Walenta, Albert H Heintze, J Schürlein, B Nucl. Instrum. Methods 10.1016/0029-554X(71)90413-7 373-380 92 1971 1971 Killian, T J Nucl. Instrum. Methods 10.1016/0029-554X(80)90728-4 355-62 176 1-2 Green s function capacitance matrix computer simulation drift chamber drift distance electron trajectories track reconstruction program 1980 1980 The author describes a general purpose program for drift chamber studies. First the capacitance matrix is calculated using a Green's function technique. The matrix is used in a linear-least-squares fit to choose optimal operating voltages. Next the electric field is computed, and given knowledge of gas parameters and magnetic field environment, a family of electron trajectories is determined. These are finally used to make drift distance vs time curves which may be used directly by a track reconstruction program. The results are compared with data obtained from the cylindrical chamber in the Axial Field Magnet experiment at the CERN ISR. (1 refs). Charpak, Georges Southworth, Brian Phys. Teach. 10.1119/1.2339524 26-31 15 1 drift chamber multiwire proportional chamber particle detectors principles of operation teaching 1977 1977 The principles of operation of the two detectors are described and some applications outlined. (2 refs). Shimoyama, T Mayajima, M Shibamura, E 2000 2000 Nagayoshi, T Takada, A Kubo, H Miuchi, K Orito, R Okada, Y Takeda, A Tanimori, T Ueno, M Bouianov, O Bouianov, M Nucl. Instrum. Methods Phys. Res., A 457-465 546 2005 2005 The physical processes of charge collection and gas multiplication of a Micro Pixel Chamber (mu-PIC) were studied in detail using a three-dimensional simulation. The collection efficiencies of primary electrons and gas multiplication factors were calculated for several electrode structures. Based on those studies, we analyzed the optimization of the electrode structure of the mu-PIC, in order to obtain a high gas gain of more than 10^4 and a simultaneous suppression of discharges. Consequently, we found that these characteristics strongly depend on the substrate thickness and the anode diameter of the mu-PIC. In addition, a gas gain of 10^5 would be expected for a mu-PIC having a thick substrate of > 150um. Popescu, Sorina Frankenfeld, Ulrich Schmidt, Hans Rudolf 0 2 30 Alice TPC detector Alice TPC readout chamber CO2 gas N2 gas Ne gas TPC cooling strategy discharges drift gas drift length electric field front end electronics gas density local fluctuation gas mixture nonsaturated electron drift velocity operating parameters temperature stability temperature variation thermal influences three component mixture 2004 2004 The ALICE TPC detector will be operated with a gas mixture of 90% Ne and 10% CO/sub 2/ at the electric field of 400 V/cm. Recent studies favor a three-component mixture by adding about 5% N/sub 2/, which will improve the stability of the gas against discharges. These operating parameters lead to a non-saturated drift velocity for electrons but also impose that all external influences on the drift gas must be reduced to minimum. The most problematic influence is temperature variation, which can lead to local fluctuation in the gas density and therefore directly affects the drift velocity. For the Alice TPC, the aim is to have a temperature stability of 0.1 degrees C over the full drift length (2.5 m). The main heat contribution comes from the readout chambers front-end electronics and one estimates that a total of 30.2 kW must be removed. The test results discussed here give qualitative and quantitative information about the thermal behavior of the chambers for validation of the TPC cooling strategy. Kobayashi, S Doke, T Dmitrenko, V V Jpn. J. Appl. Phys. 333-334 42 1 2003 2003 Drift velocities of electrons in a mixture of Xe (20 atm)-He (3 atm) were measured using a cylindrical high-pressure xenon chamber. The drift velocities were found to be greater than 3x10 sup 5 cm/s above the reduced electric field of 2.0x10 sup - sup 1 sup 8 V centre dot cm sup 2 at room temperature, which are close to those in Xe-H sub 2 (0.3%). The mixture of He gas into high-pressure xenon improved the resolving time of detectors because it increased the electron drift velocities. This implies that a high-pressure xenon chamber mixed with sup 3 He instead of He gas operates as a gamma-ray detector sensitive to thermal neutrons. (author) Adinolfi, M Aloisio, A Ambrosino, F Andryakov, A Antonelli, A Antonelli, M Anulli, F Bacci, C Bankamp, A Barbiellini, G Bellini, F Bencivenni, G Bertolucci, Sergio Bini, C Bloise, C Bocci, V Bossi, F Branchini, P Bulychjov, S A Cabibbo, G Calcaterra, A Caloi, R Campana, P Capon, G Carboni, G Cardini, A Casarsa, M Cataldi, G Ceradini, F Cervelli, F Cevenini, F Chiefari, G Ciambrone, P Conetti, S Conticelli, S Lucia, E D Robertis, G D Sangro, R D Simone, P D Zorzi, G D Dell'Agnello, S Denig, A Domenico, A D Donato, C D Falco, S D Doria, A Drago, E Elia, V Erriquez, O Farilla, A Felici, G Ferrari, A Ferrer, M L Finocchiaro, G Forti, C Franceschi, A Franzini, P Gao, M L Gatti, C Gauzzi, P Giovannella, S Golovatyuk, V Gorini, E Grancagnolo, F Grandegger, W Graziani, E Guarnaccia, P Von Hagel, U Han, H G Han, S W Huang, X Incagli, M Ingrosso, L Jang, Y Y Kim, W Kluge, W Kulikov, V Lacava, F Lanfranchi, G Lee-Franzini, J Lomtadze, F Luisi, C Mao Chen Sheng Martemyanov, M Matsyuk, M Mei, W Merola, L Messi, R Miscetti, S Moalem, A Moccia, S Moulson, M Müller, S Murtas, F Napolitano, M Nedosekin, A Panareo, M Pacciani, L Pagès, P Palutan, M Paoluzi, L Pasqualucci, E Passalacqua, L Passaseo, M Passeri, A Patera, V Petrolo, E Petrucci, Guido Picca, D Pirozzi, G Pistillo, C Pollack, M Pontecorvo, L Primavera, M Ruggieri, F Santangelo, P Santovetti, E Saracino, G Schamberger, R D Schwick, C Sciascia, B Sciubba, A Scuri, F Sfiligoi, I Shan, J Silano, P Spadaro, T Spagnolo, S Spiriti, E Stanescu, C Tong, G L Tortora, L Valente, E Valente, P Valeriani, B Venanzoni, G Veneziano, Stefano Wu, Y Xie, Y G Zhao, P P Zhou, Y Nucl. Instrum. Methods Phys. Res., A 25-28 461 1-3 2001 2001 The tracking detector of the KLOE experiment is 4 m diameter, 3.3 m length drift chamber, designed to contain a large fraction of the decays of low-energy K sub L produced at the Frascati DAPHINE phi-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering inside the sensitive volume. The tracking information is provided by 58 layers of stereo wires defing 12,582 cells, 2x2 cm sup 2 in size in the 12 innermost layers and 3x3 cm sup 2 in the outer ones. Details of the chamber design, calibration procedure and tracking performances are presented. Creti, P Cambiaghi, M Ferrari, R Fraternali, M Gaudio, G Lanza, A Livan, M Bagnaia, P Bini, C Cardini, A De Cecco, S De Zorzi, G Gauzzi, P Gentile, S Lacava, F Pontecorvo, L Rosati, S Veneziano, Stefano Orestano, D Pastore, F Spiriti, E Ar-CO2 Atlas Calypso MDT monitored drift tube muon spectrometer test-beam 1999 1999 In the summer 1998 we have exposed to the Cern H8 test beam the BIL prototype Calypso filled with an Ar(93) CO2 (7) gas mixture, which is the current baseline for the Atlas MDT chambers. A possible problem of this gas mixture is the important variation of the drift velocity along the drift path. The aim of the test was to assess the possibility of operating the chamber and measuring the r-t relation in such conditions. Moreover we checked the performance of the chamber with a large-area (50 x 50 cm^2) beam using a hodoscope trigger and two precision trackers. Atac, M Taylor, W E 1974 1974