Development of a Relic Neutrino Detection Experiment at PTOLEMY: Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield

Abstract

Figure 2: The small-scale PTOLEMY prototype installed at the Princeton Plasma Physics Laboratory (February 2013). Two horizontal bore NMR magnets are positioned on either side of a MAC-E filter vacuum tank. The tritium target plate is placed in the left magnet in a 3.35T field, and the RF tracking system is placed in a high uniformity 1.9T field in the bore of the right magnet with a windowless APD detector and in-vacuum readout electronics. Contents Contents ii 7 Trigger and Data-Acquisition 8 Time-of-flight 9 Muon veto 10 e-Gun Calibration 11 Vacuum system 12 Cooling systems

First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background

“…The neutrinos began to stream freely at k B T ∼ MeV, and continue to stream freely through the cosmos to this day. Unlike with photons, direct detection of the CNB is exceedingly difficult [1].…”

“…Since contributions to anisotropy arising after recombination project differently, we zero out contributions from the integrated Sachs Wolfe (ISW) effect. model, normalized to give the amplitude of the relative shift between the fiducial 3.046 neutrino species and a single specie, along with numerically obtained phase shifts obtained from 100 different simulated cosmologies with varying neutrino species drawn from Nν = [1,6] relative to the fiducial cosmology, rescaled by the amplitude parameter given in equation 3. Also included is the analytic approximation given by [6], which they also found to be ∼ 25% higher than the numerical result at 3000.…”

PTOLEMY: A Proposal for Thermal Relic Detection of Massive Neutrinos and Directional Detection of MeV Dark Matter

“…An experimental realization of this concept was proposed based on PTOLEMY [1] in 2013; since then, many of those points that were considered as major obstacles toward the realization of the detector have been overcome. To mention the most important ones: high radio-pure graphene for the substrate of a tritium target appears now as a viable choice, single electron RF detection has been successfully achieved and Transition Edge Sensors (TES) with extremely good energy resolution may be employed to discriminate the few signal events from the overwhelming background.…”

Detection Prospects of the Cosmic Neutrino Background

“…Moreover, a realistic proposal for the CνB detection is the PTOLEMY project 14 , which is designed to employ 100 grams of 3 H as the capture target using a combination of a large-area surface-deposition tritium target, the MAC-E filter, the RF tracking, the time-of-flight systems, and the cryogenic calorimetry. Finally, the event rate of PTOLEMY are calculated to reach the observable level:…”

“…Among several possibilities 3 , the most promising one seems to be the neutrino capture experiment using radioactive β-decaying nuclei [4][5][6][7][8][9][10][11][12][13] . The proposed PTOLEMY project 14 aims to obtain the sensitivity required to detect the CνB using 100 grams of 3 H as the capture target. Other interesting possibilities include the electron-capture (EC) decaying nuclei [15][16][17][18] , the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance [19][20][21] , and the atomic de-excitation method 22 .…”