Diagnosis of dynamitron accelerator faults through the observation of narrow nuclear resonances

Overview & Synopsis

Narrow nuclear resonances, initially used to calibrate the energy of the Birmingham Radiation Centre 3MV Dynamitron, have proved useful in discovering and identifying accelerator fault conditions. Short-term energy stability (over e few minutes) of a few tens of eV is common. However, variations of many kV occur for several days before the failure of a thermionic rectifier. The beam energy ripple, as reflected in the full width at half maximum of narrow (p,γ) resonances, has also been analysed to indicate the frequency causing the bulk of the ripple, thus often leading to the identification and correction of faults. Typical faults usually produce increased ripple at either the 50 Hz or 128 kHz oscillator frequency.