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AMoRE is an international project to search for the neutrinoless double beta decay of $^{100}$Mo using a detection technology consisting of magnetic microcalorimeters (MMCs) and molybdenum-based scintillating crystals. Data collection has begun for the current AMORE-I phase of the project, an upgrade from the previous pilot phase. AMoRE-I employs thirteen $^\mathrm{48depl.}$Ca$^{100}$MoO$_4$ crystals and five Li$_2$$^{100}$MoO$_4$ crystals for a total crystal mass of 6.2 kg. Each detector module contains a scintillating crystal with two MMC channels for heat and light detection. We report the present status of the experiment and the performance of the detector modules., Comment: 8 pages, 4 figures, published in Journal of Low Temperature Physics (2022)

$^{208}\mathrm{Pb}$ is a doubly magic nucleus which has been studied extensively by many experiments and nuclear models. Its properties, such as excitation energies, spins, and parities of the ground and excited states are well known. However, some $\ensuremath{\gamma}$ transitions with ${E}_{\ensuremath{\gamma}}g3$ MeV from the excited states to the ground state in $^{208}\mathrm{Pb}$ have never been observed. The intensities of these $\ensuremath{\gamma}$ transitions are important issues for $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ decay searches because these transitions can make non-negligible background signals depending on their intensities. We conducted a measurement to search for the 3197.7, 3475.1, and 3708.4 keV transitions, which are emitted from the second, third, and fourth excited states in $^{208}\mathrm{Pb}$, respectively. A 2 kg ${\mathrm{ThO}}_{2}$ sample was measured using a 100% relative efficiency high-purity germanium detector for 39.5 days at Y2L, an underground laboratory in Yangyang, Korea. We improved upper limits for intensities of the 3197.7, 3475.1, and 3708.4 keV $\ensuremath{\gamma}$ transitions as $l1.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}%, l1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}%$, and $l1.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}%$, respectively. These upper limits are at least a factor of 19 better than the previous results.

Three different ice core samples from Antarctica were analyzed to identify activity concentrations of radioactive isotopes. Tracking migration of radioactive isotopes to Antarctica can provide a key clue to understand global environmental changes caused by radiation exposures because the Antarctic ice cores can preserve unique characteristics of various environmental conditions. We are particularly interested in the 137Cs nucleus, because it is closely related to radiation exposure from nuclear power plant accidents and nuclear bomb tests. With its half life of 30.17±0.03 years, 137Cs can also be used to assess the age of sedimentation occurring after around the year 1945. We selected three ice core samples, called Tarn8, Styx27, and H25, from different time periods; the Tarn8 sample is known to be from earlier than ~ 1000 AD, the Styx27 sample is approximately from the year 1945, and the H25 sample is from the year 2012. Radioactive isotope measurements of the ice core samples were performed using a 100% HPGe detector at Cheongpyeong Underground Radiation Laboratory (CURL). We measured the activity of 137Cs in the H25 sample to be 0.98 ± 0.82 mBq/kg. Although the activity has a large uncertainty mainly due to the limited sample quantity, the 137Cs isotopes in the Antarctic ice core were measured for the first time in Korea.

The goal of the Advanced Mo-based Rare process Experiment (AMoRE) is to search for the neutrinoless double beta decay of $$^{100}$$ Mo using low-temperature detectors consisting of Mo-based scintillating crystals read out via metallic magnetic calorimeters. Heat and light signals are measured simultaneously at millikelvin temperatures, which are reached using a cryogen-free dilution refrigerator. The AMoRE-Pilot experiment, using six $$^{100}$$ Mo-enriched, $$^{48}$$ Ca-depleted calcium molybdate crystals with a total mass of about 1.9 kg, has been running in the 700-m-deep Yangyang underground laboratory as the pilot phase of the AMoRE project. Several setup improvements through different runs allowed us to achieve a high energy resolution and an efficient particle discrimination. This article briefly presents the status of the AMoRE-Pilot experiment, as well as the plans for the next, larger-scale, experimental stages.

We constructed an underground laboratory called Cheongpyeong Underground Radiation Laboratory (CURL) for measuring the radioactivity levels of various samples by using HPGe detectors. CURL is located underground at a depth of 1000-m water equivalent in the Cheongpyeong Pumped Storage Power Plant. We developed a shielding system, which consists of 15-cm-thick Pb blocks and 5-cm-thick Cu blocks and completely surrounds a 100% HPGe detector. We measured the background radiations and the gamma peaks from sources with and without the shield. The shielding efficiencies were also estimated using MCNP5 simulations, and they were compared to our measured data. The shielding system blocked more than 99.99% of gamma rays with energies up to 3.0 MeV. The HPGe detector with the shielding system at CURL blocked both high-energy cosmic rays and background radiation from surrounding rocks and materials. Our CURL detector system was optimized for gamma-ray measurements of meterials with ultra-low radioactivity.

A calcium molybdate ( $\text{CaMoO}_{4}$ ) crystal scintillator, with molybdenum enriched in $^{100}\text{Mo}$ and calcium depleted in $^{48}\text{Ca}$ ( $^{40}\text{Ca}{}^{100}\text{MoO}_{4}$ ), was developed by the Advanced Molybdenum based Rare process Experiment (AMoRE) collaboration to search for a neutrinoless double beta ( $0\nu \beta \beta $ ) decay of $^{100}\text{Mo}$ . We are planning to use about 10 kg of $^{40}\text{Ca}{}^{100}\text{MoO}_{4}$ crystals as cryogenic bolometers for the first phase of the experiment (AMoRE-I) at the Yang Yang underground laboratory (Y2L) in Korea. This experiment calls for an extremely low level of radioactive contamination in detectors, particularly by thorium, uranium, and radium decay chains. We measured scintillation properties and radioactive contamination of $\text{CaMoO}_{4}$ and $^{40}\text{Ca}{}^{100}\text{MoO}_{4}$ crystals at the Y2L. We also estimated the acceptable level of internal radioactive background using Monte Carlo simulation for the AMoRE-I.

A scintillating crystal that contains a candidate isotope for DBD provides a promising technique for the high detection-efficiency and good energy resolution. The AMoRE (Advanced Molybdenum based Rare process Experiment) collaboration is studying the potential of CaMoO4 scintillation crystals for searches for looMo 0v DBD.

In order to understand the scintillation characteristics of nuclear recoil events in CsI(Tl) crystals and for application to the analysis of Dark Matter (DM) searches, we study quenching and channeling effects with simulations of recoil ion motion in CsI(Tl) and experiments using neutrons impinging on the crystal. The electronic energy loss versus penetration depth of recoil ions in a CsI(Tl) target are simulated by the SRIM and MARLOWE programs and modified by the application of a measured scintillation efficiency function. They are used to produce quenching factors as a function of recoil energy. The application of the MARLOWE code to a monocrystalline target yields a light yield distribution including tails which are correlated with ions' enhanced ranges. The 2.4 MeV pulsed neutrons impinging on a monocrystalline CsI(Tl) target and an array of neutron detectors located at different scattering angles are used to measure the light yield distribution and the status of the measurement is reported.

This study was carried out to estimate the effects of breed and environment such as sex, test station, test year, test season, parity, initial and final weight on average daily gain, age at 90kg, backfat thickness, feed efficiency, lean percent and selection index on the basis of the performance data collected from 25,790 pigs of Duroc, Yorkshire and Landrace breeds which were performance-tested at the Korea Swine Testing Station from 1991 to 2002. The results obtained in the study are summarized as follows; 1. The means of the major economic traits were estimated as 959.95±0.699g for average daily gain, 138.36± 0.072days for age at 90kg, 1.41±0.001cm for backfat thickness, 2.33±0.001 for feed efficiency, 56.71±0.018% for lean percent and 221.65±0.113 for selection index. 2. The effect of breed was statistically significant for all studied traits. Briefly, Duroc showed the best per- formance for the average daily gain and age at 90kg. Landrace had the best performances for the backfat thickness and lean meat percent. In feed efficiency and selection index, Yorkshire had a better score than other breeds. 3. The least-squares means of female and male for the traits studied were 923.05±1.289g and 974.53±0.856g for average daily gain, 139.74±0.145days and 137.21±0.097days for age at 90kg, 1.49±0.002cm and 1.39± 0.002cm for backfat thickness, 2.43±0.002 and 2.28±0.002 for feed efficiency, 56.43±0.034% and 56.81± 0.023% for lean percent and 211.37±0.194 and 224.61±0.129 for selection index. Therefore, males were superior to females for all traits examined. 4. The effect of test station was statistically significant for all traits except for selection index. Performances for age at 90kg, backfat thickness, feed efficiency and lean meat percent collected from Test station 2 were higher than those from Test station 1. However, Test station 1 showed better average daily gain. 5. The initial weight and final weight included as a covariate in this study had a significant influence on average daily gain, age at 90kg, backfat thickness, feed efficiency and selection index. From the absolute values of the estimated regression coefficients, it was inferred that the final weight had greater effect for the investigated traits than the initial weight.

The effect of Fe addition on the cycle performance of FeS2 cathode for Li/FeS2 cell was investigated. In Li/FeS2 cell without Fe addition, a large voltage drop was observed in the initial discharge process, and the cell showed poor cycle performance during 40 charge/discharge cycles. On the other hand, the Li/FeS2 cell with 10 wt-%Fe delivered a higher discharge capacity of ∼670 mAh g−1 FeS2 in the first discharge and exhibited better cycle performance than the cell without Fe addition. The rate capability of the cell was also greatly improved by the addition of Fe in the FeS2 cathode.

New limits are presented on the cross section for Weakly Interacting Massive Particle (WIMP) nucleon scattering in the KIMS CsI(T) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24524.3 kg\cdotdays. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 keV to 11 keV. The 90% upper limit of NR event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(T) is 0.0098 counts/kg/keV/day which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20 GeV/c2., 5 pages, 6 figures

We developed a SrCl 2 crystal scintillator for 0υ Electron Capture/β+ decay search, and 4π CsI(Tl) tagging detector to reduce the background. This experimental system was installed at the YangYang underground laboratory which is for the WIMP search by KIMS group. The system ran for 60 days and we have finished analyzing for 2 hits back to back coincidence signal selection.

KIMS is a dark matter search experiment using low background CsI(TB) crystals at Yangyang Underground Laboratory in Korea. With a total exposure of 3409 kg⋅d data, we set a new limit on WIMP‐nucleon cross section. We achieved the most stringent limit on the spin‐dependent interaction for a pure proton case. We were able to exclude the DAMA signal region for both spin‐dependent and spin‐independent interaction for the WIMP mass greater than 20 GeV/c2. KIMS experiment is upgraded with 12 CsI(TB) crystals corresponding to a total mass of 104 kg and accumulating data since Jan. 2008.

Cu-based amorphous (Cu54Zr22Ti18Ni6) coating was produced through cold spraying as a new fabrication process. The microstructure and macroscopic properties of the amorphous coating layer were investigated and compared with those of the cold-sprayed, pure Cu coating. Amorphous powder was prepared via gas atomization, and Al 6061 was used as the substrate plate. The X-ray diffraction results showed that Cu-based amorphous powder could be successfully deposited through cold spraying sans any crystallization. The Cu-based amorphous coating layer (300-400 μm thick) had 4.87% porosity. The hardness of the Cu-based amorphous coating was 412.8 Hv or 68% of the hardness of the injection-casted bulk amorphous material. The wear resistance of the Cu-based amorphous coating was found to be three times higher than that of the pure Cu coating. The results of the 3-point bending test showed that the adhesion strength of the Cu-based amorphous coating layer was higher than the pure Cu coating. The hard Cu-based amorphous particle was also observed to be able to deform soft substrate easily through particle collisions; thus generating strong adhesion between the coating and substrate. Note, however, that the amorphous coating layer unexpectedly showed lower corrosion resistance than the pure Cu coating, possibly due to the higher porosity of the cold-sprayed amorphous coating.

The prototype strain of the human adenovirus type 35 (AV35) was examined. BamHI, EcoRI, HindIII, KpnI, PstI, and SalI restriction endonucleases were used for the mapping of DNA fragments. Three original maps were constructed, and previously published maps were somewhat modified. A PstI-specific fragment library was also prepared and characterized using the pBR322/E. coli system. Some of the recombinants seem to be applicable for rapid DNA diagnostics, and for the comparative mapping of type- and subgroup-specific DNA sequences. The comparative presentation of physical maps of subgroup B human adenoviruses might improve the efficiency of genotyping of adenoviruses using restriction endonucleases.

Cloned PstI fragments of human adenovirus 35 (AV35) genome were compared with the DNA of representatives of human adenovirus subgroups A (type 12), B (type 7), C (types 1, and 5), D (type 8), and E (type 4), using blot hybridization techniques. The E1b region of AV35 was found to be more distantly related to those of other subgroups than E1a regions sequences and examined by others. DNA hybridization was observed only between E1b of AV35 and the DNA of AV4, thus the recombinant constructed might be applied as B-subgroup-specific diagnostic probe. Common nucleotide sequences were detected within the E3 regions of serotypes 1, 4, 5, 7, 8, and 35. On the basis of inter-subgroup homology, and PstI-fragments it may be concluded, that the structure of E3 sequences of AV7 and AV35 DNA are closely related to those of AV3 DNA sequenced by Signäs et al. [18]. E4 regions were compared only of serotypes representing subgroups B, C, and D. These sequences were subgroup specific, similarly to E1b regions.