The DRS, which is fixed to lie along the beam axis (at zero degrees), is 13 meters long and weighs approximately 90 tons. The first components downstream from the target chamber are a triplet of large-bore (15 cm) quadrupole magnets, which horizontally capture a large opening angle and gives a parallel focus through the velocity filters; vertically, they capture a large opening angle and are set to maximize transmission through the dipole magnet. Next, the DRS has two 1.2-meter long velocity filters - each with a vertical magnetic field generated by a dipole magnet and a horizontal electric field generated by a pair of charged titanium plates ( < +/- 300 kV). A slit assembly located between the two velocity filter chambers will intercept the majority of the primary beam. The next components are a second triplet of quadrupole magnets, which are used to give a horizontal point-to-point focus at a velocity-dispersed intermediate focal plane. A pair of sextupole magnets, for correction of second order aberrations, straddle a second slit chamber located at the intermediate focal plane. The particles are dispersed along this focal plane according to their velocity. The sextupoles are followed by a 50-degree dipole magnet, which is dispersion matched to the velocity filters to produce a 1 part in 300 mass/charge focus at the final focal plane. A third triplet of quadrupole magnets gives large vertical transmission and gives a mass dispersion of 0.1 %/mm at the end of the device.
Two target chambers are being fabricated for the DRS: a large chamber that accomodates the Silicon Detector Array (SIDAR), a number of annular silicon strip detectors used to measure (p,p), (p,alpha), and (p,p') reactions, and a small chamber allowing the close placement of an array of barium fluoride detectors for the detection of capture gamma rays from the target.
A differentially-pumped, windowless Hydrogen gas target system is being constructed for the DRS. This target will enable measurements of inverse kinematics proton-capture reactions with heavy-ion radioactive beams using a target of pure hydrogen. This gas target system will have a number of advantages (higher yields, lower backgrounds) over the use of polyethelene targets.
The DRS focal plane detection system consists of a position and timing detector - a carbon-foil microchannel plate detector (MCP) - and a dual energy-loss and residual-energy detector - a gas ionization counter (IC). Further details on these focal plane detector systems are available.
Daresbury Recoil Separator-Front Left
Daresbury Recoil Separator-Rear Left
Daresbury Recoil Separator-Rear Right
Daresbury Recoil Separator-Dipole Magnet
The Response of an Isobutane Filled Ion Chamber to Heavy Ions, A.N. James et al., Nucl. Inst. Meth. 212 (1983) 545.
