Fixed-target pp and pA collisions with a proton beam at the TeV scale provide unique laboratories for the study of the nucleon’s internal dynamics and, more in general, for the investigation of the complex phenomena arising in the non-perturbative regime of QCD. Due to the substantial boost of the reaction products in the laboratory frame, fixed-target collisions allow to access the poorly...
The LHCspin project aims at unpolarized (SMOG2) and polarized fixed-target measurements by means of a gas target upstream of the LHCb detector, close to the vertex detector VELO. The forward geometry of the LHCb spectrometer (2 < 𝜂 < 5) allows for the reconstruction of particles produced in fixed-target collisions, with center-of-mass energies ranging from √sNN = 72 GeV with Pb beam and √sNN =...
Photo-electron sources using GaAs-based photocathodes are used to provide high-brightness and high-current beams of (spin-polarized) electrons for accelerator applications such as free-electron lasers (FELs) and energy recovery linacs (ERLs). Such cathodes require a thin surface layer consisting of Cs and an oxidant in order to achieve negative electron affinity (NEA) for efficient...
The Electron Ion Collider (EIC) is a new Nuclear Physics Facility that will use collisions between polarized Ions and polarized electrons to study the inner structure of the Nucleon. The EIC will be sited at Brookhaven National Laboratory (BNL) and is designed in collaboration with JLab to address profound questions about nucleons. For this purpose, the EIC takes advantage of the entire...
The Electron Ion Collider (EIC) is a new Nuclear Physics Facility that will use collisions between polarized Ions and polarized electrons to study the inner structure of the Nucleon. The EIC will be sited at Brookhaven National Laboratory (BNL) and is designed in collaboration with JLab to address profound questions about nucleons. For this purpose, the EIC takes advantage of the entire...
In the last 60 years Sona-transition units are used to invert occupation numbers of pure states through a fast-changing magnetic field through a zero crossing point. The inversion of the magnetic quantisation axis is then changing fast enough such that the Lamor precession cannot follow. In addition, we observed that spectroscopy measurements of the hyperfine splitting are possible. In our...
After the discovery of the Lamb shift in 1947 by Willis Eugene Lamb and Robert C. Retherford it was used to create Lamb shift polarimeter to separate the 2S$_{1/2}$ α$_1$ and α$_2$ hyperfine substates of hydrogen as well as the α$_3$ substate of deuterium. But for a new project at the Technical University of Munich, the bound-beta decay of a neutron into a hydrogen atom and a neutrino, a Lamb...
With a dedicated apparatus it was shown that the nuclear polarization of hydrogen atoms and its isotopes, produced by a polarized atomic beam source (ABS), can be preserved during the recombination into molecules. In this way, polarized $H_2$ and $D_2$ molecules in hyperfine substates where both nucleons have the same nuclear spin are generated. In more recent experiments the ABS was used to...
A new dynamically polarized target of irradiated ammonia (NH$_3$ and ND$_3$) has been constructed for use with the CLAS12 spectrometer system in Hall B at Jefferson Lab. The new target is used to polarize protons and deuterons in the longitudinal orientation at a temperature of 1 K and a field of 5 T. Its first use with CLAS12 includes measurements of spin structure functions via deep...
Polarized $^3$He nuclear targets have been invaluable surrogates for polarized neutron targets in spin-dependent scattering studies of the quark and gluon structure of matter. Traditional polarized $^3$He targets have seen dramatic improvements in the last three decades, however they have been limited in their use in spectrometers that utilize high-magnetic-field tracking systems, such as...
The relaxation times of protons and deuterons in a frozen-spin hydrogen-deuteride (HD) target are more than 1 year under the normal experimental conditions (T ~ 0.1 K and B ~ 1 T). These targets have been used successfully for photoproduction experiments both at CLAS in Jefferson Lab (JLab) and at LEGS in Brookhaven Lab. In order to explore its performance under...
Nuclear physics experiments requiring highly spin polarized positron beams are now proposed at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory (JLab). To achieve this, a new polarized positron injector is imagined, where the positron beam polarization is derived from the bremsstrahlung of an intense continuous-wave (CW) spin polarized electron beam produced...
The cross section of the primary reaction in a tokamak fusion reactor, D + T --> α + n, would be increased by 50% if the fuels were fully polarized along the local magnetic field. In a large-scale fusion reactor such as ITER, the power gain could be as much as 75% due to increased alpha heating. Such a boost would be a significant step towards establishing a burning plasma. The...
Constant current continuous wave Nuclear Magnetic Resonance (NMR) has
been an essential tool for polarized target experiments in Nuclear and
High-energy physics. Q-meter based phase-sensitive detection can provide
accurate monitoring of the polarization over the course of a scattering
experiment with limitations due to some operational parameters. In this talk,
we present recent studies...
The Gerasimov-Drell-Hearn (GDH) sum rule states that the difference between the parallel and antiparallel cross sections of a polarized photon hitting a polarized target is proportional to the square of the anomalous magnetic moment of the target. We plan to use the GDH sum rule to study the nuclear structure of the deuteron. To do that, we put our target material into a Frozen Spin setup,...
The nuclear spin polarization of solid-state targets is determined by magnetic nucleon resonance using the Q-meter technique. In this lecture, the possibility of replacing this Q-meter with a "cheap" vector-network analyzer will be presented.
Nuclear physics experiments performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory (JLab) require highly polarized electron beams, produced from strained super-lattice GaAs/GaAsP photocathodes. To prolong the photocathode operational lifetime, the photogun and adjoining beamline should be maintained at the lowest possible pressure. This presentation...
The first direct measurement of charged particle Electric Dipole Moment (EDM) was performed by the Jülich Electrical Dipole Moment Investigations (JEDI) collaboration. These investigations were carried out using polarized deuteron beams at the COoler SYnchrotron (COSY) located at the Forschungszentrum Jülich in Germany. The search for an EDM demands high precision measurements, separating the...
A versatile solution is being pursued for the challenging magnetic problem of producing internal fields in compact spaces. It is a promising tool for trapping fields around a polarized target, while shielding out external fields from spectrometers, and in addiction, for generating holding fields for accumulation and transport of polarized fuel in nuclear fusion tests.
The bulk...
CryPTA (Cryogenic Polarized Target Applications) is a joint research activity of the European Research Association for Hadron Physics STRONG2020 and deals with developments in the field of polarized solid-state targets. Our focus is on the development of active polarized target technologies and the further development of superconducting coils for applications in the polarized target and...
A storage ring experiment with frozen spin polarized colliding proton beams, capable of detecting time reversal (T) symmetry violation in ``elastic'' $pp$ (or $dd$) scattering is described. Operating below the pion production threshold (laboratory fixed hydrogen target proton kinetic energy 400\,MeV) but above the 69.5\,MeV laboratory energy at which proton-carbon scattering asymmetry...
The matter-antimatter asymmetry may be explained through CP-violation by observing a permanent electric dipole moment (EDM) of subatomic particles. An advanced approach to measure the EDM of charged particles is to apply a unique method of "Frozen spin" on a polarized beam in an accelerator. To increase the experimental precision step by step and to study systematic effects, the EDM experiment...
For the high-precision measurements in the experiments at the new Mainz Energy recovering Superconducting Accelerator (MESA), it is necessary to know exactly the long-term spin properties of the electron beam.
For this purpose, a test setup has been built at the Institute for Nuclear physics. Different preparation methods of a photocathode with nitrogen trifluoride and oxygen are...
A high intensity polarised beam has to be delivered to the P2 experiment at Mainz Energy Recovering Superconducting Accelerator Facility (MESA). The absolute error of the beam polarisation should be ≤0.5 %. To track the polarisation, a Mott polarimeter will be installed after the pre-acceleration of the polarised beam to 5 MeV energy. The goal of this work is to deploy a 5 MeV Mott polarimeter...
STERN-GERLACH-EXPERIMENT
Frankfurt am Main
DEPARTURE: 13.15 pm,
side entrance of the HIM building
RETURN: 16.15 pm at Frankfurt
KLOSTER EBERBACH
Eltville
DEPARTURE: 13.15 pm,
side entrance of the HIM building
RETURN: 17.00 pm at Eltville
The talk will discuss the current efforts to generate and operate spin-polarized ion beams at the GSI/FAIR storage ring facilities, aimed at a new class of experiments in atomic, quantum and fundamental physics with light and heavy highly charged ions and exotic nuclei [1]. To this end, as a first step, we plan to install the polarized atom beam source ANKE, capable of providing polarized...
At the FZ Jülich a polarized ion source produces a pulsed beam of nuclear spin polarized 𝐻− or 𝐷− ions for stripping injection into the storage ring COSY. Before injection, the nuclear polarization needs to be determined and optimized. Until now, this is done with a device called Low Energy Polarimeter (LEP), which is based on the polarization dependent elastic scattering of protons on a...
The Thomas Jefferson National Accelerator Facility (JLab) operates the Continuous Electron Beam Accelerator Facility which produces a polarized electron beam which is delivered to four experimental halls and is utilized to probe the fundamental nature of matter. Parity-violating electron scattering experiments are one category of experiments that are run at JLab. For these experiments,...
A novel method of laser-plasma acceleration employing dynamically polarized gas-jet targets (HCl/HBr gas) has been proposed to generate 100-MeV polarized proton beams. To achieve the beam polarization measurement in laser-plasma experiments at multi-Petawatt lasers, we have developed a polarimeter based on $p$-Carbon scattering, detected with the help of solid-state nuclear track detectors,...
Molecular photodissociation is an innovative method for the preparation of polarized atoms and molecules. It is a fundamental chemical process that involves the absorption of one or more polarized photons by a molecule including its fragmentation into polarized atomic (or molecular) fragments. Recently, T. P. Rakitzis’ group produced high densities of spin polarized hydrogen atoms applying...
The proposed polarized 3He++ acceleration in RHIC and future Electron- Ion Collider (EIC) will require on the order of 2∙1011 ions per source pulse. A new technique had been proposed for production of high intensity polarized 3He++ ion beam. It is based on ionization and accumulation of the 3He gas (polarized by optical-pumping and metastability-exchange technique in the high magnetic 5.0 T...
Since 2005, the Polarized Atomic Hydrogen Gas Jet Target polarimeter (HJET) is used to precisely measure absolute polarization of the proton beams at the Relativistic Heavy Ion Collider (RHIC). In Run 22, the polarized proton beams were resumed at RHIC after four years of heavy ion beam operation. Here we compare HJET performance in the 255 GeV proton Runs 17 and 22. Regardless some changes in...
The Standard Model (SM) of Particle Physics cannot explain the matter-antimatter asymmetry in the Universe, which is why physics beyond the SM must be pursued. The search for permanent Electric Dipole Moments (EDMs) of elementary particles can be a powerful tool to probe new sources of CP-violation. Finding an EDM would be a convincing indicator for physics beyond the SM.
Storage rings make...
T-shape cells fed with polarized hydrogen or deuterium atoms were used at several storage rings like COSY, DESY or IUCF to serve as polarized internal targets. To avoid polarization losses of the stored atoms, e.g. by recombination into molecules, different surface materials are used to solve these problems. For example, aluminum with its ceramic monolayer of aluminum oxide, Teflon or a water...
The COMPASS experiment at CERN is using a transversely solid polarized deuteron target with a muon beam to measure the TMD PDFs in SIDIS in 2022.
The target system consists of a 50 mK dilution refrigerator, a 2.5 T solenoid magnet, three sets of 70 GHz microwave system. Solid $^6$LiD beads of the target material was contained in 3-target-cell of 30-60-30 cm long with a 3 cm diameter. The...
In the neutron p-resonant absorption of $^{139}$La, it is known that the Parity Non-Conservation effect (PNC) is enhanced by a factor of 10$^{6}$ compared to the nucleon-nucleon scattering. According to recent experiments with neutron-gamma reactions in $^{139}$La, it is highly possible that violating effects of the Time-reversal symmetry is also amplified with the similar mechanism of the PNC...
