Compact TXLine 1H/X Broadband Probe
for 900 MHz UWB magnet

900 MHz 1H/X broadband probe.

1. DESCRIPTION

This 1H/X broadband transmission line probe is operating in NHMFL's new 900 MHz ultra-wide bore magnet, which became operational in August 2004. The new probe utilizes advantages of compact transmission line design which we developed for high frequency magnets. High field magnets are physically long and present challenge for conventional transmission line probes, where RF circuit is mounted outside the magnet. RF losses in Tx line would accumulate very fast over several wavelengths from magnet's bottom to its sweet spot. In our 900 MHz magnet, this distance is almost 5 wavelengths at proton frequency. To avoid unnecessary losses, entire transmission line design is compacted within 7" of space in probe head. Parts of transmission line are responsible for transmitting power to the coil, isolating channels, and balancing the RF circuit for better RF homogeneity. The compact design results in probe with light weight and with higher efficiency of low-frequency X channel.

Similar, 3.2mm broadband MAS probe is being built for the 900 MHz magnet this year.

2. FEATURES