| Title |
Magnetic field diffusion in metallic and superconducting cylinders / |
| Translation of Title |
Mangetinio lauko difuzija į metalinius ir superlaidžius cilindrus. |
| Authors |
Vertelis, Vilius |
| DOI |
10.15388/vu.thesis.209 |
| Full Text |
|
| Pages |
204 |
| Keywords [eng] |
magnetic field diffusion ; superconductivity ; electromagnetic launch |
| Abstract [eng] |
In this dissertation, magnetic field diffusion is investigated in cylindrical conductors and superconductors. This effect is studied both experimentally and using numerical modelling. The objects of investigation were close to realistic application scenarios: the effect of magnetic field expulsion was studied in a series augmented hexagonal railgun with a conductive cylindrical payload; pulsed magnetic flux penetration was investigated inside a thin-walled superconducting BiSrCaCuO tube; the effects of the magnetic field, temperature and nanosecond duration electrical pulses were studied in thin YBaCuO films deposited on Al2¬O¬¬3 with CeO¬2 sublayer; properties of type II superconducting armatures were investigated for coil launcher application. It was obtained that the magnetic field is noticeably disturbed in the proximity of a conductive payload during the operation of series augmented hexagonal railgun. A quick, nondestructive method based on a lumped parameter was proposed to evaluate the superconducting properties of thin-walled superconducting tubes. The origin of the electrical instability observed in the YBaCuO samples was explained in terms of electrothermal model. It was shown that type II superconducting armatures can outperform normal conductors when diving current pulses with lower amplitudes and time derivatives are used. |
| Dissertation Institution |
Vilniaus universitetas. |
| Type |
Doctoral thesis |
| Language |
English |
| Publication date |
2021 |
