**Table 1:** Comparison of the characteristic cyclotron time of some species with their heat exchange time with protons, in the lower corona.
Species	q/m^a	$\tau_{\rm c}$ (s)^b	$\tau^{\rm\tiny E}$ (s)^c
e^-	1758	$4 \times 10^{-7}$	120
p⁺	1	$6 \times 10^{-4}$	3
Mg X	0.37	$2 \times 10^{-3}$	1
Fe X	0.16	$4 \times 10^{-3}$	2

^a Charge-to-mass ratio, normalized to the proton one. Mg X and Fe X are the ion species having the highest and lowest values of q/m, respectively, in the spectrum observed by SUMER.
^b $\tau_{\rm c} = 2 \pi \frac{m}{q ~ B}$ , with q the charge and m the mass of the particle, and B the magnetic field.
^c Heat exchange time with protons $\tau_{\rm\scriptsize ep}^{\rm\tiny E}$ and $\tau_{\rm\scriptsize ip}^{\rm\tiny E}$ (e.g. Wesson 2004, p. 68).
All these times are calculated with the following conditions: $B=1~{\rm Gauss}$ , electron density $n_{\rm e}=10^{14}~{\rm m}^{-3}$ , and proton and electron temperatures both equal to 10⁶ K ( $\beta \approx 0.35$ ).

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