Related Experiment Video
Updated: Aug 8, 2026
10:52
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Polarized proton collisions at 205 GeV at RHIC
Physical Review Letters
|May 23, 2006
Summary
Brookhaven Relativistic Heavy Ion Collider (RHIC) experiments show that stronger intrinsic spin resonances at higher energies impact polarized proton beam survival. Maintaining beam polarization requires careful control of vertical orbit distortions.
Area of Science:
- Nuclear Physics
- Particle Physics
- Accelerator Physics
Background:
- Brookhaven Relativistic Heavy Ion Collider (RHIC) accelerates polarized protons to 100 GeV.
- Siberian snakes preserve polarization up to 100 GeV.
- Intrinsic spin resonances strengthen significantly beyond 100 GeV.
Purpose of the Study:
- Investigate the impact of stronger intrinsic spin resonances on polarization survival.
- Determine the tolerance for vertical orbit distortions at higher energies.
Main Methods:
- Acceleration of polarized protons to 205 GeV at RHIC.
- Measurement of polarization at top energy.
- Analysis of polarization survival sensitivity to orbit distortions.
Main Results:
- Polarized protons successfully accelerated to a record 205 GeV.
- Significant polarization was measured at the top energy.
- Polarization survival demonstrates sensitivity to vertical orbit distortions.
Conclusions:
- Higher energy operation at RHIC is feasible with polarized protons.
- Controlling vertical orbit distortions is crucial for maintaining polarization.
- Understanding intrinsic spin resonances is key for future high-energy polarized proton physics.
Related Concept Videos
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
01:13¹H NMR: Complex Splitting
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
01:04¹³C NMR: ¹H–¹³C Decoupling
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
02:24Polar Covalent Bonds
Covalent bonds are formed between two atoms when both have similar tendencies to attract electrons to themselves (i.e., when both atoms have identical or fairly similar ionization energies and electron affinities). Nonmetal atoms frequently form covalent bonds with other nonmetal atoms. For example, the hydrogen molecule, H2, contains a covalent bond between its two hydrogen atoms. When two separate hydrogen atoms with a particular potential energy approach each other, their valence orbitals...
01:07Proton (¹H) NMR: Chemical Shift
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei in a...
Absorption signals of all the protium nuclei in a...