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We have obtained a high resolution, high S/N UVES spectrum of the bright QSOHE2243-6031 to analyze the damped Ly-alpha system (DLA) observed at z=2.33. Themetallicity of this system is 1/12 solar at a neutral hydrogen column densityof log N(HI)=20.7. From the observed ratios [Zn/Cr]=-0.01+/-0.05 and[S/Si]=-0.06+/-0.03$ we conclude that dust is very likely absent from the ISMof this protogalaxy. We observe an enhancement of the alpha/Fe-peak ratios of+0.2 dex for various elements, a marked odd-even effect in Mn, and a strongunderabundance of N relative to Si and S, [N/Si,S]=-1 at [Si/H]=-0.86. All ofthese ratios support an environment that is in an early evolutionary stage,where the onset of star formation has begun only shortly before the DLA wasobserved. We also perform a cloud-by-cloud analysis -- without precedent athigh redshift -- and find a tight correlation of all low-ionization specieswith respect to FeII extending over 2.5 orders of magnitude in N(FeII). Weinterpret this trend as being due to homogeneous physical conditions (very mildionization effects, common dust-destruction histories, same chemicalcomposition) and propose that this line of sight encounters absorbing cloudsthat share a common environment. In addition, photoionization models show thatthese single clouds are shielded from the external ionizing radiation, so thefraction of ionized gas is small and, except for argon, does not influence themeasured metal abundances. The observed AlIII/low-ion ratios suggest the mildlyionized gas occurs in shells surrounding neutral cores of AlII.Comment: To be published in A&

Metal abundances and ionization conditions in a possibly dust-free damped Lyα system at $\mathsf{\vec{z}=2.3}$