The Short One: Lab Book 2014_07

The Short One: Lab Book 2014_07_31

Summary:

The day felt productive! Honest! However, looking back at the lab book, it doesn't look like a whole lot happened. It could have been the two meetings sandwiching the beginning and end of the day. Anyway, here's the cool stuff that did happen. After fretting for a bit about where to get more computer time to run simulations on the can crusher code, I tried out +The SageMathCloud. It's so cool! The simulator runs a little bit faster than my laptop and without out all the incessant fan blowing! In addition, I can setup simulations in parallel, something I couldn't benefit from when limited to my one local machine. The simulator proper has been partitioned into its own file. The simulations are now much more manageable, containing only setup parameters and results. One new feature was added to the simulator. The driven can modeling coils can now be made superconducting. I'm not sure I trust the results yet. The graph above shown the magnetic field that should be available over the surface of the smallest and the largest sample sizes that have been proposed. For more on this calculation, see the derivation[1], and of course, the simulator. Permission to use the pulsed magnet has been given, so with any luck, there will be some experimental results here soon.

If you're new to the experiment, please scroll to the bottom for all the background.

Lab Book 2014_07_31 Hamilton Carter

Sage Cloud start time

5:51 AM

Started sim locally at 5:53 AM

Sim complete at 5:54 on Sage Cloud took 3 minutes!

Testing again locally… Started sim at 5:59 AM

Finished at 6:03 AM

SageCloud is a minute faster than the laptop

For instructions on how to load files into a sage worksheet, look here

https://groups.google.com/d/topic/sage-cloud/9JT6o0q74Gk/discussion

For broad documentation on the same topic, look here

http://www.sagemath.org/doc/tutorial/introduction.html?highlight=attach

The search for best practices

https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1TSND_enUS425US425&ion=1&espv=2&ie=UTF-8#q=large+sagemath+projects+best+practices&safe=off

At 4 K, the critical field for Pb is about 480 Gauss.

References:

1. Derivation of magnetic field coordinates

http://copaseticflow.blogspot.com/2014/07/math-notes-cylindrical-r-coordinate.html

2. Simulator on github

https://github.com/hcarter333/cancrusher

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. My experiment will look for H-rays emitted by both a Pb and a YBCO superconductor when it is quenched by a strong magnetic field.

This series of articles chronicles both the experimental lab work and the theory work that’s going into completing the experiment.

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

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Copasetic Flow

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