4 Irradiation Facility and Setup

The heavy ion species used for the SEE studies on this product were provided and delivered by the TAMU Cyclotron Radiation Effects Facility [3] using a superconducting cyclotron and advanced electron cyclotron resonance (ECR) ion source. Ion beams are delivered with high uniformity over a 1-in diameter circular cross-sectional area for the in-air station. Uniformity is achieved by means of magnetic defocusing. The intensity of the beam is regulated over a broad range spanning several orders of magnitude. For the bulk of these studies, ion fluxes between 10⁴ and 10⁵ ions/s-cm² were used to provide heavy-ion fluences between 10⁶ and 10⁷ ions/cm². For these experiments Praseodymium (Pr) ions were used. Ion beam uniformity for all tests was in the range of 91% to 98%. Figure 4-1 shows the test boards as it was used for exposure at the TAMU facility. The 1-mil Aramica window allows in-air testing while maintaining the vacuum within the accelerator with only minor ion energy loss. The air space between the device and the ion beam port window was maintained at 40 mm for all runs. For more information on the effective LET range and depth for the experiments, see Table 4-1.

Figure 4-1 Evaluation Board Mounted in Front of Heavy Ion Beam Exit Port at the TAMU Accelerator Facility With a 40-mm Air Gap