Figure 1 illustrates the enhancement of high mass ion yield with the C₆₀⁺ primary beam, compared with gallium.

In this case, the sample was Gramicidin D, a polypeptide. The molecular ion at m/z 1881 is present in the spectrum acquired with C₆₀⁺, while effectively absent in the spectrum from gallium. This action can be explained in terms of generally accepted sputtering theory. When C₆₀⁺ is used as a primary projectile, the momentum of each ion is lower compared with an atomic projectile with the same energy. So, the C₆₀⁺ impact is 'softer', dissipating energy into a larger region of the surface. The size and structure of the C₆₀⁺ molecule may also contribute to the softer impact.

Although the impact is softer, the energy available for sputtering from the surface remains the same and the higher mass particle is not disadvantaged in terms of yields. Indeed, the shallower penetration assists in giving energy to molecules at the surface. Moreover, molecular dynamics theory suggests that the wider spatial dissipation of energy in the collision region results in a much higher probability for the lift-off of large molecules.