The use of the gas-filled magnet technique for the detection of medium mass ions

The use of the gas-filled magnet technique for the detection of intermediate mass (A∼ 20-40) recoil nuclei produced in (p,α) reactions in inverse kinematics has been investigated. Through a series of calibration measurements with 27Al, 28,29Si and 33S beams the optimum parameterization for calculating the average charge-state distribution in a gas-filled magnet has been determined. By measuring the magnetic rigidity, the time-of-flight and the differential energy loss of the particles at the focal plane of a gas-filled Enge Split Pole spectrograph it was possible to separate and identify the (p,α) reaction products from elastically scattered particles at very small scattering angles. This technique was then tested by measuring the p(33S,30P)α and p(37K,34Cl)α reactions.