial test with just the Ni + H
Would the demonstration of a reproducible higher temperature for the Ni + H compared to pure Ni be a meaningful test?
How long does a test really has to last?
Does vacuum or other neutral gas purging needed?
