Small current instrumentation for precision radioactive dose measurements A growing range of medical treatments and diagnostic procedures use radioactive sources. The strength of these sources is often measured using ionisation chambers whose output is an electrical current in the range from picoamperes (10-12 A) to microamperes (10-6 A). Robust, traceable calibration of the electrical current readout is vital for validating the stability and… Read More
Measurement of sub-picoampere direct currents with uncertainties below ten attoamperes Scientists at e-SI-Amp partner Physikalisch-Technische Bundesanstalt (PTB) have developed a stable current amplifier for the sub-picoampere measurement range. The low noise and stability makes direct current measurements with uncertainties of less than 10 attoamperes (1 attoampere = 10-18 A) readily achievable. The “ultrastable low-noise current amplifier” (ULCA) enables traceable measurement and generation of small currents… Read More
Robust operation of a GaAs tunable barrier electron pump KRISS and NPL have demonstrated robust operation of a gallium arsenide tunable-barrier single-electron pump operating with 1 part-per-million accuracy at a temperature of 1.3 K and a pumping frequency of 500 MHz. NPL and KRISS scientists showed that the current from a gallium arsenide electron pump was still accurately quantised at the level of 1… Read More
High-accuracy current generation in the nanoampere regime from a silicon single-trap electron pump A gigahertz single-electron (SE) pump with a semiconductor charge island is promising for a future quantum current standard. However, high-accuracy current in the nanoampere (10-9 A) regime is still difficult to achieve because the performance of SE pumps tends to degrade significantly at frequencies exceeding 1 GHz. NTT (Japan) and NPL (UK) have shown robust… Read More
First 10 part-per-billion quantum realisation of the ampere Researchers from the Laboratoire National d’Essais (LNE) have developed a quantum current standard able to generate currents of values in a range from microamperes (10-6 A) to milliamperes (10-3 A) accurately linked to the elementary charge with a targeted relative uncertainty of 10 parts in a billion. This breakthrough relies on an error-free application of… Read More
Robustness of single-electron pumps at sub-ppm current accuracy level A new accuracy record in measurements on single-electron pumps has been demonstrated by PTB. 0.16 µA/A of relative combined uncertainty was reached within less than 1 day of measurement time. Robustness tests of pump operation on the sub-ppm level revealed good stability of tunable-barrier pumps against variations in the operating parameters. Single-electron (SE) pumps are promising… Read More
e-SI-Amp@CPEM 2016 The Conference on Precision Electromagnetic Measurements is the most important conference in the field of electrical metrology. Held every two years, it brings together representatives from National Measurement Institutes, Universities and Industry to discuss state of the art measurement techniques and issues surrounding the measurement system. The conference in 2016 was held in Ottowa, Canada. A significant… Read More Error thrownCall to undefined function simplexml_load_string()
