Hikaru Inoue

Excitation function of Ge(p,xnyp) reactions and production of 68Ge

Abstract Cross sections for the Ge(p,xn) 71–74As, (p,pxn) 68.69Ge, (p,αxn) 66.67Ga and (p,αpxn) 65Zn reactions were measured by the activation method in the proton energy range of 19–64 MeV. The thick target yields of product nuclides were estimated by using the observed excitation functions. The thick target yield of 68Ge at 64 MeV was 48 μCi/μA·h in the optimal irradiation condition (Ep = 64 → 28 MeV, target thickness of 1.8 g/cm2). As a result, the proton reaction on germanium is a useful reaction to produce a large amount of 68Ge for the positron computer tomograph in medical diagnosis.

Precision measurement of gamma-ray energies in the range 450–600 KeV

Abstract Energies of five gamma rays were measured with Ge(Li) spectrometers which were calibrated by using gamma-ray energy standards of 198 Au and 192 Ir. Observed energies are 477.6064(26) KeV for 7 Be, 511.8562(23) KeV for 106 Ru, 514.0076(22) KeV for 85 Sr, 531.0329(24) KeV for 147 Nd and 569.7035(41) KeV for 207 Bi. These gamma rays are useful for energy standards, especially for the energy measurement of position annihilation radiation.

Precision energy measurement of the 106Ru 512 keV gamma ray compared with the position annihilation radiation

Abstract The energy of the 106 Ru 512 keV gamma ray is determined with a high resolution Ge(Li) detector in comparison with the energy of the positron annihilation in aluminum. The value is (511860.5±3.1) eV.

Source position effect in gamma-ray energy measurements with Ge(Li) detectors

Abstract The source position effect for gamma-ray pulse heights was investigated with two planar and three coaxial Ge(Li) detectors at the gamma-ray energies of 303 keV, 512 keV and 1275 keV. The peak shift in the pulse height spectrum was measured as a function of the source-to-detector distance and of the source angle from the detector axis. A clear shift of the peak center was observed for the planar detectors, and a smaller shift for the coaxial detectors. It was found that the shift was almost independent of the bias voltage. These experimental results are difficult to explain by the field increment effect and the charge trapping effect in the detector. The rise time effect was not observed in any of the planar detectors.

Gamma-ray energy measurement for 177mLu with a precision pulser

Abstract Energies of 38 gamma rays in the range 100–460 keV emitted in the decay of 177m Lu were measured precisely with a Ge spectrometer based on the gamma-ray primary energy standards of 169 Yb and 192 Ir. The nonlinearity correction for the spectrometer was obtained from the amplitude of the pulser pulses as determined from the dc voltage measured with a high precision digital voltmeter. Our experiment shows that this method is convenient and capable of determining the gamma-ray energy with an accuracy of 10 ppm or less when based on two standard lines in gamma-ray spectra. The final energy values are obtained from adjustment by the Ritz rule. Forty-three gamma-ray energies were determined within errors of 10 ppm and they are useful for secondary energy standards.

Gamma-ray energies of 192Ir

Abstract The energy of the 192Ir 296 keV gamma ray has been measured with the standard of 183Ta by using Ge(Li) detectors. The observed value is 295.949±0.004 keV on the basis of the 1969 physical constants. Other gamma-ray energies of 192Ir are obtained from energy differences of previous measurements and the Ritz rule.

Pion Beam Development for the LAMPF Biomedical Project

Common to both static and dynamic patient irradiations at the LAMPF linac is the problem of maintaining good quality control of beams form a secondary channel. A major contributor to therapy beam variation has been change in electron contamination due to the change in target geometry and proton beam steering. The electron variation problem is described and a solution is presented that has been realized as a result o a new target geometry that allows some control of the electron fraction. (GHT)

Correction equations of coincidence summing using75Se radionuclide in the efficiency of HpGe detector

Correction equations of the coincidence-summing effect for efficiencies of HpGe detector based on the decay scheme were developed by considering the summing up to triple coincidence. The correction equations which do not dependent on the kind of the Ge detector are very useful for efficiency calibrations of a Ge detector in the energy region from 60 to 400 keV by using75Se radionuclide even with very short source-to-detector distances.

Gamma-ray energies from the decay of 152Eu

Gamma-ray energies of 152Eu were measured with the uncertainties of 1.1–7.3 eV in the region of 290–720 keV using Ge spectrometers. To determine the 719 keV γ-ray energy of 152Eu, we measured the 125 and 592 keV cascade γ-ray energies of 185Os which provide the 717 keV cross-over γ-ray energy. Seven γ-ray energies of 152Eu in the region of 770–1400 keV were obtained from the sum of the cascade γ-ray energies.

Charged particle detector system for Coulomb excitation experiment with NORDBALL

Abstract A charged particle detector system for Coulomb excitation experiments with the multi-γ-ray detector system, NORDBALL, has been designed and constructed. The system consists of five position sensitive Si detecors and an annular type Si detector, which are installed in the central space of a BaF2 inner ball. The experiments have been carried out by using the beams of 32S, 48Ti and 58Ni ions. The combination of the new charged particle detector system and NORDBALL proves to have an excellent performance for heavy-ion-induced Coulomb excitation experiments.