Assuming thermal equilibrium is fully achieved, at 1,000 K, the ion yields estimated according to equations ( ) and ( ) are 10 -16 and 10 -12 , respectively. At 2,200 K, the estimated ion yields become 10 -6 for the case of equation ( ) and 10 -5 for the case of equation (13). For the case of equation ( ), after making a number of assumptions such as the amount of sodium chloride in the sample, the plume pressure at the time thermal equilibrium is achieved and others, the ion yield is estimated to be 2.9 × 10 -5 (see supporting information for calculations).