The Electrical Distribution Feed Box for the LHC Prototype Cell

The Electrical Distribution Feed Box (DFB) for the Large Hadron Collider (LHC) Prototype Cell (String 2) is a 6 meter-long 4.6 K / 0.135 MPa liquid helium cryostat which supports and cools 13 kA and 600 A High-Temperature Superconductor (HTS) current leads. These are used for powering the String 2 main dipole and quadrupole superconducting magnets, together with their correctors. The DFB also incorporates the l-plate between its saturated liquid helium bath and the magnet pressurized superfluid helium bath at 1.9 K/ 0.13 MPa. The DFB is built within the frame of a collaboration between CERN and the Budker Institute of Nuclear Physics (Novosibirsk, Russian Federation). It is a complex cryostat satisfying a number of constraints (space available, accessibility, integration) and combining different technologies such as mechanical and electrical engineering, superconductivity, cryogenics and vacuum. The current status of the design and construction of the DFB for the LHC Prototype Cell, together with an outlook towards the LHC arc DFB's, is given

The Insulation Vacuum Barrier for the Large Hadron Collider (LHC) Magnet Cryostats

The sectorisation of the insulation vacuum of the LHC magnet cryostats, housing the superconducting magnets, which operate in a 1.9 K superfluid helium bath, is achieved by means of vacuum barriers. Each vacuum barrier is a leak-tight austenitic stainless steel thin-wall structure, mainly composed of large diameter (between 0.6 m and 0.9 m) bellows and concentric corrugated cylinders. It is mounted in the Short Straight Section (SSS) [1], between the magnet helium enclosure and the vacuum vessel. This paper presents the design of the vacuum barrier, concentrating mostly on its expected thermal performance, to fulfil the tight LHC heat in-leak budgets. Pressure and leak test results, confirming the mechanical design of two prototypes manufactured in industry, and the preparation of one of these vacuum barriers for cryogenic testing in an SSS prototype, are also mentioned

The New Superfluid Helium Cryostats for the Short Straight Sections of the CERN Large Hadron Collider (LHC)

The lattice of the CERN Large Hadron Collider (LHC) contains 364 Short Straight Section (SSS) units, one in every 53 m long half-cell. An SSS consists of three major assemblies: the standard cryostat section, the cryogenic service module, and the jumper connection. The standard cryostat section of an SSS contains the twin aperture high-gradient superconducting quadrupole and two pairs of superconducting corrector magnets, operating in pressurized helium II at 1.9 K. Components for isolating cryostat insulation vacuum, and the cryogenic supply lines, have to be foreseen. Special emphasis is given to the design changes of the SSS following adoption of an external cryogenic supply line (QRL). A jumper connection connects the SSS to the QRL, linking all the cryogenic tubes necessary for the local full-cell cooling loop [at every second SSS]. The jumper is connected to one end of the standard cryostat section via the cryogenic service module, which also houses beam diagnostics, current feedthroughs, and instrumentation capillaries. The conceptual design fulfilling the tight requirements of magnet alignment precision and cryogenic performance are described. Construction details, aimed at minimizing costs of series manufacturing and assembly, while ensuring the high quality of this complex accelerator component, are given

The HIE-ISOLDE Superconducting Cavities: Surface Treatment and Niobium Thin Film Coating

CERN has designed and prepared new facilities for the surface treatment and niobium sputter coating of the HIE-ISOLDE superconducting cavities. We describe here the design choices, as well as the results of the first surface treatments and test coatings

Design, Production and First Commissioning Results of the Electrical Feedboxes of the LHC

A total of 44 CERN designed cryogenic electrical feedboxes are needed to power the LHC superconducting magnets. The feedboxes include more than 1000 superconducting circuits fed by high temperature superconductor and conventional current leads ranging from 120 A to 13 kA. In addition to providing the electrical current to the superconducting circuits, they also ensure specific mechanical and cryogenic functions for the LHC. The paper focuses on the main design aspects and related production operations and gives an overview of specific technologies employed. Results of the commissioning of the feedboxes of the first LHC sectors are presented

THE HIE-ISOLDE SUPERCONDUCTING CAVITIES: MECHANICAL DESIGN AND FABRICATION

The HIE-ISOLDE superconducting linac at CERN will be based on 101.28MHz niobium sputtered copper Quarter Wave Resonators (QWRs), which will be installed downstream of the present REX-ISOLDE linac. The current design considers two basic cavity geometries (geometric 0 of 0.063 and 0.103). We report here on the choices for the mechanical design of the high beta cavities, as well as on the specific details of the fabrication of the first copper prototypestatus: publishe

Conceptual design of the Cryogenic Electrical Feedboxes and the Superconducting Links of LHC

Powering the superconducting magnets of the LHC arcs and long straight sections is performed with more than 1000 electrical terminals supplying currents ranging from 120 A to 13’000 A and distributed in 44 cryogenic electrical feedboxes (DFB). Where space in the LHC tunnel is sufficient, the magnets are powered by locally installed cryogenic electrical feedboxes. Where there is no space for a DFB, the current will be supplied to the magnets by superconducting links (DSL) connecting the DFBs to the magnets on distances varying from 76 m to 510 m