1. CCEM Comité Consultatif d’ Électricité et Magnétisme Report of the President to the 22 nd CGPM Ernst O. Göbel PTB Braunschweig and Berlin, Germany

2. CCEM Structure of the CCEM E. O. Göbel, PTB, President T. J. Witt, BIPM, Executive Secretary 22 members + director of the BIPM, 4 observers Four working groups: Working Group on Electrical Methods to Monitor the Stability of the Kilogram / Chairman: I. Robinson, NPL Working Group on AC Measurements of the Quantized Hall Resistance Chairman: E. Braun, PTB (until Sept. 2002); J. Melcher, PTB (since Sept. 2002) Working Group on Key Comparisons (until Sept. 2002); Working Group on Low Frequencey Quantities (since Sept. 2002) Chairman: H. Bachmair, PTB Working Group on Radiofrequency Quantities Chairman: L. Erard, BNM (until Sept. 2002), J. P. Randa, NIST (since Sept. 2002)

3. CCEM Meetings: CCEMSept. 2000, BIPM Sept. 2002, BIPM WG: Key ComparisonsSept. 2000, BIPM now: WG: Low Frequency June 2001, BIPM QuantitiesSept. 2002, BIPM WG: Radiofrequency QuantitiesSept. 2000, BIPM June 2001, BIPM Sept. 2002, BIPM WG: Monitoring the StabilityMay 2000, Sydney of the KilogramJune 2002, Ottawa July 2003, Paris WG: AC Measurements of the QHEMay 2000, Sidney Sept. 2000, BIPM June 2002, Ottawa Sept. 2002, BIPM

4. CCEM STATUS OF LEAST-SQUARES ADJUSTMENT OF FUNDAMENTAL CONSTANTS

5. CCEM Fundamental Constants:

6. CCEM K J-90 and R K-90 remain comfortably coherent with the most recent (1998) CODATA values (however the 2002 K J value might differ slightly when the new value for the Avogadro constant is included) The relative standard uncertainty assigned to R K has been reduced by a factor of 2 to 1 x 10 -7 (CIPM approved in 2000); i.e. the representation of the Ohm using the QHE and R K-90 agrees with the SI-Ohm within 1x10 -7 with a reproducibility which is much better (~10 -9 ) K J-90 ; R K-90

7. QHE - Key Comparisons CCEM

8. Revised Technical Guidelines for Reliable Measurements of the Quantized Hall Resistance F. Delahaye, BIPM, and B. Jeckelmann, METAS Metrologia, to be published www.bipm.org

9. CCEM ELECTRICAL METHODS TO MONITOR THE STABILITY OF THE INTERNATIONAL PROTOTYPE OF THE KILOGRAM Required for Monitoring the Stability of the Kilogram:  < 10 -8 !

10. CCEM NPL in operation after considerable reconstruction. Target uncertainty < 3 parts in 10 8 in 2004 NIST in test operation after complete reconstruction. Operation in vacuum, electromagnetically shielded environment, new support system, incorporation of programmable Josephson system. Daily runs show typical standard deviation of about 0.06  W/W. Target uncertainty  1 in 10 8 Watt balance (Planck constant)

11. METAS in test operation (100 g mass); different construction; A new magnet will be mounted by the end of 2003. BNM design phase completed; under construction. BIPMdesign phase. CCEM Watt balance (contd.)

12. Mass levitation (flux quantum) NMIJ/AIST:achieved relative uncertainty: 1x10 -6, basic studies (precision trajectory measurement, trapped magnetic flux etc.) VNIIM/ MIKES:Nb films on monocrystalline sapphire films; superconducting levitation frame weighing 100 g CCEM

13. Avogadro co-operation CCEM Determination of the Avogadro constant using Silicon Single Crystals BIPM PTB IMGC NMIJ CSIRO NIST NPL IRMM Achieved rel. uncertainty: 1.7 x 10 -7, however:

14. CCEM N A = 6.022 135 53 (103) x 10 23 /mol Comparison of the Avogadro constant

15. SET: Single Electron Tunneling Devices for Metrological Applications current capacitance temperature photons on demand CCEM

16. COUNT Counting Electrons One by One: Measurement of Very Small Electrical Currents 2000 - 2001 - 2002 A research project supported by the European Commission under Framework Programme 5 (Contract No. G6RD-CT 1999-00046) CCEM

17. COUNT Instrumentation for precise generation of small currents based on SET pumps; Aim: 1x10 -6 for current of a few pA Instrumentation for measurement of small currents based on SET counter; Aim: 1x10 -5 for a current of a few pA Achieved: 3.2 pA with  = 4x 10 -6 (type A) CCEM

18. Capacitance standard, based on the quantization of electrical charge Example with numbers: C = 1 pF, N = 10 8  U  16 V Relevant for metrology if the relative uncertainty becomes better than 10 -7 ! N C U „Measuring the electron´s charge and the fine-structure constant by counting the electrons on a capacitor“, Williams et al., J. Res. Nat. Inst. Stand. Technol. 97, 299 (1992) Capacitance Standard NIST (1992) CCEM

19. NIST 1996:This experiment is feasible with a relative uncertainty of 10 - 8 NIST 1999: First measurement of a cryo-cap´s capacitance by using the SET method „A capacitance standard based on counting electrons“, M. W. Keller et al., Science 285, 1706 (1999) NIST 2003:Reproducibility (  )  = 1  10 -7 Total uncertainty (C)  1  10 -6 C cryo-cap  10 pF compared to a calc. capacitor 7 junction SET pump (error rate  10 -8 ) SET electrometer (null detector; sensitivity 10 -3 · e) CCEM Capacitance Standard (contd.)

20. CCEM A)Si based SETTs (NIST) smaller charge offset; parallel integration B) Single Cooper Pair Tunneling (SCPT) Devices (NIST, PTB) C)Single Electron Transport by Surface Acoustic Waves (SETSAW) (NPL, Univ. Cambridge, PTB) B) and C): higher operation frequency Alternatives:

21. CCEM AC Measurement of the QHE BIPM, NRC, METAS, PTB, NML, IEN, NIST Specially designed samples and multiple series connection   1 x 10 -7

22. CCEM

23. 1V Programmable Standard NIST Programmable from +1.1 V to -1.1 V 1  s settling time Output Step Height = 2 to 4 mA

24. CCEM JAWS homepage www.jaws-project.nl Participants Josephson Arbitrary Waveform Synthesizer (JAWS) (supported by the EC)

25. JAWS CCEM AC voltage standard for arbitrary waves based on Josephson Arbitrary Waveform Synthesiser Objectives:f = 1 Hz - 10 kHz U 0 = 10 mV  < 10 -4

26. CCEM 102 CIPM and RMO Key Comparisons (total 516) recorded in KCDB 17 completed (total 103) 9094 CMC entries (total 15830) CCEM Key Comparison and Calibration and Measurement Capabilities

27. CCEM indeed is very active! Thanks for your attention!