Modifications to the SPS LSS6 Septa for LHC and the SPS Septa Diluters

The Large Hadron Collider required the modification of the existing extraction channel in the long straight section (LSS) 6 of the CERN Super Proton Synchrotron (SPS), including the suppression of the electrostatic wire septa. The newly set up fast extraction will be used to transfer protons at 450 GeV/c as well as ions via the 2.9 km long transfer line TI 2 to Ring 1 of the LHC. The girder of the existing SPS DC septa was modified to accommodate a new septum protection element. Changes were also applied to the septum diluter in the fast extraction channel in LSS4, leading to the other LHC ring and the CNGS facility. The requirements and the layout of the new LSS6 extraction channel will be described including a discussion of the design and performance of the installed septum diluters

Septa and Distributor Developments for H- Injection into the Booster from LINAC4

The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum-like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented

Development of an Eddy Current Septum for LINAC4

A linear accelerator (linac) is the first stage of the CERN accelerator complex. The linac defines the beam quality for subsequent stages of acceleration and the reliability has to be high as a fault of the linac shuts down all other machines. The existing linacs at CERN were designed 30 or more years ago: recent upgrades allowed the linacs to reach LHC requirements but also showed that they are at the limit of their brightness and intensity capabilities. A replacement Superconducting Proton Linac (SPL) has been proposed; the initial part of the SPL is termed LINAC4. The LINAC4 injection bump would be made up of a set of four pulsed dipole magnets; the first of these magnets (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which injected $H^{-}$ beam must pass. The initial specifications for BS1 required; a deflection of 66 mrad at 160 MeV, achieved with a peak field of 628 mT and a length of 250 mm: the field fall time was $40 \mu$s with a flattop of at least $100 \mu$s. The ripple of the flattop should be below ±1%. This paper discusses the design of an eddy current septum for BS1

Automatic high voltage conditioning of the electrostatic LEP separators without conventional programming

The TS Tool Kit is a generic, fully data-driven, and user-configurable software system developed at CERN for supervisory, control, and data acquisition applications. It provides a comprehensive framework to solve fairly complex process control problems requiring response times of the order of a second, without any need for conventional programming. The characteristics and benefits of this approach are discussed at the example of the new high voltage conditioning process for the electrostatic LEP separators

Synchrotron Radiation Effects at LEP

With the increase of the LEP beam energy, synchrotron radiation effects become ever more important. Around the experiments, masks have been successfully used to absorb the higher rates, and photon bac kgrounds have not been a problem. Elsewhere around the ring, however, the increased radiated power has adversely affected various accelerator components; sections of the vacuum chamber, electronics, c ables and beam instrumentation equipment have all suffered. Furthermore, the use of wiggler magnets to control the bunch size has given rise to local problems on nearby separator equipment. These effe cts will be presented, together with the steps taken to avoid further difficulties at the higher energies and higher beam currents foreseen in future

Modification of the LEP electrostatic separator systems for operation with bunch trains

To meet the LEP2 luminosity requirements for W-pair production, it is planned to operate LEP with Bunch Trains from 1995 onwards. This new mode of operation entails significant modification both to the existing separator hardware and its control system. The changes have been implemented so as to provide maximum flexibility for the realisation of the Bunch Train scheme, and also make a return to operation with Pretzel separation possible during 1995. Two LEP Interaction Points (IP) were equipped with new separators in late 1994, enabling first tests with the collision of one train of four e+ bunches with one train of e- bunches. During the 1994/95 shutdown, four separators have been installed in the two remaining experimental IPs, and eight separators in the non-experimental IP have been displaced to new positions. Details are given of optics requirements for the separator installations, the polarity of the closed orbit separator bumps, system modifications, and performance considerations. Results are presented of investigations into the effects of separator polarity on High Voltage performance and on the commissioning of the new hardware systems during tests of the Bunch Train scheme in 1994

On the reservation or rescission of the system of re-education through labor

劳动教养制度，是我国社会主义革命和建设中的一大创举，是一项具有中国特色的社会主义法律制度。然而在依法治国的战略推进中，劳教制度的历史局限性及其造成的弊端非常明显，在国际国内经常成为人们诟病的话题。尽管50多年来，尤其是改革开放以来，劳动教养制度对惩治和预防违法犯罪、维护社会政治稳定和治安稳定，保障改革开放和经济建设的顺利进行发挥了重要作用，但至今为止没有一部法律作为其存在的支撑和显而易见的违反法律程序的事实，使得这项制度经常有存、废、改的争论，不得不面对几乎走到尽头的困境。本文通过介绍劳动教养制度的概念、性质，并对我国现行劳动教养制度进行总结与反思，分析其所显示出来的弊端，在此基础上提出重构我...The system of re-education through labor was a big creation during our socialist revolution and construction and is a China-characteristic socialist legal system. However, in the advance of the strategy of “ruled by law”, the historic limits and the defects of the System became more and more obvious, and aroused quite a lot of criticisms both home and abroad. In the past 50 more years, especially ...学位：法律硕士院系专业：法学院法律系_法律硕士(JM)学号：X200512013

Technical Challenges for the Head-on Collisions and Extraction at the ILC

An interaction region with head-on collisions is considered as an alternative to the baseline ILC configuration. Progress in the final focus optics design includes engineered large bore superconducting final doublet magnets and their 3D magnetic integration in the detector solenoids. Progress on the beam separation optics is based on technical designs of electrostatic separator and special extraction quadrupoles. The spent beam extraction is realized by a staged collimation scheme relying on realistic collimators

Analysis of the performance of the SPS extraction channel equipment in 1997

In 1997 the SPS ran with high proton intensities (peak above 4.8x1013 protons per pulse) at 450 GeV/c, essential for the neutrino physics program. The SPS also provided lepton beams at 22 GeV for injection into LEP. The equipment used to extract the proton beams is generally very sensitive to the set-up and state of both the SPS machine and the hardware itself; this note contains an analysis of the performance of this extraction equipment in 1997. We describe the modifications to the hardware installations made during the 1996-1997 shutdown, the problems encountered in operation in 1997, the measurements and investigations undertaken, and the conclusions reached. Recommendations are made concerning changes to the hardware installations and operation