One of the most critical elements for the protection of CERN's Large Hadron Collider (LHC) is its beam loss monitoring (BLM) system. It must prevent the superconducting magnets from quenching and protect the machine components from damages, as a result of critical beam losses. By measuring the loss pattern, the BLM system helps to identify the loss mechanism. Special monitors will be used for the setup and control of the collimators. The specification for the BLM system includes a very high reliability (tolerable failure rate of 10 -7 per hour) and a high dynamic range of 10 8 (10 13 at certain locations) of the particle fluencies to be measured. In addition, a wide range of integration times (40 μs to 84 s) and a fast (one turn) trigger generation for the dump signal are required. This paper describes the complete design of the BLM system, including the monitor types (ionization chambers and secondary emission monitors), the design of the analogue and digital readout electronics as well as the data links and the trigger decision logic. Beam Loss Monitoring System for the LHC Eva Barbara Holzer, Bernd Dehning, Ewald Effinger, Jonathan Emery, Gianfranco Ferioli, Jose Luis Gonzalez, Edda Gschwendtner, Gianluca Guaglio
An unprecedented amount of energy will be stored in the circulating beams of LHC. The loss of even a very small fraction of a beam may induce a quench in the superconducting magnets or cause physical damage to machine components. A fast (one turn) loss of 3 · 10 -9 and a constant loss of 3 · 10 -12 times the nominal beam intensity can quench a dipole magnet. A fast loss of 3 · 10 -6 times nominal beam intensity can damage a magnet. The stored energy in the LHC beam is a factor of 200 (or more) higher than in existing hadron machines with superconducting magnets (HERA, TEVATRON, RHIC), while the quench levels of the LHC magnets are a factor of about 5 to 20 lower than the quench levels of these machines. To comply with these requirements the detectors, ionisation chambers and secondary emission monitors are designed very reliable with a large operational range. Several stages of the acquisition chain are doubled and frequent functionality tests are automatically executed. The failure probabilities of single components were identified and optimised. First measurements show the large dynamic range of the system. Large Hadron Collider Project AbstractAn unprecedented amount of energy will be stored in the circulating beams of LHC. The loss of even a very small fraction of a beam may induce a quench in the superconducting magnets or cause physical damage to machine components. A fast (one turn) loss of 3 · 10 −9 and a constant loss of 3 · 10 −12 times the nominal beam intensity can quench a dipole magnet. A fast loss of 3 · 10
A wide range current digitizer card is needed for the acquisition module of the beam loss monitoring systems in the CERN Injector Complex. The fully differential frequency converter allows measuring positive and negative input currents with a resolution of 31 nA in an integration window of 2 µs. Increasing the integration window, the dynamic range covers 210 10 were the upper part of the range is converted by measuring directly the voltage drop on a resistor. The key elements of this design are the fully differential integrator and the switches operated by an FPGA. The circuit is designed to avoid any dead time in the acquisition and reliability and failsafe operational considerations are main design goals. The circuit will be discussed in detail and lab and field measurements will be shown.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.