SearcharxivSearch

arXiv subjects

Daniel Ferenc

Publications and source records attributed to Daniel Ferenc.

10 recordsLinked to original sources

Tandem-ABALONETM Photosensors with $2\times2\pi$ Acceptance for Neutrino Astronomy

The primary goal of the novel photosensor technology called ABALONETM (U.S. Pat. 9,064,678) has been to enable the next-generation of astroparticle physics experiments to open new windows on the universe with large-area detectors of unprecedented performance, radio-purity, robustness, and integration flexibility. This foundational technology provides the means for modern, scalable and cost-effective production. The wide range of possible application-specific detector configurations can also make a difference in homeland security and medical imaging. Thus far, we have reduced to practice two such detector configurations: (i) the composite sandwich Panel assembly that hosts matrices of closely packed ABALONE units (U.S. Pat. 10,823,861), and, quite differently, the Tandem Detector Modules that host two back-to-back oriented ABALONE photosensors. This article for the first time presents the latter configuration, specifically designed to provide $2\times2\pi$ angular acceptance for neutrino astronomy and other large-area radiation detectors.

physics.ins-det

Helium Migration through Photomultiplier Tubes -- The Probable Cause of the DAMA Seasonal Variation Effect

The interpretation of the DAMA seasonal variation pattern as a Dark Matter (DM) effect rests on the assumption that all sources of variable background have been excluded from the measurement. We have identified an overlooked background that mimics the DM signature -- a large, patently existing effect that has nothing to do with detection within the scintillators. This process takes place exclusively within the individual photomultiplier tubes (PMTs), with two familiar actors (thermionic electrons and helium atoms), two familiar processes (helium penetration of glass and ion afterpulsing), and a simple storyline: (a) After defeating the insulation of the DAMA detector, helium atoms from the variable local environment penetrate the PMT vacua; (b) Thermionic electrons from the PMT photocathode ionize helium atoms; (c) Secondary electrons from each helium ion impact in the photocathode form an afterpulse, and thus effectively boost and extend the waveform. We demonstrate that the accidental coincidences of such inflated dark noise waveforms, originating from any pair of PMTs, mimic scintillation events at a rate of $\approx$ 1 cpd/kg/keV, which is consistent with DAMA result. The reported seasonal variation of $\sim$ 1% thus implicates an equivalent variation of helium concentration in the local environment. We predict that the DAMA detector with a modified readout logic -- blinded for the DM scintillation events \textendash will measure the same, helium -- driven seasonal variation pattern as the original detector.

physics.ins-det

ABALONE Photosensors for the IceCube Experiment

The ABALONE Photosensor Technology (U.S. Pat. 9064678) is a modern, scalable technology specifically invented for cost effective mass production, robustness, and high performance. We present the performance of advanced fused silica ABALONE Photosensors, developed specifically for the potential extension of the Ice Cube neutrino experiment, and stress tested for 120 days. The resulting performance makes a significant difference: intrinsic gain in the high 100 million range, total afterpulsing rate of only 0.005 ions per photoelectron, subnanosecond timing resolution, single photon sensitivity, and unique radiopurity and UV sensitivity, thanks to the fused silica components, at no additional cost to the assembly process.

physics.ins-det

The Novel ABALONE Photosensor Technology: 4-Year Long Tests of Vacuum Integrity, Internal Pumping and Afterpulsing

The ABALONE Photosensor Technology (U.S. Patent 9064678 2015) has the capability of supplanting the expensive 80 year old Photomultiplier Tube (PMT) manufacture by providing a modern and cost effective alternative product. An ABALONE Photosensor comprises only three monolithic glass components, sealed together by our new thin film adhesive. In 2013, we left one of the early ABALONE Photosensor prototypes intact for continuous stress testing, and here we report its long term vacuum integrity. The exceptionally low ion afterpulsing rate (approximately two orders of magnitude lower than in PMTs) has been constantly improving. We explain the physical and technological reasons for this achievement. Due to the cost-effectiveness and the specific combination of features, including low level of radioactivity, integration into large-area panels, and robustness, this technology can open new horizons in the fields of fundamental physics, functional medical imaging, and nuclear security.

physics.ins-det

Universal Pion Freeze-out Phase-Space Density

Results on the pion freeze-out phase-space density in sulphur-nucleus, Pb-Pb and pion-proton collisions at CERN-SPS are presented. All heavy-ion reactions are consistent with the thermal Bose-Einstein distrtibution f=1/(exp(E/T)-1) at T~120 MeV, modified for expansion. Pion-proton data are also consistent with f, but at T~180 MeV.

hep-ph

Imaging Hybrid Photon Detectors with Minimized Dead Area and Protection Against Positive Ion Feedback

Imaging Hybrid Photon Detectors (HPD) have been developed for integration in large area Cherenkov detectors for high energy physics and astrophysics. The presented designs - developed particularly for the experiments MAGIC, LHCb and AQUA-RICH - comprise very good imaging properties, protection against positive ion feedback and(or) minimum dead area. The underlying innovations are discussed in some detail.

physics.ins-det

Solution to the ion feedback problem in Hybrid Photon Detectors and Photo Multiplier Tubes

A general solution to the positive ion feedback problem in Hybrid Photon Detectors (HPD), photo multipliers (PM) and other similar detectors was found in the insertion of a permanent electrostatic potential barrier which prevents drift of positive ions from the anode, or the first dynode, towards the photocathode. In this paper we present the method as applied to the Intevac HPD.

physics.ins-det

New Developments in Hybrid Photon Detectors

New developments in HPD design are presented, triggered by applications in high energy physics and astrophysics. The presented HPD designs are based on three innovations. (i) In order to achieve the highest possible surface coverage in a RICH detector, we introduced a photoelectron focussing method which is efficient to the periphery of the photocathode. (ii) To prevent positive ion feedback in HPDs, we introduced a permanent potential barrier in front of the anode. (iii) To replace a transmittive by a reflective photocathode, we arrived at a conceptually new HPD design with surprisingly good imaging characteristics, high quantum efficiency and low cost.

physics.ins-det

How to Test the Existence of the Early Parton Cascade Using Photon HBT Correlations?

We report on a possible application of the HBT phenomenon in testing the existence of two hypothetical phenomena. First, it is argued that the existence of a rapidly developing parton cascade in the earliest stages of a high energy nuclear collision process can be tested by studying two-photon HBT correlations over a wide longitudinal momentum scale - corresponding to the early photon emission time from the hypothetical parton system. This method provides the needed selectivity for the early emitted photons, since the photons emitted at later times correlate over progressively narrower momentum scales. Second, in a similar way we argue that the existence of a hypothetic dark matter candidate, the Weakly Interacting Massive Particle (WIMP), may be tested by studying HBT correlations of cosmic gamma rays at a relatively long detection time scale - corresponding to the very narrow spectral line of the photons emerging from WIMP annihilations. Background photons leave no signature since they essentially do not correlate.

nucl-ex