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Maple Test Blank For IsoTrace Terminal Cover Plate


A ring-like shape milled from a block of unfinished maple block. The top surface has a complex topography, with two opposite quadrants taller than the other two. The top surface has a shallow step around the outside edge.

Accession Number:

Alternative Name:

Primary Materials: Maple wood


Dimensions (cm): Diameter = 24, Height = 5.


This wooden piece was produced while testing the programming of a computer controlled milling (CNC) machine that was later used to produce the same shape out of stainless steel.

Condition: Very Good

Associated Instruments:


Department of Physics Machine Shop, University of Toronto

Date of Manufacture: c. 2000


Shortly after its creation, this object was placed on display in a shallow display cabinet in the subbasement of the McLennan Physical Laboratories building that commemorated the upgrading of the IsoTrace Tandem Accelerator.

It was accessioned to the University of Toronto collection in the summer of 2018.

Additional Information and References:

Historical Notes:

After around twenty years of almost continuous operation, the glass accelerator tubes on the IsoTrace tandem accelerator had developed microscopic cracks. A major upgrade was undertaken, the first phase of which was completed in March of 2000. During this process, the column assembly was removed from the pressure vessel and shipped to High Voltage Engineering Europa in the Netherlands.

Researchers and technicians at the University of Toronto undertook to solve inaccuracies in the accelerator tube caused by around 150 glue joints which together caused a misalignment of around 2mm at the high voltage terminal. This sag was initially counteracted with a tension bar made of Delrin and stainless steel. In the new arrangement, installed during the upgrade process, a new insulator was installed that supported the tube and stripper housing assembly at its centre.

The addition of this new insulator required considerable modification to the top high voltage terminal cover plate. This wooden test piece was produced during the process of machining a stainless steel metal opening that was welded into the new terminal cover plate.