Copasetic Flow

Work is proceeding on testing the systems that will be used in the experiment.  While the glass Dewar’s silvering blocks gamma radiation in the 22 keV range substantially, it fits nicely inside the yoke magnet whose field can be easily measured.  A temperature gauge was located; vacuum testing was started for the inner Dewar and lid, (including the instrumentation ports.)  Scroll to the bottom for the background of the experiment. All about the temperature gauge Today, just pictures of the gauge.  For an idea of scale, its rectangular footprint is about the size of a nickel.  The four wire sockets on the left are for attaching a four point probe to measure the resistance of the gauge. The Dewar lid with all the attachments The easiest way to seal the Dewar lid was to put the instrumentation stick back in place.  An experimental stage to hold the Pb sample still needs to be designed. Testing the vacuum pump before testing the D...

For background on the experiment, please scroll down. We can get a cheap piece of 3/4 inch diameter Pb from Rotometals .  Here are the details 3/4 17.14 per foot Nuclead has the same thing.  Check for purity and price. Also there’s Mayco . Next question, how pure does pure have to be? Pb purity data: The following are reference articles about superconductors.  Each of them describes the purity of the Pb samples used.  The lower bar is set by the RMP article referenced below, as well as one other that mentions the use of ‘commercial’ grade material and the evidence of a transition to a superconducting state for this material.  The final reference from 1886 in the section defines commercial level material to have a quality not lower than 99% pure.  This information is being researched to determine what purity of sample we should use.  It would seem that a higher purity sample will produce fewer unexpected experimental results, as we...

Took apart the apparatus at the bottom of the proposed Dewar stick.  This is stick that will eventually support all the required apparatus in liquid helium.  Pictures follow.  Per normal, if this is your first day on the site, scroll to the bottom for the experimental background. The inside of the Dewar measure out at 1 and 1/8 inches.  That works out to about 1.25 cm.  Then, plugging that into an expression for the size of cylinder we can get to fit Working with square cylinders Inscribe a square inside a circle circle radius 0.5625 1.42875 cm square side 0.795495129 1.010279 cm Square radius 1.010278814 The above distances are to the wall of the Dewar.  If we back off of this a little bit and give ourselves  an 1/8 of an inch clearance at all the corners, we get ...

In all likelihood, we’ll go with a resistive measurement, (to detect the superconducting state or lack thereof), using a small lead wire.  The following setup is from an Alfred Leitner video.   We’ll use something even simpler, probably just a lead wire with a four point probe attached.  By the way, if you're new to the game, scroll to the bottom for background information. We could sputter a line of lead onto a glass slide, but I don’t see the benefit yet. Working on finding out what it is. Check this out later in the day per shaping samples: https://plus.google.com/116395125136223897621/posts/9c7dFfZ7ijT I’m performing the check on the resistance of the primary coil as its cooled by liquid nitrogen.  The idea is that yesterday’s increase in output ignal with the superconductor ooled may have noly been do to the primary pulling more current as its resistance ramped down.  Here are a few pictures of the assembly being taken apart for the present...

If you're new to the experiment, scroll to the bottom for background that will catch you up with what's going on. Liquid Nitrogen Fill The liquid nitrogen Dewar has been filled.  It’s initial and final weights were 146 and 170 pounds, respectively.  I’m guessing I must have read the initial weight incorrectly, but we may be paying too much for ’45 liters’ of nitrogen which might be closer to 13. liters/pound 0.5606 start 146 finish 170 net 24 Total Liters 13.4544 I’m doing the same measurement as yesterday with the sample immersed in liquid nitrogen.  There seems to be no change.  I have however invented a reasonably good vibration detector for the vacuum pump across the room, see video here . I’m going to try a new configuration of the two coils next.  Pancake coils will be constructed with one placed on each of the opposi...