Abstract

Theoretical work on the heavier noble gases, xenon in particular, has suggested that the temperature dependence of the rate at which orthopositronium (o‐Ps) decays is non‐linear with increasing temperature [1]. However, there is little experimental data on the heavier noble gases to support the theory, and the data that does exist is inconclusive [2]. This non‐linearity is in opposition to both the theoretical and experimental work on the lighter noble gases like helium, neon and argon, which have shown a linear dependence with respect to temperature [3]. The goal of this experiment is to investigate the temperature dependence of the decay rate of o‐Ps in xenon gas. We will use a high‐pressure gas cell with a positron source inside as the basic setup of the experiment. So far, design and construction has been completed on the temperature control system, including the temperature controller electronics, the heaters, and the insulated housing for the gas cell. In addition, construction is nearly complete for the gas handling system. Pressure and temperature tests are underway on the seal of the gas cell. The first sets of data over our temperature range of 20 to 300 deg. C. will be collected in the near future.