Measurement of the temperature of cold highly charged ions produced in an electron beam ion trap

The temperature of highly charged titanium ions produced and trapped in an electron beam ion trap was determined by precisely measuring the broadening of K-shell emission lines in Ti19+ caused by the thermal Doppler motion. While interacting with a 3330 V electron beam the measured temperature of the titanium ions ranges from about 700 eV when the ions are confined in a deep trap to about 70 eV for ions in a shallow trap. The latter value represents the lowest temperature at which the K-shell X-ray emission from highly charged titanium ions has ever been recorded. (orig.)