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• Polarized_target abstract "The polarized targets are used as fixed targets in scattering experiments. In high energy physics they are used to study the nucleon spin structure of simple nucleons like protons, neutrons or deuterons. In deep inelastic scattering the hadron structure is probed with electrons, muons or neutrinos. Using a polarized high energy muon beam, for example, on a fixed target with polarized nucleons it is possible to probe the spin dependent part of the structure functions.In the simple parton model the nucleon consists of quarks and gluons and their interaction is governed by quantum chromodynamics. An alternative method to the fixed targets is to use two colliding polarized beams. Several institutes and laboratories work in this field.An international workshop on \"Polarized Sources, Targets and Polarimetry\" takes place every two years.The nuclear spins in the solid targets are polarized with dynamic nuclear polarization method typically in 2.5 or 5 T magnetic field.The magnetic field can be generated with a superconducting magnet filled with liquid helium. The more traditional iron magnets are not preferred due to their large mass and limited geometrical acceptance for the produced particles. The target polarization during the experiment is determined with the nuclear magnetic resonance method. The integrated enhanced NMR-signals are compared to the signals taken in superfluid helium-4 bath at well known calibration temperatures around 1 K, where the spin magnetization follows the Curie law and the nuclear polarization can be calculated from the temperature by using the Brillouin function. During the polarization build up a microwave generator is used to pump the paramagnetic centers in the target material close to the electron spin resonance frequency (about 70 GHz in 2.5 T field).In the helium-3 gas targets optical pumping is used to polarize the nucleons.In the frozen spin targets low temperatures are needed to preserve the polarization for long data taking periods (for the highest possible integrated luminosity) and to reach maximum nuclear polarization for the best figure of merit. Usually a dilution refrigerator with high cooling power is used to reach temperatures below 300 mK during the polarization build up and below 50 mK in frozen spin mode.To preserve the paramagnetic centers in the target material it has to be kept all the time at cryogenic temperatures typically below 100 K. A horizontal dilution cryostat with the possibility to load directly the target material into the helium-3/4 mixing chamber from a liquid nitrogen bath is needed for this reason. While the beam should interact with the target material scattering from the target construction materials is not desired. This leads to an additional requirement of small material budget in terms of radiation length. Thin and low density construction materials are used for this reason in the region of the incoming beam and the scattering products.The properties of a good polarized target material are high number of polarizable nucleons compared to the total amount of nucleons, high polarization degree, short polarization build up time, slow polarization loss rate in frozen spin mode, good resistance against radiation damage and easy handling of the target material. For the dynamic nuclear polarization the material has to be doped with free radicals. Two different ways are usual: chemical doping by mixing with free radicals and creation of F-centers by irradiation in an intensive electron beam. Commonly used target materials are butanol, ammonia,lithium hydrides and their deuterated counterparts. A very interesting material is hydrogen deuteride, because it has the maximal content of polarizable nucleons.High proton polarizations have been reached in a large naphthalene single crystal using optically excited triplet states of fully deuterated pentacene guest moleculesat temperatures around 100 K and magnetic field of 0.3 T.Hyperpolarized carbon-13 has been studied for medical imaging applications.".
• Polarized_target wikiPageExternalLink wwwcompass.cern.ch.
• Polarized_target wikiPageID "35776952".
• Polarized_target wikiPageLength "11637".
• Polarized_target wikiPageOutDegree "58".
• Polarized_target wikiPageRevisionID "704972575".
• Polarized_target wikiPageWikiLink Ammonia.
• Polarized_target wikiPageWikiLink Brillouin_and_Langevin_functions.
• Polarized_target wikiPageWikiLink Butanol.
• Polarized_target wikiPageWikiLink Carbon-13.
• Polarized_target wikiPageWikiLink Category:Particle_physics.
• Polarized_target wikiPageWikiLink Cryogenics.
• Polarized_target wikiPageWikiLink Curies_law.
• Polarized_target wikiPageWikiLink Deep_inelastic_scattering.
• Polarized_target wikiPageWikiLink Deuterium.
• Polarized_target wikiPageWikiLink Dilution_refrigerator.
• Polarized_target wikiPageWikiLink Dynamic_nuclear_polarisation.
• Polarized_target wikiPageWikiLink Electromagnet.
• Polarized_target wikiPageWikiLink Electron.
• Polarized_target wikiPageWikiLink Electron_paramagnetic_resonance.
• Polarized_target wikiPageWikiLink F-Center.
• Polarized_target wikiPageWikiLink Gluon.
• Polarized_target wikiPageWikiLink Hadron.
• Polarized_target wikiPageWikiLink Helium-3.
• Polarized_target wikiPageWikiLink Helium-4.
• Polarized_target wikiPageWikiLink Hydrogen_deuteride.
• Polarized_target wikiPageWikiLink Hyperpolarization_(physics).
• Polarized_target wikiPageWikiLink International_Temperature_Scale_of_1990.
• Polarized_target wikiPageWikiLink Isotopic_labeling.
• Polarized_target wikiPageWikiLink Linear_particle_accelerator.
• Polarized_target wikiPageWikiLink Liquid_helium.
• Polarized_target wikiPageWikiLink Liquid_nitrogen.
• Polarized_target wikiPageWikiLink Lithium_hydride.
• Polarized_target wikiPageWikiLink Luminosity_(scattering_theory).
• Polarized_target wikiPageWikiLink Medical_imaging.
• Polarized_target wikiPageWikiLink Microwave.
• Polarized_target wikiPageWikiLink Muon.
• Polarized_target wikiPageWikiLink Muon_spin_spectroscopy.
• Polarized_target wikiPageWikiLink Naphthalene.
• Polarized_target wikiPageWikiLink Neutrino.
• Polarized_target wikiPageWikiLink Neutron.
• Polarized_target wikiPageWikiLink Nuclear_magnetic_resonance.
• Polarized_target wikiPageWikiLink Nucleon.
• Polarized_target wikiPageWikiLink Nucleon_spin_structure.
• Polarized_target wikiPageWikiLink Optical_pumping.
• Polarized_target wikiPageWikiLink Particle_physics.
• Polarized_target wikiPageWikiLink Parton_(particle_physics).
• Polarized_target wikiPageWikiLink Pentacene.
• Polarized_target wikiPageWikiLink Perturbative_QCD.
• Polarized_target wikiPageWikiLink Proton.
• Polarized_target wikiPageWikiLink Quantum_chromodynamics.
• Polarized_target wikiPageWikiLink Quark.
• Polarized_target wikiPageWikiLink Radiation_hardening.
• Polarized_target wikiPageWikiLink Radiation_length.
• Polarized_target wikiPageWikiLink Radical_(chemistry).
• Polarized_target wikiPageWikiLink Relativistic_Heavy_Ion_Collider.
• Polarized_target wikiPageWikiLink Scattering.
• Polarized_target wikiPageWikiLink Solid.
• Polarized_target wikiPageWikiLink Spin_(physics).
• Polarized_target wikiPageWikiLink Spin_polarization.
• Polarized_target wikiPageWikiLink Superconducting_magnet.
• Polarized_target wikiPageWikiLink Superfluidity.
• Polarized_target wikiPageWikiLink Triplet_state.
• Polarized_target wikiPageWikiLinkText "Polarized target".
• Polarized_target wikiPageWikiLinkText "fixed-target".
• Polarized_target wikiPageUsesTemplate Template:Reflist.
• Polarized_target subject Category:Particle_physics.
• Polarized_target type Physic.
• Polarized_target comment "The polarized targets are used as fixed targets in scattering experiments. In high energy physics they are used to study the nucleon spin structure of simple nucleons like protons, neutrons or deuterons. In deep inelastic scattering the hadron structure is probed with electrons, muons or neutrinos.".
• Polarized_target label "Polarized target".
• Polarized_target sameAs Q7209166.
• Polarized_target sameAs m.0jt348g.
• Polarized_target sameAs Q7209166.
• Polarized_target wasDerivedFrom Polarized_target?oldid=704972575.
• Polarized_target isPrimaryTopicOf Polarized_target.