High temperature field evaporation of Ta emitter was studied by means of magnetic atom probe with mass resolution ～200 at the temperatures T from 300 K to 2500 K. The instrument contains the unique source of field ions with focusing, not depending on a value of field strength F. At the room T only three-charged ions Ta{sup}+3 are observed. Increasing T leads to necessary reduction of value evaporation field F{sub}(ev) that causes change the charge of the evaporated ions. At the more high temperature T > 500 K dominate already two-charged ions Ta{sup}+2. From to temperature T = 1950 K in interval T = 1950 - 2350 K single-charged ions Ta{sup}+ are observed too. At the T > 1900 K two-charged ions vastly dominate, velocity of their evaporation V ～5 pul/sec then values V for single and three-charged ions V ～0.1 - 0.3 pul/sec. Two and three-charged ions exist with different intensity in all interval T, single-charged ions exist at high T only.
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