NNR IN RAPIDLY ROTATED METALS By - Nottingham eTheses ...

5.1 EQUIPMENT
- 58 -
CHAPTER 5
EXPERIMENTAL PROCEDURE
The variable frequency pulse spectrometer used in this work
was a Bruker B-KR 322s, a schematic diagram of which is shown in
Figure 5.1. The rf is generated to an accuracy of 1 part in 108
by the Schmondal frequency synthesiser and split into two main
channels. DC gating pulses are supplied by four separate pulse
units feeding in pairs to each channel. The resulting rf pulses
are amplified to a peak power of 500 W and output to the transmit-
ter coil is the probe head. Induced transients in the receiver
coil are passed via a tuned preamplifier and a variable attenuator
to a wide band main amplifier before diode or phase sensitive
detection. The resulting signal is amplified in a final stage
postamplifier.
The spectrometer was augmented by a Bruker B-KR 300z 15 pulse
gated integrator (PGI).
tudes at fixed points on
sampling times between 0
grator time constant was
output voltage level was
voltmeter
(DVM).
This was used to measure signal ampli-
the detected transient decay curves. Gate
.5 us and 10 ms could be used and the inte-
adjustable between 10 us and 100 s. The
displayed on a Solatron LM 1420.2 digital
Signal averaging was undertaken by a Data Laboratories DL 102
200 point signal averager. In this instrument input voltages within