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RITU - Recoil Ion Transport Unit


Name and Model (Year of Manufacture / Installation)

Danfysik RITU (Recoil Ion Transport Unit) (1994/1994)

General Information

Gas-filled recoil separator.

RITU is based on a standard DQQ magnetic configuration, with an extra vertically focusing quadrupole magnet in front of the dispersive element added, thus giving it a QDQQ configuration (see table below for detailed specifications). This gives an angular acceptance of 10 msr, the maximum rigidity is 2.2 Tm, the bending angle is 25 degrees, and the dispersion is 10 mm. The construction of the RITU separator was finished during 1994 and a wide-ranging experimental program was started. Alongside the strong experimental program, technical development work for the separator has continued. A differential pumping system was implemented, allowing windowless operation, hence improving beam focusing. Also a new dipole chamber was installed into RITU, which reduced the amount of scattered beam at the focal plane and therefore lowered the overall background.

Key Specifications        

Magnetic configuration


Maximum beam rigidity

2.2 Tm

Angular acceptance

10 msr


10 mm/% of Bρ

Dipole bending radius

1.85 m

Dipole bending angle

25 degrees

Dipole entrance angle

0 degrees

Dipole exit angle

-25 degrees

Dipole pole gap

100 mm

Q1 effective length

350 mm

Q1 maximum gradient

13.5 T/m

Q1 aperture diameter

105 mm

Q2,3effective length

600 mm

Q2,3maximum gradient

6.0 T/m

Q2,3aperture diameter

200 mm


Location, Contact Person

Department of Physics, YS150 / Juha Uusitalo