The development of a high intensity Cs sputter negative ion source with multi-sample mechanism for AMS applications has been completed. In order to meet the particular requirements of AMS the source was specially designed with the emphasis on high output

low memory effect

low emittance as well as reliability and stability in structure and performance. The source prototype has been tested intensively on the test stand for more than one year. During the period some important modifications were made. 10μA Be0-

5/μA Al-

4. 5μA Fe-

350μA C- etc. have been delivered. The emittance was measured to be very good and ranges from 2 to 4πmm

mrad. MeV1/2 for beams less than 100μA The memory effect and ioniza-tion efficiency have also been measured or evaluated. The first two source prototypes will be moved to the EN tandem at Peking University

Beijing

and the 6 MV home-made tandem in Sanghai Institute of Nadoar Research for 14C and 10Be measurements respectively.