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

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

PENGARUH PENAMBAHAN CACAHAN LIMBAH PLASTIK JENIS HIGH DENSITY POLYETHYLENE (HDPE) PADA

Waste is a very complex problem in urban area. Plastic waste is increasing every year. Kupang with population of 291,794 people generate waste reaches 926 m3/day. Organic waste to 700 m3 and inorganic waste about 226 m3. Concrete is planned by strength quality 25 MPa. Based on the analysis in this study obtained that concrete flexural strength value increased due to the addition of HDPE plastic shredded into the concrete, with chopped levels are added to the concrete at 0%, 0.50% and 0.90% .0,70%. Flexural strength value of normal concrete without the addition of shredded plastic (0%) is 4.12 MPa, flexural strength of concrete with the addition of shredded plastic 0.50% is 4.30 MPa increased 4.37% from normal concrete flexural strength, flexural strength of concrete with the addition of shredded plastics 0.70% is 4.21 MPa increased 2.19% from the normal concrete flexural strength and flexural strength of concrete with the addition of shredded plastic 0.90% is 3.94 MPa decreased 3.64% of flexural strength normal concrete

VUV FEL driven RF gun

In this paper we describe the regeneration of electron bunches from the RF gun by back-reflected radiation from VUV SASE FEL at the TESLA Test Facility (TTF) at DESY. The SASE FEL was running at the wavelength 96 nm with 30– 100 fs pulses, SASE pulse energy was up to 20 μJ . “Nominal” electron bunches for lasing were produced by RF gun with Cs 2 Te photocathode driven by UV quantum laser system. “Parasitic” bunches with a charge up to 1– 1.5 nC were extracted from the RF gun due to VUV FEL radiation reflected from the mirror (placed downstream of the undulator) to the cathode. Nontrivial dependence of a charge on a SASE pulse energy was found