Biomagnetic separation system with double ring profile

A biomagnetic separation system with double ring profile comprising:

• an outer ring with inner radius R1 and outer radius R2, the outer ring comprising a number of permanent magnets n2 greater than 4 and of the same geometry forming a quadrupolar Halbach cylinder and a magnetization direction progression Δγ2 of:
• Δγ2=3Δθ2
• wherein Δθ2=2π/n2 is the angular distance between two consecutive magnets, and
• an inner ring with outer radius R1 and inner radius R0, the inner ring comprising a number of permanent magnets n1 of the same geometry forming a Halbach cylinder having a number of pole pairs N greater than 2 and n1>2N, the inner ring magnets having a magnetization direction progression Δγ of:
• Δγ=(N+1)Δθ
• wherein Δθ=2 π/n1 is the angular distance between two consecutive magnets, where the inner ring is concentric with the outer ring and defines an inner bore;
• and
• a cylindrical vessel of an inner radius Z0, the cylindrical vessel inserted into the bore of the inner ring coaxially with the geometric center of the rings,
• wherein the outer ring having a remanence Br1 and filling factor f1;
• the inner ring having a remanence Br2 and filling factor f2;
• and
• the inner ring fulfills the following conditions:
• Nz
• N
• -
• 2
• >
• 2
• ⁢
• kf
• ⁡
• (
• 1
• -
• R
• 0
• R
• 2
• )
• ;
• R
• 1
• >
• R
• 0
• 1
• -
• 2
• ⁢
• kf
• ⁡
• (
• 1
• -
• R
• 0
• R
• 2
• )
• N
• ⁢
• z
• N
• -
• 2
• N
• -
• 1
• ;
• wherein k>1, z is the ratio Z0/R0 and f=(Br2+f2)/(Br1*f1).