This paper uses Synopsys Sentaurus TCAD to study single-event transients (SET) in 22 nm Fully-Depleted Silicon-On-Insulator (FDSOI) devices. The study first explores the impact of different LET values on SET characteristics. The results indicate that as LET increases from 10 MeV·cm²/mg to 35 MeV·cm²/mg, the peak transient current rises from 180 μA to 700 μA, and the pulse width extends from 10 ps to 13 ps, demonstrating the significant impact of higher LET values on single-event transients. The study also investigates the effect of different incident positions. When the single particle hits the source, gate, and drain electrode centers, the collected charges are 1.12 fC, 5.41 fC, and 2.22 fC, respectively. The gate collects the most charge, indicating it is the most sensitive area. Finally, the study examines three different bias voltages. In the off state, the devices exhibit the highest transient current (190 μA) and pulse width (16 ps), reflecting the most significant impact on single-event characteristics.