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Solid state detectors made of Si (4.8x8 [mm.sup.2]) and GaAs (6.4x8 [mm.sup.2]) pixel matrices bump-bonded to the Omega2 and Omega3 electronic read-out systems, developed at CERN for H.E.P. experiments, have been used to obtain autoradiographic images of clusters of human epithelial cells and DNA fragments separated via electrophoresis, both labeled with 32p. The system has shown a good minimum detectable activity per unit area of 2. [10.sup.-4] cps [mm.sup.-2], and has proved linear for count rate in the range 0.2-20 cps, typical of autoradiography. The pixel dimensions are 75x500 [[[micro]meter].sup.2] (Si-Omega2) and 50x500 [[[micro]meter].sup.2] (GaAs-Omega3), respectively. We are able to clearly localize clusters of cells which have incorporated the radioactive tracer and DNA fragments on an electrophoretic gel on paper (blots).

An analogue VLSI cell for hybrid pixel detector readout, ANAPIX, has been designed and tested. The chip has been manufactured in the FASELEC SACMOS 3 micron technology. A peak detector allows asynchronous signals to be processed without precise trigger timing. An equivalent noise charge of about 100 electrons r. m. s. has been achieved on the cell alone. The cell has been wire bonded to a silicon detector pixel matrix and in the laboratory energy spectra from radioactive gamma and beta sources have been recorded with an equivalent noise charge of 200 electrons rms. The dynamic range design target of 500 to 50000 electrons was not achieved yet, due to a non linearity around 4000 electrons. This problem is to be solved in the design of the second generation to be manufactured in a one micron technology. This new cell is to be connected via bump bonding to a detector, the first assemblies are expected to be ready in 1995.

A silicon pixel detector, developed in RD19, and consisting of 4 planes, [similar to] 30 [cm.sup.2] each, is operating for the first time in the lead ion experiment WA97 at CERN. The 288 CMOS readout chips are bump-bonded to 48 Si detector matrices, assembled in 8 identical arrays. The total number of pixel cells is nearly 300 000 and each cell, 75 [[micro]meter] x 500 [[micro]meter], contains a complete signal processing chain. Overall dead area is less than 3%.

We report the results obtained with a novel readout system for scintillating fibres and x-ray imaging based on the combination of a silicon pixel detector and one stage of light amplification using a 2nd generation image intensifier. The pixel detector is a hybrid assembly of a high resistivity silicon detector bump-bonded to a CMOS binary readout chip and can be read out at a speed of 15 MHz. Each pixel element measures 75[[micro]meter] x 500[[micro]meter]. Scintillating fibre ribbons and scintillating crystals are coupled to the detector array using one stage of light amplification provided by a micro-channel plate (MCP) image intensifier with fiberoptic faceplates. We have used the system to image electron tracks in a bundle of scintillating fibre ribbons. Further we have shown how the system can be used for imaging 122 keV x-rays such as those used in nuclear medicine. The system provides the possibility of single photon counting, high spatial resolution and Compton rejection.

Large linear silicon drift detectors have been developed and are in production for use in several experiments. Recently 15 detectors were used as a tracking device in BNL-AGS heavy ion experiment (E896). The detectors were successfully operated in a 6.2T magnetic field. The behavior of the detectors, such as drift uniformity, resolution, and charge collection efficiency are presented. The effect of the environment on the detector performance is discussed. Some results from the experimetal run are presented. The detectors performed well in an experimental enviromental. This is the first tracking application of these detectors.