Dear Mark, Hallbach array is a special configuration of permanent magnets. I believe we can arrange the coils in the same way. Anyway,oOn the picture you sent there are 7 coils that were simulated on November 6. So I take those force vs. x data and now compute particle dynamics in saline. The algorithm is a simple one: 1. Calculate magnetic force and drag force for current position x and speed 2. Calculate acceleration = force / mass 3. Calculate speed increment = acceleration * time step 4. Calculate coordinate x increment = speed * time step I have programmed the above algorithm with Excel (the full text is listed in Module1.pdf). Now with help of Excel I can compute particle dynamics for any force_vs_coordinate distribution. Please see the picture attached. The picture illustrates the particle dynamics in 5 seconds. The particle starts at x=0 (some 40 cm to the left from the coil). The particle accelerates almost instantly and reaches maximum speed (2 cm/s). At this speed the magnetic force is equal to the drag force. Then speed rises slowly as the particle moves in the area with higher magnetic force. In 5 seconds the particle covered the distance of 12 cm. It took 2.5 hours to implement and test the algorithm. Alas that is one-time investment. Now I can easily compute particle dynamics for any force_vs_coordinate data. Please let me know if I should computer the particle dynamics further (x= 12 cm... 50 cm) or take some other coils configuration. Best regards, Alex On 28.12.2018 17:10, Mark Arokiaraj wrote: > Dear Alex, > > Kindly compute the particle dynamics and let us see the particle movements in the 7 coils with 3 in row central Hallbach (picture attached). > > with regards, > Mark