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Singh B.,McMaster University | Abriola D.,International Atomic Energy Agency | Baglin C.,LBNL | Demetriou V.,International Atomic Energy Agency | And 6 more authors.
Nuclear Data Sheets | Year: 2013

The evaluated spectroscopic data are presented for 11 known nuclides of mass 211 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th). The 211Pa nuclide is included here but its identification remains uncertain. For 211Hg, 211Tl, 211Ac and 211Th nuclei, only the ground-state information is available. Their decay characteristics are mostly unknown. 211Fr is suggested to decay partially through ε decay mode, but its decay scheme remains poorly known. While high-spin excitations, including several isomers, are well studied in 211Pb, 211Bi, 211Po, 211At, 211Rn and 211Fr, the particle-transfer data are available for only 211Po and 211Bi.This evaluation was carried out as part of joint IAEA-ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna and ICTP, Trieste, August 6-17, 2012. This work supersedes previous A=211 evaluation (2004Br45) published by E. Browne which covered literature before January 2003. © 2013 Elsevier Inc.

Singh B.,McMaster University | Mukherjee G.,Variable Energy Cyclotron Center | Abriola D.,International Atomic Energy Agency | Basu S.K.,VECC | And 5 more authors.
Nuclear Data Sheets | Year: 2013

The evaluated spectroscopic data are presented for 12 known nuclides of mass 215 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa). For 215Hg, 215Tl, 215Pb, and 215Pa nuclei, no excited states are known. The decay characteristics of 215Hg and 215Tl are unknown. The decay scheme of 215Pb is considered as incomplete. Ordering of γ cascades in the decay of 36.9-s isomer of 215Bi and for high-spin states above 2251 keV in 215Fr are not established. High-spin excitations, including several isomeric states, are well known in 215Bi, 215Po, 215Rn, 215Fr, 215Ra, and 215Ac. No particle-transfer reaction data are available for any of the A=215 nuclei.The rms charge radii for 215Pb, 215Bi, 215Po, 215Rn, 215Fr and 215Ra have been evaluated by Daniel Abriola, from extrapolation or interpolation of available evaluated data in 2013An02 for radii of respective Z chains using formula 9 in 2004An14.This evaluation was carried out as part of ENSDD-workshop at VECC, Kolkata for Nuclear Structure and Decay Data, organized and hosted by VECC and Board of Research in Nuclear Sciences (BRNS) in Kolkata, India, November 26-29, 2012. This work supersedes the previous A = 215 evaluation (2001Br31) published by E. Browne which covered literature prior to May 2001. © 2013.

Mitra J.,VECC | Khan S.A.,VECC | Mukherjee S.,Bose Institute of India | Paul R.,University of Calcutta
Journal of Instrumentation | Year: 2016

The ALICE experiment at the CERN Large Hadron Collider (LHC) is presently going for a major upgrade in order to fully exploit the scientific potential of the upcoming high luminosity run, scheduled to start in the year 2021. The high interaction rate and the large event size will result in an experimental data flow of about 1 TB/s from the detectors, which need to be processed before sending to the online computing system and data storage. This processing is done in a dedicated Common Readout Unit (CRU), proposed for data aggregation, trigger and timing distribution and control moderation. It act as common interface between sub-detector electronic systems, computing system and trigger processors. The interface links include GBT, TTC-PON and PCIe. GBT (Gigabit transceiver) is used for detector data payload transmission and fixed latency path for trigger distribution between CRU and detector readout electronics. TTC-PON (Timing, Trigger and Control via Passive Optical Network) is employed for time multiplex trigger distribution between CRU and Central Trigger Processor (CTP). PCIe (Peripheral Component Interconnect Express) is the high-speed serial computer expansion bus standard for bulk data transport between CRU boards and processors. In this article, we give an overview of CRU architecture in ALICE, discuss the different interfaces, along with the firmware design and implementation of CRU on the LHCb PCIe40 board. © 2016 IOP Publishing Ltd and Sissa Medialab srl.

Here, we aim to develop an efficient material by eco-friendly green synthetic route that was further characterized to be crystalline ranging in nano-dimension for filtering high arsenic content groundwater. The thermal stability of iron(III)-cerium(IV) mixed oxide nanoparticle agglomerates (NICMO) was well established from the consistent particle size at different temperature and also from differential thermal analysis. The bimetal mixed oxide contained agglomerated crystalline nano-particles of dimension 10-20nm held together by crystal packing forces, and its corresponding empirical composition was FeCe1.1O7.6. Appearance of a weak band at 534cm-1 in the spectrum of nano-structured iron(III)-cerium(IV) mixed oxide (NICMO) is presumed for the presence of hetero-metal bonding via oxygen linkage (i.e., Fe-O-Ce). Equilibrium sorption data described Langmuir and D-R isotherm equations fairly well particularly for As(III) with relatively high monolayer sorption capacity [55.513mgg-1 for As(V), 86.293mgg-1 for As(III)] in the absence of any foreign ions. Chemo-sorption is the actual nature of the reaction taking place in As(III) with the sorption process getting more favorable with the increase of temperature in contrast to As(V) in which the degree of interaction suggested physiosorption type reactions. Splitting of band in FTIR spectrum of As(V) suggested the dominance of mono protonated monodentate complex [S-OAsO2(OH)] on the oxide surface. As(III) sorption mechanism taking place over NICMO surface under sufficient time lag confirmed oxidation of surface adsorbed As(III) to As(V) in a thermodynamically controlled sorption reaction. © 2013 Elsevier B.V.

Rashid M.H.,VECC | Mallik C.,VECC
CYCLOTRONS 2010 - 19th International Conference on Cyclotrons and Their Applications | Year: 2010

Magnetic cylindrical lens is used mostly in beam lines to focus and transport low energy beam. It is well known that focusing power of a magnetic solenoid lens depends on the ratio of particle momentum and electric charge. A solenoid rotates also an ion beam while focusing it and the phase space areas of the beam in x- and y-plane get entangled and increased. The paper reported here describes an effort to design a new magnetic einzel lens (MEL) using a pair of Glaser solenoid lens (GSL) in anti-solenoid mode for the first time to get zero rotation of the exit beam. Analytical formulae have been generated to deduce the scalar magnetic potential and field along the central axis of the lens. Thereafter, beam optics and particle tracking is done using the combined field of a pair of GSL's constituting the MEL. The required focusing power of the designed lens is achieved for a beam of given rigidity.

Srivastava S.,VECC | Pandit V.S.,VECC
PCaPAC 2012 - 9th International Workshop on Personal Computers and Particle Accelerator Controls | Year: 2012

This paper presents a novel scheme for the direct estimation of a PID (Proportional Integral Derivative) controller parameters (Kp, Ti, Td).The proposal discussed here is only applicable to first and second order stable systems. The formulation begins with system parameter identification (Transfer function of the process), which has been obtained using system identification toolbox of MATLAB. The pole zero cancellation technique is applied to estimate PID controller parameters which inturn results into the matched coefficients of the system parameters to the Controller parameters. An additional tuning parameters a is proposed in our method, which provides an additional flexibility of tuning the response time of the controller without disturbing the controller parameters. The proposed scheme is bench marked using real time case of dc motor speed control. The effectiveness and robustness of the proposed auto tuning algorithm are verified by the simulation results. © 2012 by the respective authors.

Micro hardness of sintered zinc oxide (ZnO) ceramics made from two different particle sizes was measured in a relatively wider range of applied test load (0.2-49N). Experimentally measured apparent hardness data were analyzed to understand the indentation size effect (ISE) in the full range of load. Meyer's law was successfully utilized to describe the ISE behavior though it was unable to generate true hardness data. Load independent true hardness was assessed from the measured diagonal of the indented impression and the test load using the modified PSR model. True hardness numbers determined with this empirical method vary within 1.50-1.83GPa depending on grain size of the sintered products. Indentation fracture toughness was measured with slightly higher test load of 9.8-49N. Nature of crack emanated at the corners of the indent was identified as radial median type. The quantity P/C3/2 was observed to be independent on applied load for all the samples with experimental scatter. Fracture toughness calculated from the length of the indentation induced cracks exhibits dependence on grain size. Maximum fracture toughness of 2.50±0.30MPam1/2 was observed for the ground ZnO sample sintered at 1300°C for 1h duration. © 2015 Elsevier B.V.

Chakrabarti A.,VECC | Srivastava D.K.,VECC
Nuclear Physics News | Year: 2015

Variable Energy Cyclotron Centre (VECC) derives its name from the first variable energy Cyclotron in the country that was built at Kolkata during the 1970s. This was the first major accelerator to be built in the country and marked the beginning of India's effort toward developing medium-scale accelerators. With the Cyclotron coming to life in the late 1970s, India's journey toward exploring the atomic nucleus made a vibrant start. This created for the first time in the country a group of physicists and engineers trained both in accelerator-based physics and also in accelerator design and construction. A good many of these people went on to contribute later in the development of research facilities at Indore, Mumbai, Delhi, and other places in the country. With more favorable government grants in basic sciences that started flowing in from the beginning of the present century, VECC has taken up the task of building new and advanced accelerators, first a K 500 Superconducting Cyclotron and then an ISOL based Rare Ion Beam (RIB) facility, and also advanced detectors and detector arrays for carrying out forefront research in nuclear physics. © 2015, Taylor & Francis.

Roy T.K.,VECC | Sanyal D.,VECC | Bhowmick D.,VECC | Chakrabarti A.,VECC
Materials Science in Semiconductor Processing | Year: 2013

The temperature dependent (30-550 °C) resistivity of zinc oxide (ZnO) has been studied by the standard four probe resistivity method. The room-temperature resistivity of the sample is measured as 0.75 M Ωm. Resistivity versus temperature plot of the sample shows normal NTCR (negative temperature coefficient of resistance) behavior up to 300 °C. However, a crossover from NTCR to a PTCR (positive temperature coefficient of resistance) behavior is observed at ∼300 °C. The origin of the PTCR behavior is explained with the defects present in the ZnO annealed up to 550 °C. Temperature dependent S-parameter (positron annihilation line-shape parameter) indicates the formation of oxygen vacancy like defects in this temperature region. At the PTCR region, the activation energy for the electron conduction is calculated ∼2.6 eV. This value is very close to the theoretically predicted defect level energy of 2.0 eV for oxygen vacancies present in ZnO. © 2012 Elsevier Ltd.

Basak S.,VECC | Pandey H.K.,VECC | Chakrabart A.,VECC
PCaPAC 2012 - 9th International Workshop on Personal Computers and Particle Accelerator Controls | Year: 2012

This paper presents the simulation work and results in Matlab Simulink for the analogue Inphase-Quadrature (IQ) based Low Level Radio Frequency (LLRF) control of RF cavity voltage. The RF cavity chosen here is the Radio Frequency Quadrupole (RFQ) cavity in our RIBproject. All the subsystems in the IQ based RF control were modelled using the Simulink blocks/components. The envelope simulation was carried out using the IQ model of RF cavity. The PI controller was properly tuned to achieve good control performance in time. The simulation graphs showing the time evolution of the RF cavity voltage with a step change of the input reference signal is presented. The simulation graphs showing the control response time needed to correct a disturbance is presented. The simulation results showing Nichols plots of the control loop and the gain and phase margin values obtained from them are presented, which are good enough for stability considerations. © 2012 by the respective authors.

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