Magnetic field Helmholtz

Measuring and Using Numbers Using the values for the current in Helmholtz coils (/) from Data Table 2, the value for k from Data Table 1, and the equation B = kl, calculate the values for magnetic field strength (B) and enter them in Data Table 3. Then calculate the square of the field strength (B2) and enter the values in Data Table 3. 

In order to focus on the driving force for phase transitions induced by a magnetic field it is advantageous to use the magnetic flux density as an intensive variable. This can be achieved through what is called a Legendre transform [12], A transformed Helmholtz energy is defined as... 

Thomson et al. reached the transform limit by incorporating two improvements.21 First, Helmholtz coils were placed around the interaction region to cancel the earth s magnetic field. Second, the time interval allowed for the collisions had previously been defined by the laser pulse and the field ionization... 

The difference between the magnetron and other vacuum tubes is that the electron flow passes along a spiral this route is created by an external magnetic field B (Fig. 3.4). The electron cloud produces resonance cavities several times in its trip to the anode. These cavities work as Helmholtz resonators and produce oscillations of fixed frequency, determined by the cavity dimensions small cavities produce higher frequencies, large cavities smaller frequencies. The antenna in the right zone collects the oscillations. 

The equipment to carry out this test consists of a pair of Helmholtz coils, which creates the non-uniform magnetic field, and a small, nonmagnetic sample holder, included between the coils and... 

One of the first things one notices about an EPR spectrum is that it is a first-derivative spectrum rather than the more typical absorption presentation. This is due to an instrumental artifact. To enhance the sensitivity of the EPR spectrometer, the magnetic field is modulated. To obtain field modulation, a small set of Helmholtz coils are place about the sample in line with the external field. These coils allow the amplitude of the external field, to change by a small amount ( 0.01 20G) at a frequency of 100 kHz (smaller frequencies can also be used, but are less sensitive). Because the spectrometer is tuned to only detect signals that change amplitude with field changes at... 

As described above, instability of the interface between the electrolyte and molten metal is a significant problem that is one root cause of the energy inefficiency of Hall cells. Expressed simply, the interface is deformed by the electromagnetic body forces arising from the interaction between currents in the cell and the magnetic field. The currents are themselves affected by the interface position because it determines the distance between the top surface of the aluminum and the bottom of the anode. There is therefore the possibility that interface deformation leads to further interface deformation. Other mechanisms for generating waves at the interface may be significant, for example, the Kelvin-Helmholtz... 

To calibrate and test the terahertz circular dichroism spectrometer, we successfully measured magnetic terahertz circular dichroism in a semiconductor. A Helmholtz coil was fabricated that produced an axial magnetic field, homogeneous in the transverse direction. A doped,... 

The magnetic-field gradients are provided by a Helmholtz coil wound on to the outside of an insulating glass Dewar flask. This Dewar flask is kept at a constant temperature by the flow of room-temperature air which is forced into the annular space between the outer wall of the Dewar flask and the glass support. As mentioned before, keeping the gradient coils at a constant (room) tempera-... 

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