The KLOE detector performance summary after the end of data-taking (#1593)
1 INFN - Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Frascati, Italy
On April 30th 2018 the KLOE detector at the INFN Laboratori Nazionali di Frascati concluded the data-taking campaign at the e+e- DAFNE phi-factory.The KLOE experiment has being operated in two different runs, in 2000-2005 and in 2014-2018, collecting a total integrated luminosity of 8/fb at the centre-of-mass energy of the Phi meson.
The original apparatus was composed by two large sub-detectors. A huge Drift chamber, the biggest ever built, with a gas volume of 50000 liters filled with 12500 sense wires, and a lead-scintillating fiber Electromagnetic Calorimeter among the best ones for energy and timing performance at low energies. This set-up has been upgraded for the second run with new state-of-art detectors with the purpose of improving the performance and extending the physics reach.
Two new calorimeters were installed close to the interaction region in order to improve the geometrical acceptance for photons at low angle: one using LYSO crystal, the other using a Tungsten and scintillating tiles structure, both with SiPM readout. Two couples of lepton taggers were installed to tag events with a double initial-state-radiation, useful for the study of gamma-gamma collisions. To improve the vertex reconstruction capability of the tracking system, a new Inner Tracker was installed inside the Drift Chamber. This was realized as a cylindrical GEM detector, exploiting a novel idea developed at Frascati, for the first time applied on a high-energy physics experiment.
All the detectors will be described in detail, along with their performance during the many years of operation with e+e- collisions.
Keywords: high energy physics experimet, gas detector, calorimeter, tracking detector, cylindrical GEM
Lab-on-Fiber as dosimeter for the ultra high dose scenario (#1927)
F. Fienga1, 3, P. Vaiano2, G. Quero2, G. Gorine3, 7, M. Giaquinto2, V. Di Meo4, A. Ricciardi2, P. Casolaro6, L. Campajola6, G. Breglio5, F. Ravotti3, S. Buontempo1, 3, A. Crescitelli4, E. Esposito4, A. Cutolo2, M. Consales2, A. Cusano2
1 Istituto Nazionale di Fisica Nucleare (INFN), Napoli Section, Napoli, Italy
Current radiation monitoring systems employed in High Energy Physics (HEP) experiments at the CERN Large Hadron Collider (LHC) and in the accelerator tunnel itself are based on solid-state devices, includingRadiation sensitive Field Effect Transistors (RadFETs) and p-i-n diodes. In particular, RadFETs allow to measure ionizing radiation for doses up to 100 kGy, while p-i-n diodes are adopted for evaluating fluence levels of up to 1015particles/cm2. However, the Future Circular Collider (FCC), currently being designed, willallow h-h collisions at an unprecedented energy level of 100 TeV, about 8 times higher than in today's LHC, achieving radiation levels exceeding several tens of MGy with fluence levels above 1017particles/cm2. This scenario reveals a limitation of the current dosimetry technology, whose sensitivity and operational range are mainly affected by the thickness of the active layer. In order to overcome these limitations, here we propose an Optical Fiber (OF) dosimeter based on the Lab-on-Fiber (LOF) concept, which comprises the integration of functionalized materials on the OF, defined at micro and nano-scale, for the development of miniaturizedand multifunctional probes. In particular, this new LOF dosimeter consists in a metallo-dielectric resonator realized onthe OF tip. The principle of operation of the proposed platform lies on the excitation of localized surface plasmon resonances sustained by such hybrid structure and on the compaction undergone by the PMMA layer upon exposure to proton beam. Several LOF prototypes have been irradiated with a 24 GeV/c proton beamavailable at the IRRAD facility bunker at CERN for 9 days for a total cumulated dose, of about 1.8 MGy. Preliminary results reported here demonstrate the effectiveness of the proposed platform as dosimeter for high dose up to MGy dose levels and pave the way for their future application in HEP experiments.
Keywords: Lab-on-Fiber technology, Fiber optic sensors, High Energy Physics, Proton beam, Dosimetry
Challenges in dosimetry and testing in the CERN CHARM mixed radiation field Facility (#2509)
S. Danzeca1, C. Cangialosi1, S. Bonaldo1, 2, R. Castellotti1, 3, A. Infantino1, R. Garcia Alia1, M. Brugger1, A. Masi1, S. Gilardoni1
1 CERN, Geneve, Genève, Switzerland
The CERN High energy AcceleRator Mixed field (CHARM) facility provides a unique complex radiation environment characterized by particle energy spectra representative of high energy accelerators, ground and atmospheric conditions as well as space applications. It is conceived to be an irradiation facility for the qualification of large electronic systems and components in a mixed field radiation environment representative of the one of the Large Hadron Collider (LHC). In order to quantify the degradation and evaluate the radiation effects on the electronics, the dosimetry of this complex mixed irradiation field is mandatory. The huge size of the available test area, the multiple facility configuration (i.e targets and shielding used) make the radiation levels monitoring a challenge. In addition, the operation at CHARM depends on the availability and quality of the primary beam. Beam steering and beam intensity can have a strong impact in the radiation field generated and thus, on the facility dosimetry. Being a large facility with the possibility of hosting bulky equipment the self-shielding effect of the test equipment installed has to be assessed and evaluated. This work highlights the main parameters used to describe the radiation field and the challenge encountered in the CHARM dosimetry. Indeed, a deep knowledge of these peculiarities become essential to characterize properly operation of the facility.
Keywords: CHARM, irradiation facility, dosimetry, radiation effects, mixed field
SciFi - A large Scintillating Fibre Tracker for LHCb (#1814)
B. D. Leverington1
1 Universitaet Heidelberg, Physikalisches Insitut, Heidelberg, Baden-Württemberg, Germany
On behalf of the LHCb Collaboration
The LHCb detector will be upgraded during the Long Shutdown 2 (2019-2020) of the LHC in order to manage the higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. The new Scintillating Fibre (SciFi) Tracker covers a total detector area of 340 m2 and should provide a spatial resolution for charged particles better than 100 µm in the bending direction of the LHCb spectrometer. The detector consists of individual sensitive detector modules (0.5 m × 4.8 m), each comprised of eight scintillating fibre mats with a length of 2.4 m as the active detector material. The 13 cm wide fibre mats have 6 layers of densely packed blue emitting fibres with a diameter of 250 µm. The scintillation light is detected with arrays of multi-channel silicon photomultipliers (SiPMs). A custom ASIC, the PACIFIC, will be used to digitize the SiPM signals. Subsequent digital electronics performs clustering and data-compression before the large volume of data is sent via optical links to the DAQ system. To reduce the thermal noise of the SiPM that has increased after being exposed to an integrated lifetime neutron fluence of up to 1012 neq/cm2, the SiPMs arrays are cooled to -40o C with a more greenhouse friendly coolant, Novec. The SiPMs are insulated from the environment by a so-called cold-box, a complex object produced through additive manufacturing, and flushed with dry air. A large full-size proto-type detector assembly was built in the spring of 2018. Serial assembly of the detector elements will commence at the end of 2018 with the underground detector installation foreseen to start at the end of 2019.
An overview of the detector concept will be presented along with the experience from the protype and series production of the detector components complemented by the most recent test and quality assurance results.
Keywords: LHCb upgrade, scintillating fibre, silicon photomultiplier, asic, tracker
First Beam Collision Experiences with the TOP Barrel PID Detector in the Belle II Experiment (#1664)
1 University of Hawaii at Manoa, Department of Physics and Astronomy, Honolulu, Hawaii, United States of America
The B factory experiment Belle at the KEKB collider at KEK (Tsukuba, Japan) experimentally investigated the decays of B-mesons, contributing to the 2008 Nobel Prize in Physics for Kobayashi and Maskawa. The upgrade of the accelerator and experiment to SuperKEKB and Belle II will refine the measurements of previous B factories with vastly improved precision. First beam collisions are being recorded since April 2018. This first phase of luminosity running is planned to continue until Summer 2018. The Time of Propagation (TOP) detector is a novel Cherenkov barrel particle identification system developed to fully replace the Belle barrel PID systems. The detector is based on quartz radiator bars read out by Micro-Channel Plate PMTs. The readout electronics of the TOP system are built around a switched capacitor array waveform sampling ASIC operating at 2.7 GSa/s. Acquired waveforms are processed in real time in the front end electronics, extracting the individual timing of detected optical photons to better than 100 ps. This talk presents the current status of commissioning, calibration and operation of the Belle II TOP detector during the first beam collision runs recorded this year."
Keywords: RICH, fast timing, micro channel plate photo multiplier tube, Waveform Sampling ASIC
A Reconfigurable Monolithic Active Pixel Sensor in Radiation-hard Technology for Outer Tracking and Digital Electromagnetic Calorimetry (#2309)
L. Gonella1, P. Allport1, R. Boseley1, L. Chen2, J. Dopke2, S. Flynn1, I. Kopsalis1, K. Nikolopolous1, P. Phillips2, T. Price1, A. Scott3, I. Sedgwick3, G. Villani2, N. Watson1, M. Warren4, F. Wilson2, A. Winter1, S. Worm1, Z. Zhang2
1 University of Birmingham, School of Physics and Astronomy, Birmingham, United Kingdom
Digital calorimetry relies on a highly granular detector where the cell size is sufficiently small so that only a single particle in a shower enters the cell in a single readout cycle. The DECAL sensor, a depleted monolithic active pixel sensor (DMAPS), has been proposed as a possible technology for future digital calorimeters, such as for the FCC-hh barrel EM calorimeter. A DECAL sensor prototype has been fabricated in the TJ 180nm CMOS imaging process. The prototype has a pixel matrix of 64×64 pixels with a pitch of 55 μm × 55 μm, and reads out using fast logic at 40 MHz. It can be reconfigured to function as either a strip sensor for particle tracking or as a pad sensor, counting the number of pixels above threshold for digital calorimetry. The talk will present results of chip characterisation, including analogue performance, and reconfigurability, along with results of test structures implemented in a radiation-hard version of the TJ 180nm CMOS imaging process. Monte Carlo simulations in the FCCSW framework that have guided design choices such as the pixel pitch, the reconfigurable summing logic requirements, and dead time restrictions will also be shown.
Keywords: Calorimeters, MAPS, Silicon detectors, Instrumentation