A Search for Correlated Low-energy Electron Antineutrinos in KamLAND with Gamma-Ray Bursts


Search for Supernova Relic Neutrinos at KamLAND


Supernova Neutrino Burst Search at KamLAND


Status of 48Ca double beta decay search in CANDLES


Limits on Astrophysical Antineutrinos with the KamLAND Experiment


Search for Solar Flare Neutrinos with the KamLAND Detector


The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment


Low background measurement in CANDLES-III for studying the neutrinoless double beta decay of 48Ca


Search for Low-energy Electron Antineutrinos in KamLAND Associated with Gravitational Wave Events


Quenching factor measurement of NaI (Tl) using monochromatic neutrons for dark matter search

Proceedings of the 35th Workshop on Radiation Detectors and Their Uses


Development of highly radiopure NaI(Tl) scintillator for PICOLON dark matter search project

Progress of Theoretical and Experimental Physics


Detectors for direct dark matter search at KamLAND

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment


Status of 48Ca double beta decay search and its future prospect in CANDLES


Measurement of the scintillation response of neutron scattering in NaI(Tl) scintillator for dark matter search

Proceedings of the 33rd Workshop on Radiation Detectors and Their Uses


Upgrading of shielding for rare decay search in CANDLES

Progress in Nuclear Science and Technology


Improved search for two-neutrino double electron capture on 124 Xe and 126 Xe using particle identification in XMASS-I


Direct dark matter search by annual modulation with 2.7 years of XMASS-I data


Background studies of high energy γrays from ( n , γ) reactions in the CANDLES experiment


Development of CANDLES low background HPGe detector and half-life measurement of 180Tam


Identification of 210Pb and 210Po in the bulk od copper samples with a low-background alpha particle counter


Search for solar KaluzaKlein axions by annual modulation with the XMASS-I detector


A measurement of the time profile of scintillation induced by low energy gamma-rays in liquid xenon with the XMASS-I detector


Status and future prospect of 48Ca double beta decay search in CANDLES


KamLAND SENSITIVITY TO NEUTRINOS FROM PRE-SUPERNOVA STARS


Search for double-beta decay of 136Xe to excited states of 136Ba with the KamLAND-Zen experiment


Search for the proton decay mode p→ν¯K+ with KamLAND

Physical Review D, Particles, Fields, Gravitation and Cosmology


STUDY OF ELECTRON ANTI-NEUTRINOS ASSOCIATED WITH GAMMA-RAY BURSTS USING KamLAND


Measurement of airborne radioactivity from the Fukushima reactor accident in Tokushima, Japan


Study of 48Ca Double Beta Decay by CANDLES


Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment


徳島における福島第一原子力発電所事故に伴う大気中人工放射性核種の測定

The airborne radioactive isotopes from the Fukushima Daiichi nuclear plant was measured in Tokushima,western Japan. The continuous monitoring has been carries out in Tokushima, Japan. From March 23, 2011 thefission product 131I was observed. The radioisotopes 134Cs and 137Cs were also observed in the beginning of April.However the densities were extremely smaller than the Japanese regulation of radioisotopes.

Natural Science Research, Faculty of Integrated Arts and Sciences, The University of Tokushima

徳島大学総合科学部自然科学研究


SEARCH FOR COSMIC DARK MATTER BY MEANS OF THIN AND WIDE AREA NaI(Tl) ARRAY

"RADIATION DETECTORS AND THEIR USES", Proceedings of the 24th Workshop on Radiation Detectors and Their Uses


Probing new physics models of neutrinoless double beta decay with SuperNEMO

The European Physical Journal C - Particles and Fields


「市内中心部で星空観望会∼徳島市内の天体観望会と街の活性化∼」

「市内中心部で星空観望会∼徳島市内の天体観望会と街の活性化∼」


Proton inelastic scattering to the dilute alpha-cluster condensed 02+ state at Ex=7.654 MeV in 12C


Study of 48Ca double beta decay with CANDLES


Dark matter search by means of segmented scintillator (PICO-LON)


MOON for Double-Beta Decays and Neutrino Nuclear Responses


Study of Double Beta Decay of 48Ca by CANDLES


Dark matter search by means of thin NaI(Tl) scintillator array

RADIATION DETECTORS AND THEIR USES Proceedings of the 23rd Workshop on Radiation Detectors and Their Uses


Evidence for α-Cluster Condensation in the 02+ state at Ex=7.654 MeV in 12C via the (p,p') Reaction at 300 MeV


Isovector dipole resonances of 4He and Neutrino Heating in Supernova


Highly segmented inorganic crystal has been shown to have good performance for dark matter search. The energy resolution of ultra thin and large area NaI(T1) scintillator has been developed. The estimated sensitivity for spin-dependent excitation of 127I was discussed. The recent status of low background measurement at Oto Cosmo Observatory is reported


Double beta decay experiments and ν-mass sensitivities

This is a brief report on Majorana neutrino(ν) mass to be studied by neutrino-less double beta decays (0νββ). The ν-mass depends on the nuclear structure of the ββ isotope, the effective detector volume and the background rate. Subjects discussed include 1 0νββ and ν- mass, 2 0νββ nuclear matrix elements, and 3 0νββ experiments and ν-mass sensitivities.


MOON for a next-generation neutrino-less double-beta decay experiment; present status and perspective

The performance of the MOON detector for a next-generation neutrino-less double-beta decay experiment was evaluated by means of the Monte Carlo method. The MOON detector was found to be a feasible solution for the future experiment to search for the Majorana neutrino mass in the range of 100-30 meV.


Analogs of the giant dipole and spin-dipole resonances in 4He and in alpha clusters of 6,7Li studied by the 4He, 6,7Li(7Li,7Be,γ) reactions


Excitation and charged particle decay of the analogs of the dipole resonance in the alpha cluster of 6Li

Intrinsic excitation of α cluster in A=6 nuclei were searched for by using the 6Li(3He,t) and 6Li(7Li,7Be) charge exchange reactions at the incident energy of 450 and 455 MeV at 0o. Charged particle decay from the dipole resonance at around 25 MeV in 6Be and 6He was measured. The dominant decay channels of the resonance are found to be d+3He+n for 6Be and d+t+p for 6He. The invariant mass spectra for 3He+n and 3H+p show clear enhancement in comparison with phase-space spectra, and suggests that α cluster in 6Be and 6He are excited to 4Li and 4H.


Multilayer Scintillator Responses for Mo Observatory of Neutrino Experiment Studied Using a Prototype Detector MOON-1

An ensemble of multilayer scintillators is discussed as an option of the high-sensitivity detector MOON (Mo Observatory of Neutrinos) for spectroscopic measurements of neutrinoless double beta decays. A prototype detector MOON-1, which consists of 6-layer plastic scintillator plates, was built to study the photon responses of the MOON-type detector. The photon responses, i.e., the number of scintillation photons collected and the energy resolution, which are key elements for high-sensitivity experiments, are found to be 1835±30 photoelectrons for 976 keV electrons and σ=2.9±0.1% (ΔE/E=6.8±0.3% in FWHM) at the Qββ∼3 MeV region, respectively. The multilayer plastic scintillator structure with high energy resolution as well as a good signal for the background suppression of β γ rays is crucial for the MOON-type detector to achieve inverted-hierarchy neutrino-mass sensitivity. It will also be useful for medical and other rare-decay experiments as well.

Journal of the Physical Society of Japan


WIMPS Search by Exclusive Measurements with Thin Multilayer NaI(T1) Scintillators (PICO-LON)

Proceedings of Sixth International Workshop "Identification of Dark Matter"


The Performance of Thin NaI(Tl) Scintillator Plate for Dark Matter Search

A thin (0.05cm) and wide area (5×5cm^2) NaI(Tl) scintillator was developed. The performance of the thin NaI(Tl) plate, energy resolution, single photoelectron energy and position sensitivity were tested. An excellent energy resolution of 20% (FWHM) at 60 keV was obtained. The single photoelectron energy was calculated to be approximately 0.42±0.02keV. Position information in the 5×5cm^2 area of the detector was also obtained by analyzing the ratio of the number of photons collected at opposite ends of the detector. The position resolution was obtained to be 1cm (FWHM) in the 5×5cm^2 area.


The MOON-1 detector construction and the study of backgrounds from radioactive isotopes

MOON is a multilayer system of plastic scintillators and 100Mo films for 100Mo 0νββ decays. A prototype detector MOON-1 was built with 6 layers of plastic scintillators and 142g of 100Mo films for background (BG), energy and position resolution studies of the MOON detector. No serious BG from natural radioactive isotopes (RI) for 0νββ detection was found.


MOON for spectroscopic studies of double beta decays and the present status of the MOON-1 prototype detector

The MOON (Molybdenum Observatory Of Neutrinos) project, as an extension of ELEGANT V, aims at spectroscopic studies of double beta decays from 100Mo with a sensitivity of the Majorana neutrino mass around 30 meV. Measurements with good energy and position resolutions enable one to select true signals and to reject background ones. A prototype MOON detector (MOON Phase-1A) with 142 g 100Mo was built and is running at the Oto underground laboratory. The present report describes briefly the outline of the MOON project and the present status of MOON-1.


WIMPs search by means of thin NaI(Tl) array

A thin plate of NaI(Tl) with the dimension of 5cm×5cm×0.05cm has been developed for WIMPs search. The thin NaI(Tl) showed the good performance for energy resolution and low energy threshold. The advantages for WIMPs search, especially, inelastic excitation of nuclei by spin-dependent interaction between WIMPs and 127I is discussed.


WIMPs Search by Means of the Highly Segmented Scintillator

The highly sensitive method to search for WIMPs dark matter particles is proposed. An array of thin NaI(Tl) plate has the great selectivity for distinguishing the WIMPs events and background ones. The principle of signal selection for WIMPs is described. The high sensitivity for SD (spin-dependent) type WIMPs is expected by applying multi-layer system of NaI(Tl) detector.


Spectroscopy of low energy solar neutrinos by MOON-Mo Observatory Of Neutrinos

Nuclear Physics B - Proceedings Supplements


MOON (Mo Observatory Of Neutrinos) for double beta decay

The MOON (Molybdenum Observatory Of Neutrinos) project aims at studies of double beta decays with a high sensitivity of <mν >∼0.03 eV and real-time studies of low-energy solar neutrinos. Two β rays from 100Mo are measured in coincidence for the 0νββ studies. The inverse β rays from solar neutrino captures of 100Mo are measured in delayed coincidence with the following β decay of 100Tc. Measurements with good energy resolution and good position resolution enable one to select true signals. A prototype MOON detector (MOON 1) is now under development. The present report describes briefly the outline of the MOON project and the status of MOON 1.


環境中のラドン，トロン及びその子孫核種の動態調査研究

環境中のラドン，トロン及びその子孫核種の動態調査研究

Radiation Biology Research Communications


Excitations of the alpha cluster in A=6 and 7 nuclei

6Heのt+tクラスター分子状態を(7Li,7Be)反応で励起された共鳴状態からのt粒子崩壊過程を測定して調べた．励起エネルギーEx=18 MeVにt+tと考えられる分子共鳴を見つけた．t粒子崩壊分岐比は90±10%で，tの2体崩壊していることが分かった．


Cluster fragmentations of deep(1s)-hole states in light nuclei


Giant dipole resonances and the analogs of alpha-clusters in A=6 and 7 nuclei


t+3He molecular structures in 6Li studied by (3He,a) reaction at 450 MeV


Search for neutrino-less double beta decay of 48Ca by CaF2 scintillator

A CaF2 scintillation detector system (ELEGANT VI) has been operating at Oto Cosmo Observatory to study double beta decays of 48Ca. No events were observed around the Q-value energy region after the analysis of 4.23 kg yr data. To derive the lower limit for the half-life of the neutrino-less double beta decay of 48Ca, the expected number of background events in that energy region was estimated by a Monte Carlo simulation using the measured activities of 214Bi and 220Rn inside CaF2 crystals. A new lower limit is obtained to be 1.4×1022 yr at the 90% C.L. An experimental sensitivity is 5.9×1021 yr at the 90% C.L.


野島断層500mボーリングコアの深度方向に対するガンマ線放出核種の放射能濃度分布


徳島県における大気·雨水中ラドン子孫核種及びBe-7の濃度

徳島県における大気·雨水中ラドン子孫核種及びBe-7の濃度


Tri-nucleon cluster structure in A=6 nuclei above cluster decay threshold


Highly sensitive measurement of α-rays in NaI(Tl) scintillator by pulse shape discrimination with charge-sensitive analog-to-digital converter

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment


Neutrino Studies in 100Mo and MOON-Mo Observatory Of Neutrinos


Limits on Majorana neutrino mass and right-handed weak currents by neutrinoless double beta decay of 100Mo


Determination of Th-Chain Concentration in a High Sensitivity Detector


Determination of U-Chain Concentration in NaI(Tl) Scintillator by Delayed Coincidence Method


Limits on Majoron emitting neutrinoless double-beta decay of 100Mo


Evidence for the di-triton resonance in 6He

Proceedings of Int. Symp. on Clustering aspects of quantum many-body systems


6Liにおけるαクラスターの励起した共鳴状態を(7Li,7Be)反応でΔS=0とΔS=1励起を区別して調べた．ΔS=0とΔS=1スペクトルに共通してα粒子のGDRやSDRの励起エネルギーに対応する励起エネルギー領域にΔL=1共鳴が観測された．6Liはd+αやt+3Heクラスター構造を基底状態に持つ．これらの励起と考えられる共鳴状態も観測された．


Li同位体におけるαクラスターの励起した共鳴状態を(7Li,7Be)反応でΔS=0とΔS=1励起を区別して調べた．ΔS=0とΔS=1スペクトルに共通してα粒子のGDRやSDRの励起エネルギーに対応する励起エネルギー領域にΔL=1共鳴が観測された．Li同位体の基底状態に見られる他のクラスター構造を反映した励起と考えられる共鳴状態についても観測された．

Progress of Theoretical Physics Supplement


Dipole excitation of α-clusters in 6Li and 7Li.

6Liと7LIにおけるαクラスターの励起した共鳴状態を(7Li,7Be)反応でΔS=0とΔS=1励起を区別して調べた．ΔS=0とΔS=1スペクトルに共通してα粒子のGDRやSDRの励起エネルギーに対応する励起エネルギー領域にΔL=1共鳴が観測された．散乱断面積や共鳴幅はα粒子のGDRやSDRとよく一致した．


Double beta decays of 100Mo by ELEGANT V at Oto Cosmo Observatory

Exclusive measurements of neutrino-less double beta decays (0νββ) of 100Mo were made by means of ELEGANT V. The present status of the double beta decay experiment with ELEGANT V is presented. The data at Oto lab., being combined with the data at Kamioka, gives stringent limits on half-lives for 0νββ and mν < 1.7eV.

Nuclear Physics B - Proceedings Supplements


マレーシアのAMANGと徳島の岩石からの放射能

マレーシアのAMANGと徳島の岩石からの放射能


Soft Dipole Resonance in the Neutron-Skin Nucleus 6He

A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at Ex = 4+/-1 MeV and with a width of 4+/-1 MeV in 6He via the 6Li( 7Li, 7Be) reaction at an incident energy of 65A MeV and forward scattering angles including 0 degrees. Its cross section is deduced to be sigma(0 degrees ) = 0.9+/-0.2 mb/sr. This value is comparable to that of the giant dipole resonance simultaneously measured.

ソフトダイポール共鳴の候補を6Li(7Li,7Be)反応で6Heに見出した．この共鳴はαクラスターと中性子ハローとの双極子振動と考えられている．この反応は直接反応過程が主である．散乱角0°で，その共鳴の散乱断面積が0.9±0.2 mb/srであった．この強度は同時に測定されたGDRに比べ，クラスター模型で計算されるsum ruleになっていることが分かった．この論文はAPSのPhysics News Updateで取り上げられ，新聞にも報道された．APSの2000年度の物理の成果20傑に選ばれた．


Limits on the annual modulation of WIMPs-nucleus scattering with large-volume NaI(Tl) scintillator


徳島における環境放射能計測の現状

徳島における環境放射能計測の現状


Measurement of Radon Daughters Attached to Aerosol in Tokushima

Natural Science Research, Faculty of Integrated Arts and Sciences, The University of Tokushima


Gamow-Teller transitions in (7Li,7Be) reaction at 65 AMeV

入射エネルギー65-MeV/Aでの(7Li,7Be)反応での6Li, 12C, 28Si におけるGT遷移強度を調べた．この反応は前方散乱角では核子-核子有効相互作用の中心力による直接過程が主であることが分かった．β崩壊から得られたGT強度に比例している事を示した．


Isovector electric monopole resonance in 60Ni

60Ni(7Li,7Be)反応で，ΔS=0励起によるアイソベクトル型モノポール共鳴(IVMR)を調べた．ΔS=1励起と比較して，ΔS=0, ΔL=0の共鳴が60CuでEx=20±2 MeV，幅Γ=10±2 MeVで存在することが分かった．これは60NiではEx=31 MeVのIVMRに対応していることが分かった．


GSO-Detection system "NYMPHS" for (7Li,7Be-γ) reaction at intermediate energies

(n,p)型荷電変換反応である(7Li,7Be)反応で反応粒子7Beとそのγ線との同時計数測定して，(7Li,7Be)反応の二つの反応過程(7Li,7Be_0)と(7Li,7Be_1)を区別して測定できる装置''NYMPHS''を設計製作した．この装置の検出効率は7Be_1からの0.43 keVγ線に対して20%であった．磁気分析器と組み合わせることで，原子核12Cと90Zrにおける(7Li,7Be)反応で二つの反応過程が分離できることが分かった．

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment


The (7Li,7Be) reaction as a spin-probe for isovector excitations

(7Li,7Be)反応は原子核スピン-アイソスピン応答をΔS=0とΔS=1遷移を区別して調べられるユニークな反応である．これは反応粒子7Beとそのγ線との同時計数測定して実現された．原子核6Li, 7Li, 12C, 90ZrでΔS=0とΔS=1励起を区別して，その有用性を示した．


Spin-isospin responses of 71Ga for solar neutrinos studied by 71Ga(3He,tγ)71Ge reaction

71Ga(3He,t)反応で原子核のaxial-vector charged-weak応答で励起されるGTRを調べた．71Gaは太陽ニュートリノ検出用の原子核であるため，この応答を通してニュートリノを検出されることもあるため，その強度を実験的に求めるため，中性子崩壊閾値付近までのGTRからのγ崩壊強度を測定し，71Ga(ν,e) 71Geと71Ga(ν,eγ)71Ge反応によるニュートリノ検出過程を調べた．


Double Beta Decays and ELEGANT V and VI at Oto Cosmo Observatory


What can we learn from particle- and gamma-decay of charge-exchange giant resonances?

荷電変換反応では巨大共鳴の1p-1hの集団運動を励起できるため，共鳴状態からの粒子崩壊過程を調べることで共鳴状態の幅について求められる．さらに，基底状態や低励起状態へのγ崩壊過程は共鳴状態が残留相互作用でsum-rule 強度がどれだけ他の状態へ失われるかの情報も与える．GTRの強度がどのような状態に逃げているのかを調べられる．208Biや12Cでの測定結果をもとにGTRの強度分布について議論した．

Proceedings of Int. Symp. on New facet of spin giant resonances in nuclei


Isovector resonances in light nuclei studied by the (7Li,7Be) reaction


Limits on neutrino-less double beta decay of 100Mo


Limits on axial coupled dark matters studied by inelastic scsattering from 127I in NaI

Nuclear Physics B - Proceedings Supplements


Study of Neutrino and Dark Matter by High Sensitivity ββ and X ray Spectrometer ELEGANTS

Progress of Particle and Nuclear Physics


Limits on single- and multinucleon decays in 127I by inclusive measurements of nuclear γ and x rays

Baryon-number-violating nucleon decays were studied by searching for x and γ rays associated with radioactive residual nuclei produced by single- and multinucleon decays in 127I. Large volume NaI(Tl) detectors were used for the study. New lower limits of τ(n)>4.7×1024 yr and τ(p)>3.0×1024 yr were obtained on the mode-independent mean lives for the neutron and proton decays in 127I, respectively. Lower limits of τ(nn)>2.1×1024 yr, τ(nnn)>1.8×1023 yr, and τ(nnnn)>1.4×1023 yr were deduced for the first time on the mode-independent mean lives for dineutron, trineutron, and tetraneutron decays in 127I, respectively.


Search for exotic nuclear transition by using the large volume NaI detector of ELEGANTS V


Application of a large-volume NaI scintillator to serach for dark matter

Application of a large-volume NaI scintillator to search for the cold dark matter (DM) in the Universe is discussed. A low-noise(~5keV) and low-background(~5/keV/kg/day) were achieved even with a large (36.5kg) NaI scintillator. Light output efficiencies for 23Na and 127I were measured as 0.4+/-0.2 and 0.05+/-0.02, in the recoil energy range of 5-100keV and 40-300keV, respectively. NaI is shown to have merits of a large volume, large cross sections for dark matter, and of 100% abundance eof finite-spin nucleus, but to have the demerits of a small form factor due to the finite-size effect of 127I at the presently measured energy region.


Purification of the NaI(Tl) crystal for dark matter search project PICOLON


Search for cosmic dark matter by means of ultra high purity NaI(Tl) scintillator

Proceedings of the 31 st Workshop on Radiation Detectors and Their Uses


Search for neutrino-less double beta decay of 48 Ca CANDLES

Proceedings of Physics(INPC2916) The 26th International Nuclear Physics Conference


KAMLAND-PICO PROJECT TO SEARCH FOR DARK MATTER


CANDLES Search for neitrino-less double beta decay of 48Ca

EPJ WEB of Conferences Proceedings of INPC 2013 International Nuclear Physics Conference


地球を一周してきた放射性物質

地球を一周してきた放射性物質


HAM Radio Observation of meteor in Tokushima

徳島におけるアマチュア無線を使った流星の電波観測

Natural Science Research, Faculty of Integrated Arts and Sciences, The University of Tokushima

徳島大学総合科学部自然科学研究


Radioactivirie from Amang in Malaysia and Rocks in Tokushima


Measurement of Radon Daughters Attached to Aerosol in Tokushima


Nuclear Rare Decays Studied with GSO Scintillator


Anti-Compton-Type Ge-NaI Detector System at the University of Tokushima

Proc. of 12th Workshop on Radiation Detectors and Their Uses, KEK Tsukuba


GSO Scintillation Detector System for the (7Li,7Be) Experiment at Intermediate Energies

Proc. of 11th Workshop on Radiation Detectors and Their Uses, KEK Tsukuba


Study of Nuclear Rare Decays by GSO Scintillator


Search for exotic neutrino-electron interactions using solar neutrinos in XMASS-I


Precision Analysis of the 136Xe Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements


Search for dark matter in the form of hidden photons and axion-like particles in the XMASS detector


A SEARCH FOR ELECTRON ANTINEUTRINOS ASSOCIATED WITH GRAVITATIONAL-WAVE EVENTS GW150914 AND GW151226 USING KAMLAND


Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen


Direct dark matter search by annual modulation in XMASS-I


Journal of the Physical Society of Japan


Search for spin-coupled dark matter by studuing the axial-vector excitation of nuclei

Axial-vector (spin) excitation of 127I by inelastic scattering of dark matter (DM) was studied to search for spin-couled DM. The inelastic process from 127I has the advantages of a large cross-section, a large scintillation output and of a known nuclear matrix element. Stringent limits by direct measurements were obtained on the purely spin-coupled DM candidates.