Back to Search
Start Over
The NSCL cyclotron gas stopper – Entering commissioning
- Source :
- Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 376:256-259
- Publication Year :
- 2016
- Publisher :
- Elsevier BV, 2016.
-
Abstract
- Linear gas stopping cells have been used successfully at NSCL to slow down ions produced by projectile fragmentation from the 100 MeV/u to the keV energy range. These ‘stopped beams’ have first been used for low-energy high precision experiments and more recently for NSCLs re-accelerator ReA. A gas-filled reverse cyclotron is currently under construction by the NSCL to complement the existing stopping cells: Due to its extended stopping length, efficient stopping and fast extraction is expected even for light and medium-mass ions, which are difficult to thermalize in linear gas cells. The device is based on a 2.6 T maximum-field cyclotron-type magnet to confine the injected beam while it is slowed down in ≈100 mbar of LN2-temperature helium gas. Once thermalized, the beam will be transported to the center of the device by a traveling-wave RF-carpet system, extracted along the symmetry axis with an ion conveyor and miniature RF-carpets, and accelerated to a few tens of keV of energy for delivery to the users. The superconducting magnet has been constructed on a 60 kV platform and energized to its nominal field strength. The magnet’s two cryostats use 3 cryo-refrigerators each and liquid-nitrogen cooled thermal shields to cool the coil pair to superconductivity. This concept, chosen not to have to rely on external liquid helium, has been working well. Measurements of axial and radial field profiles confirm the field calculations. The individual RF-ion guiding components for low-energy ion transport through the device have been tested successfully. The beam stopping chamber with its 0.9 m-diameter RF carpet system and the ion extraction system are being prepared for installation inside the magnet for low-energy ion transport tests.
- Subjects :
- Cryostat
Nuclear and High Energy Physics
Range (particle radiation)
010308 nuclear & particles physics
Cyclotron
chemistry.chemical_element
Field strength
Superconducting magnet
01 natural sciences
law.invention
Nuclear physics
chemistry
law
Magnet
0103 physical sciences
Atomic physics
010306 general physics
Instrumentation
Beam (structure)
Helium
Subjects
Details
- ISSN :
- 0168583X
- Volume :
- 376
- Database :
- OpenAIRE
- Journal :
- Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
- Accession number :
- edsair.doi...........65e2bc160e13b4ba25ae6c0e8def2048