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The nonevaporable getter pump St707 (Zr-V-Fe) from SAES Getters, Inc. may be activated and operated at lower temperatures. However, its application to a UHV system has not been reported yet. This paper reports the characteristics of the St707 getter strip in a UHV system as a liaearly distributed pump. The getter is activated at ^400°C for 30 min. The pumping behavior of the getter strip for H, and CO is studied. The initial pumping speeds for H. and CO are 300 &/s*m and 190 &/s*m, respectively; and decrease slowly with increasing gas load to

A large measure of the successfil operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line UIOB. One meter long beam tube samples were fabricated f?om aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. *Work performed under the auspices of the U.S. Department of Energy, under contract DE-AC02-7GCH000 16 and W-3 1-109-ENG-3 8. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line UlOB using white light with a critical energy of 487ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between IO" and1023 photons per meter for a PSD measurement. Desorption yields for H,, CO, CO,, CH, and H,O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods develolped in other laboratories.

Experimental measurements of photodesorption coefficients of H2, CH4, CO and CO2 are being done to obtain data necessary to predict the vacuum performance of the Collider. Experiments have been done or are planned for warm tubes (i.e. room temperaturc), cold tubes (i.e. 4.2 K) and liner configurations (i.e. 4.2 K, 20 K and 80 K). Two synchrotron radiation beamlines have been constructed on the VEPP-2M storage ring at BINP, Russia. The photon critical energy is 284 eV, as in the SSC Collider, angle of incidence is 10 mrad. To date approximately fifteen warm beam tubes have been tested, including electrodeposited Cu, high purity bulk Cu and Nitronic 40 S S , several cleaning procedures, with and without in-situ baking and with and without magnetic field. The maximum integrated photon dose was achieved was 20102~ photondm on the high intensity beamline. Several experiments have been done on the VUV ring at BNL to check a subset of the BINP data and to extend the integrated photon flux up to photondm, or 100 days of SSC operation. The data from the warm experiments will be used to evaluate the best tubes to be used in the more time consuming cold experiments.

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