Aston Labs

Propagation of ion trajectories

•  4th order Runge-Kutta
• 10 ns steps
• 840 ms simulated transient

Space charge effects

• added to the force due to the electric field
• for the ith ion:

• bold symbols are vectors
• “S” = relative strength of the space charge effect 
• Changing S allows space charge effects to be calculated as a function of number of ions without increasing computational demands

Ions for simulation

50 ions each:

[Val5]-Angiotensin II

• [M+2H]2+
• m = 1031.5187561 Da
• z = +2
• m/z = 516.7672031 Th

Lys-des-Arg9-Bradykinin

• [M+2H]2+
• m =1031.5551459 Da
• z = +2
• m/z = 516.7853980 Th

Initial positions randomly generated

• normally distributed
• centered about (x = 0, y = 7 mm, z = -4.5)
• standard deviations ?x = ?y = ?z = 0.025 mm

Initial energies randomly generated

• normally distributed
• centered about (KEx = 0, KEy = 3460, KEz = 0) 
• standard deviations ?x = ?y =15 eV  and ?z = 5 eV

Post Trajectory Processing

• Ion image detection (model independent)
• Fast Fourier Transform of average z velocity
• 222 (4,194,304) points