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Title The Qweak High Performance LH2 Target
Authors James Brock, Silviu Covrig Dusa, James Dunne, Christopher Keith, David Meekins, Josh Pierce, Gregory Smith, Adesh Subedi
JLAB number JLAB-PHY-23-3772
LANL number arXiv:2303.07497
Other number DOE/OR/23177-5782
Document Type(s) (Journal Article) 
Associated with EIC: No
Supported by Jefferson Lab LDRD Funding: No
Funding Source: Nuclear Physics (NP)
Other Funding:DOE
 

Journal
Compiled for Nuclear Instruments & Methods in Physics Research, Section A
Volume 1053
Page(s) 168316
Refereed
Publication Abstract: A high-power liquid hydrogen target was built for the Jefferson Lab Qweak experiment, which measured the tiny parity-violating asymmetry in ?e p scattering at an incident energy of 1.16 GeV, and a Q2 = 0.025 GeV2. To achieve the luminosity of 1.7 × 1039 cm?2 s?1, a 34.5 cm- long target was used with a beam current of 180 ?A. The ionization energy-loss deposited by the beam in the target was 2.1 kW. The target temperature was controlled to within ±0.02 K and the target noise (density fluctuations) near the experiment?s beam helicity- reversal rate of 960 Hz was only 53 ppm. The 58 liquid liter target achieved a head of 11.4 m (7.6 kPa) and a mass flow of 1.2 ± 0.3 kg/s (corresponding to a volume flow of 17.4 ± 3.8 l/s) at the nominal 29 Hz rotation frequency of the recirculating centrifugal pump. We describe aspects of the design, operation, and performance of this target, the highest power LH2 target ever used in an electron scattering experiment to date.
Experiment Numbers: E08-016
Group: Hall C
Document: pdf
DOI: https://doi.org/10.1016/j.nima.2023.168316
Accepted Manuscript: 1-s2.0-S0168900223003066-main.pdf
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