A compact range telescope for K+ measurements

We present range telescopes for measurements of low energy K+ mesons together with first in-beam results. The hardware trigger, based on the observation of the μ+ from the K+ → μ+ + νμ decay channel, is designed for subthreshold hadron-nucleus and heavy ion reactions, where the kaon fraction of the total number of charged particles is ⪡ 10−4. The geometrical efficiency is ∼15% and the total efficiency ∼4% for K+ registration in the present version of the detector.