Detector modules and spectrometers for the TIME-Pilot [CII] intensity mapping experiment

This proceeding presents the current TIME-Pilot instrument design and status with a focus on the close-packed modular detector arrays and spectrometers. Results of laboratory tests with prototype detectors and spectrometers are discussed. TIME-Pilot is a new mm-wavelength grating spectrometer array under development that will study the Epoch of Reionization (the period of time when the first stars and galaxies ionized the intergalactic medium) by mapping the fluctuations of the redshifted 157:7 μm emission line of singly ionized carbon ([CII]) from redshift z ~ 5:2 to 8:5. As a tracer of star formation, the [CII] power spectrum can provide information on the sources driving reionization and complements 21 cm data (which traces neutral hydrogen in the intergalactic medium). Intensity mapping provides a measure of the mean [CII] intensity without the need to resolve and detect faint sources individually. We plan to target a 1 degree by 0.35 arcminute field on the sky and a spectral range of 199-305 GHz, producing a spatial-spectral slab which is 140 Mpc by 0.9 Mpc on-end and 1230 Mpc in the redshift direction. With careful removal of intermediate-redshift CO sources, we anticipate a detection of the halo-halo clustering term in the [CII] power spectrum consistent with current models for star formation history in 240 hours on the JCMT. TIME-Pilot will use two stacks of 16 parallel-plate waveguide spectrometers (one stack per polarization) with a resolving power R ~ 100 and a spectral range of 183 to 326 GHz. The range is divided into 60 spectral channels, of which 16 at the band edges on each spectrometer serve as atmospheric monitors. The diffraction gratings are curved to produce a compact instrument, each focusing the diffracted light onto an output arc sampled by the 60 bolometers. The bolometers are built in buttable dies of 8 (low freqeuency) or 12 (high frequency) spectral channels by 8 spatial channels and are mated to the spectrometer stacks. Each detector consists of a gold micro-mesh absorber and a titanium transition edge sensor (TES). The detectors (1920 total) are designed to operate from a 250 mK base temperature in an existing cryostat with a photon-noise-dominated NEP of ~2 * 10^(-17) WHz^(-1-2). A set of flexible superconducting cables connect the detectors to a time-domain multiplexing SQUID readout system

The haptic perception of spatial orientations

This review examines the isotropy of the perception of spatial orientations in the haptic system. It shows the existence of an oblique effect (i.e., a better perception of vertical and horizontal orientations than oblique orientations) in a spatial plane intrinsic to the haptic system, determined by the gravitational cues and the cognitive resources and defined in a subjective frame of reference. Similar results are observed from infancy to adulthood. In 3D space, the haptic processing of orientations is also anisotropic and seems to use both egocentric and allocentric cues. Taken together, these results revealed that the haptic oblique effect occurs when the sensory motor traces associated with exploratory movement are represented more abstractly at a cognitive level

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Design Considerations to Improving Sensitivity in Superspec: an Onchip KID-Based, Mm-Wave Spectrometer

SuperSpec is an ultra-compact on-chip spectrometer for mm/submm astronomy. SuperSpec's compact size and wide spectral bandwidth will be uniquely powerful to perform multi-object spectroscopy for high redshift surveys, and for tomographic studies of the epoch of reionization (EoR). SuperSpec employs the use of kinetic inductance detectors (KID) to build highly multiplexed arrays. A full instrument of~ 500 channels can be lithographed on a few cm2 of silicon. In this thesis, we explored electromagnetic designs to improve sensitivity of KIDs. We show that we can reliably remove up to 753 of the current design's inductor volume to obtain improvements in sensitivities up a factor of four. We also explored two filter designs that can deliver higher power to the detectors. Our half-wave transmission line filters can only deliver up to 503 of power to the detectors. Both ring resonators and backshorted detectors can deliver unity power, however we found that the large coupling length needed in order to properly use ring resonators would be impractical in a. filterba.nk. Lastly we explored different filterbank designs. Multiple detectors read out together in a single channel has higher resolving power than single detector channels. Backshorted detectors offer higher resolving power than two paired detector channels, but under-performs three or more paired detector channels.</p

SuperSpec: the on-chip spectrometer: characterization of a full 300 channel filterbank (Conference Presentation)

SuperSpec is a new technology for millimeter and submillimeter spectroscopy. It is an on-chip spectrometer being developed for multi-object, moderate resolution (R = ~300), large bandwidth survey spectroscopy of high-redshift galaxies for the 1 mm atmospheric window. SuperSpec targets the CO ladder in the redshift range of z = 0 to 4, the [CII] 158 um line from z = 5 to 9, and the [NII] 205 um line from z = 4-7. All together these lines offer complete redshift coverage from z = 0 to 9. SuperSpec employs a novel architecture in which detectors are coupled to a series of resonant filters along a single microwave feedline instead of using dispersive optics. This construction allows for the creation of a full spectrometer occupying only 20 cm squared of silicon, a reduction in size of several orders of magnitude when compared to standard grating spectrometers. This small profile enables the production of future multi-object spectroscopic instruments required as the millimeter-wave spectroscopy field matures. SuperSpec uses a lens-coupled antenna to deliver astrophysical radiation to a microstrip transmission line. The radiation then propagates down this transmission line where upon proximity coupled half wavelength microstrip resonators pick off specific frequencies of radiation. Careful tuning of the proximity of the resonators to the feedline dials in the desired resolving power of the SuperSpec filterbank by tuning the coupling quality factor. The half wavelength resonators are then in turn coupled to the inductive meander of kinetic inductance detectors (KIDs), which serve as the power detectors for the SuperSpec filterbank. Each SuperSpec filter bank contains hundreds of titanium nitride TiN KIDs and the natural multiplexibility of these detectors allow for readout of the large numbers of required detectors. The unique coupling scheme employed by SuperSpec allows for the creation of incredibly low volume (2.6 cubic microns), high responsivity, TiN KIDs. Since responsivity is proportional to the inverse of quasiparticle-occupied volume, this allows SuperSpec to reach the low NEPs required by moderate resolution spectroscopy to be photon limited from the best ground-based observing sites. We will present the latest results from SuperSpec devices. In particular, detector NEPs, measured filter bank efficiency (including transmission line losses), and spectral profiles for a full ~ 300-channel filterbank. Finally, we will report on our system end to end efficiency and total system NEP

Snowmass 2021 CMB-S4 White Paper

This Snowmass 2021 White Paper describes the Cosmic Microwave Background Stage 4 project CMB-S4, which is designed to cross critical thresholds in our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. We provide an overview of the science case, the technical design, and project plan