Performances of 4-gap timing RPCs for relativistic ions in the rangeZ= 1–6

Abstract

We present the performance of Multi-gap timing RPCs under irradiation by fully stripped relativistic ions (γβ =2.7, Z=1-6). A time resolution of 80 ps at high efficiency has been obtained by just using standard 'off the shelf' 4-gap timing RPCs from the new HADES ToF wall. The resolution worsened to 100 ps for ∼ 1 kHz/cm 2 proton flux and for ∼ 100 Hz/cm 2 Carbon flux. The chambers were operated at a standard field of E = 100 kV/cm and showed a high stability during the experiment, supporting the fact that RPCs are a convenient choice when accommodating a very broad range of ionizing particles is needed. The data provides insight in the region of very highly ionizing particles (up to ×36 mips) and can be used to constrain the existing avalanche and Space-Charge models far from the usual 'mip valley'. The implications of these results for the general case of detection based on secondary processes (n, γ) resulting in highly ionizing particles with characteristic energy distributions will be discussed, together with the nature of the time-charge correlation curve.

Challenges for resistive gaseous detectors towards RPC2014

“…Feedback towards critical technological improvements is, however, very little in this case. Either scenario (6.1, 6.2), implemented with the necessary degree of detail, might be already sufficient to describe the, as yet, totally unexplained response to photons [77], neutrons [78] and heavy ions [79,80]. Figure 10.…”

“…Either scenario (6.1, 6.2), implemented with the necessary degree of detail, will be presumably sufficient to describe the, as of today, totally unexplained response to photons [83], neutrons [84] and heavy ions [85,86].…”

“…Although the first system is almost surely discontinued in virtue of a scintillator calorimeter (see [82], however), it will be very interesting to see the evolution of the latter. Dedicated studies of the detector response under heavy ions are scarce [85,86,98] and they will undoubtedly shed light on the detector behavior, specifically on the space charge phenomena and the ionization quenching factors for highly ionizing particles, that are totally unknown for RPC-mixtures as of today. For illustration, the RPC time response for the heaviest nuclei studied to date (Xe) is shown in figure 16 at different fluxes [86].…”

Technical design of the RPC-based ToF wall (iTOF) for the R3B experiment at FAIR

“…[10]. Our R&D project for implementing this technology in this domain covered the design of the RPC (size, geometry, granularity, suited materials, number of gaps, field distribution, ...), as well as the (very-) front-end electronics (vFEE) to couple to the detector.…”

Structural design of an RPC-based time-of-flight wall for ions (iTOF) for the R3B-FAIR experiment

“…At the time we started our activities there was no available information concerning RPCs detection of heavy ions, the first appearing in ref. [11]. Our R&D project for implementing this technology in this domain covered the design of the RPC (size, geometry, granularity, suitable 2012 JINST 7 P11015 materials, number of gaps, field distribution, etc.…”