Uncertainties, often in order of magnitude, in ion-molecule reaction rate coefficients measurements lead to a big variance in theoretical models of the chemical universe. We need more accurate rate coefficients in order to improve the accuracy of these models.
Fortunately, there are numerous ways to measure the rate coefficient in the lab with accuracy of tens of percent. Moreover, rate coefficients in general are temperature dependent, that is why we are also trying to measure them at different collisional temperatures.
In the presented work we are going to focus on the characterisation of the atomic H beam source, which is used on apparatus constructed for the measurement of the absolute rate constant temperature dependence of ions/anions with atomic hydrogen, specifically on the beam temperature characteristics and the number density, which was found to be [H] = (1.02 +- 0.06) . 108 cmMINUS SIGN 3.