| Subject | English | French |
| radiat. | first Townsend coefficient | premier coefficient de Townsend |
| radiat. | Townsend coefficient | coefficient d'ionisation (ionization coefficient, de Townsend) |
| tech., el. | Townsend coefficient | coefficient de Townsend |
| radiat. | Townsend coefficient | constante d'ionisation (ionization coefficient) |
| radiat. | Townsend coefficient | coefficient de Townsend (ionization coefficient) |