Laser-driven polarized hydrogen and deuterium internal targets

Technical Report · Tue Aug 01 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/166414· OSTI ID:166414

Jones, C. E.; Fedchak, J. A.; Kowalczyk, R. S. ^[1]

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1. and others

After completing comprehensive tests of the performance of the source with both hydrogen and deuterium gas, we began tests of a realistic polarized deuterium internal target. These tests involve characterizing the atomic polarization and dissociation fraction of atoms in a storage cell as a function of flow and magnetic field, and making direct measurements of the average nuclear tensor polarization of deuterium atoms in the storage cell. Transfer of polarization from the atomic electron to the nucleus as a result of D-D spin-exchange collisions was observed in deuterium, verifying calculations suggesting that high vector polarization in both hydrogen and deuterium can be obtained in a gas in spin temperature equilibrium without inducing RF transitions between the magnetic substates. In order to improve the durability of the system, the source glassware was redesigned to simplify construction and installation and eliminate stress points that led to frequent breakage. Improvements made to the nuclear polarimeter, which used the low energy {sup 3}H(d,n){sup 4}He reaction to analyze the tensor polarization of the deuterium, included installing acceleration lenses constructed of wire mesh to improve pumping conductance, construction of a new holding field coil, and elimination of the Wien filter from the setup. These changes substantially simplified operation of the polarimeter and should have reduced depolarization in collisions with the wall. However, when a number of tests failed to show an improvement of the nuclear polarization, it was discovered that extended operation of the system with a section of teflon as a getter for potassium caused the dissociation fraction to decline with time under realistic operating conditions, suggesting that teflon may not be a suitable material to eliminate potassium from the target. We are replacing the teflon surfaces with drifilm-coated ones and plan to continue tests of the polarized internal target in this configuration.

• Research Organization: Argonne National Lab., IL (United States)
• OSTI ID: 166414
• Report Number(s): ANL--95/14; ON: DE96000985
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
66 PHYSICS
DEUTERIUM TARGET
HYDROGEN 1 TARGET
LASER RADIATION
POLARIZED TARGETS
PROGRESS REPORT
TESTING