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Lab Book 2014_05_24 Electrical and Cooling Work

Prep work for magnet power supply testing was done today.  A three phase switch box was wired along with an extension cord to reach from the switch box to the power supply.  The input side of the water chilling system was constructed complete with a flow meter.  Only the output side setup remains.


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.

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

Checking wire for use with magnet supply

The specs for the wire are as follows:
Product Features
AWG Size:

Allowable Ampacity:

Amp or Amperage:

Cable Type:


Color Code Chart:


Fully Annealed Stranded Bare Copper
Conductor Stranding:


Fitting Type:



Thermoset CPE


Cut To Length
No of Conductors:

Nom. Insulation Thickness:

.045 Inches
Nom. O.D.:

.575 Inches
Oil Resistant:

Product Family:

Industrial Cable
Product Type:

Flexible & Portable Cord




Sunlight Resistant:

Temp. Rating:

-40C to 90C



Water Resistant:

The cable looks like it will just handle the current we want to run through it.

A heavier type P-122 with both a male and female connector is being modified to be fit to the wall mounted switch box. The male connector will be removed and attached to one of the longer E42543 cables. 

The female connector will be left in place and the exposed wires will be attached to the switch box.

The exposed wires on the E42543 cable will be attached to the magnet power supply on the terminal block shown below

The schematic that indicates L1, L2, and L3 are the proper choices is shown below

Checked for shorts between the four leads of the cable and there are none.  The green conductor is attached to the keyed slot of the jack which I’m assuming is the neutral.

I checked the box to make sure all three hot wires were indeed hot, when energized, which they were:

I then turned the breaker off and made sure there was no voltage on the box.

The box was wired to the cord including the green neutral conductor.

Finally, the plug was wired.

Magnet Cooling System
An elbow was placed on the detachable section of the quick-connect for the magnet cooling water so that the water flow meter could be placed in the circuit upright.


1.  Hirsch, J. E., “Pair production and ionizing radiation from superconductors”, 


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