Wednesday, May 28, 2014

Lab Book 2014_05_27 Special Relativity, Proper Acceleration, and Magnet Prep

Meetings, Magnets, and Special Relativity
Spent the morning attending a meeting and getting to do just a tiny little bit of special relativity research, regarding proper acceleration in the instantaneously moving rest frame.  The rest of the day was spent debugging, first the liquid nitrogen Dewar, and then the leak detector.  The leak detector is still not up to snuff.  Prep work was done for lifting the magnet that will supply the quenching field for the superconducting samples.

New to these posts?
The hole theory of superconductivity, a BCS compatible modle, predicts that when a superocnductor is brought back to its normal state quickly, it will emit x-rays.  We plan to experimentally verify this or set a new lower limit for its detection.  Scroll to the bottom for more complete information of what this physics experiment is about and what we hope to achieve.

Relativistic range work:
Reviewed and followed Brehme’s derivation of proper acceleration and its meaning.  Proper acceleration is used in the Walter rapidity paper as well as all my rapidity style derivations and winds up in the MacColl and Shahin papers as well.  Here are my notes on Brehme’s interpretation:



For the full scratch-pad LaTex write up of the above notes see https://www.writelatex.com/read/jrvqwgbqbvvj.

Liquid Nitrogen Dewar Refill
An attempt was made to fill the liquid nitrogen Dewar through the lid rather than through the liquid nozzle again.  This resulted in the lid once again not being seated properly and the Dewar not properly developing pressure.  The lid is to be reseated.  Upon reseating, the pressure slowly climbed again and we were able to get liquid nitrogen out of the Dewar.



Magnet Lift and Move
The short bar was placed back in the lifting A-frame.  The A-frame was test fit and does just straddle the magnet.

Ace Bolt and Screw has located the eye bolts we need to lift the magnet!  They’re in Dallas and hopefully will be here by Thursday.  It'll be time for another field trip with the kids!



Background
Hirsch's theory of hole superconductivity proposes a new BCS-compatible model of Cooper pair formation when superconducting materials phase transition from their normal to their superconducting state[1].  One of the experimentally verifiable predictions of his theory is that when a superconductor rapidly transitions, (quenches), back to its normal state, it will emit x-rays, (colloquially referred to here as H-rays because it's Hirsch's theory).

A superconductor can be rapidly transitioned back to its normal state by placing it in a strong magnetic field.  The experiment being performed proposes to look for H-rays emitted by a Pb superconductor when it is quenched by a strong magnetic field.

The lab book entries in this series detail the preparation and execution of this experiment… mostly.  I also have a few theory projects involving special relativity and quantum field theory.  Occasionally, they appear in these pages.

Call for Input
If you have any ideas, questions, or comments, they're very welcome!

References

1.  Hirsch, J. E., “Pair production and ionizing radiation from superconductors”, http://arxiv.org/abs/cond-mat/0508529 

No comments: