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 using a superconducting cyclotron and an advanced electron cyclotron resonance (ECR) ion source. At the fluxes used, ion beams had good flux stability and high irradiation uniformity over a 1-in diameter circular cross-sectional area for the in-air station. Uniformity is achieved by magnetic defocusing. The flux of the beam is regulated over a broad range spanning several orders of magnitude. For these studies, ion flux of 7.26 × 10⁴ to 1.65 × 10⁵ ions/cm²·s was used to provide heavy-ion fluence of 9.96 × 10⁶ to 1.01 × 10⁷ ions/cm².

For the experiments conducted on this report, there were 4 ions used: Krypton (Kr), Silver (Ag), Praseodymium (Pr), and Holmium (Ho). Kr was used to obtain LET_EFF of 30.5, 37.3, and 40.6 MeV·cm²/mg. Ag was used to obtain LET_EFF of 47.8 MeV·cm²/mg. Pr was used to obtain LET_EFF of 65 and 75 MeV·cm²/mg. Lastly, Ho was used to obtain LET_EFF of 75 MeV·cm²/mg. The total kinetic energy for each of the ions are shown in Table 4-1.

Figure 4-1 shows the TPS7H500x-SP SEE Test Board used for the data collection at the TAMU facility. Although not visible in this photo, the beam port has a 1-mil Aramica window to allow in-air testing while maintaining the vacuum within the accelerator with only minor ion energy loss. The in-air gap between the device and the ion beam port window was maintained at 40 mm for all runs.

Figure 4-1 Photograph of the TPS7H500x-SP SEE Test Board in Front of the Heavy-Ion Beam Exit Port at the Texas A&M Cyclotron