Performance of a fast digital integrator in on-field magnetic measurements for particle accelerators.

The fast digital integrator has been conceived to face most demanding magnet test requirements with a resolution of 10 ppm, a signal-to-noise ratio of 105 dB at 20 kHz, a time resolution of 50 ns, an offset of 10 ppm, and on-line processing. In this paper, the on-field achievements of the fast digital integrator are assessed by a specific measurement campaign at the European Organization for Nuclear Research (CERN). At first, the architecture and the metrological specifications of the instrument are reported. Then, the recent on-field achievements of (i) ±10 ppm of uncertainty in the measurement of the main field for superconducting magnets characterization, (ii) ±0.02 % of field uncertainty in quality assessment of small-aperture permanent magnets, and (iii) ±0.15 % of drift, in an excitation current measurement of 600 s under cryogenic conditions, are presented and discussed.

[1]  C. Schott,et al.  High accuracy magnetic field measurements with a Hall probe , 1999 .

[2]  Pasquale Arpaia,et al.  Digital Integrator for Fast Accurate Measurement of Magnetic Flux by Rotating Coils , 2007, IEEE Transactions on Instrumentation and Measurement.

[3]  K. Kawahata,et al.  A rotating coil probe for the magnetic field measurement on a long pulsed tokamak , 1999 .

[4]  A Godeke,et al.  A superconducting transformer system for high current cable testing. , 2010, The Review of scientific instruments.

[5]  P. Skyba,et al.  Precision analog integrator with voltage hold. , 2007, The Review of scientific instruments.

[6]  L. Bottura.  Field dynamics in superconducting magnets for particle accelerators , 1998 .

[7]  Ieee Nuclear.  The Proceedings of the 19th IEEE/NPSS Symposium on Fusion Engineering : 19th SOFE : January 22-25, 2002, Atlantic City, New Jersey , 2002 .

[8]  B N Wan,et al.  A new low drift integrator system for the Experiment Advanced Superconductor Tokamak. , 2009, The Review of scientific instruments.

[9]  L. Bottura,et al.  A fast sextupole probe for snapback measurement in the LHC dipoles , 2000, IEEE Transactions on Applied Superconductivity.

[10]  S. Sanfilippo,et al.  Field decay and snapback measurements using a fast Hall plate detector , 2002 .

[11]  Seong-Heon Seo,et al.  Development of a digital integrator for the KSTAR device. , 2010, The Review of scientific instruments.

[12]  L. Walckiers,et al.  Estimation of Mechanical Vibrations of the LHC Fast Magnetic Measurement System , 2008, IEEE Transactions on Applied Superconductivity.

[13]  L. Walckiers,et al.  Twin rotating coils for cold magnetic measurements of 15 m long LHC dipoles , 2000, IEEE Transactions on Applied Superconductivity.

[14]  Pasquale Arpaia,et al.  submitter : Performance simulation of a digital integrator for magnetic measurements at CERN , 2008 .

[15]  Maury Tigner,et al.  Handbook of Accelerator Physics and Engineering (2nd Edition) , 2013 .

[16]  L. Walckiers,et al.  Magnetic measurement with coils and wires , 2011, 1104.3784.

[17]  P Galbraith.  Portable Digital Integrator , 1993 .

[18]  P. Arpaia,et al.  Active compensation of field errors within ±2 ppm in superconducting magnets , 2011 .

[19]  R. H. Carcagno,et al.  A Fast Continuous Magnetic Field Measurement System Based on Digital Signal Processors , 2006, IEEE Transactions on Applied Superconductivity.

[20]  Alexander Wu Chao,et al.  Handbook of Accelerator Physics and Engineering: (3rd Printing) , 1999 .

[21]  Arjan Verweij,et al.  Superconducting Transformer and Regulation Circuit for the CERN cable test facility , 2006 .

[22]  A. Verweij,et al.  Critical Current Measurements of the Main LHC Superconducting Cables , 2007, IEEE Transactions on Applied Superconductivity.

[23]  Animesh Jain.  Basic theory of magnets , 1997 .

[24]  Pasquale Arpaia,et al.  Performance Improvement of a DSP-Based Digital Integrator for Magnetic Measurements at CERN , 2009, IEEE Transactions on Instrumentation and Measurement.