Measurement of the 38Ar(p, n)38mK threshold using a gaseous target

Abstract The problems of measuring a (p, n) threshold accurately with a gaseous target are discussed. A procedure possible in the case of a beam with a large energy straggling is illustrated for 38 Ar. Comparison with the threshold for the 35 Cl(p, n) reaction measured under the same conditions leads to a threshold energy of (7007.9±1.6) keV for the 38 Ar(p, n) 38m K reaction.