Extraction at 5.5 kA

Extraction at 5.5 kA

slowed down 10 times

Original sound

Magnet is a good mechanical resonator with Q~100!

When current is extracted from the magnet, sounds are recorded (step-like change of elastic strain?), followed by a prolonged (0.5-1 s) ringing of the structure at its resonance modes, with occasional bursts of mechanical activity (thermal relaxation?)

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M. Marchevsky --- WAMSDO, CERN 2013

Frequency of the sounds

Very high frequency sound is detected at Imag>10 kA

10248 A

(Sound slowed down 10x)

#

M. Marchevsky --- WAMSDO, CERN 2013

Sound from the Quench Antennas

HQ01d magnet, ramping at 100 A/s

Flux jumps

Mechanical vibrations

M. Marchevsky et al., ASC 2012 presentation

Inductive quench antenna is an electromagnetic microphone! It picks up vibrations of the current-carrying (or magnetized) structures

By correlating EM QA and piezo-sensor signals, one can potentially differentiate between flux jumps, conductor motion and other mechanical motion in magnets

#

M. Marchevsky --- WAMSDO, CERN 2013

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