In November 2004, Paleo Labo Co., Ltd., which is a private company to make a variety of scientific researches on archaeological remains, introduced a compact AMS system for 14C dating business. The system is called as CAMS-500 (NEC, U.S.A.) that is based on a 500 kV Pelletron accelerator equipped with ordinary AMS items. As it was designed to be very compact in size with a low voltage accelerator, special ideas were applied. Argon gas pressure of the charge exchanging system is set to be very high to dissociate molecular ions such as 13CH and 12CH2, which cause the machine background. Straggling of the ions scattered by the high density argon gas causes poor transmission through the gas stripper canal. The ion optical devices such as an ion lens, a beam steerer or a beam shifter were simplified and reduced. For the system, only one eintzel lens and two steerers are equipped, resulting in simple operation and hard tuning. With all these features, reproducibility of the measurements on 14C/12C and also on 13C/12C is considerably high compared to that by ordinary higher energy AMS system. We have tried to find out the best gas pressure of the stripper for the lowest background and the highest transmission. The data show that at the best gas pressure for the lowest background the transmission is reduced to be about 85% from the maximum value. With this system we have already measured more than 900 archaeological samples with fairly good precision only in five months. Some data on standard samples with high precision and low machine background will be shown. A statistical basic data on archaeological samples will also be presented.
See more of Poster Session I
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)