Personnel: Researchers and Technologists: 35; Technicians: 21; Other technical and scientific personnel: 12; Graduate students and scholarships holders: 12; Administrative personnel: 1.5

The Electromagnetism Division is responsible for the standards of electric and magnetic quantities. The research activities pursued in its laboratories are devoted to measurement standards and techniques, the electromagnetic properties of materials including nano-technology, and the fabrication of quantum devices for metrology. Measurement techniques cover a range spanning from DC to millimetre waves.

The Division is organized into eight research programs, namely:

• Quantum devices and voltage standard
• Resistance and impedance metrology
• AC voltage, current and power metrology at low and high frequencies
• Mathematical modelling and applications to materials and devices
• Electromagnetic fields and power systems
• Nanostructures and nanodevices
• Magnetic materials and measurements
• Physics of magnetic systems

The graphs below provide a few data concerning personnel, areas of activity, and related products in the year 2008.

Work on measurement standards was pursued in 2008 both to improve existing standards and to establish new ones. With a view to the realization of an AC voltage standard with quantum accuracy, programmable Josephson arrays of 1600 junctions were built and characterized in DC. In the search for new radiation sensors, transition edge sensors (TES) of type Ti/Pd/Ti were built, achieving good stability and high transition steepness. A prototype of a room temperature thermometer based on the measurement of Johnson noise in resistors was set up and found in agreement with the thermodynamic temperature scale within 1·10^-4. A demonstrator of a pendulum system for the measurement of the Planck constant by means of electric and cinematic measurements was built. A thermal converter for voltage measurements up to 1 GHz was developed. The measurement capability of electric fields was extended from 2 kHz to 100 kHz and that of electromagnetic fields was extended from 1 GHz to 4 GHz. A programmable calibrator for partial discharge measurement systems and a setup for the calibration of electrostatic discharge generators were also built.

Work on modelling was addressed to the evaluation of magnetization processes in nanometric systems starting from the numerical integration of the Landau-Lifshitz equation. Homogenization methods were also developed to obtain the effective magnetic properties of non linear composite materials. In the framework of the development of innovative actuators, a new setup for the dynamic characterization of magnetostrictive materials was built.

The nanotecnology laboratory produced and characterized a first Single Electron Transistor (SET) of hybrid type (Cu/AlOx/Cu), with the long term aim of producing a quantum standard of current. Quantum dots of SiC emitting in the ultraviolet range were also produced. Within the effort to realize quantum Hall effect devices of a new type, an optical technique to detect graphite monolayers (graphene) was devised and graphene optical constants in the visible spectrum were determined.

In the study of the magnetic properties of materials, several characterization methods were developed: a calorimetric-fieldmetric method for the measurement of power losses, a Peltier-cell method for the measurement of isothermal magnetocaloric entropy change, microwave and high speed magneto-optical measurements. Permeability and loss properties in soft magnetic tapes and ferrites were determined between DC and 1 GHz, giving their theoretical interpretation. Progress was made in the interpretation of spin-torque phenomena by measuring dot and anti-dot system domain structure and by applying the generalized Landau-Lifshitz equation.

In 2008 the Division was involved in several new research cooperation projects. Of these six were Joint Research Projects (JRP) of the iMERA Plus program on Metrology sponsored by EURAMET, concerning: Power and Energy standards, Nanomagnetism and Spintronics, Quantum Voltage Systems, Ultimate Quantum Hall Effect Devices, Measurements of Field Strength and Specific Absorption Rate, Traceable measurements for biospecies and ion activity in clinical chemistry. At European level the FP7 project "Solid State Energy Efficient Cooling" aimed at the exploitation of the magnetocaloric effect for room temperature refrigeration was also started. Other new research projects at national and local region level concerned: mitigation of MRI magnetic fields, shielding of energy transport systems, development of sensors and techniques for monitoring environment and for the agricultural and food sector.

Important equipment improvements were made possible in 2008. The most relevant concerns the establishment at INRIM of a new nanofabrication laboratory for which a Dual Beam Scanning Electron Microscope, a Field Emission Gun Scanning Electron Microscope and an X ray diffractometer were purchased.

To comply with INRIM's role as National Metrology Institute, the Division reproduces the electric and magnetic units of measurement and maintains the respective standards. Traceability to the SI is based on voltage and resistance units, referred to natural constants by means of Josephson and quantum Hall effects, and it is transferred to impedances, AC voltage and current, electric power at low and high frequency, electric and magnetic fields, magnetic flux and magnetic induction. Within the participation in the Mutual Recognition Arrangement (MRA) of the CIPM, at the end of 2008 the Division had 207 calibration and measurement capabilities (CMC) internationally agreed and published in the BIPM Key Comparison Data Base.

The Division also participates in the MRA measurement comparison program: in 2008 measurements were carried out for the comparisons of electric field intensity above 1 GHz and of sea water salinity. Also two comparisons sponsored by the International Electrotechnical Commission (IEC) and concerning hysteresis parameters of permanent magnets were carried out.

International cooperation is of the utmost importance in metrological work. The Division participates in the activities of the Consultative Committee of Electricity and Magnetism (CCEM) and of the EURAMET Technical Committee on Electricity and Magnetism.

To disseminate the SI units to the users, mainly secondary accredited calibration laboratories, in 2008 the Division delivered 614 calibration certificates, 58 measurement certificates and 22 test reports. Most certificates concern some of the Division 207 CMCs, and are internationally recognised. Support to the INRIM accreditation service was also given, particularly by organizing interlaboratory comparisons in the fields of voltage and resistance.

In 2008 the Division worked on seven contracts with industry, among them one concerning the exposure of workers to electric and magnetic fields.

Knowledge is mainly transferred by publication of scientific papers (69 in 2008, indexed by the ISI-Thomson Web of Science), participation in conferences, and organization of doctorate courses. Twelve invited presentations were delivered at International Conferences. Two patents were also developed, one regarding the contactless measurement of temperature in turbo-molecular pumps, the other concerning shielding pipes for electrical energy transmission lines.

Cooperation in research with foreign metrology Institutes, international and national universities and participation in scientific and standardisation organisations are also carefully pursued.