Irradiators: Cabinet Systems

Stellar-Rad™ cabinet irradiators are for smaller-volume applications in blood irradiation, cell and small animal irradiation, materials processing, and agricultural uses like cannabis purification, phytosanitary assurance and the sterile insect technique (SIT). In blood irradiation, up to eight blood bags are irradiated to a uniform 25 Gy in four minutes to prevent transfusion-associated graft versus host disease. In research applications, Stellar-Rad™ units will provide high uniformity over a wide range of dose rates, up to about 14 Gy/min. In SIT, targets are commonly irradiated to precise doses set between 60 and 100 Gy, depending on the insect species. Doses are still being established for cannabis purification but are upwards of 1 kGy.

The SX-160 models, operating to 160 kV, were designed for these doses and applications. SX-160-1 and SX-160-2 will use one or two pairs of the flat panel x-ray sources (FPXS), respectively, as the main part of the system, which also includes the tray and slide, cabinet and shielding, on-board HV power and control systems for the modules, main power and cabinet system controls. They will use simple air-fan cooling to maintain ambient temperature. The upper and lower panels shield each other from stray radiation, so relatively light cabinet shielding is required, and this is placed close in. SX-160 units can be small enough to fit on a benchtop and be carried by two people.

In operation, the Stellar-Rad™ operator slides easy-to-use trays holding the material in between pairs of upper and lower FPXS. These emit a highly uniform pattern of x-rays from both sides, which ensures a uniform dose throughout. FPXS has high power efficiency compared with x-ray tubes, which means Stellar-Rad™ consumes far less power than x-ray tube irradiators and can use standard wall power. The cooling and insulation system has no moving fluids or cooling lines to break down. The high voltage power sources are built into the same casing as the FPXS, eliminating the need for bulky and troublesome high voltage cables.

Stellar-Rad™ will be an attractive alternative to Cs-137 irradiators for the TA-GVHD application. Cs-137 is a dangerous isotope that can be used in a dirty bomb. The Office of Radiological Security of the U.S. Department of Energy runs an innovative program to encourage the transition from isotope to electrical sources for irradiation.