RESUMO
This brief presents a monolithically integrated fully differential linear HV amplifier as the driver of an ultrasonic transducer. The linear amplifier is capable of transmitting HV arbitrary signals with a very low harmonic distortion, which is suitable for tissue harmonic imaging and other ultrasonic modes for enhanced imaging quality. The amplifier is designed and implemented using the 0.7-µm CMOS silicon-on-insulator process with 120-V devices. The amplifier, when driving a load of 300 pF in parallel with 100 Ω, is capable of transmitting a sine-wave signal with a frequency of up to 4.4 MHz, a maximum signal swing of 180 Vpp, and a second-order harmonic distortion (HD2) of -56 dBc but only dissipating an average power of 62 mW with a 0.1% duty cycle.
RESUMO
Eight beams of 0.35-microm laser with pulse duration of about 1.0 ns and energy of 260 J per beam were injected into a cylindrical cavity to generate intense x-ray radiation on the Shengguang II high power laser facility. Plastic foils with a thickness in the range of about 3.0-45 microm were attached on the diagnostic hole of the cavity and ablated by the intense x-ray radiation. The radiative energy transport through plastic foils with different thicknesses has been studied experimentally. The burn-through time of the plastic foils has been obtained. For comparison, we also simulated the experimental results with Planckian and non-Planckian x-ray spectrum source, respectively. It is shown that for thick plastic foil the simulation with non-Planckian x-ray spectrum source is in good agreement with the experiment.
