Table 1. Standard air density as a function of elevation above sea level (at 70F and 50% relative humidity). M echanical ventilation can be divided into three types: negative-, positive-, and neutral-pressure ventilation. Negativepressure systems use fans to exhaust air, thereby creating a slight partial vacuum that draws fresh air in from outdoors. Negative-pressure ventilation systems are use...

The 2.5 MeV injector for the Spallation Neutron Source is currently under construction at LBNL, which includes a 2.5 MeV high power, high duty factor four vane RFQ made of four modules. Transverse mode stabilization is obtained through a series of cross coupling rods. Each of the four RFQ modules is equipped with twenty fixed tuners, two active power and two vacuum ports. Fine frequency tuning ...

Storage and cooling of highly charged ions require ultra-high vacuum levels obtainable by means of cryogenic methods. We have developed a linear Paul trap operating at 4 K capable of very long ion storage times of about 30 h. A conservative upper bound of the H(2) partial pressure of about 10(-15) mbar (at 4 K) is obtained from this. External ion injection is possible and optimized optical acce...

A multilayered microchip (25 x 95 mm) used for vacuum distillation is designed, fabricated and tested by rectification of a water-methanol mixture. The polymer chip employs a cooling channel to generate a temperature gradient along a distillation channel below, which is separated into a channel (72 microm deep) for liquid phase and a channel (72 microm deep) for vapor phase by an incorporated m...

Reduction of the 6-dimensional phase-space of a muon beam by several orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. The channel consists of a series of low frequency (325 MHz-650 MHz) normal conducting pillbox cavities, which are enclosed with thin beryllium windows (foils) to incr...

The aim of the present work is to study the effect of annealing on the vibration damping capacity of high-chromium (16%) ferromagnetic steel. The alloys were prepared from raw materials of 99.9% purity melted in a high frequency induction furnace under high vacuum. The samples were heat-treated in vacuum at various temperatures (800 to 1200oC) for 1 hour followed by slow cooling (120oC/h). The ...

We present two simple cryogenic rf ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 h. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The...

We report unusual negative thermal expansion and viscoelastic properties in graphene oxide paper. The paper was prepared from aqueous GO dispersions using a simple vacuum evaporation technique. From room temperature to 150 C, this paper-like graphene oxide sheet exhibits a constant negative thermal expansion coefficient of 67 · 10 / C along the in-plane direction. Peculiar hysteresis loops of t...

We report on the design, operation, and performance of a thermal evaporation chamber capable of evaporating organic thin films. Organic thin films are employed in a diverse range of devices and can provide insight into fundamental physical phenomena. However, growing organic thin films is often challenging and requires very specific deposition parameters. The chamber presented here is capable o...