Precise wavelength measurements of potassium He- and Li-like satellites emitted from the laser plasma of a mineral target

Atomic models of high-Zmulticharged ions are extremely complex and require experimental validation.Oneway to do so is to crosscheck the predicted wavelengths of resonance transitions in He-and Li-like ions against precise spectroscopic measurements that use the spectral lines of H-like ions for spectra calibration;these reference data can be modeled with outstanding precision.However,for elements with Z of at least 15,it is quite difficult to create a hot dense plasma with a large concentration ofH-like charge states.To mitigate this issue,the suggestion here is to use as laser targets particular minerals comprising elements with moderate(between 15 and 30)and low(less than 15)Z,with emission from the latter delivering perfect reference lines over a whole range o fHe-and Li-like moderate-Z emission under examination.This approach is implemented to measure the wavelengths of resonance transitions(1snp→1s^(2) for n=2,3)in He-likeKions and their dielectronic satellites by irradiating plates of orthoclase(KAlSi_(3)O_(8))with0.5-kJ subnanosecond laser pulses.X-ray spectra of the laser-generated plasma contain the investigated lines of highly charged K-ions together with precisely known reference lines of H-like Al and Si atoms.The K-shell spectral line wavelengths are measured with a precision of around 0.3 mA.