Calabazas Creek Research, Inc. has a program to develop a gyrotron producing up to 5 kW pulse power at various frequencies from about 600 GHz to 2 THz. The operating mode at 1 THz is TE15.4. The magnetic field is 37.6 Tesla. This is provided by a pulse magnet designed to operate repetitively, with a pulse repetition frequency of about 10 Hz. By reducing the magnetic field, lower order modes can be excited. Frequencies to 2 THz will be generated using the second harmonic. The program includes the design of the electron gun, cavity, magnet and its power supply, output structure and output window.