The crystal is annealed for {HEAD ~ a period} of time and at a temperature to provide substantially maximum acoustic attenuation at {TAIL ~ the operating frequency} of the transducer 
The crystal is annealed for { HEAD ~ a period } of time and at a temperature to provide substantially maximum acoustic attenuation at { TAIL ~ the operating frequency } of the transducer
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH