39 research outputs found
Ultra-cold methods for polarized atomic hydrogen
Using the ultra-cold electron-spin-polarized atomic hydrogen technique, one can produce a slow monochromatic beam for use as a polarized jet target. We will first review the development of the ultra-cold technique and then discuss the recent progress on Michigan’s Mark-II ultra-cold proton-spin-polarized hydrogen jet target. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87438/2/119_1.pd
Michigan ultra-cold polarized atomic hydrogen jet target
To study spin effects in high energy collisions, we are developing an ultra-cold high-density jet target of proton-spin-polarized hydrogen atoms. The target uses a 12 Tesla magnetic field and a 0.3 K separation cell coated with superfluid helium-4 to produce a slow monochromatic electron-spin-polarized atomic hydrogen beam, which is then focused by a superconducting sextupole into the interaction region. In recent tests, we studied a polarized beam of hydrogen atoms focused by the superconducting sextupole into a compression tube detector, which measured the polarized atoms’ intensity. The Jet produced, at the detector, a spin-polarized atomic hydrogen beam with a measured intensity of about 2.8⋅1015 H s−12.8⋅1015Hs−1 and a FWHM area of less than 0.13 cm2. This intensity corresponds to a free jet density of about 1⋅1012 H cm−31⋅1012Hcm−3 with a proton polarization of about 50%. When the transition RF unit is installed, we expect a proton polarization higher than 90%. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87742/2/856_1.pd
Status of the Michigan Ultra‐Cold Spin‐Polarized Hydrogen Jet
Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic‐hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2004 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87591/2/639_1.pd
Polarized atomic hydrogen beam studies in the Michigan ultra-cold jet
Studies of an ultra-cold jet of polarized hydrogen atoms are described. This atomic beam is formed by the acceleration of cold (0.3 K) atoms emerging from a region of high magnetic field (12 T). The maximum measured density was about 1012 atoms cm−3.1012atomscm−3. The beam’s full width half maximum size was less than 4 mm. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87560/2/674_1.pd
Polarized Atomic Hydrogen Beam Tests in the Michigan Ultra‐Cold Jet Target
Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87681/2/872_1.pd
Relative luminosity measurement of the LHC with the ATLAS forward calorimeter
In this paper it is shown that a measurement of the relative luminosity
changes at the LHC may be obtained by analysing the currents drawn from the
high voltage power supplies of the electromagnetic section of the forward
calorimeter of the ATLAS detector. The method was verified with a reproduction
of a small section of the ATLAS forward calorimeter using proton beams of known
beam energies and variable intensities at the U-70 accelerator at IHEP in
Protvino, Russia. The experimental setup and the data taking during a test beam
run in April 2008 are described in detail. A comparison of the measured high
voltage currents with reference measurements from beam intensity monitors shows
a linear dependence on the beam intensity. The non-linearities are measured to
be less than 0.5 % combining statistical and systematic uncertainties.Comment: 16 page
Source of polarised deuterons
The proposed project assumes the development of a universal high-intensity source of polarized deuterons (protons) using a charge-exchange
plasma ionizer. The design output current of the source will be up to 10 mA
for and polarization will be up
to of the maximal vector () and tensor (+1,-2) polarization.
The project is based on the equipment which was supplied within the framework
of an agreement between JINR and IUCF (Bloomington, USA). The project will be
realized in close cooperation with INR (Moscow, Russia). The source will be
installed in the linac hall (LU-20) and polarization of beams will be measured
at the output of LU-20. The main purpose of the project is to increase the
intensity of the accelerated polarized beams at the JINR Accelerator Complex up
to 1010 d/pulse. Calculations and first accelerator runs have shown that
the depolarization resonances are absent for the deuteron beam in the entire
energy range of the NUCLOTRON. The source could be transformed into a source of
polarized negative ions if necessary. The period of reliable operation without
participation of the personnel should be within 1000 hours. The project should
be implemented within two to two and a half years from the start of funding