A cutaway section of a three-cell, test unit for an electron accelerator. This was an experimental section constructed to test manufacturing techniques and radiofrequency properties for the THERAC 25 accelerator developed at CRNL for cancer treatment. The THERAC linear accelerator operated at a frequency of 3 GHz and was commercialized by the Commercial Products Division of AECL. The full-length accelerator, which was mounted on a gantry that could be rotated around the patient under full computer control, was just over two meters in length and the cancer patient could be treated directly with the electron beam or a tungsten converter could be inserted in the beam path to allow for a deeper-penetration gamma mode. This test section, which measures 18 cm in length and is mounted on a 25 cm by 13 cm wooden base, was presented to Warren Funk on his departure from AECL in 1990. He was one of the key members of the group that developed the THERAC 25 at CRNL.