arXiv subjects

A. Kalinin

Publications and source records attributed to A. Kalinin.

At least 19 recordsLinked to original sources

arXiv2025

Testing strong-field QED to second-order in the highly correlated atomic system berylliumlike Pb78+ by electron-ion recombination spectroscopy

A low-energy storage ring with an ultracold electron cooler has been coupled with a heavy-ion accelerator facilitating high-resolution electron-ion collision spectroscopy of the heaviest few-electron ions. In the present work resonant electron-ion recombination of berylliumlike Pb$^{78+}$ ions was measured in the collision-energy range 9.3-16.5eV and a value of 244.937(30) eV is derived for the Pb$^{78+}$($2s^2\;^1S_0 - 2s\,2p\;^3P_1$) excitation energy. This result agrees with the most recent (less accurate) theoretical value of 244.942(52) eV [Malyshev et al., Physical Review A 110, 062824 (2024)], which has been calculated by applying strong-field QED rigorously up to the second order. The present investigation suggests that further technical improvements can potentially increase the experimental accuracy by an order of magnitude.

physics.atom-ph↗

arXiv2022

Integration of maXs-type microcalorimeter detectors for high-resolution x-ray spectroscopy into the experimental environment at the CRYRING@ESR electron cooler

We report on the first integration of novel magnetic microcalorimeter detectors (MMCs), developed within SPARC (Stored Particles Atomic Physics Research Collaboration), into the experimental environment of storage rings at GSI, Darmstadt, namely at the electron cooler of CRYRING@ESR. Two of these detector systems were positioned at the 0$^\circ$ and 180$^\circ$ view ports of the cooler section to obtain high-resolution x-ray spectra originating from a stored beam of hydrogen-like uranium interacting with the cooler electrons. While previous test measurements with microcalorimeters at the accelerator facility of GSI were conducted in the mode of well-established stand-alone operation, for the present experiment we implemented several notable modifications to exploit the full potential of this type of detector for precision x-ray spectroscopy of stored heavy ions. Among these are a new readout system compatible with the multi branch system data acquisition platform of GSI, the synchronization of a quasi-continuous energy calibration with the operation cycle of the accelerator facility, as well as the first exploitation of the maXs detectors' time resolution to apply coincidence conditions for the detection of photons and charge-changed ions.

physics.ins-det↗

arXiv2022

X-ray emission associated with radiative recombination for Pb$^{82+}$ ions at threshold energies

For bare lead ions, decelerated to the low beam energy of 10 MeV/u, the x-ray emission associated with radiative recombination (RR) at "cold collision" conditions has been studied at the electron cooler of CRYRING@ESR at GSI-Darmstadt. Utilizing dedicated x-ray detection chambers installed at 0° and 180° observation geometry, we observed for the very first time for stored ions the full x-ray emission spectrum associated with RR under electron cooling conditions. Most remarkably, no line distortion effects due to delayed emission are present in the well resolved spectra, spanning over a wide range of x-ray energies (from about 5 to 100 keV) which enable to identify fine-structure resolved Lyman, Balmer as well as Paschen x-ray lines along with the RR transitions into the K-, L and M-shell of the ions. To compare with theory, an elaborate theoretical model has been applied. By considering the relativistic atomic structure of Pb$^{81+}$, this model is based on a sophisticated computation of the initial population distribution via RR for all atomic levels up to Rydberg states with principal quantum number $n=$ 165 in combination with cascade calculations based on time-dependent rate equations. Within the statistical accuracy, the experimental x-ray line emission is in very good agreement with the results of the theoretical model applied. Most notably, this comparison sheds light on the contribution of prompt and delayed X-ray emission (up to 70 ns) to the observed X-ray spectra, originating in particular from Yrast transitions into inner shells.

physics.atom-ph↗

arXiv2022

Ontological model identification based on data from heterogeneous sources

The development of a company often entails the emergence of autonomous data sources with different structural and technological organization. This can lead to the inability of data analysis at a high level and a violation of the integrity and reliability of data within the organization, hindering the adoption of high-quality decisions and further development of the company. This problem can be solved by implementing a higher abstraction, representing heterogeneous organization data in a single space by combining them into a single knowledge graph. We propose a framework capable of autonomous construction of an organization's knowledge graph based on semi-structured data from various sources by finding links between sources based on data with an arbitrary structure, and combining document collections into single entities. The results of tests show the applicability of the developed approach for constructing a knowledge graph based on partially-structured data from various sources and the high efficiency of the approach based on the metrics of completeness of data storage subsystems coverage (11 out of 11) and filtering false connections (there are only 2.5 connections of collections with neighbors on average in the final graph).

cs.IR↗

arXiv2019

Magnetic fields alter tunneling in strong-field ionization

When a strong laser pulse induces the ionization of an atom, momentum conservation dictates that the absorbed photons transfer their momentum $p_γ=E_γ/c$ to the electron and its parent ion. Even after 30 years of studying strong-field ionization, the sharing of the photon momentum between the two particles and its underlying mechanism are still under debate in theory. Corresponding experiments are very challenging due to the extremely small photon momentum ($~10^{-4}$ a.u.) and their precision has been too limited, so far, to ultimately resolve the debate. Here, by utilizing a novel experimental approach of two counter-propagating laser pulses, we present a detailed study on the effects of the photon momentum in strong-field ionization. The high precision and self-referencing of the method allows to unambiguously demonstrate the action of the light's magnetic field on the electron while it is under the tunnel barrier, confirming theoretical predictions, disproving others. Our results deepen the understanding of, for example, molecular imaging and time-resolved photoelectron holography.

physics.atom-ph↗

arXiv2018

Determination of the He-He, Ne-Ne, Ar-Ar, and H$_{2}$ interaction potential by wave function imaging

We report on a direct method to measure the internuclear potential energy curve of diatomic systems. A COLTRIMS reaction microscope was used to measure the squares of the vibrational wave functions of H$_{2}$, He$_{2}$, Ne$_{2}$, and Ar$_{2}$. The Schrödinger equation relates the curvature of the wave function to the potential V(R) and therefore offers a simple but elegant way to extract the shape of the potential.

physics.atom-ph↗

arXiv2018

The role of spin and angular momentum in strong-field ionization

The spin polarization of electrons from multiphoton ionization of Xe by 395 nm circularly polarized laser pulses at $6\cdot10^{13}$ W/cm$^2$ has been measured. At this photon energy of 3.14 eV the above threshold ionization peaks connected to Xe$^+$ ions in the ground state ($J=3/2$, ionization potential $I_p=12.1$ eV) and the first exicted state ($J=1/2$, $I_p=13.4$ eV) are clearly separated in the electron energy distribution. These two combs of ATI peaks show opposite spin polarizations. The magnitude of the spin polarization is a factor of two higher for the $J=1/2$ than for the $J=3/2$ final ionic state. In turn the data show that the ionization probability is strongly dependent on the sign of the magnetic quantum number.

physics.atom-ph↗

arXiv2016

Imaging the He$_2$ quantum halo state using a free electron laser

We report on coulomb explosion imaging of the wavefunction of the quantum halo system He$_2$. Each atom of this system is ionized by tunnelionization in a femto second laser pulse and in a second experiment by single photon ionization employing a free electron laser. We visualize the exponential decay of the probability density of the tunneling particle over distance for over two orders of magnitude up to an internuclear distance of 250 Å. By fitting the slope of the density in the tunneling regime we obtain a binding energy of 151.9 $\pm$ 13.3 neV, which is in agreement with most recent calculations.

physics.atom-ph↗

arXiv2015

Mixing Effects in the Crystallization of Supercooled Quantum Binary Liquids

By means of Raman spectroscopy of liquid microjets we have investigated the crystallization process of supercooled quantum liquid mixtures composed of parahydrogen (pH$_2$) diluted with small amounts of up to 5\% of either neon or orthodeuterium (oD$_2$), and of oD$_2$ diluted with either Ne or pH$_2$. We show that the introduction of Ne impurities affects the crystallization kinetics in both the pH$_2$-Ne and oD$_2$-Ne mixtures in terms of a significant reduction of the crystal growth rate, similarly to what found in our previous work on supercooled pH$_2$-oD$_2$ liquid mixtures [M. Kühnel et {\it al.}, Phys. Rev. B \textbf{89}, 180506(R) (2014)]. Our experimental results, in combination with path-integral simulations of the supercooled liquid mixtures, suggest in particular a correlation between the measured growth rates and the ratio of the effective particle sizes originating from quantum delocalization effects. We further show that the crystalline structure of the mixture is also affected to a large extent by the presence of the Ne impurities, which likely initiate the freezing process through the formation of Ne crystallites.

cond-mat.mtrl-sci↗

arXiv2014

Interatomic-Coulombic-decay-induced recapture of photoelectrons in helium dimers

We investigate the onset of photoionization shakeup induced interatomic Coulombic decay (ICD) in He2 at the He+*(n = 2) threshold by detecting two He+ ions in coincidence. We find this threshold to be shifted towards higher energies compared to the same threshold in the monomer. The shifted onset of ion pairs created by ICD is attributed to a recapture of the threshold photoelectron after the emission of the faster ICD electron.

physics.atm-clus↗

arXiv2013

Vibrationally Resolved Decay Width of Interatomic Coulombic Decay in HeNe

We investigate the ionization of HeNe from below the He 1s3p excitation to the He ionization threshold. We observe HeNe$^+$ ions with an enhancement by more than a factor of 60 when the He side couples resonantly to the radiation field. These ions are an experimental proof of a two-center resonant photoionization mechanism predicted by Najjari et al. [Phys. Rev. Lett. 105, 153002 (2010)]. Furthermore, our data provide electronic and vibrational state resolved decay widths of interatomic Coulombic decay (ICD) in HeNe dimers. We find that the ICD lifetime strongly increases with increasing vibrational state.

physics.atm-clus↗

arXiv2013

Ion impact induced Interatomic Coulombic Decay in neon and argon dimers

We investigate the contribution of Interatomic Coulombic Decay induced by ion impact in neon and argon dimers (Ne$_2$ and Ar$_2$) to the production of low energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S$^{14+}$, 0.125 MeV/u He$^{1+}$, 0.1625 MeV/u He$^{1+}$ and 0.150 MeV/u He$^{2+}$ as projectiles and study ionization, single and double electron transfer to the projectile as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentum vectors of the ion pairs of the fragmenting dimer into Ne$^{q+}$/Ne$^{1+}$ and Ar$^{q+}$/Ar$^{1+}$ (q = 1, 2, 3) in coincidence with at least one emitted electron.

physics.atm-clus↗

arXiv2013

A measurement of the evolution of Interatomic Coulombic Decay in the time domain

During the last 15 years a novel decay mechanism of excited atoms has been discovered and investigated. This so called ''Interatomic Coulombic Decay'' (ICD) involves the chemical environment of the electronically excited atom: the excitation energy is transferred (in many cases over long distances) to a neighbor of the initially excited particle usually ionizing that neighbor. It turned out that ICD is a very common decay route in nature as it occurs across van-der-Waals and hydrogen bonds. The time evolution of ICD is predicted to be highly complex, as its efficiency strongly depends on the distance of the atoms involved and this distance typically changes during the decay. Here we present the first direct measurement of the temporal evolution of ICD using a novel experimental approach.

physics.atom-ph↗

arXiv2012

Compact Cryogenic Source of Periodic Hydrogen and Argon Droplet Beams for Relativistic Laser-Plasma Generation

We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art high-power lasers in which a precise synchronization between the laser pulses and the droplets is mandatory. We show this by irradiating argon droplets with multi-Terawatt pulses.

physics.plasm-ph↗

arXiv2009

Latest Beam Test Results of the FONT4 ILC Intra-train Feedback System Prototype

We present the design and preliminary results of a prototype beam-based digital feedback system for the Interaction Point of the International Linear Collider. A custom analogue front-end processor, FPGA-based digital signal processing board, and kicker drive amplifier have been designed, built, and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The system was measured to have a latency of approximately 140 ns.

physics.acc-ph↗

arXiv2008

Crab cavities for linear colliders

Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

physics.acc-ph↗

arXiv2005

Asymmetry measurement of charged hadron production in pA collisions at 40 GeV

The single spin asymmetry of charge hadron production by a 40 GeV/c proton beam with 39% transverse polarization incident on nuclei (C, Cu) has been measured using the Focusing Double Arm Spectrometer (FODS). The measurements were carried out for hadrons with high Xt (82 deg. in c.m.) and with high Xf (one arm at 51 deg. and the other arm at 99 deg. in c.m.). The results are presented for charged pions, kaons, protons and antiprotons with high Xt.

hep-ex↗

arXiv2005

A Test Facility for the International Linear Collider at SLAC End Station A, for Prototypes of Beam Delivery and IR Components

The SLAC Linac can deliver damped bunches with ILC parameters for bunch charge and bunch length to End Station A. A 10Hz beam at 28.5 GeV energy can be delivered there, parasitic with PEP-II operation. We plan to use this facility to test prototype components of the Beam Delivery System and Interaction Region. We discuss our plans for this ILC Test Facility and preparations for carrying out experiments related to collimator wakefields and energy spectrometers. We also plan an interaction region mockup to investigate effects from backgrounds and beam-induced electromagnetic interference.

physics.ins-det↗