Temperature-dependent relative self-absorption measurements in 27Al

Nuclear resonance fluorescence measurements provide direct sensitivity to ground-state transition widths by probing the photoexcitation process of nuclear resonances. A technique in Relative Self-Absorption (RSA) measurements, which are done at multiple absorber temperatures, was developed and tested with 27Al Darmstadt High Intensity Photon Setup Superconducting Linear Accelerator. The advantage this technique, over regular RSA, is possibility overcome need for theory input on effective temperatures uncertainties that they introduce measured level widths. preliminary results first test-measurements presented proceedings.