RHIP, a radio-controlled high-voltage insulated picoammeter
A picoammiter system has been developed by prototyping and engineering. It consists in a current-voltage converter, based on an operational amplifier with very low input current, a high precision ADC, a radio controlled data acquisition unit and the computer-based control, visualization and storage. The picoammiter is characterized by a precision of the order of a tenth of picoamperes and it can measure currents between points laying at potentials of the order of a ten of kilovolts. The current-voltage converter and the radio transmitter are battery powered and a number of strategies have been implemented to limit the power consumption. The system is designed for multichannel application and up to 256 parallel channels can be controlled. The overall implementation is cost-effective to make the availability of multichannel setups easily affordable. The design, implementation and performance of the picoammiter system are described.
First performance evaluation of a Multi-layer Thick Gaseous Electron Multiplier with in-built electrode meshes—MM-THGEM
We describe a new micro-pattern gas detector structure comprising a multi-layer hole-type multiplier (M-THGEM) combined with two in-built electrode meshes: the Multi-Mesh THGEM-type multiplier (MM-THGEM). Suitable potential differences applied between the various electrodes provide an efficient collection of ionization electrons within the MM-THGEM holes and a large charge avalanche multiplication between the meshes. Different from conventional hole-type multipliers (e.g. Gas Electron Multipliers - GEMs, Thick Gas Electron Multipliers—THGEMs, etc.), which are characterized by a variable (dipole-like) field strength inside the avalanche gap, electrons in MM-THGEMs are largely multiplied by a strong uniform field established between the two meshes, like in the parallel-plate avalanche geometry. The presence of the two meshes within the holes allows for the trapping of a large fraction of the positive ions that stream back to the drift region. A gas gain above 105 has been achieved for single photo-electron detection with a single MM-THGEM in Ar/(10%)CH4 and He/(10%)CO2, at standard conditions for temperature and pressure. When the MM-THGEM is coupled to a conventional THGEM and used as first cascade element, the maximum achievable gains reach values above 106 in He/(10%)CO2, while the IBF approaches of 1.5% in the case of optimum detector-bias configuration. This IBF value is several times lower compared to the one obtained by a double GEM/THGEM detector (5–10%), and equivalent to the performance attained by a Micromegas detector.
White-Collar Crime in Modern England: Financial Fraud and Business Morality, 1845-1929.
List of tables Acknowledgments Introduction 1. The new economy: transformation of finance and opportunities for crime 2. The railway mania 3. Banking and credit fraud 4. Stock fraud 5. Company fraud: promotion 6. Company fraud: management 7. Company law and the courts 8. Business ethics and professionalization Conclusion Notes Bibliography Index.