arXiv subjects

Toma-Stefan Cezar

Publications and source records attributed to Toma-Stefan Cezar.

3 recordsLinked to original sources

arXiv2026

MAGGIE: A Magnetic Gravitational Wave Induction Experiment

Gravitational waves (GWs) can induce effective electromagnetic currents when interacting with external electric and magnetic fields, as described by linearized gravity modifications to Maxwell's equations. This coupling enables a novel detection approach for high-frequency gravitational waves (HFGWs) using axion haloscope experiments. Here we present the MAGnetic Gravitational wave Induction Experiment (MAGGIE), the first lumped-element HFGW detector proposed in Europe, designed to probe HFGWs in the kHz-MHz regime by leveraging a 14 T solenoidal magnet at the University of Hamburg. The GW-induced magnetic flux is captured by a custom-designed pickup loop optimized for the expected symmetry of the effective current. A figure-8-shaped geometry, oriented to break the azimuthal symmetry, is implemented, together with a blind-loop configuration, for real-time noise rejection and calibration. The readout scheme is tailored for continuous signals and time-domain transient searches, using waveform templates for primordial black hole (PBH) mergers. The expected experimental reach in terms of strain spectral noise density at the 40 MHz high-frequency end is projected to reach $\sim 4 \times 10^{-16}/\sqrt{\mathrm{Hz}}$ for transient searches, and in terms of strain, projected to reach $\sim 10^{-19}$ for 1 year of continuous search. This allows MAGGIE to constrain currently unexplored regions of the HFGW parameter space.

gr-qc↗

arXiv2026

ADAMOS: Axion Daily Modulation Searches for Dark Matter at 20 GHz

The ADAMOS (Axion Daily Modulation Searches) project aims to explore the nature of dark matter (DM) through a novel axion haloscope experiment. We propose to construct a fixed-frequency cavity resonator operating at 20 GHz at the University of Hamburg, using an innovative "thin-shell" design that preserves a large detection volume at high frequencies. The experiment will be installed in an existing 14 T superconducting magnet and connected to a highly sensitive RF chain with continuous in situ calibration to eliminate temperature-dependent gain drifts, constituting an essential improvement based on lessons learned from previous attempts. ADAMOS will conduct simultaneous searches for three classes of axion signals: (1) conventional cold DM axions, (2) relativistic axions from axion quark nugget annihilations exhibiting daily modulations, and (3) transient enhancements from streaming DM. By targeting this unexplored frequency regime with a robust, calibrated, and versatile setup, ADAMOS will open new discovery channels in a previously unexplored region of the dark sector.

hep-ex↗

arXiv2026

A Modular Zero-Dead-Time Data Acquisition and Real-Time GPU Processing Platform for High Throughput Physics Experiments

High-throughput physics experiments require efficient and increasingly complex real-time processing. This paper presents a modular, software-defined platform combining high-bandwidth PCIe digitizers with consumer GPUs to achieve continuous, zero-dead-time data acquisition. Utilizing NVIDIA CUDA, the system provides a scalable pipeline for real-time fast Fourier transforms and statistical averaging. Benchmarks demonstrate that the platform can sustain continuous processing at sampling rates up to 500 MSa/s, effectively managing data throughputs of 1 GB/s. To validate the in-situ zero-dead-time architecture, end-to-end phase continuity tests were conducted, constraining fractional data loss to below $10^{-12}$. Furthermore, long-term system stability was demonstrated through an uninterrupted one-month data acquisition run. In its current deployment for the WISPLC dark matter experiment, the platform operates at 124 MSa/s with a resolution bandwidth of 0.1 Hz. This implementation enabled a significant reduction in data storage requirements using real-time spectral averaging. The callback-driven software architecture, multi-GPU workload distribution, and custom hardware shielding solutions are detailed, establishing this platform as a flexible and cost-effective alternative to traditional hardware-based pipelines.

physics.ins-det↗