| 摘要 |
<p>A method to adjust the operating temperature of cathodes given in an aspect of the present invention includes: acquiring an approximate equation approximating a correlation between an emission current value in an electron beam source using a cathode, and an operating temperature of the cathode at which a bias voltage becomes saturated on the emission current; measuring the current density of an electron beam from the cathode in a state where an n^th (n is an integer) emission current value and an n^th cathode operating temperature are set in the electron beam source; determining whether the measured current density is within a tolerance range; changing the n^th emission current value to an (n+1)^th emission current value if the measured current density is not within the tolerance range; calculating the operating temperature of the cathode corresponding to the (n+1)^th emission current value using the approximate equation; and setting the calculated operating temperature as an (n+1)^th cathode operating temperature in the electron beam source.</p> |
