High-resolution reflection-type crystal spectrometers have been used for x-ray energies up to 13 keV, e.g., theK-shell radiation of heliumlike Kr. In order to extend crystal spectrometer measurements to higher energy x rays from higher-Zelements, we employ the crystal in transmission. The geometry we use is known as DuMond geometry. Using such a transmission-type crystal x-ray spectrometer, we have measured theK-shell radiation of various highly charged high-Zions. In particular, we present a measurement of the1s2p 1P1→1s2 1S0transition in heliumlike xenon, Xe52+. For this transition, we measure a linewidth of 34 eV, which demonstrates that the resolving power we achieved with the new spectrometer is on the order of 1000. ©1997 American Institute of Physics.