[en] The distributed ion pumps incorporated along accelerator ring beam ducts are those of utilizing the deflection magnetic field of the ring, and they have been used for many accelerator rings. In order to effectively operate distributed ion pumps, the distributed ion pump elements (penning cells) suitable to the parameters (duct size, intensity of magnetic field, applied voltage and so on) of respective rings must be adopted. This time, for the purpose of pressure improvement in the TRISTAN accumulation ring (AR), the distributed ion pumps for the AR were designed, and a number of the distributed ion pumps having different structures and dimensions were made for trial. Their exhaust speed was measured, and the optimal pump for the AR was decided. Moreover, based on the results of measurement, the new empirical formula was proposed by improving the former empirical formula for exhaust speed. The finally selected distributed ion pumps were incroporated in the actual beam ducts, and the method of rise, attained pressure and exhaust speed were investigated. The trial manufacture, assembling and incorporation in beam ducts and the test in the actual beam ducts are reported. (K.I.)