Related papers: Hydrogen in the LCLS2 Beamline Vacuum
The understanding of complex and/or large vacuum systems operating at cryogenic temperatures requires a specific knowledge of the vacuum science at such temperatures. At room temperature, molecules with a low binding energy to a surface are…
The PIP-II linac Cryogenic Distribution System (CDS) is characterized by extremely small heat inflows and robust mechanical design. It consists of a Distribution Valve Box (DVB), Intermediate Transfer Line, Tunnel Transfer Line, comprising…
It is commonplace in helium cryogenic systems to utilize vacuum insulation to mitigate convective heat transfer to the low temperature fluids. While the insulating vacuum meaningfully improves cryogenic system thermal performance, failure…
The superconducting cavities in the continuous wave (CW) linacs of LCLS-II are designed to operate at 2 K, where cooling costs are very expensive. One source of heat is presented by the higher order mode (HOM) power deposited by the beam.…
A quasi-resonant laser induces a long-range attractive force within a cloud of cold atoms. We take advantage of this force to build in the laboratory a system of particles with a one-dimensional gravitational-like interaction, at a fluid…
We consider cold polar molecules confined in a helical optical lattice similar to those used in holographic microfabrication. An external electric field polarizes molecules along the axis of the helix. The large-distance inter-molecular…
Thermal motions in the 2D Lennard-Jones liquid near solidification are studied at equilibrium and under shear flow conditions. At the temperatures of the study, the liquid is significantly aggregated. On times of few to few tens of…
The Linac Coherent Light Source (LCLS) at Stanford Linear Accelerator Center (SLAC) is in the process of being upgraded to a superconducting radio frequency (SRF) accelerator and renamed LCLS-II. This upgrade requires thirty five 1.3 GHz…
In this paper, we study the long-time behavior of full Ericksen-Leslie system modeling the hydrodynamics of nematic liquid crystals between two dimensional unit spheres. Under a weaker assumption for Leslie's coefficients, we give the key…
SPIRAL2 is a superconducting LINAC subject to cryogenic thermo-acoustic oscillations occurring in its valves-boxes. 4 years of monitoring and experimental investigations with thousands of datasets turned these unwanted effects into an…
Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in…
The technical properties of helium II ('superfluid' helium) are presented in view of its applications to the cooling of superconducting devices, particularly in particle accelerators. Cooling schemes are discussed in terms of heat transfer…
Frozen hydrogen filaments or droplets/pellets in vacuum are of great interest as target for many experiments at hadron and lepton accelerators as well as at high-power laser systems. Especially in case of large distances between the…
Helium has the lowest boiling point of any element in nature at normal atmospheric pressure. Therefore, any unwanted substance like impurities present in liquid helium will be frozen and will be in solid form. Even if these solid impurities…
Future use of liquid hydrogen (LH$_2$) as an effective energy carrier will require elimination or minimization of hydrogen boil-off that is not utilized by demands in the value chain. The present work promotes local area cooling (LAC) as a…
The cryogenic buffer gas beam (CBGB) is an important tool in the study of cold and ultracold molecules. While there are known techniques to enhance desired beam properties, such as high flux, low velocity, or reduced divergence, they have…
While well studied in the absence of beam-beam and while colliding head-on, the stability of the LHC beams can be very critical in intermediate steps. During the squeeze, the long-range beam-beam interaction becomes a critical component of…
A system of identical particles interacting through an isotropic potential that allows for two preferred interparticle distances is numerically studied. When the parameters of the interaction potential are adequately chosen, the system…
We report on the low temperature behaviour of the colloidal electrolyte by means of Molecular Dynamics simulations, where the electrostatic interactions were modeled using effective screened interactions. As in previous works, we have found…
We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high…