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In this study, we evaluated and compared the pulse shape discrimination (PSD) performance of a typical photomultiplier tube (PMT) with that of multipixel photon counters (MPPCs), also known as silicon photomultipliers (SiPMs). We used CsI(Tl) scintillators for both setups and mainly evaluated the PSD performance in the $\alpha $ – $\beta $ separation. We used the charge comparison method, that is, identifying the particle type based on the ratio of the charges collected in two time gates: Short gate (SG) for the delayed part and long gate (LG) for the entire digitized waveform. With the same LG = 2250 ns, the PMT setup showed a better PSD performance with the figure of merit (FOM) being 3.33 (in $\alpha $ – $\beta $ separation), whereas the FOM of the MPPC setup was 2.26. This inferior performance of the MPPC setup was due to its slow response, mainly the slow decay time in the waveform of one photoelectron (p.e.) of the MPPCs. This study aimed to determine the relationships of the PSD performance with the number of p.e. collected and the time characteristics of the scintillator–photosensor coupling. From these relationships, we estimated the SG to obtain $\text {FOM}_{\text {max}}$ and afterward confirmed a method to further increase the PSD performance. The estimated SG gave a comparable FOM without an extensive search for the optimized SG for obtaining the actual $\text {FOM}_{\text {max}}$ in analysis. To further increase the PSD performance of the MPPC setup, we used a new data acquisition (DAQ) system and extended the LG to 8000 ns to collect more p.e. and mitigate the slow response of the MPPCs. Using the new DAQ system, we obtained an FOM of 3.91 for the MPPC setup, that is, an increase by a factor of 1.7.

For simple applications, such as the calibration of a charged particle detector, a multi-MeV proton generator may be preferable to cyclotrons or electrostatic accelerators such as Van de Graaff generator. Thus, a proton generating system, consisting of an 18 GHz superconducting (SC)-ECR ion source and a deuterated polyethylene target, was developed at the Research Center for Nuclear Physics at Osaka University. A

Gamow-Teller (GT) transitions starting from the ${T}_{z}=+2$ nucleus $^{64}\mathrm{Zn}$ to the ${T}_{z}=+1$ nucleus $^{64}\mathrm{Ga}$ were studied in a ($p,n$)-type ($^{3}\mathrm{He},t$) charge-exchange reaction at a beam energy of 140 MeV/nucleon and scattering angles close to ${0}^{\ensuremath{\circ}}$. Here, ${T}_{z}$ is the $z$ component of the isospin $T$. The experiment was conducted at the Research Center for Nuclear Physics (RCNP) in Osaka, Japan. An energy resolution of $\ensuremath{\approx}34$ keV was achieved by applying beam matching techniques to the Grand Raiden magnetic spectrometer system. With our good resolution, we could observe GT strength fragmented in many states up to an excitation energy of $\ensuremath{\approx}11$ MeV. By performing angular distribution analysis, we could identify states in $^{64}\mathrm{Ga}$ excited by GT transitions. The reduced GT transition strengths [$B$(GT) values] were calculated assuming the proportionality between the cross sections and the $B$(GT) values. Shell-model calculations using the GXPF1J interaction reproduced the $B$(GT) strength distribution throughout the spectrum. States with isospin $T=3$ were identified by comparing the $^{64}\mathrm{Zn}\text{(}{}^{3}\text{He,}t{\text{)}}^{64}\text{Ga}$ spectrum with a $^{64}\mathrm{Zn}(d,^{2}\mathrm{He})^{64}\mathrm{Cu}$ spectrum. Relative excitation energies of the corresponding structures are in good agreement, supporting the robustness of isospin symmetry in the mass number $A=64$ nuclei.

For simple applications, such as the calibration of a charged particle detector, a multi-MeV proton generator may be preferable to cyclotrons or electrostatic accelerators such as Van de Graaff generator. Thus, a proton generating system, consisting of an 18 GHz superconducting (SC)-ECR ion source and a deuterated polyethylene target, was developed at the Research Center for Nuclear Physics at Osaka University. A 3He2+ beam of 400 eμA was generated by the SC-ECR ion source with the acceleration voltage of 20 kV in an experiment that utilized the fusion reaction 3He + deuteron (D) → proton(P) + 4He. Protons with energies of the order of several MeV were successfully generated at 3.67 Hz at the atmosphere side of the target in the experimental setup, using a novel target base with a thin aluminum window.

A new DC muon beamline MuSIC was set up at the Research Centre for Nuclear Physics (RCNP), Osaka University. The MuSIC beamline provides an intense low-energy muon beam with distinc- tive devices of superconducting solenoid magnets. A beamline commissioning and a feasibility study for $\mu$SR (Muon spin rotation, relaxation and resonance) are in progress. In the commissioning, ∼10$^5$ count/(sec·1$\mu$A-proton) of negative muons and ∼10$^6$ count/(sec·1$\mu$A-proton) of positive muons were measured with TOF setup in the experimental port using 60 MeV/$c$ muon beam. The non-destructive elemental analyses and nuclear physics experiments with a negative muon beam have been recently started. In a feasibility study for μSR with a positive muon beam, we observed spin asymmetry spectra with a test sample in a magnetic field of 0.004 Tesla using a newly constructed $\mu$SR spectrometer.

At the new DC muon beamline MuSIC at Research Center for Nuclear Physics (RCNP), Osaka University, the beamline construction from the solenoid system of the muon production to the experimental port was completed. A beamline commissioning and a feasibility study for μSR are now in progress. With newly refurbished spectrometer installed at the experimental port, we succeeded in observing μSR spectra and μ-e decay asymmetry in a simple setup down to 4 K. We are still under development of other μSR appratuses.

Ordinary muon capture (OMC) on enriched Mo100 isotopes was studied for the first time to investigate neutrino nuclear responses for neutrinoless double-β decays and supernova neutrino nuclear interactions. Muon capture on Mo100 proceeds mainly as Mo100(μ,xn)Nb100-x with x being the number of neutrons emitted from negative muon capture. The Nb isotope mass distribution was obtained by measuring delayed γ rays from radioactive Nb100-x. By using the neutron emission model after the muon capture, the neutrino response (the strength distribution) for OMC was derived. The OMC strength distribution shows a giant resonance (GR) at the peak energy around 11-14 MeV, suggesting the concentration of the OMC strength at the muon GR region.

Proton generator of several MeV for easy use like calibration of charged particle detector is needed instead of cyclotrons or electrostatic accelerators like Van de Graaff. So a proton generating system which consists of 18 GHz superconducting (SC)-ECR ion source and deuterated polyethylene target has been developed at the Research Center for Nuclear Physics (RCNP), Osaka University. The 3He2+ beam of 200eμA has been provided by SC-ECR ion source with 20 keV acceleration voltage and as a result of feasibility test of 3He+deuteron (D)→proton(P)+4He fusion reaction, the protons of 14.67 MeV have been obtained in 0.5Hz successfully.

Using $\gamma $ -ray beams produced in the inverse Compton scattering between ${\hbox{CO}}_2$ laser photons and relativistic electrons, we have calibrated electron beam energies in the nominal energy range 550–974 MeV at the synchrotron radiation facility NewSUBARU. The laser Compton-scattering (LCS) $\gamma $ -ray beams were produced at energies from 561 to 1728 keV and detected with a high-purity germanium detector. The electron beam energies were determined by reproducing the full energy peaks of the $\gamma $ -ray beams by Monte Carlo simulations. The accuracy of the calibration is $(5.5 - 9.4) \times {10^{ - 5}}$ . The reproducibility of the electron beam energy is excellent in an independent injection and deceleration. The present energy calibration of the electron beams offers a standard for the energy calibration of high-energy LCS $\gamma $ -ray beams produced with a ${\hbox{Nd:YVO}}_4$ laser. As applications of the energy calibration, we investigated the energy linearity of a $3.5^{\prime\prime} \times 4.0^{\prime\prime}$ ${\hbox{LaBr}}_3({\hbox{Ce}})$ detector in the response to $\gamma $ -rays at energies up to 10 MeV and the energy profile of the high-energy LCS $\gamma $ -ray beams.

Spectroscopy for neutron-rich nuclei 9He and 12Be has been performed by means of heavy-ion double charge exchange (HIDCX) (18O, 18Ne) reaction on stable target nuclei 9Be and 12C, respectively. Several clear peaks in 12Be at low excitation energy region even above neutron separation energy have been observed in one-shot measurement, whereas no prominent signals of 9He have been observed owing to the small cross section. It is shown that the HIDCX reaction is a new powerful spectroscopic tool for study of unstable neutron-rich nuclei.

The $\ensuremath{\gamma}$-ray strength functions and level densities of $^{73,74}\mathrm{Ge}$ have been extracted up to the neutron-separation energy ${S}_{n}$ from particle-$\ensuremath{\gamma}$ coincidence data using the Oslo method. Moreover, the $\ensuremath{\gamma}$-ray strength function of $^{74}\mathrm{Ge}$ above ${S}_{n}$ has been determined from photoneutron measurements; hence these two experiments cover the range of ${\mathrm{E}}_{\ensuremath{\gamma}}\ensuremath{\approx}1$--13 MeV for $^{74}\mathrm{Ge}$. The obtained data show that both $^{73,74}\mathrm{Ge}$ display an increase in strength at low $\ensuremath{\gamma}$ energies. The experimental $\ensuremath{\gamma}$-ray strength functions are compared with $M1$ strength functions deduced from average $B(M1)$ values calculated within the shell model for a large number of transitions. The observed low-energy enhancements in $^{73,74}\mathrm{Ge}$ are adopted in the calculations of the $^{72,73}\mathrm{Ge}(n,\ensuremath{\gamma})$ cross sections, where there are no direct experimental data. Calculated reaction rates for more neutron-rich germanium isotopes are shown to be strongly dependent on the presence of the low-energy enhancement.

The 30-deg white neutron beam at the Research Center for Nuclear Physics (RCNP) cyclotron facility has been characterized as a probe suitable for testing of single-event effects (SEE) in semiconduc...

Photodisintegration of $^{9}\mathrm{Be}$ through the $1/{2}^{+}$ state near neutron threshold and cluster dipole resonance below giant dipole resonance was measured with quasi-monochromatic $\ensuremath{\gamma}$-ray beams produced in the inverse Compton scattering of laser photons. The cross section for the $1/{2}^{+}$ state is revisited, being consistent with the 2001 data. The cross section for the cluster dipole resonance is consistent with the cluster dipole sum-rule which however degenerates for the two-body $(n\text{\ensuremath{-}}^{8}\mathrm{Be})$ and three-body $(n\text{\ensuremath{-}}\ensuremath{\alpha}\text{\ensuremath{-}}\ensuremath{\alpha})$ configurations.

Electron capture cross-sections have been measured for 3He+ ions in Rb vapor. The deduced data were used for evaluating the performance of the proposed polarized 3He ion source (SEPIS) based on the spin-exchange collisions. Measurements of the 3He+ beam components after passing through the target were made as a function of the Rb target thickness at energies ranging from 1.0 to 19 keV. The Rb vapor thickness was varied by changing the Rb cell temperature and the thicknesses were calibrated by observing the Faraday rotation angles of a probe laser ( λ = 782.0 nm ) penetrating the Rb vapor under the presence of a magnetic field ( ∼ 0.26 T ) . Assuming that the double electron capture and stripping of 3He0 atoms are neglected, the electron capture cross-sections σ c were deduced. It was found that the observed energy dependence of σ c significantly deviated from that of the He + 4 + Cs system which was measured in the past. Lastly, the observed energy dependence of σ c was compared with the theoretical calculation assuming the semi-classical close-coupling method based on the molecular-orbital expansion. It was found that the calculated results, as a whole, reproduced the experimental results except for the data collected at 1 keV. This qualitative reproduction partly supports the appropriateness of the above theory which predicts the large spin-exchange cross-sections at low energies.

In order to investigate the contamination due to the radioactive isotopes (RIs) in NaI(Tl) scintillator for dark matter search, a simple method of pulse shape discrimination (PSD) to extract α-rays energy spectrum was developed. Two linear signals of different timings were input into a single module charge-sensitive analog-to-digital converter. The α- and the γ-rays were discriminated by comparing the total charge integration of a pulse with the partial one. As a result, the α-rays energy spectrum with NaI(Tl) was successfully and clearly extracted. The present work showed that the PSD method was performed by the minimum electronic circuits. The sensitivity was high enough to measure RIs of a few μBq/kg in high pure NaI crystals for dark matter search.

The cold dark matter search has been carried out at Oto Cosmo Observatory with the large volume NaI(Tl) scintillators of ELEGANT V(ELE-V). The new limits on WIMPs could be obtained by the analysis of the annual modulation. Recently, the performance of NaI(Tl) detector in ELE-V was successfully improved. these are also discussed.

Using Geant4, a complex simulation code of the interaction between laser photons and relativistic electrons was developed. We implemented physically constrained electron beam emittance and spacial distribution parameters and we also considered a Gaussian laser beam. The code was tested against experimental data produced at the γ-ray beam line GACKO (Gamma Collaboration Hutch of Konan University) of the synchrotron radiation facility NewSUBARU. Here we will discuss the implications of transverse missallignments of the collimation system relative to the electron beam axis.

Highly-monochromatic γ-ray beams are produced at the NewSUBARU synchrotron radiation facility by the inverse Compton scattering of laser photons from relativistic electrons. The latest s-process study in nuclear astrophysics with the γ-ray beam is presented., SCOPUS: cp.j, info:eu-repo/semantics/published

Photoneutron cross sections for seven samarium isotopes, 144Sm, 147Sm, 148Sm, 149Sm, 150Sm, 152Sm and 154Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

We have accurately determined U-chain concentration in a detector by means of the β–α delayed coincidence method. This method can measure the radioactivity of the order of 10 −7 Bq / kg . It corresponds to the concentration of the order of 0.01 ppt under the assumption that the U-chain is in the secular radioactive equilibrium, by a signal-to-noise ratio of one to one.

Photoneutron cross sections were measured for the seven stable samarium isotopes ${}^{144,147,148,149,150,152,154}\mathrm{Sm}$ near the neutron threshold with quasi-monochromatic laser-Compton scattering $\ensuremath{\gamma}\phantom{\rule{0.28em}{0ex}}\mathrm{rays}$. Our photoneutron cross sections are found to be low by 20%--37% relative to existing data. The photoneutron data are analyzed with the talys reaction code by considering the Skyrme Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random phase approximation (QRPA) model and the axially symmetric deformed Gogny HFB plus QRPA model of the $E1$ $\ensuremath{\gamma}\text{\ensuremath{-}}\mathrm{ray}$ strength. Using the $\ensuremath{\gamma}\text{\ensuremath{-}}\mathrm{ray}$ strength function constrained by the present photoneutron data, we made a thorough analysis of the reverse $(n,\ensuremath{\gamma})$ cross sections including the radioactive nucleus $^{151}\mathrm{Sm}$ with a half-life of 90 yr. The radiative neutron capture cross section for $^{153}\mathrm{Sm}$ with the half-life of 1.928 d is deduced with the $\ensuremath{\gamma}\text{\ensuremath{-}}\mathrm{ray}$ strength function method.

We propose a method that prevents single event latchup (SEL) using deep P-well on P-substrate. To confirm the effectiveness of the proposed method, SEL and single event upset (SEU) are evaluated for three well configurations; double-well, ordinary triple-well and the proposed deep P-well on P-substrate. Neutron irradiation test shows that the proposed method achieves SEL prevention without SEU increase.

A versatile calorimeter has been developed to study astrophysical S factors for fusion reactions with gaseous targets. The number of incident projectiles are deduced from the deposited power. The principal technique employed here is based on the heat flux sensor output transferred linearly from the heat flow. Absolute values at various energies are obtained by calibration with current measurements by using a Faraday cup. This calorimeter is presently applied in measurement of the solar 3He+3He fusion reaction with an accuracy better than 2%.

The radon emanation rates for materials were measured by using the electrostatic precipitation method as a radon monitor. It was found that a low level of radon was emanated from several material components in ELEGANT V. The radon monitor has been developed for the highly sensitive measurements of low-level radon concentration. The system was shown to have a sensitivity to radon concentrations as low as 1.6 mBq / m 3 for one day measurement. The system was also used as the radon concentration monitor for the gas inside the airtight box of the ELEGANT V at Oto Cosmo Observatory.

A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at ${E}_{x}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4\ifmmode\pm\else\textpm\fi{}1\mathrm{MeV}$ and with a width of $4\ifmmode\pm\else\textpm\fi{}1\mathrm{MeV}$ in ${}^{6}\mathrm{He}$ via the ${}^{6}\mathrm{Li}({}^{7}\mathrm{Li},{}^{7}\mathrm{Be})$ reaction at an incident energy of $65A\phantom{\rule{0ex}{0ex}}\mathrm{MeV}$ and forward scattering angles including $0\ifmmode^\circ\else\textdegree\fi{}$. Its cross section is deduced to be $\ensuremath{\sigma}(0\ifmmode^\circ\else\textdegree\fi{})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.9\ifmmode\pm\else\textpm\fi{}0.2\mathrm{mb}/\mathrm{sr}$. This value is comparable to that of the giant dipole resonance simultaneously measured.

Out of plane measurements of the angular correlations for the 12C(e, e(')n) reaction have been performed for the first time in the giant resonance region. The cross sections were directly separated into the longitudinal and transverse, longitudinal-transverse, and transverse-transverse components. The cross section at the peak of the giant resonance ( omega = 22.5 MeV) has been found to be almost all longitudinal. It was reproduced by the multipole expansion with E0 and E2 components besides E1. The longitudinal-transverse component might have a maximum around 24 MeV. The transverse-transverse component is very small over the giant resonance.

A compact low-energy, high current accelerator has been constructed for the study of fusion reactions relevant to the field of nuclear astrophysics. It consists of a modified NANOGUN™, a low-energy beam transport, a windowless gas target, a beam calorimeter, and a detector system. The accelerator and the NANOGUN ion source with a single extraction electrode provides 930 μA 3He1+ of 20 keV at a gas target chamber. A two-electrode extraction has been tested for a few source voltages. The obtained target current is 75, 140, 110, 110, 105, 78, and 80 μA for 20, 25, 30, 35, 38, 40, and 45 kV potential, respectively. The transport efficiency from the source to the target is 5.7%.

Development of low background CdZnTe detectors is in progress to study neutrino-less double beta decay. The kq product (mobility times lifetime) for holes was measured in a set of CdZnTe detectors at various temperatures between #223C and !403C in order to investigate charge collection e$ciencies for holes. The sensitivity of CdZnTe detectors to neutrino-less b'EC decays of 64Zn (64Zn#ECP64Ni#b') is estimated from these data. ( 1999 Elsevier Science B.V. All rights reserved.

For a selective excitation of spin-flip strength, ( 6 Li, 6 He) reactions can be a useful tool, because: a) 6 Li and 6 He have ground-state spin and parity values J π = 1 + and 0 + , respectively; b) 6 He has no particle-stable excited state, thus effects from ejectile excitation can be avoided. The ( 6 Li, 6 He) experiments were performed at 100 MeV/nucleon, at which incident energy the reaction is expected to be single-step dominant. Through the analysis of the good-resolution ( 6 Li, 6 He) data on 13 C, 26 Mg, 27 Al and 58 Ni targets, the evidence for a proportional relationship between 0° cross sections and the corresponding Gamow-Teller transition strengths is examined. Suppression of non-spin flip excitations is discussed based on the hindrance of the excitation of the isobaric analog state.

The isovector electric monopole resonance (IVMR) was studied by the ${}^{60}\mathrm{Ni}{(}^{7}\mathrm{Li}{,}^{7}\mathrm{Be}{)}^{60}\mathrm{Co}$ reaction at 65A MeV and at forward scattering angles including zero degrees. We confirmed the existence of the IVMR at an excitation energy of $20\ifmmode\pm\else\textpm\fi{}2\mathrm{MeV}$ with a width of $10\ifmmode\pm\else\textpm\fi{}2\mathrm{MeV}$ in ${}^{60}\mathrm{Co}$, which is an analog of the ${T}_{0}+1$ isospin component of the IVMR estimated at ${E}_{x}\ensuremath{\approx}31\mathrm{MeV}$ in ${}^{60}\mathrm{Ni}$. The result presently obtained is consistent with previous results using the pion charge-exchange reaction.

A γ-ray detector system “NYMPHS” was built for 7Be-γ coincidence measurements to separate (7Li, 7Beg.s.) and (7Li, 7Be0.43MeV) channels in the (7Li, 7Be) reaction at intermediate energies. NYMPHS is composed of 22 GSO scintillators, each with a volume of about 30 cm3. A typical energy resolution was about 9% at Eγ = 0.66 MeV. The absolute detection efficiency of NYMPHS was 0.200 ± 0.005 for the 0.43 MeV 7Be γ-ray. NYMPHS combined with a magnetic spectrograph showed good performance for 7Be-γ coincidence measurements in the (7Li, 7Be) reactions on 12C and 90Zr targets at EL = 65A MeV.

The ( 7 Li, 7 Be) reaction was found to be used to separate ΔS = 0 and ΔS = 1 transitions through the coincidence measurement of the γ-ray from deexcitation of the 0.43 MeV state of 7 Be at an incident energy of 65 A MeV on 6 Li, 7 Li, 12 C and 90 Zr nuclei. The reaction was shown to proceed predominantly via one-step reaction process. Predominance of one-step process means utility for derivation of spin-flip and non spin-flip strengths for isovector excitations in medium heavy nuclei at intermediate incident energies. The relative nuclear spin-strength P sf was deduced for isovector excitations.

Differential cross sections and analyzing powers ( ${A}_{y}$) have been measured for the proton knockout reaction from ${s}_{1/2}$ orbits of three kinds of target nuclei at ${E}_{p}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}392\mathrm{MeV}$. The ${A}_{y}$ values are reduced from those of free proton-proton scattering and the reduction rate is found to depend on target. For the present setting, where the recoil momentum is almost zero, an averaged density seen through this reaction can be estimated and it reaches almost half of the saturation density in some cases. The reduction of ${A}_{y}$ shows a monotonically decreasing function of the averaged density, which strongly suggests the existence of a nuclear medium effect on the nucleon-nucleon interaction.

Angular correlations for the {sup 12}C(e,e{sup {prime}}n){sup 11}C reaction in the giant resonance region have been measured for forward scattering at an effective momentum transfer of 0.35fm{sup -1}. The angular correlation for the ground-state transition indicates a strong forward-backward asymmetry at the peak of the giant dipole resonance ({omega}=22.5MeV), which is different from the nearly symmetric angular correlations observed for the {sup 12}C(e,e{sup {prime}}p{sub 0}){sup 11}B reaction. Recent random-phase approximation predictions fail to reproduce the experimental angular correlations for both (e,e{sup {prime}}n{sub 0}) and (e,e{sup {prime}}p{sub 0}), predicting the opposite patterns to those observed. {copyright} {ital 1997} {ital The American Physical Society}

A new polarized ion source was constructed at RCNP. It employs the cold (∼30 K) atomic beam technology and an electron cyclotron resonance ionizer. The source has been operational since fall in 1994 to provide polarized protons to experimental researches at 200–400 MeV. After the first operation of the source, developments have been performed to increase the long term stability of the source and to improve the beam polarization. The source works for longer than one month before cleaning the dissociator. Proton beam intensity from the source is 50–100 μA and the polarization is 70% or better after acceleration with the K400 RCNP ring cyclotron.

Applying a bridged-T type all-pass network to a resonator described as a parallel circuit, the output voltage of the resonator shows a band-pass feature over a certain frequency range, while the input impedance is always constant against frequency. This feature is considered to realize the ferrite-loaded tuning-free rf accelerating cavity. It has several merits such as a simple cavity structure without bias windings, an easy operation without feedback control of the bias current, applying new ferrite with favorable rf characteristics and so on. The accelerating system is applicable to a proton-synchrotron for radio therapy or a cooler-synchrotron for nuclear physics studies in a multi-GeV region. This paper presents a theory of the system, the characteristics of the new ferrite, which is currently developed, and design studies of the network based on preliminary measurements of an equivalent lumped circuit.

Differential cross sections and analysing powers for the reaction 9 Be(p → , p′) have been measured at incident proton energies of 54.7 and 74.7 MeV. The new data, supplemented by existing data in the energy range from 30 to 220 MeV, has been subjected to various analyses with the aim of obtaining optical potentials to calculate final-state interaction effects in proton-knockout reactions. A conventional optical model analysis fails to give a description that is in simultaneous agreement with all elastic scattering data. A considerable improvement is obtained by including the quadrupole contribution to elastic scattering, both with phenomenological and microscopic potentials. Finally, the influences of the various reaction mechanisms and of the differences between the derived potentials are studied when applied to (e,e′p) and (γ,p) calculations in the distorted wave impulse approximation.

Decay neutrons from the [sup 40]Ca([ital e],[ital e][prime][ital n])[sup 39]Ca reaction were studied in the giant resonance region. The cross sections and angular distributions, separated for [ital n][sub 0] and [ital n][sub 1] decays, were obtained for excitation energies between 19 and 27 MeV, at the effective momentum transfer of 0.35 fm[sup [minus]1]. Legendre polynomial coefficients obtained from fitting the data are compared with those from the ([ital e],[ital e][prime][ital p]) reaction. In the energy range 19--21 MeV, the interference coefficients [ital b][sub 1] and [ital b][sub 3] for the ground state transition are in agreement, but the noninterference coefficient [ital b][sub 2] is different. The different behavior of the angular distribution for protons and neutrons may suggest the interference of the decay from a [ital T]=0 quadrupole resonance and the [ital T]=1 giant dipole resonance. A similar tendency was also seen in comparing with the ([ital e],[ital e][prime][ital p][sub 1]) reaction. The Legendre polynomial coefficients for the [ital n][sub 0] decay in the ([ital e],[ital e][prime][ital n]) reaction, transformed to the photon point, agree well with those of the ([gamma],[ital n][sub 0]) reaction. The reduced total cross section is consistent between the ([ital e],[ital e][prime][ital n]) and ([gamma],[ital n])more » reactions, but the cross section for ([ital e],[ital e][prime][ital n][sub 0]) is larger than that of ([gamma],[ital n][sub 0]) near the peak of the resonance. The values of the longitudinal-transverse interference term are close to zero in the present region, which is rather small compared with the value near the resonance of the ([ital e],[ital e][prime][ital p]) reaction.« less

The absolute electrofission cross sections of Au and Ta were measured in the range 25--180 MeV. The deduced photofission cross section shows, for both Au and Ta, a pronounced dip around the photopion threshold ([similar to]140 MeV). This ([gamma],[ital f]) dip is interpreted as a consequence of a probable photopion absorption in a stopped pion regime.''

Differential cross sections and analyzing powers for the proton-proton bremsstrahlung have been measured at 389 MeV incident energy. At the present kinematical conditions, an enhancement of the cross sections due to the Δ current contribution is predicted. The measured cross sections are larger than the theoretical predictions including the Δ current contribution.

We have developed a robust latch for achieving high reliability in LSI. The latch can attenuate multi-node single-event-upset (MNSEU) and single event transient on local-clock (SETLC). The robust latch has Dual-clock-buffers (DCB) and Double-height-cell (DHC) technologies. Results on neutron acceleration experiments show that DHC can dramatically attenuate MNSEU and DCB can protect almost SETLC of the latch. In addition, we investigate optimum design in well structure.