New VR magnification ratios of QSO 0957+561

We present VR magnification ratios of QSO 0957+561, which are inferred from the GLITP light curves of Q0957+561A and new frames taken with the 2.56m Nordic Optical Telescope about 14 months after the GLITP monitoring. From two photometric approaches and a reasonable range for the time delay in the system (415-430 days), we do not obtain achromatic optical continuum ratios, but ratios depending on the wavelength. These new measurements are consistent with differential extinction in the lens galaxy, the Lyman limit system, the damped Ly-alpha system, or the host galaxy of the QSO. The possible values for the differential extinction and the ratio of total to selective extinction in the V band are reasonable. Moreover, crude probability arguments suggest that the ray paths of the two components cross a similar dusty environment, including a network of compact dust clouds and compact dust voids. As an alternative (in fact, the usual interpretation of the old ratios), we also try to explain the new ratios as caused by gravitational microlensing in the deflector. From magnification maps for each of the gravitationally lensed images, using different fractions of the surface mass density represented by the microlenses, as well as different sizes and profiles of the V-band and R-band sources, several synthetic distributions of V-band and R-band ratios are derived. In some gravitational scenarios, there is an apparent disagreement between the observed pair of ratios and the simulated distributions. However, several microlensing pictures work well. To decide between either extinction, or microlensing, or a mixed scenario (extinction + microlensing), new observational and interpretation efforts are required.Comment: PS and PDF versions are created from the LaTeX file and 5 EPS figures, two additional figues (Figs. 6 and 7) in JPEG format, scheduled for the ApJ 20 January 2005 issu

PENINGKATAN KEMAMPUAN MENGENAL BILANGAN MELALUI PERMAINAN EDUKATIF DENGAN MEDIA BIJI KARET DI TAMAN KANAK-KANAK

Artikel ini bertujuan untuk mengetahui: (1) Perencanaan pembelajaran mengenal bilangan melalui permainan edukatif dengan media biji karet (2) Pelaksanaan pembelajaran mengenal bilangan melalui permainan edukatif dengan media biji karet (3) Respons anak dalam pembelajaran mengenal bilangan melalui permainan edukatif dengan media biji karet (4) Peningkatan kemampuan anak dalam mengenal bilangan melalui permainan edukatif dengan media biji karet. Penelitian ini dilakukan selama dua siklus. Hasil perhitungan menunujukkan bahwa terjadi peningkatan yang cukup berarti pada kemampuan guru dalam merencanakan dengan kriteria baik dan melaksanakan pembelajaran dengan kriteria baik dari siklus I ke siklus II. Peningkatan juga ditunjukkan dengan respon anak dalam pembelajaran mengenal bilangan mengalami peningkatan sebesar 41,995% pada siklus I ke 63,995% pada siklus II. Peningkatan juga ditunjukkan dengan kemampuan anak yang meningkat sebanyak 63,55% pada siklus I ke 78,66% pada siklus II. Dengan demikian pembelajaran melalui permainan edukatif dengan media biji karet mampu meningkatkan kemampuan anak mengenal bilangan pada anak usia 5-6 tahun di TK Aisyiyah Bustanul Athfal Kec. Nanga Pinoh Kab.Melawi. Kata Kunci : Mengenal Bilangan, Lambang Bilangan, Media Biji Karet.   Abstract : This research aims to know: (1) The plan in learning number by using rubber seed as an educational game (2) The practice of learning number by using rubber seed as an educational game (3) pupils repond in learning number by using rubber seed as an educational game (4)whetherthere is some improvement of pupils ability in learning number by using rubber seed as an educational game. This research was completed in two circles. By calculating data, the researcher found that there was some significant improvement in teacher’s capabilility, with good grade, to plan and implement lesson from circle 1 to circle 2. Other improvement also found in pupils respond in learning number from 41,995% in circle 1 to 63,995% in circle 2. Pupils ability in recognizing number also increased from 63,55% in circle 1 to 78,66% in circle 2. In brief, learning number by using rubber seed as an educational game is able to improve 5-6 years old pupils abitity to recognize number in TK Aisyiyah Bustanul Athfal Kecamatan Nanga Pinoh. Kabupaten Melawi. Keywords: Recognizing Number, Number, Rubber Seed Medium

Characterisation of strip silicon detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity up to 6 · 1034 cm−2 s −1 . A consequence of this increased luminosity is the expected radiation damage at 3000 fb−1 after ten years of operation, requiring the tracking detectors to withstand fluences to over 1 · 1016 1 MeV neq/cm2 . In order to cope with the consequent increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 µm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 µm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 µm thick full size radial (end-cap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout chips (ABCN-25). A resolution better than the inter strip pitch of the 74.5 µm strips was achieved for both detectors. The effect of the p-stop diffusion layers between strips was investigated in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stop regions between the strips rather than the strip pitch

Charge collection and field profile studies of heavily irradiated strip sensors for the ATLAS inner tracker upgrade

The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to a fluence of 1×1016 neq/cm2, exceeding the maximum of 1.6×1015 neq/cm2 expected for the strip tracker during the high luminosity LHC (HL-LHC) period including a safety factor of 2. The ATLAS12, n+-on-p type sensor, which is fabricated by Hamamatsu Photonics (HPK) on float zone (FZ) substrates, is the latest barrel sensor prototype. The charge collection from the irradiated 1×1 cm2 barrel test sensors has been evaluated systematically using penetrating β-rays and an Alibava readout system. The data obtained at different measurement sites are compared with each other and with the results obtained from the previous ATLAS07 design. The results are very consistent, in particular, when the deposit charge is normalized by the sensor's active thickness derived from the edge transient current technique (edge-TCT) measurements. The measurements obtained using β-rays are verified to be consistent with the measurements using an electron beam. The edge-TCT is also effective for evaluating the field profiles across the depth. The differences between the irradiated ATLAS07 and ATLAS12 samples have been examined along with the differences among the samples irradiated with different radiation sources: neutrons, protons, and pions. The studies of the bulk properties of the devices show that the devices can yield a sufficiently large signal for the expected fluence range in the HL-LHC, thereby acting as precision tracking sensors

Embedded pitch adapters: a high-yield interconnection solution for strip sensors

A proposal to fabricate large area strip sensors with integrated, or embedded, pitch adapters is presented for the End-cap part of the Inner Tracker in the ATLAS experiment. To implement the embedded pitch adapters, a second metal layer is used in the sensor fabrication, for signal routing to the ASICs. Sensors with different embedded pitch adapters have been fabricated in order to optimize the design and technology. Inter-strip capacitance, noise, pick-up, cross-talk, signal efficiency, and fabrication yield have been taken into account in their design and fabrication. Inter-strip capacitance tests taking into account all channel neighbors reveal the important differences between the various designs considered. These tests have been correlated with noise figures obtained in full assembled modules, showing that the tests performed on the bare sensors are a valid tool to estimate the final noise in the full module. The full modules have been subjected to test beam experiments in order to evaluate the incidence of cross-talk, pick-up, and signal loss. The detailed analysis shows no indication of cross-talk or pick-up as no additional hits can be observed in any channel not being hit by the beam above 170 mV threshold, and the signal in those channels is always below 1% of the signal recorded in the channel being hit, above 100 mV threshold. First results on irradiated mini-sensors with embedded pitch adapters do not show any change in the interstrip capacitance measurements with only the first neighbors connected

Evaluation of the performance of irradiated silicon strip sensors for the forward detector of the ATLAS Inner Tracker Upgrade

The upgrade to the High-Luminosity LHC foreseen in about ten years represents a great challenge for the ATLAS inner tracker and the silicon strip sensors in the forward region. Several strip sensor designs were developed by the ATLAS collaboration and fabricated by Hamamatsu in order to maintain enough performance in terms of charge collection efficiency and its uniformity throughout the active region. Of particular attention, in the case of a stereo-strip sensor, is the area near the sensor edge where shorter strips were ganged to the complete ones. In this work the electrical and charge collection test results on irradiated miniature sensors with forward geometry are presented. Results from charge collection efficiency measurements show that at the maximum expected fluence, the collected charge is roughly halved with respect to the one obtained prior to irradiation. Laser measurements show a good signal uniformity over the sensor. Ganged strips have a similar efficiency as standard strips

Mapping The In-Plane Electric Field Inside Irradiated Diodes

A significant aspect of the Phase-II Upgrade of the ATLAS detector is the replacement of the current Inner Detector with the ATLAS Inner Tracker (ITk). The ATLAS ITk is an all-silicon detector consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker have been developed to withstand the high radiation environment in the ATLAS detector after the High Luminosity Upgrade of the Large Hadron Collider at CERN, which will significantly increase the rate of particle collisions and resulting particle tracks. During their operation in the ATLAS detector, sensors for the ITk strip tracker are expected to accumulate fluences up to 1.61015neq/cm2 (including a safety factor of 1.5), which will significantly affect their performance. One characteristic of interest for highly irradiated sensors is the shape and homogeneity of the electric field inside its active area. For the results presented here, diodes with edge structures similar to full size ATLAS sensors were irradiated up to fluences comparable to those in the ATLAS ITk strip tracker and their electric fields mapped using a micro-focused X-ray beam (beam diameter 23m2). This study shows the extension and shape of the electric field inside highly irradiated diodes over a range of applied bias voltages. Additionally, measurements of the outline of the depleted sensor areas allow a comparison of the measured leakage current for different fluences with expectations for the corresponding active areas

Radiation effects of CERN-PS 24 GeV/c protons in silicon strip sensors, evaluated with ATLAS18 ITk strip sensor test structures

Test structures from the ATLAS18 ITk strip detector wafers were irradiated with 24 GeV/c protons. These test structures were positioned at various angles with respect to the proton beam. Blocks of G10 material were placed in front of these test structures to study the effect of scattering of primary protons on the received particle fluence. The results confirm that both the incidence angle of the beam and scattering significantly influence the actual fluence to which the samples are exposed. Miniature strip detectors, first irradiated with protons, were also irradiated with reactor neutrons, to a combined fluence of φneq = 1.6 x 1015  cm−2. The combination of proton and neutron fluences matched the combination expected in the most exposed part of the strip detector in the ALTAS Inner Tracker (ITk). Good charge collection was measured confirming that the strip detectors are sufficiently radiation hard for successful operation to highest fluences expected at the HL-LHC

Unusual annealing of charge collection efficiency of silicon strip detectors, ATLAS18, irradiated to high fluences with 23 GeV protons

Extensive studies were performed on highly irradiated ATLAS18 mini strip detectors to evaluate their annealing behaviour. Collected charge was measured after several steps of annealing at 60 °C. For detectors irradiated with neutrons or low energy protons the collected charge exhibited a beneficial effect of short-term annealing which was followed by a decrease in charge collection efficiency at longer annealing times. After irradiation with 23 GeV protons to fluences above Φeq∼1.2⋅1015 cm−2, the collected charge remained unchanged or decreased after the first few tens of minutes of annealing. Edge-TCT measurements indicated that this unusual annealing behaviour is related to the double-peak electric field profile in the detector. Mixed irradiation with 23 GeV protons and neutrons to fluences matching the expected in the upgraded ATLAS experiment showed this unusual annealing effect will not impact the operation of the ITk strip detector.</p

Setups for eliminating static charge of the ATLAS18 strip sensors

Construction of the new all-silicon Inner Tracker (ITk), developed by the ATLAS collaboration for the High Luminosity LHC, started in 2020 and is expected to continue till 2028. The ITk detector will include 18,000 highly segmented and radiation hard n+-in-p silicon strip sensors (ATLAS18), which are being manufactured by Hamamatsu Photonics. Mechanical and electrical characteristics of produced sensors are measured upon their delivery at several institutes participating in a complex Quality Control (QC) program. The QC tests performed on each individual sensor check the overall integrity and quality of the sensor. During the QC testing of production ATLAS18 strip sensors, an increased number of sensors that failed the electrical tests was observed. In particular, IV measurements indicated an early breakdown, while large areas containing several tens or hundreds of neighbouring strips with low interstrip isolation were identified by the Full strip tests, and leakage current instabilities were measured in a long-term leakage current stability setup. Moreover, a high surface electrostatic charge reaching a level of several hundreds of volts per inch was measured on a large number of sensors and on the plastic sheets, which mechanically protect these sensors in their paper envelopes. Accumulated data indicates a clear correlation between observed electrical failures and the sensor charge-up. To mitigate the above-described issues, the QC testing sites significantly modified the sensor handling procedures and introduced sensor recovery techniques based on irradiation of the sensor surface with UV light or application of intensive flows of ionized gas. In this presentation, we will describe the setups implemented by the QC testing sites to treat silicon strip sensors affected by static charge and evaluate the effectiveness of these setups in terms of improvement of the sensor performance