Slide kVp, mAs, and filtration and watch the bremsstrahlung curve and characteristic peaks shift in real time.
Reference technique — move a slider to compare against the dashed curve.
Characteristic line at 69 keV
Above 70 kVp, projectile electrons can eject tungsten K-shell electrons and the discrete K-characteristic x-rays appear. Tungsten emits five of them; they are customarily drawn as the single vertical line shown here. Only a change of target material moves this line — kVp, mAs and filtration cannot.
Source: Bushong, Radiologic Science for Technologists, 12e, Ch. 8