Drift chamber

Benitez J J, Centeno M A, Merdrignac O M, Guyader J, Laurent Y and Odriozola J A 1995 DRIFTS chamber tor in situ and simultaneous study of infrared and electrical response of sensors Appl. Spectrosc. 49 1094-6... 

In two recent papers [8,10], we have initiated studies aimed at understanding the catalytic behavior of WZ and PtWZ. Our observations, which motivated the present study, can be summarized as follows, a) Water of reduction results in the formation of Br0nsted acid sites, as monitored by pulsed addition of pyridine to a DRIFTS chamber at room temperature [8,10]. In this paper, we have complemented those results with similar pyridine adsorption experiments at... 

More recent versions of this design feature an added focusing system, called a radial drift chamber, in front of the detector. Gas ionization occurs within this drift chamber, which is composed of a set of concentric charged rings sandwiched between two lens-shaped metal grids. The cluster of electrons is then focused by the drift chamber, making its direction normal to the surface of the multiwire detector. 

Snowden-Ifft, D. R, Martoff, C. J., Burwell, J. M. 2000. Low pressure negative ion drift chamber for dark matter search, Phys. Rev. D61, 101301 Spergel, D. N. Steinhardt, P J. 2000. Observational Evidence for Self-Interacting Cold Dark Matter, Phys. Rev. Lett. 84, 3760 Spergel, D. N., et al. 2003. First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations Determination of Cosmological Parameters, ApJS 148,175... 

Fig. 9. Experimental setup for observation of ultrarelativistic A2e a) - channel scheme p - internal proton beam, T - film target, F - polyester film,CL - collimators, H -horizontal magnetic field, C - plexiglas converter b) - magnet and detectors MP - poles of spectrometer magnet, VC - vacuum chamber, DC1, DC2 and DC3 - drift chambers, SI and S2 - scintillation counters, C - gas Cherenkov counters...

Charged particles were detected by the telescopes Ti and T2. The track coordinates were measured by drift chambers. The time interval between detector hits in Ti and T2 was measured by scintillation hodoscopes. Electrons and positrons were rejected by gas Cherenkov counters, and muons by scintillation... 

Fig. 15. Schematic top view of the DIRAC spectrometer. Moving from the target station toward the magnet there are four MicroStrip Gas Chambers (MSGC), two Scintillating Fibre Detectors (SFD) and an Ionization Hodoscope (IH). Located downstream from the dipole magnet, on each arm of the spectrometer, are 4 modules of Drift Chambers (DC), a Vertical and a Horizontal Hodoscope (VH, HH), a Cherenkov counter (C), a Preshower detector (PSh) and, behind an iron absorber, a Muon counter (Mu)...

Spark chambers (or "streamer chambers") are a set of 5 to 10 metal plates thin enough for high-energy particles to cross them, in a chamber filled with He or Ne when particles cross the plates, a trigger signal sets up a strong electric field, and sparks fly from plate to plate two photographic films mounted perpendicular to the plates and to each other record the spark tracks across the plates. The spark chamber has been superseded by drift chambers and silicon detectors. 

A variation of the detector described above is the so-called drift chamber. The drift chamber determines the position from the time it takes the electrons produced by the incoming particle to drift to the nearest anode wire. A two-dimensional MWPC has also been constructed for detection of neutrons scattered from biological samples. It is a He gas-filled counter that detects neutrons through the (n, p) reaction. 

A very promising type of sohd-state detector is the solid-state drift chamber (SSD) detector, featuring excellent energy resolution at high count rates. A FWHM below 140 eV at 5.9 keV can be achieved with thermoelectrical cooling (Peltier effect). SSDs exist in a large variety of sizes up to 2 cm diameter. 

The large area, 2m x 2m, of AGATE has lead to the selection of drift chambers for the tracking detector, rather than the spark chambers used in EGRET. Drift chambers have fewer wires and much less deadtime per event. The power per wire is low enough to use many layers in order to reduce the multiple scattering of the electron and positron before the gamma-ray direction can be measured. 

A 16 layer prototype of l/2m x l/2m drift chambers has been built. Muon tracks are used to study position resolution, efficiency, and noise. Preliminary work has also begun on the spacecraft requirements. 

Key words gamma-ray detectors - pair production - drift chambers... 

Fig. 1. I i>ical muon event recorded with the l/2mxl/2m prototype drift chambers with 90% Xe and 10 % methane at 1 atm. The crosses indicate the position of the anodes which are separated by 4 cm. Each horizontal row of anodes constitutes a frame which is 1 cm high, and the total stack height is 50 cm. Half of the frames are offset by half a drift cell to eliminate the left/right ambiguity. The triangles are the hit positions corresponding to left or right drift towards the anode. The numbers on the right hand side are residuals in units of mm for each point used in the reconstruction.

Fig. 2. Distribution of the residuals to a straight line fit of muon tracks for two different gas mixtures. The data are fit by a Gaussian function. The standard deviation is a measure of the i>atial resolution attainable with these drift chambers.

Cuddapah, R. et al. 1993, Development of a High Energy Geunma-Ray Telescope Using Drift Chambers , 1992 IEEE Nuclear Science Symposium Vol. 1, 643-46 Fichtel, G. E. et al. 1994, The First Energetic GammarRay Ex >eriment Telescope Catar log , Ap J Supp 94, 551-581... 

Mukherjee, R. et al. 1994, Development of Large Area Drift Chambers for High Energy Gamma-Ray Astrophysics in Aprile, E., ed(s)., SPIE Proceedings, Vol. 2305, 2-12... 

Atkinson, R. Clark, A. Taylor, S.I., Ion mobility spectrometer comprising two drift chambers, U.S. Patent 7994475, February 28, 2008. 

EUstratov, A.A., Shibkov, S.V., Nikolaev, E.N., Analysis of non-linear ion drift in spectrometers of ion mobility increment with cylindrical drift chamber. Eur. J. Mass Spectrom. 2006, 12, 153. 

A miniaturized drift chamber is particularly useful for proper functioning of DMS since this technique requires very high electric field. In miniaturized drift tube, the distance between top and bottom electrodes is scaled down to microns. Hence, a very high electric field can be obtained by applying relatively low voltages across the electrodes. 

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