Multisource radiation and microwave facility

• Main Authors: Heffernan, P. T., Curry, R. D., Miller, W. H., Kinsey, N. G., Carter, W. I.
• Format: Conference Proceeding
• Language: English
• Subjects: Aggregates; Concrete; Electron Beam Accelerator; Electron beams; Equations; Lead; MAG 1-D; Mathematical model; Power electronics; Vircator
• ISSN: 2158-4915; 2158-4923
• DOI: 10.1109/PPC.2011.6191452

A containment facility with the ability to shield ionizing radiation is a necessity for many facets of high powered electromagnetic research. The radiation facility located at the University of Missouri-Columbia Center for Physical and Power Electronics has been designed with the capability to accommodate a variety of different high power electromagnetic sources. The design constraints originated from the need to contain a 4-8 MeV Electron Beam Accelerator and a Virtual Cathode Oscillator (VIRCATOR) operating at 19.5 MW with a frequency of 1 GHz. The 4-8 MeV tunable relativistic electron beam is to be used for material irradiation, conditioning, and x-ray production. These devices will be driven by the newly reconstructed MAG 1-D pulse modulator, which is now capable of producing 250 kV pulses at 100pps. The ability to support the ionizing radiation shielding of multiple pulsed megawatt sources makes this facility unique. Construction of the facility began with the placement of 860, 6×2×2 ft. concrete blocks, totaling 3.2 million lbs. of concrete, as well as 58,000 lbs. of steel support structure. The finished structure is 48×44×23 ft., supplying ample space inside to contain multiple sources. To support this weight, a high density concrete floor was prefabricated during the original construction of the building. Three layers of the concrete blocks were placed in a staggered fashion around the entire perimeter of the facility. This produced a six foot thick wall of concrete which adequately absorbs ionizing radiation produced during the utilization of the 4-8 MeV accelerator or the HPM sources. Construction of the facility was complicated by the fact that it was being built inside of the current laboratory. The progression of construction had to be carefully planned so as to avoid disturbing the integrity of the preexisting structure. The building constraints also required foresight so as to not inhibit the ability to place blocks into specified locations later on in the construction process. The interior of the shielding structure includes an overhead lift capable of hoisting objects up to 1 ton in weight and maneuvering the components anywhere within the interior of the structure. The radiation facility utilizes a high velocity exhaust system with the ability to displace air with a laminar flow to prevent ozone buildup. The exhaust intakes were placed at floor, mid-wall, and ceiling heights in order to remove ozone or byproducts of the electron beam air