Beam Dynamics and Beam Losses - Circular Machines

A basic introduction to transverse and longitudinal beam dynamics as well as the most relevant beam loss mechanisms in circular machines will be presented in this lecture. This lecture is intended for physicists and engineers with little or no knowledge of this subject.Comment: 18 pages, contribution to the 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14 Nov 201

Beam Transfer and Machine Protection

Beam transfer, such as injection into or extraction from an accelerator, is one of the most critical moments in terms of machine protection in a high-intensity machine. Special equipment is used and machine protection aspects have to be taken into account in the design of the beam transfer concepts. A brief introduction of the principles of beam transfer and the equipment involved will be given in this lecture. The main concepts of machine protection for injection and extraction will be presented, with examples from the CERN SPS and LHC.Comment: 22 pages, contribution to the 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14 Nov 201

Identifying the Main Effects that Cause Spatial Variation in a Stereolithographic 3D-Printer with a Test Target and Graphical Analysis

This thesis investigates a stereolithography printers’ ability to resolve converging features within its build volume. This experiment employs the use of a Formlab Form 2 stereolithography device to create Geometric Element Test Target (GETT) artifacts designed in Solidworks. The sample will consist of a global arrangement of test artifacts in predetermined positions from a fractional factorial design of experiments. Each local sample will be a slanted ray GETT with designed wedge heights of 1 and 2mm. The finished array of samples are photographed and cataloged for graphical analysis. The ray step heights will be measured using a caliper and graphical analysis to observe any deviation from the digital file with respect to its volumetric arrangement. Similarly, the minimal producible width of the device will be calculated by measuring the wedge angle of the rays and the diameter of the region that cannot be produced by the printer, this will be done by using graphical analysis. The addressability of the device will be measured by counting the number of steps and dividing the measured heights by that number

Beam Stability and Optics Studies of the CNGS Transfer Line

Optics and stability of the CNGS transfer lines TT40 and TT41 were studied with beam trajectories during its commissioning in July and August 2006. Steering magnet response measurements were used to analyze the optics and the quality of the steering magnets and of the beam position monitors. A strength error of the main quadrupoles was identified with this technique and corrected during the commissioning. The dispersion was measured and found to be close to the nominal value. Finally the short and the long term stability of the transfer lines were studied. The transfer line was found to be very stable and the dominant source of short term position jitter is due to the ripple of the extraction septum and energy fluctuations in the SPS

Energy Deposition in Adjacent LHC Superconducting Magnets from Beam Loss at LHC Transfer Line Collimators

Injection intensities for the LHC are over an order of magnitude above the damage threshold. The collimation system in the two transfer lines is designed to dilute the beam sufficiently to avoid damage in case of accidental beam loss or mis-steered beam. To maximise the protection for the LHC most of the collimators are located in the last 300 m upstream of the injection point where the transfer lines approach the LHC machine. To study the issue of possible quenches following beam loss at the collimators part of the collimation section in one of the lines, TI 8, together with the adjacent part of the LHC has been modeled in FLUKA. The simulated energy deposition in the LHC for worst-case accidental losses and as well as for losses expected during a normal filling is presented

Commissioning of the Beam Interlock System for the TT40 and TT41 Transfer Lines of the SPS

The extraction area of LSS4 in the SPS and the TT40 and TT41 transfer lines have been equipped with a new interlock system to protect the machine elements against beam induced failure during operation with the high intensity CNGS beams. The system commissioning that was performed during the 2006 SPS run followed pre-defined commissioning procedures. An extensive WEB based documentation of the tests has been established to track the state of the interlock system, in particular of interlock references. This document presents a short summary of the commissioning as well as the complete documentation of the interlock tests

Management of Critical Machine Settings for Accelerators at CERN

In high energy and high intensity accelerators as the LHC, the energy stored in the beams is orders of magnitude above the damage level of accelerator components like magnets. Uncontrolled release of this energy can lead to serious damage of equipment and long machine downtimes. In order to cope with these potential risks Protection Systems were developed at CERN including two software systems: MCS (Management of Critical Settings) and RBAC (Role Based Access Control). RBAC provides an authentication and authorization facility for access to the critical parts of the control system. A second layer of security is provided by MCS which ensures that critical parameters are coherent within the software and hardware components and can only be changed by an authorized person. The MCS system is aimed at the most critical parameters in either potentially dangerous equipment or protection devices (e.g. Beam Loss Monitors). It is complementary to the RBAC infrastructure. Both systems are fully integrated in the control system for the LHC and SPS and were successfully commissioned already before first beam in the LHC. This paper will describe the MCS architecture, current status and its operational deployment in the LHC