The normal zone propagation in ATLAS B00 model coil

Self Cite

Abstract-Three pairs of 20.5 kA current leads for the ATLAS Toroid Magnets have been designed, manufactured and tested at Kurchatov Institute. The current leads have a high mechanical reliability and the vacuum tightness under 30 bars of internal pressure. The insulation between the current carrying parts and the mounting flange, the hydraulic connections and the temperature gauges withstand the overvoltage of at least 2 kV. The current leads are fully equipped with diagnostics needed for safety and control. The current leads were tested up to 24 kA. According to CERN's specification they were also tested in the absence of any cooling at very slow current discharge rate (5 A/s) from 20.5 kA to zero without any excessive overheating. Nowadays the current leads are successfully used at the ATLAS Magnet Test Facility at CERN.

Section: Test Procedures and Resultsmentioning

confidence: 99%

20.5 kA current leads for ATLAS Barrel Toroid superconducting magnets

Dudarev

Kate

Boxman

et al. 2002

Self Cite

“…While for the coil safety this is important at relatively high current, other considerations make a rapid transition over the whole coil desirable also at low currents. Preliminary studies of the quench propagation velocities on a small scale coil, made of B0 conductor had previously been performed [9], [10]. B0 presented a unique opportunity to verify the predictions.…”

Section: E Quench Propagationmentioning

confidence: 99%

Review of the ATLAS B0 Model Coil Test Program

Dolgetta

Miele²,

Acerbi³

et al. 2004

The ATLAS B0 model coil has been extensively tested, reproducing the operational conditions of the final ATLAS Barrel Toroid coils [1]. Two test campaigns have taken place on B0, at the CERN facility where the individual BT coils are about to be tested. The first campaign aimed to test the cool-down, warm-up phases and to commission the coil up to its nominal current of 20.5 kA, reproducing Lorentz forces similar to the ones on the BT coil. The second campaign aimed to evaluate the margins above the nominal conditions. The B0 was tested up to 24 kA and specific tests were performed to assess: the coil temperature margin with respect to the design value, the performance of the double pancake internal joints, static and dynamic heat loads, behavior of the coil under quench conditions. The paper reviews the overall test program with emphasis on second campaign results not covered before.

“…With the account of the dissipation in the filaments, the formulae in the two-medium approximation are at at (8a) at at (8b) while in the single medium approximation are at at (9) Naturally, at , (8) and (9) transform into (6) and (7). The two approximations (8) and (9), or (6) and (7), need to be merged into a single joint dependence representing the heat generation for all .…”

Section: B Linear Current Expulsionmentioning

confidence: 99%

“…This was done to avoid negative , which would otherwise dominate the joint dependence at . Next, in the single-medium phase, the growth of the diffusion perimeter in the stabilizer was reflected in (6) [or (9)] by , where is the number of embedded cable corners. And finally, the obtained functions and were joined using a weight factor , so that .…”

Section: B Linear Current Expulsionmentioning

confidence: 99%

Normal zone propagation model for monolith conductors with current diffusion

Lvovsky¹

2003

A model is presented which allows to analyze normal zone propagation in monolith conductors with the account of current diffusion, conductor's nonlinear properties and current sharing. Analytical description of the current diffusion heat generation is given. It is used in a 1st order ordinary differential equation (ODE) to determine the normal zone longitudinal velocity and temperature profile. The method is illustrated on the examples of conductors with copper and aluminum stabilizers. It also allows to account for the heat transferred into the insulation, which can notably reduce .Index Terms-Current diffusion, monolith conductor, normal zone propagation, Rutherford cable.