1：Experimental Design and Method Selection:

The study used hot-press sintering in an inert atmosphere to prepare Eu2+:CaF2 ceramics, with doping concentrations varied at

2：01, 04, 2, and 5 at%. Nanoparticles were synthesized via co-precipitation method. Sample Selection and Data Sources:

Samples were Eu2+-doped CaF2 ceramics with specified concentrations.

3：List of Experimental Equipment and Materials:

Equipment included X-ray diffractometer (D/Max-RB, Rigaku), field emission scanning electron microscope, spectrophotometer (Lambda 750, Perkin Elmer), ICP-OES (Prodigy 7, Leeman), fluorescence spectrophotometer (FLS920, Edinburgh Instruments), XEL accessory in FLS980, PMT Hamamatsu R928P, time correlated single photon counting module, PMT (Hamamatsu, R1306), multi-channel analyzer (ORTEC-927). Materials included Calcium Nitrate Tetrahydrate (

4：7). Materials included Calcium Nitrate Tetrahydrate (9%), Potassium Fluoride Dehydrate (9%), Europium (Ⅱ) Chloride (9%), and deionized water. Experimental Procedures and Operational Workflow:

99.9%), Potassium Fluoride Dehydrate (99.9%), Europium (Ⅱ) Chloride (99.9%), and deionized water. 4. Experimental Procedures and Operational Workflow: Nanoparticles were synthesized, then sintered in a hot-press furnace with specific temperature and pressure steps (e.g., heating to 400°C in 120 min, holding, then to 560°C at 30 MPa, holding, cooling, and polishing). Measurements included XRD, SEM, transmittance, ICP-OES, PL spectra under 355 nm laser, XEL spectra under X-rays, scintillation decay under γ-rays, and pulse height spectra.

5：Data Analysis Methods:

Data were analyzed using fitting functions (e.g., two-component exponential for decay curves), and light yields were calculated relative to a NaI:Tl standard.