Copasetic Flow

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...

OK, so that was quite the title.  I haven't done one of these in a while, but classes are about to start again and i figured I may as well get started deriving things again.  Plus, I had to do it for the can crusher magnet simulation code [1] for the experiment [3].  Here's what's really going on.  I have a Sage function that will give me the magnetic field in the z direction produced by a coil of wire that sits at z = 0 and a has a radius of 'rcoil'.  I'd like to know the magnetic field produced by the loop of wire along a circular path that is perpendicular to the plane of the current carrying coil.  A circular path perpendicular to the plane of a coil kind of begs for spherical coordinates, but the routine I have takes a z coordinate and a radius coordinate in the cylindrical coordinate system.  In the picture above, the circular path is shown, and the coil of wire is at the diameter of the circle and perpendicular to the page.  Note:  ...

Summary: Excuse a brief moment of frivolity please.   OMG, This is So *#($&#@ cool!!! OK, now that I've got that out of my system we can move on.  The can crusher simulator port from IDL to Sage is complete and it's working spectacularly well!  I was able to run simulations to find out what the temperature of the can would increase to due to the magnetic pulse.  I was also able to plot the magnetic field in a sphere around the pulisng coil to determine if the coil as specified would provide a high enough magnetic field to quench the entire superconducting Pb sample at once.  Meanwhile, work is continuing on fixing the vacuum leak detector.  I was unable to find an instrument panel bulb to attempt the kluge fix suggested below, so it looks like I'll be ordering a replacement part instead. If you're new to the experiment, you can find background by scrolling to the bottom of the page. Lab Book 2014_07_30     Hamilton Carter ...

Alternate Title:  How Could Something So Pretty be So Broken? Summary It finally became too cumbersome to work with the can crusher simulation code in script form.  the bulk of this morning was spent in meetings and reworking the can crusher code to be object oriented.  The object oriented refactoring was completed and tested and works great!  It’s now very easy to run multiple simulations and compare their results.  The next step is to write code that runs the simulation to the peak current point and then plots the magnet field in on a spherical surface that will correspond to the surface of the superconductor Pb sample being used.  There are other simulations that need to be done as well.  For example, finding out how the current traces change when the temperature of the material is 4.2 K, the temperature of liquid helium. The leak detector problem has been isolated.  The Pirani gauge that measures the vacuum on the diffusion pu...

I moved the Sage simulation of the can crusher to an object oriented implementation today.  A few days ago,I was worried this might have been a bit of overkill and just a subconcious desire on my part to place the project in a code format I'm used to seeing things in.  I hit an example yesterday that convinced me otherwiser, and only a few short, OK,  and somewhat grueling, hours later, I had a much easier to use OO simulator. Prior to yesterday, my usage mode of the can crusher code was as follows: 1.  Evaluate the cell that contained the initializaiton code.  There were some declarations of global varaibles and a little bit of code that atually ran on evaluation to place values in these variables. 2.  Evaluate the cells that contained the current calculating function and the can moving function separately. 3.  Evaluate the cell that contained the simulation code. This, as far as I knew had to be done every time I wanted to change any values a...

Summary: I made the last few fixes on the can crusher code port from IDL to  +Sage Mathematical Software System  and the can wall is now moving in simulation.  For a refresher on what the can crusher does and why the wall moves in the first place, see the embedded can crusher video post below.  Graphs were created showing how the current through the driving coil varies with time when the can is allowed to move and when it is not.  The leak detector is still broken, work will continue tomorrow on finding the root cause. For background on the experiment in general, please scroll to the end. Can Crusher Video Can Crusher code The can moving does influence the current through the coils.  Here’s a graph with the can moving, red and another without it moving, blue superimposed on the same plot.  The current graphed is the current through the driving can crusher coil, as opposed to the current through the can.   The x-axis denotes ...

Lab Book 2014_07_23     Hamilton Carter Summary: The NaI detector still isn't giving good results despite additional efforts to understand its operation and any possible problems.  Tomorrow, the base that provides voltage to the tube will be rebuilt.  The can crusher simulation code has produced its first correct looking current output results.  A pulsed mgnetic field from a can crusher will be used to quiench the superconducting Pb sample in the experiment  The cna crusheer simulation code is being used to model the magnetic fields that will be avilable. If you're new to the experiment, scroll to the bottom for background. The can crusher simulation code is alive!  I’m porting the original IDL code used in the AJP article [1] about the can crusher over to Sage.  The project is open source and is hosted on github [2].  The pulsed magnetic field from a can crusher apparatus like the one described in the article is goin...