ABSTRACT
The Radioisotope Centre (RC) has organized for the first time in Polish hospitals a comparison of activity measurements of (99)Tc(m) and (131)I. From the 58 Polish hospitals invited, 37 participated in the comparison. Each participant got about 4 mL of (99)Tc(m) eluate and two (131)I capsules, low- and high-activity. Sources were standardized in the RC before dispatch using a 4pi ionization chamber calibrated by standard solutions. Participants used their own radionuclide calibrators. The measurement results were evaluated using the E(n) criterion and the z'-score. From all 118 measurement results received from participants, 75 results (64%) lay within +/-5% of the RC value, and 99 results (84%) lay within +/-10.0%.
Subject(s)
Hospitals/standards , Iodine Radioisotopes/analysis , Technetium/analysis , Calibration , Laboratories, Hospital/standards , Observer Variation , Poland , Radioisotopes/analysisABSTRACT
The thermal component of the 8 GeV/c pi+ Au data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model when Coulomb energy is taken into account. Critical exponents tau and sigma, the critical point (p(c),rho(c),T(c)), surface energy coefficient c(0), enthalpy of evaporation DeltaH, and critical compressibility factor C(F)(c) are determined. For the first time, the experimental phase diagrams, (p,T) and (T,rho), describing the liquid vapor coexistence of finite neutral nuclear matter have been constructed.
ABSTRACT
Excitation-energy-gated two-fragment correlation functions have been studied between E(*)/A = (2-9)A MeV for equilibriumlike sources formed in 8-10 GeV/c pi(-) and p+197Au reactions. Comparison with an N-body Coulomb-trajectory code shows an order of magnitude decrease in the fragment emission time in the interval E(*)/A = (2-5)A MeV, followed by a nearly constant breakup time at higher excitation energy. The decrease in emission time is strongly correlated with the onset of multifragmentation and thermally induced radial expansion, consistent with a transition from surface-dominated to bulk emission expected for spinodal decomposition.
