A thin emulsion spectrometer using a compact permanent magnet

A 30 mm long spectrometer made of three emulsion sheets inside a compact permanent magnet has been tested with secondary beams produced by the proton synchrotron at KEK. A momentum resolution of σ(p)/p=13.3±0.3%σ(p)/p=13.3±0.3% has been obtained in the momentum range from 0.5 to 2.0 GeV/c, using the sagitta measurements of the tracks reconstructed with an automated emulsion readout system.