“MASHA” Separator



MASHA separator and analyzer is destined for separation and mass analysis of superheavy element ions with masses A=288±12, energy E=40 keV and charge state Q=+1. Separator mass resolution exceeds 1000. It’s very important for superheavy element α-decay chain identification. This separator is designed for an ion beam with 35π mmxmrad emittance (in horizontal and vertical planes) emergent ECR source with a round discharge outlet of 5 mm across diameter.

  • Setup principle circuit

The separator is of two-stage structure. The first stage of preseparation includes:

      • M1 magnet for separation of 4He1+ and 48Ca1+ ion, the vacuum chamber has corresponding outlets;
      • Q1-Q2 quadrupole doublet for beam vertical focusing and horizontal intermediate focus formation after M2 magnet;
      • M2 magnet ensuring 1,5 mm/% mass dispersion and -0,40 intermediate focus linear magnification;
      • intermediate focus preseparation slit; space division of ions of A=288 and A=250 is 18 mm at the intermediate focus.

The second stage includes:

      • Two drift gap separated 50 degree magnets M3_1 and M3_2 designed for ion mass analysis with exceeding 1000 resolution;
      • 90 degree vertically deflecting electrostatic sector capacitor transporting ions to the focal detector;
      • Q3 quadrupole magnet and S1 and S2 two hexapole magnets designed for ion optics correction;
      • focal detector in focal plane orthogonal to beam direction.
        Besides the above mentioned the separator has electrostatic dipole correctors (steerers) for vertical and horizontal beam centering.

Setup simplified drawing

The separator may be adjusted by mercury and xenon ions with mass numbers of A=184±186 and A=124±136 correspondingly.