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Discussion on Optimization of Large Oil-Pumped Ultra-High Vacuum Systems

Description: Abstract: "Discussion is directed toward eventual optimization of the largest diffusion-pump systems. Less than 100 diffusion pump fluid molecules per cm 2/sec are possible to detect using an accumulation method. Optimization discussed demands highest possible system speed compatible with the above contamination rate. Bakeable oil diffusion pump systems, with equal orifice valve-tap units, without conventional baffling, permit theoretical through-put speeds up to 0.3 of the system orifice. The average backstreaming rate of oil in two unconventionally baffled commercial pumps of 6-in. and 10-in. size is reduced to < 3 x 10-(-4) g/cm-2/24 hr, including heating and cooling the pump boiler. A Ho factor of >0.4 is maintained. Results on trapping with activated alumina, retained by a wire mesh, at both liquid-nitrogen and room temperature are included. A variety of pumping speed measurements and bakeable combination valve-trap units are discussed."
Date: September 12, 1960
Creator: Milleron, Norman & Levenson, L. L.
Partner: UNT Libraries Government Documents Department

A simple, high-yield, apparatus for NEG coating of vacuum beamline elements

Description: Non-Evaporable Getter (NEG) materials are extremely useful in vacuum systems for achieving Ultra High Vacuum. Recently, these materials have been used to coat the inner surfaces of vacuum components, acting as an internal, passive, vacuum pump. We have constructed a low cost apparatus, which allows coating of very small diameter vacuum tubes, used as differential pumping stages. Despite the relative ease of construction, we are routinely able to achieve high coating yields. We further describe an improvement to our system, which is able to achieve the same yield, at an even lower complexity by using an easily manufactured permanent magnet arrangement. The designs described are extendible to virtually any combination of length and diameter of the components to be coated.
Date: December 1, 2010
Creator: Ron, Guy; Oort, Ron & Lee, Daniel
Partner: UNT Libraries Government Documents Department

A Large Bakeable Vacuum Valve

Description: This report describes the development and design of a large bakeable valve that is based on a unique seat arrangement and a novel motion seal.
Date: August 6, 1959
Creator: Batzer, Thomas H.
Partner: UNT Libraries Government Documents Department

Vacuum Probe, Standard Leaks, and Needle Valve for Use with the Helium Leak Detector

Description: The following report is split into four parts describing the usage of a vacuum probe for leak hunting with the Helium Leak Detector, the two types of Standard Leaks that were designed to measure the sensitivity of the detector, the development of a needle valve adjusted for controlling the flow of a standard mixture of helium and air into the leak detector for a sensitivity check by the single leak method, and a worm and gear adjustment developed to facilitate throttling of the Helium Leak Detector on a vacuum header equipped with the 3/8" Kerotect angle valve.
Date: August 1945
Creator: Samuel, A. J.
Partner: UNT Libraries Government Documents Department

Survey of the Chromium-Cobalt-Nickel Phase Diagram at 1200 C

Description: Note presenting a survey of the chromium-cobalt-nickel ternary phase diagram at 1200 degrees Celsius by means of microscopic and X-ray diffraction studies on 110 vacuum-melted alloys prepared from commercial metals of the highest purity available. Three distinct phases are noted.
Date: February 1952
Creator: Manly, W. D. & Beck, Paul A.
Partner: UNT Libraries Government Documents Department

Conceptual Design of ILC Damping Ring Wiggler Straight VacuumSystem

Description: The positron and electron damping rings for the International Linear Collider will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR superconducting design. There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC Reference Design Report. Particular emphasis will be placed on photon power load calculations and the absorber design.
Date: June 22, 2007
Creator: Marks, S.; Kennedy, K.; Plate, D.; Schlueter, R.D. & Zisman, M.
Partner: UNT Libraries Government Documents Department

Ultra-high vacuum system of the Brookhaven National Synchrotron Light Source

Description: The rings of the National Synchrotron Light Source (NSLS) have been supplying light to numerous users for approximately a decade and we recently enjoyed a fully conditioned machine vacuum at design currents. A brief description of the X-Ray storage ring, the VUV storage ring and their current supply is given along with some of their features. The ultra-high vacuum system employed for the storage rings and their advantages for the necessary stored beam environments are discussed including, a brief history of time. After several hundred amp hours of stored beam current operation, very little improvement in machine performance was seen due to conditioning. Sections of the rings were vented, to dry nitrogen and replacement components were pre-baked and pre-argon glow conditioned prior to installation. Very little machine conditioning was needed to return to operation after recovering vacuum due to well established conditioning procedures. All straight sections in the X-Ray ring and the VUV ring have been filled with various insertion devices and most are fully operational. Each storage ring has a computer controlled total pressure and partial pressure monitoring system for the ring and its beam ports, to insure good vacuum.
Date: December 31, 1995
Creator: Foerster, C.L.
Partner: UNT Libraries Government Documents Department

Test results of a combined distributed ion pump/non-evaporable getter pump design developed as a proposed alternative pumping system for the PEP-II asymmetric B-Factory collider

Description: The authors have built and tested an all-in-one combination plate-type distributed ion pump/non-evaporable getter pump design (DIP/NEG) considered as a proposed alternative pumping system for the PEP-II B-Factory High Energy Ring (HER). The DIP portion of the design used a Penning cell hole size of 12 mm in a mostly uniform magnetic field of 0.18 T. The NEG portion of the design used commercially available non-evaporable getter material type St-707{trademark}. A detailed description of the design is presented along with results of pumping speed measurements.
Date: April 24, 1995
Creator: Holdener, F.; Behne, D. & Hathaway, D.
Partner: UNT Libraries Government Documents Department

High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

Description: Metal ions were extracted from pulsed discharge plasmas operating in the transition region between vacuum spark (transient high voltage of kV) and vacuum arc (arc voltage ~;; 20 V). At a peak current of about 4 kA, and with a pulse duration of 8 ?s, we observed mean ion charges states of about 6 for several cathode materials. In the case of platinum, the highest average charge state was 6.74 with ions of charge states as high as 10 present. For gold we found traces of charge state 11, with the highest average charge state of 7.25. At currents higher than 5 kA, non-metallic contaminations started to dominate the ion beam, preventing further enhancement of the metal charge states.
Date: June 19, 2008
Creator: Yushkov, Georgy Yu. & Anders, A.
Partner: UNT Libraries Government Documents Department

THE MOLECULAR AND VISCOUS EFFUSION OF SATURATED VAPORS (thesis)

Description: An investigation of the effusive behavior of saturated vapors over a range of source pressures from 10/sup -6/ atm in the molecular flow region to 1 atm is reported. The purposes of the investigation were to clarify the situation regarding the upper pressure limit to effusive flow, to examine the transition of effusive flow from molecular to viscous behavior, and to clarify some limited aspects concerning the question of vapor saturation within an effusion cell. Mass flow rates of mercury vapor effusing through a thin-edged orifice or long channels into a vacuum from a region of nearly saturated vapor were obtained. (W.D.M.)
Date: April 1, 1960
Creator: Carlson, K.D.
Partner: UNT Libraries Government Documents Department

Experimental and Theoretical Study of Electronic Transitions in Phosphorus, Phosphoryl, and Thiophosphoryl Trichlorofluorides

Description: This thesis is an investigation of the vacuum uv spectra of the phosphorus, phosphoryl, and thiophosphoryl trichlorofluorides in the region 1250 to 3000A. Assignments for absorption bands are made utilizing results from photoelectron spectra and ab initio calculations, oscillator strengths for absorption bands, and CNDO/2 molecular orbital calculations. Results from CNDO/2 calculations are compared with theoretical calculations, and experimental data are discussed with regard to the bonding in the compounds.
Date: May 1973
Creator: McAdams, Mary Jane
Partner: UNT Libraries

A Vacuum Tube for an Electrostatic Generator

Description: The purpose of this study has been to construct two accelerating tubes with small beam apertures for the Van de Graaff, modifying the prototype tube designed and tested by Wiley (20), to design and construct a vacuum system for evacuating the tubes, and to determine the characteristics of the tube under operating conditions while installed in the generator.
Date: August 1966
Creator: Pool, John Reginald
Partner: UNT Libraries

Cold vacuum drying facility design requirements

Description: This release of the Design Requirements Document is a complete restructuring and rewrite to the document previously prepared and released for project W-441 to record the design basis for the design of the Cold Vacuum Drying Facility.
Date: September 24, 1997
Creator: Irwin, J.J.
Partner: UNT Libraries Government Documents Department