Simple two-pulse detection scheme in pulsed EPR for studying low-frequency nuclear coherences
A microwave two-pulse sequence with a weak and long 180 degrees first pulse and a hard 90 degrees second pulse is employed to detect nuclear coherences in pulsed EPR. The coherences created by the first pulse are transferred after an evolution period T into an observable FID by the second pulse. The free induction is measured at some fixed delay after the second pulse; it is modulated when T is varied. As the second pulse may be switched on immediately after the first pulse, the nuclear coherences may be detected immediately as they start to freely oscillate, without loss of information within the instrumental dead time. The method is demonstrated for a sample of the radical cation of 15N-labeled bacteriochlorophyll a. Copyright 1998 Academic Press.
Dzuba
SA
Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Borovykh
IV
Hoff
AJ