Radial Drift Chamber Research Articles

NITPC technical work in progress and sketch for a WIMP observatory

Direction-sensitive WIMP detection is important for conclusively identifying a halo-WIMP signal. It would also make possible the study of galactic halo dynamics through WIMP astronomy. A large low-pressure Negative Ion TPC (NITPC) is the only technique presently known which is capable of direction sensitive WIMP detection. Several advances in NITPC technology reported here. A new capture agent (CH3NO3) with several advantages over the standard CS2 is identified. Simulations with GARFIELD show that tracks completely contained within a single drift cell can be measured using the ‘‘radial drift chamber’’ structure proposed by Nygren. DRIFT I neutron source calibration data is shown in which the ‘‘head-tail’’ orientation of tracks is able to be determined. (Supported by the U.S. NSF under NSF-PHY-0300766.)

Simultaneous track reconstruction and electron identification in the H1 radial drift chambers

Results of prototype tests of the radial-wire drift chambers of the H1 forward track detector are presented. Choice of a suitable gas mixture and careful design of the chambers to include the possibility of efficient X-ray detection have shown that tracks can be reconstructed with good accuracy (σ ≈ 110–150 μm) and that simultaneously electron identification can be achieved by pulse integral analysis of ionization energy deposition due to both d E/d x and transition radiation. For 90% electron acceptance the pion contamination is 8% at high momentum (≈ 60 GeV/ c). At lower momenta, electron identification is further enhanced by the multiple sampling of pulse integrals in such chambers, resulting at 5 GeV/ c in a pion contamination of ≈ 0.5%.

Feasibility tests of a high resolution sampling radial drift chamber

Abstract The design concept and results of feasibility tests for a vertex detector intended for use in the TPC-PEP4/9 experiment are presented. The detector is based on a slow radial drift in dimethyl ether. High resolution localization of the avalanches at the sense wire is accomplished with nearby pickup wires and the utilization of waveform sampling electronics. The avalanche angular coordinate measurements, combined with knowledge of the electric field distribution and drift velocity permit reconstruction of the trajectory using essentially all track information. Measurements with a test chamber constructed to study characteristics of avalanche localization indicate that the recoverable track information in one centimeter of dimethyl ether at 1.5 atm is equivalent to 30 measurements of 40 μm accuracy.

Radial Drift Chambers Fop CDF Forward Tracking

Radial wire drift chambers are built for the Collider Detector of Fermilab to cover forward and backward regions between 2° and 10° cones which will provide good azimuthal position information of tracks, good multi-track, and high rate capability. Results obtained from a prototype chamber show ? resolution of ?rms ? 130 ?m and a charge division accuracy of 0.7 percent along the wire (?,r) running in the saturated avalanche mode.