Two detectors for charged particle identification have been built and tested. First, a test setup for a diffusion box threshold detector, using a 5 cm thick aerogel radiator has been designed and tested at the KEK PS facility in Japan. Using white Millipore paper as a diffuse reflector inside a diffusion box, the Ĉerenkov light gets scattered randomly until it hits one of the photomultipliers. On average up to 20 photoelectrons detected for pions at 1.2 GeV/c have been observed. Second, collection of Ĉerenkov light with an acrylic wavelength shifting plate was investigated. The test setup consisted of a plate, 30 cm long, 10 cm wide, and 1 cm thick placed behind a 5 cm deep stack of aerogel tiles. On the long ends the wavelength shifter was read out by two 5-inch photomultipliers. The response of the system to pions and protons at 1.2 GeV/c momentum was measured at the KEK PS facility in Japan. On average 6 photoelectrons radiated in the aerogel could be detected.
