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Author HAWC Collaboration (Alfaro, R. et al); Salesa Greus, F. url  doi
openurl 
  Title Gamma/hadron separation with the HAWC observatory Type Journal Article
  Year 2022 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1039 Issue Pages 166984 - 13pp  
  Keywords High energy; Crab Nebula; G/H separation; Machine Learning  
  Abstract (up) The High Altitude Water Cherenkov (HAWC) gamma-ray observatory observes atmospheric showers produced by incident gamma rays and cosmic rays with energy from 300 GeV to more than 100 TeV. A crucial phase in analyzing gamma-ray sources using ground-based gamma-ray detectors like HAWC is to identify the showers produced by gamma rays or hadrons. The HAWC observatory records roughly 25,000 events per second, with hadrons representing the vast majority (> 99.9%) of these events. The standard gamma/hadron separation technique in HAWC uses a simple rectangular cut involving only two parameters. This work describes the implementation of more sophisticated gamma/hadron separation techniques, via machine learning methods (boosted decision trees and neural networks), and summarizes the resulting improvements in gamma/hadron separation obtained in HAWC.  
  Address [Alfaro, R.; Angeles Camacho, J. R.; Avila Rojas, D.; Belmont-Moreno, E.; Espinoza, C.; Garcia, D.; Hernandez, S.; Leon Vargas, H.; Sandoval, A.; Serna-Franco, J.] Univ Nacl Autonoma Mexico, Inst Fis, Mexico City, DF, Mexico, Email: tcapistran@astro.unam.mx;  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000861747900006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5371  
Permanent link to this record
 

 
Author Liptak, Z. et al; Marinas, C. url  doi
openurl 
  Title Measurements of beam backgrounds in SuperKEKB Phase 2 Type Journal Article
  Year 2022 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1040 Issue Pages 167168 - 19pp  
  Keywords  
  Abstract (up) The high design luminosity of the SuperKEKB electron–positron collider will result in challenging levels of beam-induced backgrounds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of the Belle II experiment. We report on the first background measurements performed after roll-in of the Belle II detector, a period known as SuperKEKB Phase 2, utilizing both the BEAST II system of dedicated background detectors and the Belle II detector itself. We also report on first revisions to the background simulation made in response to our findings. Backgrounds measured include contributions from synchrotron radiation, beam-gas, Touschek, and injection backgrounds. At the end of Phase 2, single-beam backgrounds originating from the 4 GeV positron Low Energy Ring (LER) agree reasonably well with simulation, while backgrounds from the 7 GeV electron High Energy Ring (HER) are approximately one order of magnitude higher than simulation. We extrapolate these backgrounds forward and conclude it is safe to install the Belle II vertex detector.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5496  
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Author Latonova, V. et al; Bernabeu, J.; Lacasta, C.; Solaz, C.; Soldevila, U. doi  openurl
  Title Characterization of the polysilicon resistor in silicon strip sensors for ATLAS inner tracker as a function of temperature, pre- and post-irradiation Type Journal Article
  Year 2023 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1050 Issue Pages 168119 - 5pp  
  Keywords HL-LHC; ATLAS ITk; Silicon micro-strip sensor; Polysilicon bias resistor; Testchip  
  Abstract (up) The high luminosity upgrade of the Large Hadron Collider, foreseen for 2029, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker (ITk). The expected ultimate total integrated luminosity of 4000 fb(-1) means that the strip part of the ITk detector will be exposed to the total particle fluences and ionizing doses reaching the values of 1.6 center dot 10(15) MeVn(eq)/cm(2) and 0.66MGy, respectively, including a safety factor of 1.5. Radiation hard n(+)-in-p micro-strip sensors were developed by the ATLAS ITk strip collaboration and are produced by Hamamatsu Photonics K.K. The active area of each ITk strip sensor is delimited by the n-implant bias ring, which is connected to each individual n(+) implant strip by a polysilicon bias resistor. The total resistance of the polysilicon bias resistor should be within a specified range to keep all the strips at the same potential, prevent the signal discharge through the grounded bias ring and avoid the readout noise increase. While the polysilicon is a ubiquitous semiconductor material, the fluence and temperature dependence of its resistance is not easily predictable, especially for the tracking detector with the operational temperature significantly below the values typical for commercial microelectronics. Dependence of the resistance of polysilicon bias resistor on the temperature, as well as on the total delivered fluence and ionizing dose, was studied on the specially-designed test structures called ATLAS Testchips, both before and after their irradiation by protons, neutrons, and gammas to the maximal expected fluence and ionizing dose. The resistance has an atypical negative temperature dependence. It is different from silicon, which shows that the grain boundary has a significant contribution to the resistance. We discuss the contributions by parameterizing the activation energy of the polysilicon resistance as a function of the temperature for unirradiated and irradiated ATLAS Testchips.  
  Address [Latonova, V.; Federicova, P.; Kroll, J.; Kvasnicka, J.; Mikestikova, M.] Acad Sci Czech Republ, Inst Phys, Slovance 2, Prague 8, Czech Republic, Email: vera.latonova@cern.ch  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001035405300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5601  
Permanent link to this record
 

 
Author HAWC Collaboration (Abeysekara, A.U. et al); Salesa Greus, F. url  doi
openurl 
  Title The High-Altitude Water Cherenkov (HAWC) observatory in Mexico: The primary detector Type Journal Article
  Year 2023 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1052 Issue Pages 168253 - 18pp  
  Keywords Physics – instrumentation and detectors; Water Cherenkov Detectors; Astrophysics; High energy physics – experiment; Nuclear experiment  
  Abstract (up) The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment in using ground-based water Cherenkov detectors for gamma-ray astronomy. HAWC is located on the Sierra Negra volcano in Mexico at an elevation of 4100 meters above sea level. The completed HAWC observatory principal detector (HAWC) consists of 300 closely spaced water Cherenkov detectors, each equipped with four photomultiplier tubes to provide timing and charge information to reconstruct the extensive air shower energy and arrival direction. The HAWC observatory has been optimized to observe transient and steady emission from sources of gamma rays within an energy range from several hundred GeV to several hundred TeV. However, most of the air showers detected are initiated by cosmic rays, allowing studies of cosmic rays also to be performed. This paper describes the characteristics of the HAWC main array and its hardware.  
  Address [Abeysekara, A. U.; Barber, A. S.; Hona, B.; Kieda, D.; Newbold, M.; Springer, R. W.] Univ Utah, Dept Phys & Astron, Salt Lake City, UT USA, Email: eduardo.delafuentea@academicos.udg.mx  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001063137300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5674  
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Author Goel, N.; Domingo-Pardo, C.; Habermann, T.; Ameil, F.; Engert, T.; Gerl, J.; Kojouharov, I.; Maruhn, J.; Pietralla, N.; Schaffner, H. doi  openurl
  Title Characterisation of a symmetric AGATA detector using the gamma-ray imaging scanning technique Type Journal Article
  Year 2013 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 700 Issue Pages 10-21  
  Keywords AGATA; Pulse shape comparison (PSC); Pulse shape analysis (PSA)  
  Abstract (up) The imaging scanning technique for the characterisation of large volume, highly segmented, HPGe detectors is demonstrated by comparing the measured spatial response of a symmetric AGATA crystal versus the theoretical calculations obtained with the Multi-Geometry Simulation (MGS) code. The signal rise-times measured as a function of the gamma-ray interaction positions, in both coaxial and planar regions of the detection volume, are presented and confronted with the expected behaviour obtained via MGS. The transition in charge carrier transport behaviour as a function of the depth is studied for the region of the complex electric field. In general, a fairly good agreement between theory and experiment is obtained. Only systematic deviations between simulation and measurement are observed in the critical front part of the AGATA detector. They may be ascribed to a non-linear impurity concentration profile of the germanium crystal.  
  Address [Goel, N.; Domingo-Pardo, C.; Habermann, T.; Ameil, F.; Engert, T.; Gerl, J.; Kojouharov, I.; Schaffner, H.] GSI Helmholtzzentrum Schwerionenforsch GmbH, D-64291 Darmstadt, Germany, Email: n.goel@gsi.de  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000312811400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1283  
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Author Hara, K. et al; Escobar, C.; Garcia, C.; Lacasta, C.; Miñano, M.; Soldevila, U. doi  openurl
  Title Charge collection study with the ATLAS ITk prototype silicon strip sensors ATLAS17LS Type Journal Article
  Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 983 Issue Pages 164422 - 6pp  
  Keywords ATLAS ITk; Microstrip sensor; Charge collection; Radiation damage  
  Abstract (up) The inner tracker of the ATLAS detector is scheduled to be replaced by a completely new silicon-based inner tracker (ITk) for the Phase-II of the CERN LHC (HL-LHC). The silicon strip detector covers the volume 40 < R < 100 cm in the radial and vertical bar z vertical bar <300 cm in the longitudinal directions. The silicon sensors for the detector will be fabricated using the n(+)-on-p 6-inch wafer technology, for a total of 22,000 wafers. Intensive studies were carried out on the final prototype sensors ATLAS17LS fabricated by Hamamatsu Photonics (HPK). The charge collection properties were examined using penetrating Sr-90 beta-rays and the ALIBAVA fast readout system for the miniature sensors of 1 cm xl cm in area. The samples were irradiated by protons in the 27 MeV Birmingham Cyclotron, the 70 MeV CYRIC at Tohoku University, and the 24 GeV CERN-PS, and by neutrons at Ljubljana TAIGA reactor for fluence values up to 2 x 10(15) n(eq)/cm(2). The change in the charge collection with fluence was found to be similar to the previous prototype ATLAS12, and acceptable for the ITk. Sensors with two active thicknesses, 300 μm (standard) and 240 μm (thin), were compared and the difference in the charge collection was observed to be small for bias voltages up to 500 V. Some samples were also irradiated with gamma radiation up to 2 MGy, and the full depletion voltage was found to decrease with the dose. This was caused by the Compton electrons due to the( 60)Co gamma radiation. To summarize, the design of the ATLAS17LS and technology for its fabrication have been verified for implementation in the ITk. We are in the stage of sensor pre-production with the first sensors already delivered in January of 2020.  
  Address [Hara, K.] Univ Tsukuba, Inst Pure & Appl Sci, Tsukuba, Ibaraki 3058571, Japan, Email: hara@hep.px.tsukuba.ac.jp  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000581808300002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4606  
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Author AGATA Collaboration (Soderstrom, P.A. et al); Gadea, A. doi  openurl
  Title Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors Type Journal Article
  Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 638 Issue 1 Pages 96-109  
  Keywords gamma-ray tracking; AGATA; Monte Carlo simulations; HPGe detectors; Fusion-evaporation reactions  
  Abstract (up) The interaction position resolution of the segmented HPGe detectors of an AGATA triple cluster detector has been studied through Monte Carlo simulations and in an in-beam experiment. A new method based on measuring the energy resolution of Doppler-corrected gamma-ray spectra at two different target to detector distances is described. This gives the two-dimensional position resolution in the plane perpendicular to the direction of the emitted gamma-ray. The gamma-ray tracking was used to determine the full energy of the gamma-rays and the first interaction point, which is needed for the Doppler correction. Five different heavy-ion induced fusion-evaporation reactions and a reference reaction were selected for the simulations. The results of the simulations show that the method works very well and gives a systematic deviation of <1 mm in the FVVHM of the interaction position resolution for the gamma-ray energy range from 60 keV to 5 MeV. The method was tested with real data from an in-beam measurement using a (30)5i beam at 64 MeV on a thin C-12 target. Pulse-shape analysis of the digitized detector waveforms and gamma-ray tracking was performed to determine the position of the first interaction point, which was used for the Doppler corrections. Results of the dependency of the interaction position resolution on the gamma-ray energy and on the energy, axial location and type of the first interaction point, are presented. The FVVHM of the interaction position resolution varies roughly linearly as a function of gamma-ray energy from 8.5 mm at 250 key to 4 mm at 1.5 MeV, and has an approximately constant value of about 4 mm in the gamma-ray energy range from 1.5 to 4 MeV.  
  Address [Soderstrom, P. -A.; Nyberg, J.; Al-Adili, A.; Atac, A.; Veyssiere, C.] Uppsala Univ, Dept Phys & Astron, SE-75121 Uppsala, Sweden, Email: P-A.Soderstrom@physics.uu.se  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000290082600015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 619  
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Author Liu, S.; Bogard, F.; Cornebise, P.; Faus-Golfe, A.; Fuster-Martinez, N.; Griesmayer, E.; Guler, H.; Kubytskyi, V.; Sylvia, C.; Tauchi, T.; Terunuma, N.; Bambade, P. url  doi
openurl 
  Title In vacuum diamond sensor scanner for beam halo measurements in the beam line at the KEK Accelerator Test Facility Type Journal Article
  Year 2016 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 832 Issue Pages 231-242  
  Keywords Diamond sensor; Beam halo; ATF2  
  Abstract (up) The investigation of beam halo transverse distributions is important for the understanding of beam losses and the control of backgrounds in Future Linear Colliders (FLC). A novel in vacuum diamond sensor (DSv) scanner with four strips has been designed and developed for the investigation of the beam halo transverse distributions and also for the diagnostics of Compton recoil electrons after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for the ILC and CLIC linear collider projects. Using the DSv, a dynamic range of similar to 10(6) has been successfully demonstrated and confirmed for the first time in simultaneous beam core (similar to 10(6) electrons) and beam halo (similar to 10(3) electrons) measurements at ATF2. This report presents the characterization, performance studies and tests of diamond sensors using an a source, as well as using the electron beams at PHIL, a low energy (<5 MeV) photo-injector at LAL, and at ATF2. First beam halo measurement results using the DSv at ATF2 with different beam intensities and vacuum levels are also presented. Such measurements not only allow one to evaluate the different sources of beam halo generation but also to define the requirements for a suitable collimation system to be installed at ATF2, as well as to optimize its performance during future operation.  
  Address [Liu, S.; Bogard, F.; Cornebise, P.; Faus-Golfe, A.; Guler, H.; Kubytskyi, V.; Sylvia, C.; Bambade, P.] Univ Paris Saclay, Univ Paris 11, CNRS, LAL,IN2P3, Orsay, France, Email: sliu@lal.in2p3.fr  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000382256400026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2786  
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Author Barrientos, L.; Borja-Lloret, M.; Etxebeste, A.; Muñoz, E.; Oliver, J.F.; Ros, A.; Roser, J.; Senra, C.; Viegas, R.; Llosa, G. doi  openurl
  Title Performance evaluation of MACACO II Compton camera Type Journal Article
  Year 2021 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1014 Issue Pages 165702 - 7pp  
  Keywords Compton camera; Hadron therapy; LaBr3; Silicon photomultipliers  
  Abstract (up) The IRIS group at IFIC-Valencia has developed a second version of a Compton camera prototype for hadron therapy treatment monitoring, with the aim of improving the performance with respect to its predecessor. The system is composed of three Lanthanum (III) bromide (LaBr3) crystals coupled to silicon photomultipliers (SiPMs). The detector energy resolution has been improved to 5.6% FWHM at 511 keV and an angular resolution of 8.0 degrees has been obtained. Images of a Na-22 point-like source have been reconstructed selecting two and three interaction events. Moreover, the experimental data have been reproduced with Monte Carlo simulations using a Compton camera module (CCMod) in GATE v8.2 obtaining a good correlation.  
  Address [Barrientos, L.; Borja-Lloret, M.; Munoz, E.; Oliver, J. F.; Ros, A.; Roser, J.; Senra, C.; Viegas, R.; Llosa, G.] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: lbarrien@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000701263400010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4976  
Permanent link to this record
 

 
Author Luo, X.L. et al; Agramunt, J.; Egea, F.J.; Gadea, A.; Huyuk, T. doi  openurl
  Title Pulse pile-up identification and reconstruction for liquid scintillator based neutron detectors Type Journal Article
  Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 897 Issue Pages 59-65  
  Keywords Pile-up; Digital; First-order derivative; Neutron-gamma discrimination; Liquid scintillator  
  Abstract (up) The issue of pulse pile-up is frequently encountered in nuclear experiments involving high counting rates, which will distort the pulse shapes and the energy spectra. A digital method of off-line processing of pile-up pulses is presented. The pile-up pulses were firstly identified by detecting the downward-going zero-crossings in the first-order derivative of the original signal, and then the constituent pulses were reconstructed based on comparing the pile-up pulse with four models that are generated by combining pairs of neutron and.. standard pulses together with a controllable time interval. The accuracy of this method in resolving the pile-up events was investigated as a function of the time interval between two pulses constituting a pile-up event. The obtained results show that the method is capable of disentangling two pulses with a time interval among them down to 20 ns, as well as classifying them as neutrons or gamma rays. Furthermore, the error of reconstructing pile-up pulses could be kept below 6% when successive peaks were separated by more than 50 ns. By applying the method in a high counting rate of pile-up events measurement of the NEutron Detector Array (NEDA), it was empirically found that this method can reconstruct the pile-up pulses and perform neutron-gamma discrimination quite accurately. It can also significantly correct the distorted pulse height spectrum due to pile-up events.  
  Address [Luo, X. L.] Acad Mil Med Sci, Natl Innovat Inst Def Technol, Beijing 100010, Peoples R China, Email: delongtmac@163.com  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000433206800010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3591  
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