Model Diesel: 32mm bore, 38mm stroke, indirect injection

[Roger B]

That's very cool. Working as a structural biologist I've sent samples to the Australian Synchrontron but never had a chance to visit in person.

And those are some monster electron beams you work with! I've done a lot of electron microscopy, but the instruments I've used were 200 or 300 kV. 3MV electrons would be something else... I guess you are going for deep penetration into the material when crosslinking? Just to nerd out a bit, what do you use for the electron source? Instruments I worked with used tungsten or LaB6 hot cathodes but the fancy cryo-EM microscopes at my uni use cold FEG sources, makes the beam more focused.

A 3 MeV electron will penetrate around 10mm of polyethylene, less in higher density materials.

The electron source is a spiral of tungsten wire about 1 cm in diameter, there is a picture of one in the white paper. As the beam is 10s of kilowatts we don’t want it too tightly focused. If it goes astray things melt quite quickly.

 

[Roger B]

Wow!
That is some technology.
In 1976 I worked for a cable maker, and we obtained the early samples of Cross-linked polyethylene insulated wires. It was my job to test them in the lab to all the tests normally used to confirm PVC, elastomer and polymer cables, so we (in the factory) could appreciate the advantages of this "new" material. All I knew then was a simple comment. "It is PE electrically, but should be almost as tough as an elastomer, unlike PVC insulation."
In one test - the 30 second flammability test - it certainly was not like other materials, as the PE naturally had NO resistance to flames. Just like applying a Bunsen flame to a wax candle, it melted and burned.
But compared to "normal" PE and PVC it was considerably more resistant to abrasion and cutting with a sharp blade. But melting it, as with in-factory welding of thermoplastic insulation, just made it into normal PE... and lost all the advantageous characteristics of cross-linked PE.
I don't remember much about cross-linked PE otherwise...
I never found out how PE was cross-linked either!
K2

This was probably chemically cross linked using the Sioplas process. Pirelli in Southampton was working on the process when I started there in 1977. BICC further developed this to the one step Monosil process. Pirelli and BICC didn’t install electron beam facilities until the early 80s.

 

[Steamchick]

Hi Roger, I was working at BICC Helsby factory back in '76 - in the production test lab., testing products we made. Hence I was given the HDPE cables to evaluate.
I enjoy and appreciate the comment: "As the beam is 10s of kilowatts we don’t want it too tightly focused. If it goes astray things melt quite quickly." - Love it!
Does it give off lots of deadly X-rays when it hits metal? I assume that blasting a PE coated wire with electrons means that some hit molecules of the metal wire and knock-off their electrons, thus emitting energy when they return to their normal orbits? Or is it neutron disturbance that causes X-rays? - I really haven't a clue, just find learning about this very interesting..
I did work with a guy who was instrumental in installing a heavy duty laser for welding steel panels together.... He described the job as making a truly light-tight box around a sword of light, where reflected laser light escaping could create a fire hazard hundreds of metres away, if only a pin-hole of the beam escaped. Not conducive to living next to it! In power terms it would be like a welding torch but 10 times hotter and more powerful - if it touched flesh - or so he explained...
I have no idea what an electron beam of that power could do to someone.
And to think that we, the masses, sat in front of Cathode Ray tubes (the TV) for hours every day for many decades, protected only by a bit of lead glass from the X-rays...
K2