Noninvasive 3D Field Mapping of Complex Static Electric Fields

Many upcoming experiments in antimatter research require low-energy antiproton beams. With a kinetic energy in the order of 100 keV, the standard magnetic components to control and focus the beams become less effective. Therefore, electrostatic components are being developed and installed in transfer lines and storage rings. However, there is no equipment available to precisely map and check the electric field generated by these elements. Instead, one has to trust in simulations and, therefore, depend on tight fabrication tolerances. Here we present, for the first time, a noninvasive way to experimentally probe the electrostatic field in a 3D volume with a microsensor. Using the example of an electrostatic quadrupole focusing component, we find excellent agreement between a simulated and real field. Furthermore, it is shown that the spatial resolution of the probe is limited by the electric field curvature which is almost zero for the quadrupole. With a sensor resolution of 61V/m/√Hz, the field deviation due to a noncompliance with the tolerances can be resolved. We anticipate that this compact and practical field strength probe will be relevant also for other scientific and technological disciplines such as atmospheric electricity or safeguarding near power infrastructure

Micromagnetic study of the impact of grain boundaries on coercivity

<p>The crystal structure, ferromagnetic properties, and thickness of grain boundaries separating the grains of a Nd2Fe14B-type permanent magnet significantly influence the figures of merit such as coercivity, remanence or the energy density product BHmax. Grain boundaries act as anisotropy defects. We use micromagnetic simulations to quantify the influence of those on coercivity/knee field.</p&gt

Borosilicate Glass MEMS Lorentz Force Magnetometer

This paper reports on a novel, miniaturized magnetomechanical transducer/sensor made of borosilicate glass with wide dynamic range. The prototype is manufactured with laser micromachining and ablation techniques. Compared to state of the art, borosilicate glass substrate offers the highest thermal shock resistance and is best suited for MEMS magnetometers, for aerospace and space applications or magnetic monitoring systems for diagnostics and plasma stability control of nuclear fusion experiments, where thermal shock resistance is a critical requirement

Equivalent Circuit Model of an Optomechanical MEMS Electric Field Strength Sensor

We present a simple equivalent circuit model for the transfer function of an optomechanical MEMS transducer capable of distortion-free electric field strength measurements. This model allows not only to qualitatively understand the characteristics of the transducer but also takes into account parasitic effects and material properties. Such parasitic effects have been observed while evaluating the first results of electric field measurements performed with the sensor. The model helped to identify and diminish these parasitic effects

Towards distributed enthalpy measurement in large-scale air conditioning systems

9th Annual IEEE International Systems Conference (SysCon), 13-16 April 2015 Vancouver, BCAir conditioning systems are among the major energy consumers in buildings. Energy-efficient operation of AC systems is an important step towards better energy management in building automation, but requires efficient monitoring of the energy or enthalpy flows within the AC installation, which is currently still difficult because of the lack of appropriate equipment. This paper introduces a distributed data acquisition system for large-scale AC systems based on low-cost flow sensors implemented by means of standard printed circuit board technology and interconnected via a wireless sensor network. A critical issue for the system installation is the placement of the sensors in the air ducts to obtain representative measurements of the air flow. To this end, extensive aerodynamical simulations are carried out to analyze the flow distributions in typical building blocks for air ducts, particularly with respect to turbulences. The simulation results are compared with experimental data from the literature and are shown to be reliable.Energie-UmweltmanagementForschung Burgenlan

3D-Printed MEMS Magnetometer Featuring Compliant Mechanism

This paper reports a novel 3D-printed MEMS resonant magnetometer with optical readout which features a mechanical conversion of a vertical oscillation into a horizontal one. This demonstrates the advantages of 3D-printing technology in terms of rapid prototyping, low costs and fast product development cycles. In addition, 3D-printing enables ‘true’ three-dimensional MEMS structures in contrast to the traditional MEMS technology which allows only two dimensional structures. The measurement approach comprises a hybrid implementation of an optical modulator, an LED and a photodetector

MEMS μ-wire magnetic field detection method@CERN

This work reports a novel construction of a micromachined MEMS magnetometer detecting static magnetic fields of CERN's reference dipole with a custom made capacitive read-out. The magnetic flux density is characterized via vibration modes of the MEMS structure which are sensed capacitively. The device consists of a single-crystal silicon clamped-free plate (cantilever) carrying a thin conductor. The cantilever and thin film metal electrodes are separated by a small gap, building a vibrating plate capacitor. Movements of the cantilever are read out conveniently by electronic circuits. A static magnetic field generates a force density acting on the conductor that alternates according to the frequency of the current. By knowing the electrical current, the deflection amplitude of the cantilever is a measure of the component of the magnetic flux density that points perpendicular to the current. The highest vibration amplitudes are expected, of course, in the vicinity of resonance frequencies of the micromachined structure. At ambient pressure the prototype sensor has a measured resonance frequency of 3.8 kHz for the fundamental mode and 20 kHz for the first antisymmetric mode. In experiments, the magnetic flux of the dipole has been characterized between 0.1 and 1 T, with a relative uncertainty of 3·10-4

Novel 3D-Printed MEMS Magnetometer with Optical Detection

This paper reports a novel 3D printed MEMS magnetometer with optical readout, which demonstrates the advantages of 3D printing technology in terms of rapid prototyping. Low-cost and fast product development cycles favour 3D printing as an effective tool. Sensitivity measurement with such devices indicate high accuracy and good structural performance, considering material and technological uncertainties. This paper is focusing on the novelty of the rapid, 3D-printing prototyping approach and verification of the working principle for printed MEMS magnetometers

Cross-Sensitivity of an Optomechanical MEMS Transducer

This work presents the investigation on a MEMS based optomechanical transducer for displacements or vibration regarding its cross-sensitivities to multidirectional input excitations. The principle of the optomechanical transducer is based on the modulation of the light flux passing through one static and one movable micromechanical aperture. This kind of transducer is of increasing interest for MEMS sensors since it has inherent benefits and can compete with state-ofthe- art readout concepts regarding its resolution. We have experimentally proven that the sensitivities of the device is 3.3 × 107 V/m in x-direction, 8.23 × 106 V/m in y-direction, while it is negligible in z-direction

MOEMS Based Single Chip Lorentz Force Magnetic Gradiometer

The functional principle of an optical gradient magnetic field sensor consisting of two independent laterally oscillating masses on a single chip is reported. These oscillations are caused by the Lorentz forces resulting from an alternating current through the masses interacting with a static magnetic field. Light is modulated by relative in-plane movement of the masses and a fixed frame and subsequently detected by two photodiodes. Evaluation of magnitude and phase of the output signal reveals information about the uniformity of the magnetic field. The sensor is capable of detecting uniaxially strength and direction of magnetic gradient fields, offset gradient fields and homogeneous fields