High-resolution RPCs for large TOF systems

Abstract

Here we report on a particular type of RPC that presents up to 99% efficiency for minimum ionizing particles and a very sharp time resolution, below 50 ps σ in the most optimized conditions. Our 9 cm 2 cells, made with glass and metal electrodes that form accurately spaced gaps of a few hundred micrometers, are operated at atmospheric pressure in non-flammable gases and can be economically produced in large quantities, opening perspectives for the construction of large area time of flight systems.

Study of timing properties of single gap high-resistive bakelite RPC

“…The same σ ij were obtained similarly for the 3 different pairs of the scintillators I, II and III. The intrinsic time resolutions of the RPC and the scintillators were obtained from the individual standard deviations σ i , σ j , which were extracted by solving the equations: σ ij 2 = σ i 2 +σ j 2 [6]. Time resolution (FWHM) of the individual scintillators were obtained as: 3.20 ± 0.07 ns (scintillator I), 3.39 ± 0.08 ns (scintillator II) and 1.98 ± 0.02 ns (scintillator III), where the quoted uncertainties include statistical and fitting errors.…”

Space charge effects in Resistive Plate Chambers

“…In the experiment one measures values that are several orders of magnitudes smaller [8,9,10]: Figure 9: A simulated avalanche in a Timing RPC. We show snapshots of the charge configuration in a 0.3 mm gas gap (500 steps).…”

“…Timing RPCs [5] with gas gaps of 0.2 to 0.3 mm are used in multi gap configurations [6] for Time-Of-Flight purposes [7]. They provide 99% efficiency and time resolutions down to 50 ps [8,9,10,11]. Different technologies with one or more resistive electrode plates are used.…”

Single-gap timing RPCs with bidimensional position-sensitive readout for very accurate TOF systems

“…A time resolution of 60 ps s was measured following the procedure described in Ref. [2], along with moderate timing tails of a few percent. (The ''300 ps tails'' are defined as the fraction of events outside the 7300 ps boundaries, with a similar definition of the ''3s tails''.)…”

“…The development of timing Resistive Plate Chambers (RPCs) [1] opened the possibility to build fine-granularity high-resolution TOF systems at a quite reduced cost per channel when compared with the standard scintillator-based technology Previous work yielded a timing resolution better than 50 ps s at 99% efficiency for single four-gap chambers [2] and an average timing resolution of 88 ps s at an average efficiency of 97% for a 32 channel system [3]. It has been also shown that each amplifying gap of 0.3 mm thickness reaches a detection efficiency close to 75% and that the avalanche develops under the influence of a strong space charge effect [4,5].…”