Comparison Euromet.EM-K8 of DC Voltage Ratio: Results
Twenty National Metrology Institutes have participated in the European DC voltage ratio key comparison (EUROMET.EM-K8). The results for the voltage ratios 1000V/10V and 100V/10V are reported
A Simple Build-Up Method for the DC Voltage Scale of a Source
We report on the performance of a simple method, known as the reference step method, to build up the dc voltage scale of a source. The key advantages of this method are that it relies on equipment that is readily available in most high-level laboratories and can be fully automated. The Type A uncertainties achieved by this approach can be less than 0.1 <formula formulatype="inline"><tex Notation="TeX">$\mu{\rm V/V}$</tex></formula>. This performance is achieved because of the excellent differential linearity of the DVM used in the method. We have validated the overall accuracy of the method by directly comparing this approach with more traditional resistive divider techniques and have established that the expanded uncertainty is better than 0.2 <formula formulatype="inline"><tex Notation="TeX"> $\mu{\rm V/V}$</tex></formula> up to 1000 V, limited only by the performance of the instruments used.
Magnetic plasma confinement for laser ion source.
A laser ion source (LIS) can easily provide a high current beam. However, it has been difficult to obtain a longer beam pulse while keeping a high current. On occasion, longer beam pulses are required by certain applications. For example, more than 10 micros of beam pulse is required for injecting highly charged beams to a large sized synchrotron. To extend beam pulse width, a solenoid field was applied at the drift space of the LIS at Brookhaven National Laboratory. The solenoid field suppressed the diverging angle of the expanding plasma and the beam pulse was widened. Also, it was observed that the plasma state was conserved after passing through a few hundred gauss of the 480 mm length solenoid field.