Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder
By K. Bandura, G. Addison, M. Amiri, J. Richard Bond, D. Campbell-Wilson, L. Connor, J. Cliche, G. Davis, M. Deng, N. Denman and 24 more. Astronomical Telescopes and Instrumentation, 2014
248 citations recorded by the source corpus.
A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ~100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ~30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.
View Paper: https://www.semanticscholar.org/paper/7941dc72b84cf657d8dd6788301f97c7c96def96
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- Pedro G. Ferreira
- D. Bacon
- M. Bhardwaj
- R. Battye
- Yashar Akrami
- K. Bandura
- M. McQuinn
- B. Andersen
Citations in the corpus
- Probing Galactic Halos with Fast Radio Bursts (2019, background): “In any event, we conclude that a project like CHIME (Bandura et al. 2014) will provide a very powerful constraint on M31’s halo gas.”
- CHIME/FRB Discovery of Eight New Repeating Fast Radio Burst Sources (2019, methodology): “First, we have updated our beam-model to include East-West aliasing of the synthesized beams, as well as an approximated forward-gain model of the primary beam, which is based on ray-tracing simulations of the CHIME Pathfinder (Bandura et al. 2014).”
- The CHIME Fast Radio Burst Project: System Overview (2018, methodology): “We have found empirically that this transform chain removes RFI in data we have captured so far (e.g., from the CHIME Pathfinder, the Galt 26-m telescope, or with a CHIME incoherent beam – see §6) to a sufficient level that simulated FRBs near detection threshold dominate the output of the dedispers”
- Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: Technical specifications and performance forecasts (2018, methodology): “Several experiments have been proposed in order to measure this signal, using single dish telescopes or interferometers (Battye et al. 2013; Bandura et al. 2014; Xu, Wang, & Chen 2015; Newburgh et al. 2016).”