[en] A CAMAC-compatible digital preprocessor useful for tasks like particle discrimination or data routing is presented. It outperforms its predecessor by doubled computing speed and other improvements. (orig.)

[en] A feedback microprocessor has been built for the TEVATRON. It was constructed to be applicable to hadron colliders in general. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor software includes a finite state machine. Each state corresponds to a specific TEVATRON operation and has a state-specific TEVATRON model. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime corrections. We also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. In this paper we will describe this device and its use to control the TEVATRON tunes as well as other possible applications. (orig.)

[en] A semi-microscopic formula of Townsend's first ionization coefficient α is proposed for the gas gain of a proportional counter. The electron movement in a counter is expressed in terms of cross sections of inelastic and ionization collisions with gas molecules by introducing a simple model which has four fixed parameters for a gas. The model parameters have been determined for typical counter gases. The results of gas gain calculated by the obtained formula indicate good agreement with experimental results for several filling gas mixtures at a variety of mixing ratios and for various counter geometries. (orig.)

[en] Radiation damage effects both in the optical transmission and in the fast luminescence component light output due to 1 GeV proton irradiation in a BaF₂ crystal scintillator were measured. It was found that the induced light absorption in a BaF₂ crystal due to the proton radiation damage is remarkably dependent on the dose accumulation rate. Also, the obtained results show that the fast component light yield is slightly sensitive to 1 GeV proton irradiation, in the absorbed doeses region up to 30-50 krad at least. (orig.)

[en] The D(d vector, p) reaction was used to measure the vector polarization of the deuteron beam from the atomic beam polarized ion source at King Fahd University of Petroleum and Minerals. The vector polarized deuteron beam was produced using a weak field transition. The polarization p_z of the deuteron beam was determined from the measured asymmetry and known analyzing power A_γ(θ) of the D(d vector, p) reaction with 200 keV deuterons. The experimentally determined value of p_z was found to be -0.462±0.029 which is 69±6% of the maximum theoretical value. Within the statistical uncertainties, the measured beam polarization agrees with the value given by the manufacturer. (orig.)

[en] The 3 ton liquid-argon time-projection chamber for the ICARUS project has been in operation since May 1991 collecting events from cosmic rays and monocromatic gamma ray source. Recent results are reported as well as an overview of the possible physics applications of this promising technique. (orig.)

[en] The paper reports the results of the computer simulation of parameters of the on-axis coupled accelerator structure for the continuous wave racetrack microtron. The operational experience with the accelerating sections on the basis of the on-axis coupled structure is described. (orig.)

[en] The DELPHI Microvertex detector, which has been in operation since the start of the 1990 LEP run, consists of three layers of silicon microstrip detectors at average radii of 6.3, 9.0 and 11.0 cm. The 73 728 readout strips, oriented along the beam, have a total active area of 0.42 m². The strip pitch is 25 μm and every other strip is read out by low power charge amplifiers, giving a signal to noise ratio of 15:1 for minimum ionizing particles. On-line zero suppression results in an average data size of 4 kbyte for Z⁰ events. After a mechanical survey and an alignment with tracks, the impact parameter uncertainty as determined from hadronic Z⁰ decays is well described by √(69/p_t)²+24² μm, with p_t in GeV/c. For the 45 GeV/c tracks from Z⁰→μ⁺μ^- decays we find an uncertainty of 21 μm for the impact parameter, which corresponds to a precision of 8 μm per point. The stability during the run is monitored using light spots and capacitive probes. An analysis of tracks through sector overlaps provides an additional check of the stability. The same analysis also results in a value of 6 μm for the intrinsic precision of the detector. (orig.)

[en] The lead-liquid argon sampling calorimeter of the SLD detector is one of the largest detectors employing cryogenic liquids now in operation. This paper details the design and performance considerations, the mechanical and cryogenic systems, the absorber design and tower segmentation, the data acquisition electronics, and the control systems of the detector. The initial operational performance of the device is discussed. Detailed resolution studies will be presented in a later paper. (orig.)

[en] Track-depth resolved VUV (vacuum ultraviolet)-luminescence due to the transition ¹A-¹X has been measured on a dense helium target with a varying helium density. With increasing excitation density, the formation of ¹A is enhanced by the ³a+³a reaction and suppressed by the ³a+³a+³a reaction. An additional peak in luminescence efficiency dL/dE is much more intense than that for VIS (visible) dL/dE. The peak is caused by charge exchange and direct excitation processes. (orig.)