Test shots may be fired TODAY…please stand by.

[Note:  for updates to this, follow us on twitter.]  The LPP crew is working intently to get the machine ready for firing – possibly today.  Time has been swallowed in the details but they are pushing for that test fire while John is still here.  He leaves tomorrow. 

The mood is calm, quiet, tense.  The crew members are each focusing on various last minute critical tasks.  They’re also awaiting a delivery - an additional piece to enable a better fit of the vacuum chamber with the turbo molecular pump, and better bolts to connect the drift tube to the assembly. 

The parts are due at 4:00.  Assuming they come, and after final assembly, the crew will run a test of the vacuum system.  If it can pump down to the target vacuum, the shots will be fired today.  Otherwise – there will still be adjustments to be made.

The crew in action

Abdelmoula arrived on Monday and jumped straight into work.  He hit the ground soldering, and is now attempting to thread a high voltage cable with a mesh shield using some improvised technique.  He seems to be taking things in stride.  That Z-pinch experience comes in handy.

The crew attached the vacuum chamber yesterday.  Murali now has to hook it up to the turbo-molecular pump, set up the manual control for the vacuum system (this involves many valves and pumps). then has to put a Faraday cage around it.  Then we can test the pump.

The crew is going on limited sleep but pushing for a finish today.  A big part of the push is due to John Thompson’s imminent departure.  He leaves tomorrow for other work commitments.  His time here with LPP has been very productive.  His work ethic is unparallelled.  He has been a steady, systematic presence here, the backbone of the design and assembly. 

We all want the first shot to go off with the whole team here to witness it.  Also, we’d like everyone to be here for trouble shooting as the initial shots will reveal any issues in the assembly.

Time lapse

After months of prep time and some costly but unavoidable delays, the device is almost fully assembled.  From a visual perspective, the assembly seems to have erupted suddenly in the past three weeks, and most dramatically since last weekend.  The steps taken to get here are listed below.  The order is roughly chronological, but note that many tasks were completed in parallel.

Design and Prep time:

Murali recalls the beginning of project, days spent at Eric’s house as they went over the design with John in California, ordered the necessary parts, and looked for a suitable lab location.  John, meanwhile, worked through the design with Beverly.  Eric and Murali found a suitable lab space and got bids from contractors to make it experiment ready.  This phase included getting permits and tending to legal and compliance matters. 

Building Construction:

By August, Gary was on board as contractor and the retrofit of the building began. The first major set back occurred here:  the building foundations were inadequate to support the 32” concrete walls.  A new foundation had to be created.  This swallowed a few weeks, which turned into a month.

Originally, John had been scheduled to come at this time, and he had a 3 week window to spend on the physical assembly portion of the project.  As it turns out, his other project got rescheduled, so he was able to come later and stay an additional 3 weeks, which has been great for LPP.  As chief designer of the device, with years of experience in such designs from _______(co) , it’s like a big set of legos or tinker toys to him, and he goes about fixing it with the focus of a teenager playing Halo XII.

Once the walls were up John, Eric and Murali began the alignment measurements for placement of the device.  A painstaking process involving lasers, tubes, plumb bobs and string.  The walls were still drying around the crew, construction workers were trundling in and out, a chaotic intersection of workers and tasks.  Lighting in the experiment room was provided by a couple of industrial heaters.  It was a dark and dingy lab.

Grounding

A grounding pole was stuck into the ground behind the building.  This involved driving a stake 6 feet deep and connecting the wire through a hole to the inside of the experiment room.  The grounding rod was set up to be connected to the Faraday cage, still to be installed, and the device itself, via copper plates around the base.

Faraday cage:

The Faraday cage was installed into the room.  As FFS member Derek noted, this gives the place that SAW XII ambiance.  Eric was disappointed that the copper mesh didn’t cover the concrete walls more attractively – he was hoping for a copper glow throughout.  We could have sprung for a finer mesh – but that would have been much more expensive and no more effective for the job.  Remember, this is the poor man’s fusion reactor they’re designing here.  No frills, low budget, high tech, spit and glue.

The Faraday cage was setback#2 – welding the strips of copper mesh together took longer than expected.  A technique was developed by John, and he trained the construction workers on it.  The smell of soldering warmed the lab for a couple of weeks. 

Electricians:

Tubes had been set in place to enable wiring of the experimental device as well as general lighting.  Electricians also came and went, confering with the LPP crew.

Unistrut:

The LPP crew worked on and through the chaos.  Parts were arriving.  Parts were delayed.  The unistrut was delayed.  It finally arrived.  This created the framework of the assembly on which everything else would rest.  The pieces of unistrut had to be sawed to size on the premises.  Much of this was handled by Joe Gorman, the contractor who remained behind after the rest of the crew took off. 

Work at the lab continued amidst loud sawing and drilling sounds – the incompatible overlap of lab and construction site.

The core of the unistrut was set up in the room to establish contact points with the floor and mark the alignment of the machine.  Then it was dismantled and the linoleum floor put in place, and a drop ceiling giving the interior a more finished look and improving working conditions considerably.

Unistrut – take two

The unistrut scaffolding was reinstalled and completed.  The feet went through the floor to ground. The 12 capacitors were put in place on the unistrut.  A bridge was made to hold the high voltage distribution box – placed between the wall where the power supply comes in, and the structure. 

Device Electrical System

The high voltage distribution box was set up with the components that would feed and regulate the capacitors.  The transmission plates were installed on top of the device, covering the capacitors.  The trigger generator was installed at the rear of the room.  Switches were placed on top of each capacitor. 

Lead bricks were placed on the plates to test compression (?). 

Mylar Insulation:  At this point, the mylar insulation sheets needed to be placed on top of the machine.  This comprised another delay as a different sheet size was decided upon.  The crew cut the sheets of mylar into the right shape to place over the transmission plates.  Ten sheets had to be cut with as much precision as possible, by human beings holding scissors.  [One day, these machines will be mass produced, and these sheets will be cut by machines.]  The sheets were put in place and then all the appropriate wires and resistors, such as the ground reference resistor, were connected.  This work was completed over the weekend.  The electrical system is designed to deliver a charge to the 12 capacitors that will ignite the gas on the shots.  There was some trouble with the fit of the switches onto the plates and the tubing and wiring – all details that come to light as assembly progresses, and all to be noted and redesigned for the day that these go into mass production.

Gas system:

Outside the facility, gas tank holders were put in place.  Three canisters of compressed Nitrogen gas (the words “non flammable” prominently displayed), one canister of Helium, and a small canister of Sulfur Hexafluoride are in position.  This week was spent setting up the tubing for gas distribution. 

The Anodes

During this time, Eric was prepping the anodes – the heart of the machine – the locus of the electric charges that are designed to generate the plasmoid.  Once the rest of the machine was assembled, the anodes went into position (Oct. 8). 

Vacuum Chamber:

The anodes were then capped with the vacuum chamber, which Eric had been prepping during this time as well.  The vacuum chamber was installed yesterday (Oct. 8) as well. 

Up to speed

This brings us to today.  At 4:00, the parts are supposed to be delivered.  We can then connect the turbo-molecular pump, test the vacuum, and possibly, hopefully, maybe, fire a test shot. 

Stay tuned.