ClearLight (Hive Addict)
11-06-02 18:21
No 377069
      Calibrating standing wave pattern of MW oven  Bookmark   

 When using your nuke for chemistry, it is useful to know where the standing waves in the oven re-enforce and cancel each other, so that the energy distribution for your reaction is in an optimal configuration.  The below is a method for seeing what the energy patterns are in your nuke.  The link has a quick time video of the pattern being generated.

Finding the hot spots in your microwave with fax paper.

If you have ever wondered why food can cook unevenly in the microwave, it is because of high and low points in the intensity of the microwave radiation field. As the waves bounce back and forth in the box, they interfere with each other. In some places they add up, and in other places they can subtract to zero intensity.

To visualize the hot and cold spots we do the following: Take a piece of blue foam insulation panel (1 inch thick Styrofoam) and cover it with a wet paper towel. Then we put a piece of thermal fax paper over this and place the whole combination inside the microwave oven. We cut the panel so it just covers the bottom.

When cooked for about 15 seconds, the water in the towel heats up where the microwave intensity is highest. The thermal paper changes color from white to black in these places. The following shows a top view of the panel after about 15 seconds of cooking: The image is about one foot wide

Infinite Radiant Light - THKRA
(Hive Bee)
11-07-02 00:28
No 377156
      yes indeedy doo  Bookmark   

and after finding these how does one go about smoothing them out into all the little nooks and crannies

OR does one avoid these? (only place objects in "hot" areas?)

i have been REsearching MO and chemistry for some time

can you point me to - a rule of thumb for altering the opening in a domestic MO so as not to become irradiated

now hold on - i realize the danger (been an electrician for over thirty years)- what i need are some basic formulae for determing lenght etc to maintain containment of the HF while still allowing glassware to protrude into the cavity.

and something else- would using multiple thyratrons (custom fit here) run into a phasing problem?

if i built a huge ass supply then running several tubes from it in parallel should work as long as the capacity was adequate, eh?

there's a ton of info on MO - RE. modification seems to be a viable way - most of the researchers started with domestic equipment and site modified the stuff for use.

also looking for a viable pulsed supply (circuit) for better control.

(Hive Addict)
11-07-02 00:37
No 377159
      wavelength  Bookmark   

of the beam is 10 cm or about 4"(3.93) so anything that is less than that and not 1/4 wavelength should be fine... if you look on the links, you'll find pages where they bored holes into the top for a camera. You can also get a rat shack mw power meter and test the hole.. also wrapping a bit of screen around the glass ware coming out should take care of any incidental radiation.

  The issues aren't about a lot of power here... you usually have to put a beaker of water in the oven to get the power down to 400 watts or so... more is not better in this case...

 I bought the sams guide to repairing microwave ovens to figure out how to modify's very helpful...

re: thyratrons... well, why is a question, but also you would have to look at the standing wave patterns and resonances created by your multiple emitters in a closed space... looks like very nasty 3rd order calculus to me, as you could end up with junk if the beam front reinforces into one of your emitters generating a lot of feed back that fries everything...  Just get a cheap 500 watt college dorm model at a garage sale and get on with chem instead of physics...

Infinite Radiant Light - THKRA
(Hive Bee)
11-07-02 00:51
No 377164
      right you are professor - it is indeed chem not ...  Bookmark   

right you are professor - it is indeed chem not physics HOWEVER my cat like brain (MEOW) keeps the curiosity factor so high that nothing ever gets physically accomplished.

the sams guide sounds real good. and the rat shack (ilovethat) meter is something way too obvious to even consider. (thank you)

the abbreviated reason for multiple sources goes like this

i reason to believe that melting metal is possible (internet) using a MO. and before I even get started i am trying to ascertain the potential and limits of pressure/temperature.

for instance given other factors as favorable just how high a temperature could theoritically be gained using MO?

and of course this brings up all kinds of polar questions to do mainly with crystalline structures of molecules - metal mainly.

my curiosity is just short of first order calculus - just trying to keep from cooking my gonads.

got about twenty discarded MO laying around in various levels of anticipation - used one for lunch.

thanks again.   you must be in this computer - HF respose!!!
(Title on BackOrder)
11-07-02 02:10
No 377187
      I really liked the grape demonstration  Bookmark   

That was pretty cool about how they used grapes to produce ball lightning in the microwave.

If at first you don't succeed, try, try again. Then give up. There's no use being a fool about it.
(Hive Addict)
11-07-02 03:05
No 377201
      I can see the darpa proposal now...  Bookmark   

  " Use of microwave induced plasma from spherical objects as a theater missile shield defense "

Infinite Radiant Light - THKRA