[en] The gas detector apparatus described includes a gas detection unit, a pumping unit and a channel forming a conductance between the detection and pumping units. The ion formation and collection unit has an anode, a separate cathode and a magnetic field source giving the electrons a curved path before they reach the anode. It can receive the gas to be detected. The characteristic feature of this apparatus is the very low conductance value in relation to the pumping rate of the ion pumping unit, therefore a change in the pumping rate of this unit has only a negligeable effect on the rate at which the ion formation and collection unit is evacuated. It can be used as a hydrogen detector and consequently as a sodium leak detector (when the liquid sodium used to remove the heat of a nuclear reactor escapes from the pipe containing it in an atmosphere containing a hydrogen releasing substance). It is also used to detect water leaks for the steam generator by measuring the hydrogen dissolved in the liquid sodium

[en] It is shown that significant H₂ pumping occurs in the walls of triode pumps. Also, H₂ is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H₂ pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump. 13 refs., 5 figs., 1 tab

[en] In a magnetically confined sputter-ion vacuum pump a multi-apertured anode electrode is interposed between a pair of reactive cathode electrode plates. An evacuable envelope encloses the anode and cathode electrodes and a magnetic circuit surrounds the vacuum envelope for producing a glow discharge confining magnetic field extending axially of the apertures in the anode. The reactive cathode plates include peripheral sealing flanges for compressing a sealing gasket into sealing engagement with a pair of sealing surfaces at opposite ends of a tubular main body portion of the envelope. A clamping ring structure, having a bolt circle formed therein, serves to clamp the two reactive cathode plates to the main body and also serves as an integral part of the magnetic circuit. Water coolant channels are brazed to the outer surfaces of the cathode plates for cooling same in use. The magnetic circuit includes a pair of ferrite magnets disposed outside the envelope on opposite sides of the cathodes and enclosed by a magnetic yoke to minimize the size and weight of the magnet and to reduce unwanted stray magnetic fields

[en] Pressure profiles, in time, are calculated as a consequence of anticipated outgassing of various beam components (e.g., rf cavities, etc.) and warm-bore beam pipes. Gold beam lifetimes and transverse beam emittance growth are given for calculated average pressures. Examples of undesirable warm-bore conditions are presented such as contaminated experimental beam pipes and warm-bore magnets (i.e., DX). These examples may prove instructive. The methods used in making these calculations are presented in Section 2. They are applicable to all linear systems. The calculations given apply to the RHIC accelerator and more specifically to warm-bore regions of the machine

[en] Credible and effective communications prove to be the major challenge in the acquisition of reliable vacuum hardware. Technical competence is necessary but not sufficient. The authors must effectively communicate with management, sponsoring agencies, project organizations, service groups, staff and with vendors. Most of Deming's 14 quality assurance tenants relate to creating an enlightened environment of good communications. All projects progress along six distinct, closely coupled, dynamic phases. All six phases are in a state of perpetual change. These phases and their elements are discussed, with emphasis given to the acquisition phase and its related vocabulary. Large projects require great clarity and rigor as poor communications can be costly. For rigor to be cost effective, it can't be pedantic. Clarity thrives best in a low-risk, team environment

[en] A two-stage cryopump having got deflecting pieces that are arranged at a distance from each other in axial direction in order to shield the second stage from external heat radiation while keeping an essentially undisturbed gas flow from the inlet opening to the second stage. (orig.)

[en] The Alternating Gradient Synchrotron (AGS) is a synchrotron for the acceleration of protons and heavy ions to tens of GeV/amu for fixed target physics research. The Relativistic Heavy Ion Collider (RHIC), with the AGS as its injector, allows the collision of heavy ion beams with energies of several hundred GeV/amu. The vacuum systems of the AGS-RHIC complex range from 10^-6 Torr in the ion sources to ultrahigh vacuum of low 10^-11 Torr in the Booster and RHIC. The status of the machines will be described with emphasis on the following areas: the performance of the Booster ultrahigh vacuum system, the development of non-magnetic vacuum components for the muon storage ring, and progress in the construction of the RHIC vacuum systems

[en] The pumping of hydrogen in diode and triode sputter-ion pumps is discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium or titanium alloy anodes is also shown to measurably impact on the speed of these pumps at.very low pressures. This stems from the fact that hydrogen is x10⁶ more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Lastly, quantitative data are given for the He speeds and capacities of both noble and conventional diode and triode pumps. The effectiveness of various pump regeneration procedures, subsequent to the pumping of He, is reported.These included bakeout and N₂ glow discharge cleaning. The comparative desorption of He with the subsequent pumping of N₂ is reported on. The N₂ speed of these pumps was used as the benchmark for defining the size of the pumps vs. their respective He speeds

[en] This paper presents a model for predicting the pumpdown characteristics of a 480 m RHIC (Relativistic Heavy Ion Collider) vacuum cryostat. The longitudinal and transverse conductances of a typical cryostat were calculated. A voltage analogue of these conductances was constructed for room temperature conditions. The total longitudinal conductance of a room temperature cryostat was thereby achieved. This conductance was then used to calculate the diameter of an equivalent long outgassing tube, having more convenient analytical expressions for pressure profiles when pumped. The equivalent of a unit outgassing rate for this tube was obtained using previously published MLI (multi-layer insulation) outgassing data. With this model one is then able to predict a cryostat pumpdown rate as a function of the location and size of roughing pumps

[en] It is shown that significant H₂ pumping occurs in the walls of triode pumps. Also, H₂ is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H₂ is pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump