[en] Aging studies for a multi-wire proportional chamber of the LHCb muon system have been performed using the CERN Gamma Irradiation Facility. The irradiated four-gap chamber corresponds to a full-size prototype with 1500 cm² sensitive area and has been operated with an Ar/CO₂/CF₄ (40:50:10) gas mixture. A linear charge of ∼0.25 C/cm for 100 m anode wire length has been accumulated over a period of 6 months, which corresponds to the charge collected in 5 LHCb years. The observed aging effects do not prohibit the use of these chambers in the LHCb experiment

[en] We present the results of the absolute gas gain measurement of a straw drift-tube filled with a binary gaseous mixture Ar-CO₂(90-10) at 2 bar absolute pressure. The measurement has been performed using an intense 1.3 GBq ¹³⁷Cs-source producing the primary ionization current. The results, as a function of the high voltage and gas parameters, were fitted and parameterized with a Diethorn's formula

[en] Impedance matching of the drift straw-tube and the amplifier influences the signal-to-noise ratio, which, in turn, determines the coordinate resolution of the detector, the minimal threshold, and the minimal gas amplification necessary for efficient signal registration by the detector. Five impedance-matching schemes for the straw-tube detector with a length of 2.5 m are studied. It is shown that ENC = 4000−5000 electrons for C_det = 20−30 pF, which is good from the practical point of view, is achieved using the simple resistor connected in series to amplifier at the open far-end of the straw-tube.

[en] A new method has been developed to check the correct behaviour of the frontend electronics of the LHCb muon detector. This method is based on the measurement of the electronic noise rate at different thresholds of the front-end discriminator. The method was used to choose the optimal discriminator thresholds. A procedure based on this method was implemented in the detector control system and allowed the detection of a small percentage of front-end channels which had deteriorated. A Monte Carlo simulation has been performed to check the validity of the method.

[en] We study signals induced in the resistive Well MPGD constructed with the single DLC layer evaporated on top of a printed circuit mesh which was designed with various configurations surrounding either single hole or group of holes. As shown, signals are induced on the output readout elements (strip/pad/pixel) by both electrons and positive ions drifting in the blind well-like hole. An additional electron component is clearly seen in signals and related to the charge dispersed along the resistive layer. We present for the first time, that the ion tail induced on the readout elements can be suppressed to the level below 1% by proper designing the detector.

[en] We report the results of first studies of the small resistive Well radiation detector (https://indico.inp.nsk.su/event/20/session/9/contribution/205/material/poster/0.pdf) based on the Well Electron Multiplier with the DLC (Diamond-Like Carbon) anode. The DLC film covers the printed circuit mesh surrounding a group of holes. The prototype built with this technology provides fast, 200 ns, evacuation of electrons from the resistive layer with surface resistivity of 25 MOhm/square. As shown with ${}^{55}$Fe X-ray source, the detector with the mesh surrounding each hole withstands 0.5 millions discharges at the gas gain of 32,000 without damage to materials and functionality.