The Multigap Resistive Plate Chamber (MRPC) is a gaseous detector; the
performance depends very much on the gas mixture as well as the design. MRPCs
are used as a timing device in several collider experiments and cosmic ray
experiments thanks to the excellent timing performance. The typical gas
mixtures of RPC-type detectors at current experiments are based on the gases
C2βF4βH2β and SF6β. These gases have very high Global Warming
Potential (GWP) values of 1430 and 23900 respectively.
The present contribution has been performed as a part of efforts to reduce
the amount of greenhouse gases used in high energy experiments. The performance
of MRPC has been measured with two different gas mixtures; C2βF4βH2β
based gas mixtures and the ecological C3βF4βH2β (HFO-1234ze). A small
MRPC was used for the tests. It has an sensitive area of 20 Γ 20 cm2; it was been built with 6 gaps of 220 ΞΌm.
In normal operation, the strong space charge created within the gas avalanche
limits the avalanche's growth. SF6β plays an important part in the
process due to its high attachment coefficient at low electric fields. It is
thus necessary to find another gas that has a similar attachment coefficient.
CF3βI is a possible candidate. Tests were performed with this gas added
to C3βF4βH2β