Thesis Introduction Study for a failsafe trigger generation

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Thesis: Introduction Study for a failsafe trigger generation system for the Large Hadron Collider

Thesis: Introduction Study for a failsafe trigger generation system for the Large Hadron Collider beam dump kicker magnets prepared by Martin Rampl

CERN - The European Laboratory for Particle Physics u u u Provides the world-leading

CERN - The European Laboratory for Particle Physics u u u Provides the world-leading facilities for particle physics (funded by 19 European countries) Particles are accelerated and collided within huge detectors Aim: Investigation of the deepest layers of matter

LHC - The Large Hadron Collider u u u 27 km-proton accelerator with two

LHC - The Large Hadron Collider u u u 27 km-proton accelerator with two counter-rotating beams (completion 2005) Superconducting magnets steer and accelerate the particles up to 7 Te. V Collisions occur within huge particle detectors

General design of the LHC beam dump (beam absorber) Kicker magnets ~1900 m Kicker

General design of the LHC beam dump (beam absorber) Kicker magnets ~1900 m Kicker magnets u u Stored Beam Energy per Ring ~334 MJ (equivalent to 150 kg of TNT) Gap of ~3 µs is left in the 89 µs (=time for 27 km) beam cycle for the dumping action

Tasks of the Trigger Generator Synchronises the rise of the magnetic field of the

Tasks of the Trigger Generator Synchronises the rise of the magnetic field of the kicker magnet with the beam gap Continues operation if the beam revolution frequency signal is failing

Critical part 1: Internal Oscillator (digital Phase-Locked loop) u u Measures continuously the beam

Critical part 1: Internal Oscillator (digital Phase-Locked loop) u u Measures continuously the beam revolution frequency Continues generation of the SYNCHR. PULSE TRAIN signal even if BEAM GAP SYNCHR. is failing

Numerical Controlled Oscillator: Digital Phase Accumulator u u Programmed value is added with every

Numerical Controlled Oscillator: Digital Phase Accumulator u u Programmed value is added with every clock cycle Overflow of the adder = Output frequency signal High resolution (f=100 MHz, N=32 bit Res. =23 m. Hz) Stability depends only on quartz oscillator

Internal Oscillator: Advantages-Disadvantages J Accuracy only dependent on the short-term J J J stability

Internal Oscillator: Advantages-Disadvantages J Accuracy only dependent on the short-term J J J stability of the high-frequency quartz oscillator stable (no temperature drifts, . . ) Reliable Simplementation into programmable logic chip Easy to adapt to new requirements L Design requires a state-of-the-art chip

Critical part 2: Output Switch OSCILLATOR and DUMP REQUEST = TRIGGER OUT

Critical part 2: Output Switch OSCILLATOR and DUMP REQUEST = TRIGGER OUT

Implementation block diagram of the Trigger Generator

Implementation block diagram of the Trigger Generator

Conclusion u Digital realisation provides perfect accuracy and stability u Implementation into Programmable logic

Conclusion u Digital realisation provides perfect accuracy and stability u Implementation into Programmable logic chip maintains high reliability u But: Redundant and failsafe systems necessary in every case

Future aspects u Prototype will be built until end of July 1999 u Final

Future aspects u Prototype will be built until end of July 1999 u Final installation will be in 2004 progress in electronics u Changes in the requirements will influence design of the Trigger Generator