Santiard, Jean-Claude Marent, K 10.5170/CERN-1999-009.431 1999 1999 The most recent member of the Gasplex family of ASICs has been designed in a 0.7 µm n-well CMOS process to meet specifications for the ALICE applications: 500 fC linear dynamic range and a peaking time of 1.2 µs. Its internal circuitry is optimized for the readout of gaseous detectors. A dedicated filter compensates the long hyperbolic signal tail produced by the slow drift of the ions and allows the shaper to achieve perfect return to the base line after 5 µs. Measurement of fabricated chips showed a noise performance of 530 e - rms at 0 pF external input capacitance and 1.2 µs peaking-time, with a noise slope of 11.2 e - rms/pF. The gain is 3.6 mv/fC over a linear dynamic range of 560 fC. Acosta, D Apollinari, G Blomqvist, J M Breedon, R Bondar, N F Bonushkin, Yu Borissov, E Bujak, A T Bylsma, B Chester, N S Chrisman, D Cline, D Dolinski, S I Durkin, S Eartly, D P Ferguson, T Feyzi, F Gilmore, J Gorn, L Gorn, W Gu, J Gutay, L J Hauser, J Hershman, S Hoftiezer, J H Kisselev, O A Ko, W Korienek, J Korytov, A V Kubic, J Layter, J Ling, T Y Loveless, R Lusin, S Matthey, C Matveev, M Medved, S A Mitselmakher, G Otwinowski, S Padley, P Petriello, F J Pishchalnikov, Yu M Prokofiev, O E Razmyslovich, B V Reeder, D Roberts, J Robl, P Rush, C J Santiard, Jean-Claude Sedov, S Smith, B Sobolev, S L Soulimov, V Tannenbaum, B Terentyev, N K Vorobyov, A A Yarba, V A Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)00627-6 182-7 453 1-2 2000 2000 Presented are the main design features of the large cathode strip chambers (CSCs) for the CMS endcap muon system as well as the performance results obtained with the two full-scale 3.4 * 1.5 m/sup 2/ six-plane prototypes. The prototype performance was within the baseline requirements: (a) higher than 99% efficiency of muon track finding at the trigger level with more than 92% probability for bunch crossing identification and better than 2 mm spatial resolution, and (b) better than 150 mu m spatial resolution in off-line. (6 refs). Witters, H Santiard, Jean-Claude Martinengo, P 10.5170/CERN-2000-010.179 2000 2000 The processing of analog information is always spoiled by additional DC level and noise given by the sensors or their additional readout electronics. The Dilogic-2 ASICcircuit has been developed in a 0.7um n-well CMOS technologyto process the data given by Analog to Digital Converters, in order to eliminate the empty channels, to subtract the base line (pedestal) and to locally store the true analog information.(Abstract only available, full text willfollow) Santiard, Jean-Claude Marent, K Gasplex CMOS gaussian 1999 1999 The most recent member of the Gasplex family has been designed in a 0.7 µm n-well CMOS process to meet specifications for the ALICE applications: 500 fC linear dynamic range and a peaking time of 1.2 µs. Its internal circuitry is optimized for the readout of gaseous detectors. A dedicated filter compensates the long hyperbolic signal tail produced by the slow motion of the ions and allows the shaper to achieve perfect return to the base line after 5 µs. Measurement of fabricated chips showed a noise performance of 530 e- rms at 0 pF external input capacitance and 1.2 µs peaking-time, with a noise slope of 11.2 e- rms/pF. The gain is 3.6 mv/fC over a linear dynamic range of 560 fC.<P><B>Summary:</B><P>The Gasplex is a 16-channel low noise signal processor built in a 1.5 µm technology and specially designed for gaseous detectors. Each channel consists of a Charge Sensitive Amplifier (CSA) followed by a filter, a Semi-Gaussian shaper and a Track/Hold circuit. The peaking time acts as a delay allowing an external trigger to store the information on a capacitor; finally, the 16 channels are multiplexed to one output. <P>The Gassiplex0.7-2 has been developed to fit the ALICE requirements, using the same circuitry principle, in a 0.7&nbsp; µm process. In gaseous detectors, the ion cloud released by the avalanche around the anode wire induces current as long as it drifts in the electric field from the anode to the cathode. The charge close to the anode can be approximated by the relationship </P><P ALIGN="JUSTIFY">q(t) = Q<SUB>0</SUB>Aln(1+t/t<SUB>0</SUB>) and the current by I(t) = I<SUB>0</SUB>B/(1+t/t<SUB>0</SUB>), where Q<SUB>0</SUB> is the total ionic charge and A, B and t<SUB>0</SUB> are constants depending on the detector geometry and the electric field.<P>The CSA stage consists of a folded cascode with a feedback capacitor of 1&nbsp;pF and an active feedback resistor of 20&nbsp;M<FONT FACE="Symbol">&#87;</FONT>. This 20&nbsp;<FONT FACE="Symbol">&#109;</FONT>s decay time constant is necessary in order to be sensitive to the largest possible fraction of detector current, which last over several tens of microseconds. <P>A deconvolution filter has been implemented to compensate the long hyperbolic tail resulting from the ion drift and convert the signal of the CSA into a quasi-step function. To perform the deconvolution, the transfer function of the deconvolver G(s) should be the exact inverse of the transfer function of the detector H(s), namely G(s) = H(s)<SUP>-1</SUP>.<P>The charge given by the detector is approximated by the sum of three weighted exponentials. Each exponential is modelled by a pole placed in the feedback of a summing amplifier to implement the inverse transformation: G(s) = Vout/Vin = A/(1+<FONT FACE="Symbol">&#98;</FONT>A); for A large G(s) ~ 1/<FONT FACE="Symbol">&#98;</FONT> and <FONT FACE="Symbol">&#98;</FONT>= K<SUB>1</SUB>/(1+sT<SUB>1</SUB>) + K<SUB>2</SUB>/(1+sT<SUB>2</SUB>) + K<SUB>3</SUB>/(1+sT<SUB>3</SUB>). After deconvolution the filter output looks like a step function with one pole given by the Rf.Cf decay time constant of the CSA. It allows the shaper to maintain a stable and precise return to the base line.<P>The Semi-Gaussian shaper has an original feature: the output of the filter go through two different integrating paths which are compared at the inputs of an OTA; it results in a S-G shape and thereby eliminates the usual differentiation capacitor. In this way the different blocks of the analog channel are DC coupled and permit a high counting rate without base line distortion. <P>The Gassiplex0.7-2 provides an individual channel calibration circuit with a precision of ±1It is also possible to switch off the filter for the readout of Silicon detectors at a gain of 2.1&nbsp;mv/fC and a dynamic range of 900&nbsp;fC. With the deconvolution filter in operation, the measured performances figures are the following: at a power consumption of 9&nbsp;mW/ch, we measured the noise as 530&nbsp;e<SUP>-</SUP> rms with 0&nbsp;pF input capacitance and a slope of 11.2&nbsp;e<SUP>-</SUP> rms/pF. The non-linearity is ±2&nbsp;fC over the 560&nbsp;fC dynamic range at a gain of 3.6&nbsp;mv/fC. The readout can be performed at 10&nbsp;MHz with a capacitive load of 30&nbsp;pF. Baarmand, M M Bonushkin, Yu Chrisman, D Durkin, S Ferguson, T Fitch,J Giacomelli, P Gorn, L Gorn, W Hauser, J Hirschfelder, J Hoftiezer, J H Hoorani, H Kisselev, O A Klem, D E Korytov, A Layter, J G Lennous, P Ling, T Y Matthey, C Medved, S Minor, C Mitselmakher, G Müller, T Otwinowski, S Preston, L Rush, C J Santiard, Jean-Claude Schenk,P Smirnov, I Soulimov, V Vaniachine, A Vercelli, T Wuest, C R Zeng, J von Goeler, E Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(98)01390-4 92-105 425 1-2 MUONS TRIGGER 1999 1999 A simple network of comparators applied to the strip signals of a cathode strip chamber allows quick hit localization to within a halfstrip width, or +/- a quarter-strip. A six-plane chamber with 6.4 mm wide strips was tested in a high-energy muon beam. The chamber was placed behind a 30 cm thick iron block. We show that patterns of hits localized to within a halfstrip allowed us to identify 300 GeV/c muon tracks with 99% probability and 0.7 mm spatial resolution in the presence of muon bremsstrahlung radiation. This technique of finding muon tracks will be used in the cathode strip chambers of the CMS Endcap Muon System. Piuz, François Andrés, Yu Braem, André Davenport, Martyn Di Mauro, A Goret, B Martinengo, P Nappi, E Paic, G Raynaud, J Santiard, Jean-Claude Stucchi, S Williams, T D Grimaldi, A Monno, E Posa, F Tomasicchio, G Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00293-4 222 433 1-2 1999 1999 We report on the design and construction of a CsI-RICH detector composed of four CsI photocathodes, of 64$\times$40 cm$^2$ each, and two C$_6$F$_{14}$ radiator trays, of 133$\times$41 cm$^2$. A detailed description of the novel elements is given and the performance of the detector is illustrated with some basic results obtained during the tests at the beam. Piuz, François Braem, André Davenport, Martyn Di Bari, D Di Mauro, A Elia, D Goret, B Martinengo, P Nappi, E Paic, G Santiard, Jean-Claude Stucchi, S Tomasicchio, G Williams, T D Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00349-6 178-89 433 1-2 1999 1999 We report on the final tests performed on a CsI-based RICH detector equipped with 2 C$_6$F$_{14}$ radiator trays and 4 photocathodes, each of 64$\times$38 cm$^2$ area. The overall performance of the detector is described, using different gas mixtures, in view of optimizing the photoelectron yield and the pad occupancy. Test results under magnetic field up to 0.9 T, photocathode homogeneity and stability are presented. 1997 1997 Bouclier, Roger Capéans-Garrido, M Garabatos, C Manzin, G Peisert, Anna Ropelewski, Leszek Sauli, Fabio Santiard, Jean-Claude Shekhtman, L I Temmel, T Fischer, G 1995 1995 Almeida, J Amadon, A Besson, P Bourgeois, P Braem, André Breskin, Amos Buzulutskov, A F Chechik, R Coluzza, C Di Mauro, A Friese, J Homolka, J Ljubicic, A Margaritondo, G Miné, P Nappi, E Dell'Orto, T Paic, G Piuz, François Posa, F Santiard, Jean-Claude Sgobba, Stefano Vasileiadis, G Williams, T D Nucl. Instrum. Methods Phys. Res., A 10.1016/0168-9002(95)00571-4 332-6 367 1-2 1995 1995 CsI photocathodes were studied in order to evaluate their potential use as large photo converters in RICH detectors for the PID system of ALICE at LHC in heavy-ion collider mode. It has been demonstrated that a quantum efficiency close to the reference value obtained on small samples can be obtained on CsI layers evaporated on large pad electrodes operated in a MWPC at atmospheric pressure. We present a survey of the results obtained in the laboratory on small samples irradiated with UV-monochromatic beams and with large area RICH detectors of proximity-focusing geometry in a 3 GeV/c pion beam.