a) Radial variation of temperature for a number of pulsation phases covering the phase range from Φ = −0.20 to Φ = 3.61 (extrapolated between 5 an 6 R_∗). b) Run of pressure and temperature for the pulsation model at different phases of the pulsation cycle between Φ = −0.2 and φ = 3.8 (solid black lines). The nearly horizontal red lines correspond to lines of constant normalized nucleation rate with values between 10^-34 and 10^-12 particles per second and per H nucleus in steps of 10^-2. The blue line corresponds to the onset of avalanche nucleation with a rate of 10^-20 s^-1 and per H nucleus. The experimental data of Nuth & Donn (1982) are indicated by green circles. The green line corresponds to the upper green line in Fig. 2.