Semiconductor Counter Research Articles

Design of Hybrid Counter using Adiabatic Quantum Flux Parametron

Power consumption is one of the most considered factors while designing any electronics digital circuit. In which, the Adiabatic Quantum Flux parametron (AQFP) is one of the best superconducting technology for reduced power factor. Adiabatic Quantum Flux Parametron (AQFP) will be powered by the use of AC (Alternating Current) in place of DC power supply. In this research article, a hybrid counter is designed based on Adiabatic Quantum Flux Parametron (AQFP). The hybrid counter is modelled using parallel counter circuits. This counter is designed based on different stages of manipulation. The different stages are based on the number of bits used in the design. Here the design is made up of 4 - bit hybrid counter with four stages of computation and due to these stages of computation, the computation cost is reduced up to 28% compared to existing semiconductor counter electronics circuits. Since the computation cost is reduced, which directly implies that the speed of design is high speed and power is also reduced in huge factors in range of nanowatts.

Detection methods of diamond diffraction peaks in ultrananocrystalline diamond/amorphous carbon composite films by X-ray diffraction measurement with semiconductor counter detector

Ultrananocrystalline diamond (UNCD)/amorphous carbon (a-C) composite films were fabricated by a coaxial arc plasma deposition (CAPD) method. Hereafter, UNCD with crystallite diameters of less than 10 nm in an a-C matrix could only be unambiguously detected by powder X-ray diffraction measurement using a synchrotron radiation source (SR-XRD) or transmission electron microscopy (TEM) observation. In this study, we succeeded in detecting diffraction peaks due to diamond-111 in the film by X-ray diffraction (XRD) using a Cu-Kα radiation source with a semiconductor counter detector. The obtained data were in agreement with the powder SR-XRD measurements of the deposited films.

Rational screening low-cost counter electrodes for dye-sensitized solar cells

Dye-sensitized solar cells have attracted intense research attention owing to their ease of fabrication, cost-effectiveness and high efficiency in converting solar energy. Noble platinum is generally used as catalytic counter electrode for redox mediators in electrolyte solution. Unfortunately, platinum is expensive and non-sustainable for long-term applications. Therefore, researchers are facing with the challenge of developing low-cost and earth-abundant alternatives. So far, rational screening of non-platinum counter electrodes has been hamstrung by the lack of understanding about the electrocatalytic process of redox mediators on various counter electrodes. Here, using first-principle quantum chemical calculations, we studied the electrocatalytic process of redox mediators and predicted electrocatalytic activity of potential semiconductor counter electrodes. On the basis of theoretical predictions, we successfully used rust (α-Fe2O3) as a new counter electrode catalyst, which demonstrates promising electrocatalytic activity towards triiodide reduction at a rate comparable to platinum.

Nonvolatile Low Power 16-bit/32-bit Magnetic Tunnel Junction Based Binary Counter and Its Scaling

We propose a nonvolatile 16-bit/32-bit magnetic tunnel junction (MTJ) based binary counter with fine-grained power gating scheme suitable for MTJ. We estimate the power consumption of the proposed counter by using simulation program with integrated circuit emphasis (SPICE) simulation. The power of the proposed 16-bit/32-bit counter is 59.1 and 72.5% smaller in case of 45 and 16 nm node, respectively, than that of the conventional complementary metal oxide semiconductor (CMOS) counter at low frequency (100 Hz). The proposed nonvolatile 32-bit counter achieves lower power at operating frequencies up to 49 kHz and 4 MHz in the case of 45 and 16 nm node, respectively, in comparison with the conventional CMOS counter. Moreover, we propose a hybrid 32-bit counter that is constructed with CMOS counter units for the beginning stages and nonvolatile MTJ based counter units for the latter stages. It achieves a lower power at operating frequencies up to 1 GHz than the conventional CMOS counter for 16 nm node. As a result, clear scalability of the proposed MTJ based multi-bit counter is obtained from the viewpoint of suppressing power.

A computer controlled automated dispensor for the eluting, calibrating and dispensing of 99Tcm-pertechnetate.

This paper describes an automated 99Tcm-Dispensor, a computer controlled device for the programmed, automated elution of 99Tcm-sodium pertechnetate, its calibration, metered delivery and dilution. The elution can be programmed up to 7 days in advance. The total radioactivity of the eluate is assayed by a semiconductor counter integrated in the shielding of the pertechnetate reservoir. The volume of eluate actually available for dispensing is measured by capacitance and is monitored continuously. The specific concentration is calculated from total activity and volume, and is corrected for decay prior to each delivery. All activity bearing sections are shielded by lead-antimony covers specified to attenuate the radiation from generators up to 2 Ci 99Mo/99Tcm. The labelling vials are inserted into the dispensing chamber within a shielding vessel manually. The sodium pertechnetate solution is dispensed prior to the optional additional delivery of normal saline. The Tc-Dispensor maintains sterility, guards against accidental radioactive contamination, and is suited to reduce the radiation burden of personnel. All operations are recorded by the computer enabling the print-out of protocols. We found the Tc-Dispensor safe, precise and accurate.

Determination of the amorphous content of superconducting films by x-ray diffraction and its relation to transition temperature

A method has been developed for the determination of the amorphous content of superconducting films (niobium-germanium) based on x-ray analysis. Measurements are made in reflection using a standard diffractometer which includes a silicon semiconductor counter. The intensity of the diffraction line of the substrate was measured at an angle outside the amorphous halo region of the films to calibrate their surface density. The second angle of measurement was chosen to be within the region of the amorphous halo but away from the diffraction lines of the substrate or crystalline components of the films under investigation. Expression have been derived for calculation of the amorphous content. For the set of films investigated, a direct correlation of the amorphous concentration and the superconducting transition temperature has been observed.

Anomalies dans la collection des charges au sein d'un detecteur Ge(Li) influence sur la resolution en temps

Abstract The analysis of the presence of a double peaking in the prompt coincidence curves obtained with a Ge(Li) detector and a scintillation counter shows that the distortion may be attributed to charge carriers trapped in the dead layers of the semiconductor counter and that this phenomenon does not lead to a worsening of the energy resolution.

Determination of mixing ratios for some cascades corresponding to 109Ag

An investigation of the gamma–gamma ray angular correlations following the decay of 109Pd was made by using a Ge(Li) semiconductor counter and NaI(Tl) gamma-ray detector. Coincidences measurements at six different angles were made between the 311 keV gamma ray (gated in the movable counter) and 390, 413, 424, 551, and 558 keV gamma rays (displayed in a multichannel analyzer (MCA)). Chance coincidences as well as coincidence background were taken into account. The following spins and mixing ratios were determined: 701 keV level 3/2, δ(390) = 0.19 ± 0.06; 724 keV level 3/2, δ(413) = 0.18 ± 0.05; 735 keV level 5/2, δ(424) = −0.27 ± 0.03; 862 keV level 5/2, δ(551) = −0.28 ± 0.04; 869 keV level 5/2, δ(558) = −0.26 ± 0.05. The result indicates that the anisotropies are consistent with mixing ratios less than 28% in all cases.

Session Chairmen Nuclear Science and Scintillation and Semiconductor Counter Symposium

Session Chairmen Nuclear Science and Scintillation and Semiconductor Counter Symposium

Semiconductor X-ray spectrometers

An outline is given of recent developments in X-ray semiconductor detectors. With current techniques, detectors having areas of 25–50 mm 2 and a few millimeters thick can be fabricated to give resolutions better than 200 eV. After a brief description of the basic mechanism of semiconductor counter operation a comparison is made between semiconductor counters and gas filled proportional devices. Detector fabrication and cryostat design is discussed in detail. The effects of various device parameters on system performance, such as energy resolution, count rate capability, efficiency, etc. are discussed and steps taken to reduce microphony demonstrated. The main applications of these detectors in X-ray fluorescence analysis, electron microprobe analysis, and scanning electron microscopy are reviewed.

Detection of high energy protons by Ge(Li) counters

The problems related to the detection of high energy particles in a semiconductor counter are discussed. Experimental results obtained with 160 MeV protons from the Orsay synchrocyclotron are shown. For an estimated beam straggling of 240 keV, the energy resolution measured with a coaxial Ge(Li) counter was 290 keV (≅2×10 −4). A scanning over the sensitive volume of the detector with these protons has shown no uncompensated zones.

Complete Fusion induced by Krypton Ions: Indications for Synthesis of Superheavy Nuclei

COMPLETE nuclear fusion has been produced by bombarding targets of germanium, cadmium and thorium with 450 MeV Kr23+ and 500 MeV Kr24+ obtained from the Orsay accelerator ALICE1. Recoiling synthesized nuclei were slowed down in helium gas, transferred through a capillary tube and deposited on a steel rod in an evacuated enclosure2. An annular silicon semiconductor counter around the capillary tube detected the alpha particles produced by the decaying nuclei. Typical bombardment times were of the order of 10 h with 108 Kr ions s−1, and the background was shown to be insignificant by bombarding for 24 h without a target in place. Further tests also showed that secondary neutrons and gamma rays did not induce nuclear reactions in the detector.

Developments in nuclear instrumentation

For some years the dominant instrument in nuclear structure physics has been the semiconductor counter of germanium or silicon (Gunnersen 1967, Taverndale 1967), and this is almost entirely due to its excellent energy resolution. Development proceeds; but before discussing it a brief description of the basic article might be in order.

Determination of Particle Parameters in theK,L, andMShells inPb207

An angular-correlation setup was applied to measure the $e\ensuremath{-}\ensuremath{\gamma}$ angular correlations involving the 570- and 1064-keV transitions in ${\mathrm{Pb}}^{207}$. The use of a Si(Li) semiconductor counter as an electron detector allowed the separation of the three $K$, $L$, and $M$ conversion lines for both transitions. $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ angular correlations were also performed. Particle parameters ${b}_{2}$ were thus esperimentally determined. The values obtained for the $K$, $L$, and $M$ shells were 1.19(7), 1.13(7), and 1.41(11) for the 570-keV transition and 1.05(5), 1.06(12), and 1.16(15) for the 1064-keV transition. Particle parameters ${b}_{4}$ were calculated from the ${b}_{2}$ values through a recursion relation. The coefficients ${A}_{4}(e)$ could not be determined directly from experiment owing to the lack of statistics, but they were obtained through the ${b}_{4}$ particle parameters and the ${A}_{4}(\ensuremath{\gamma})$ coefficients. The values for the $K$, $L$, and $M$ shells one -0.020(8), -0.025(9), and \ensuremath{\sim}-0 are for the $e(570)\ensuremath{-}\ensuremath{\gamma}(1064)$ angular correlations; and -0.049(16), -0.051(30), and -0.072(40) for the $e(1064)\ensuremath{-}\ensuremath{\gamma}(570)$ angular correlations.

Electron-gamma angular correlation arrangement using semiconductor counters

An electron-gamma angular correlation arrangement using a lithium-drifted semiconductor counter as electron detector is presented. This was placed together with a field-effect transistor in a cylindrical rotating vacuum chamber cooled at a temperature of 200°K through a cold-finger system. Three scintillation counters set at right angles complete the system. Three coincidence circuits were used together with a routing system, in order to display three different electron-conversion spectra in memory subgroups of a multichannel analyzer. A resolution of 0.6% was obtained at 1 MeV, thus permitting the separation of the three main conversion lines of both cascades of 570 and 1064 keV from the decay of 207Bi. Electron-gamma coincidences at three different angles were simultaneously recorded in the particular case of the above cascades. Values of A 2 coefficients for the three shells for both correlations are also presented.

Backscattering and bremsstrahlung of electrons in a silicon detector

Pulse height distributions of a silicon semiconductor counter were measured for monoenergetic electrons in the energy range from 300 to 1200 keV at angles of incidence from 15° to 90°. The fraction of electrons not totally absorbed in the sensitive volume is determined. The spectra were also calculated with a Monte Carlo method, taking into account backscattering and bremsstrahlung. The fraction of the low energy tail of the detector response to perpendicularly incident electrons is found to be nearly independent of energy, for both measurements and calculations. The value determined is about 0.2.

A 12-Channel Semiconductor Counter System for the NBS Electron Scattering Spectrometer

A 12-channel array of lithium-drifted silicon detectors for detecting high energy electrons in the focal plane of a magnetic spectrometer is described. The detectors are movable along the focal plane and are backed up by two large stationary plastic scintillators. The scintillators are placed one behind the other, such that a count is recorded when a triple coincidence occurs between both scintillators and a single semiconductor detector. The system has a momentum resolution of 0.036 percent, determined by the detector size and the spectrometer momentum dispersion. Discriminator curves have been obtained which show sufficiently flat plateaus to afford stable counting conditions for electron momentum greater than 20 MeV/C. Detector efficiency measurements have also been made which show that the relative efficiencies of the detectors are stable and known to less than two percent of their values. An electron scattering experiment is now in progress using these detectors.

Energy spectra of long range particles from the thermal neutron fission of 235U

Energy spectra of 1H, 2H, 3H, 4He and 6He from the thermal-neutron fission of 235U have been investigated using a semiconductor counter telescope and two-parameter analysis. Gaussian distributions were fitted to the measured distributions with the least-squares method. Relative intensities have been calculated.

Accurately defined neutron beams from D(d,n) 3He at Ed = 50 keV, using the associated particle method

Accurately collimated fast neutron beams of small angular width and known absolute intensity and energy were produced by bombarding heavy ice targets with 50 keV deuterons and operating the neutron detector in coincidence with a semiconductor counter detecting the 3He recoil nuclei. The measured beam profile agreed with the theoretically calculated profile. The beam was used to measure the absolute neutron detection efficiency and the scintillation pulse spectrum of a plastic scintillation counter bombarded by 2.55 MeV neutrons.

Some applications of semiconductor counters in high energy physics

The small size of semiconductor counters are a considerable limitation for their application to detect high energy particles. However, in experiments on accelerators there is a certain number of special problems where semiconductor counters can be rather effectively used. In particular, good spectrometric properties, non-sensitivity to the magnetic field and the compactness of the semiconductor counter allow to use it for identifying slow protons and deutrenos in elastic pp and pd scatterings. In our case the target was bombarded with the 10 GeV internal proton beam of the proton synchrotron of the Joint Institute for Nuclear Research. Semiconductor counters operating in the photodiode regime were applied to measure particle fluxes in other investigations carried out on the synchrocyclotron. Optical characteristics of lithium-drifted silicon counters of the surface-barrier type were studied. Being rather perfect fast photodiodes, the counters can be used also for determination of the spark coordinates in a spark chamber.