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1. The Simons Observatory: Cryogenic Half Wave Plate Rotation Mechanism for the Small Aperture Telescopes

Author

Yamada, K., Bixler, B., Sakurai, Y., Ashton, P. C., Sugiyama, J., Arnold, K., Begin, J., Corbett, L., Day-Weiss, S., Galitzki, N., Hill, C. A., Johnson, B. R., Jost, B., Kusaka, A., Koopman, B. J., Lashner, J., Lee, A. T., Mangu, A., Nishino, H., Page, L. A., Randall, M. J., Sasaki, D., Song, X., Spisak, J., Tsan, T., Wang, Y., and Williams, P. A.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We present the requirements, design and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background (CMB) polarization experiment at Parque Astron\'{o}mico Atacama in northern Chile that covers a wide range of angular scales using both small (0.42 m) and large (6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8~Hz, suppressing atmospheric $1/f$ noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to $\sim$50 K to reduce detector thermal loading. Under normal operation the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. The rotation angle is detected through an angular encoder with a noise level of 0.07$\mu\mathrm{rad}\sqrt{\mathrm{s}}$. During a cooldown, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance., Comment: 19 pages, 21 figures, submitted to RSI

Published
2023
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2. The Simons Observatory: Cryogenic half wave plate rotation mechanism for the small aperture telescopes

Author

Yamada, K, Bixler, B, Sakurai, Y, Ashton, PC, Sugiyama, J, Arnold, K, Begin, J, Corbett, L, Day-Weiss, S, Galitzki, N, Hill, CA, Johnson, BR, Jost, B, Kusaka, A, Koopman, BJ, Lashner, J, Lee, AT, Mangu, A, Nishino, H, Page, LA, Randall, MJ, Sasaki, D, Song, X, Spisak, J, Tsan, T, Wang, Y, and Williams, PA

Subjects
Engineering, Astronomical Sciences, Physical Sciences, Chemical Sciences, Applied Physics, Chemical sciences, Physical sciences
Abstract

We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 μrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

Published
2024

3. The Simons Observatory: Gain, bandpass and polarization-angle calibration requirements for B-mode searches

Author

Abitbol, MH, Alonso, D, Simon, SM, Lashner, J, Crowley, KT, Ali, AM, Azzoni, S, Baccigalupi, C, Barron, D, Brown, ML, Calabrese, E, Carron, J, Chinone, Y, Chluba, J, Coppi, G, Crowley, KD, Devlin, M, Dunkley, J, Errard, J, Fanfani, V, Galitzki, N, Gerbino, M, Hill, JC, Johnson, BR, Jost, B, Keating, B, Krachmalnicoff, N, Kusaka, A, Lee, AT, Louis, T, Madhavacheril, MS, McCarrick, H, McMahon, J, Meerburg, PD, Nati, F, Nishino, H, Page, LA, Poletti, D, Puglisi, G, Randall, MJ, Rotti, A, Spisak, J, Suzuki, A, Teply, GP, Verges, C, Wollack, EJ, Xu, Z, and Zannoni, M

Subjects
CMBR experiments, CMBR polarisation, gravitational waves and CMBR polarization, cosmological parameters from CMBR, astro-ph.CO, astro-ph.IM, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We quantify the calibration requirements for systematic uncertainties for next-generation ground-based observatories targeting the large-angle B-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on gain calibration, bandpass center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that gain calibration and bandpass center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio r on the order of Δ r∼10-3, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to O(10) degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on r if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on r significantly, broadening the error bar by O(10%) at most. We validate these results by reanalyzing the latest publicly available data from the collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO.

Published
2021

5. The Simons Observatory: A large-diameter truss for a refracting telescope cooled to 1 K

Author

Crowley, K, Dow, P, Shroyer, J, Groh, J, Dober, B, Spisak, J, Galitzki, N, Bhandarkar, T, Devlin, M, Dicker, S, Gallardo, P, Harrington, K, Iuliano, J, Johnson, B, Johnson, D, Kofman, A, Kusaka, A, Lee, A, Limon, M, Nati, F, Orlowski-Scherer, J, Page, L, Randall, M, Teply, G, Tsan, T, Wollack, E, Xu, Z, Zhu, N, Crowley K. D., Dow P., Shroyer J. E., Groh J. C., Dober B., Spisak J., Galitzki N., Bhandarkar T., Devlin M. J., Dicker S., Gallardo P. A., Harrington K., Iuliano J., Johnson B. R., Johnson D., Kofman A. M., Kusaka A., Lee A., Limon M., Nati F., Orlowski-Scherer J., Page L., Randall M., Teply G., Tsan T., Wollack E. J., Xu Z., Zhu N., Crowley, K, Dow, P, Shroyer, J, Groh, J, Dober, B, Spisak, J, Galitzki, N, Bhandarkar, T, Devlin, M, Dicker, S, Gallardo, P, Harrington, K, Iuliano, J, Johnson, B, Johnson, D, Kofman, A, Kusaka, A, Lee, A, Limon, M, Nati, F, Orlowski-Scherer, J, Page, L, Randall, M, Teply, G, Tsan, T, Wollack, E, Xu, Z, Zhu, N, Crowley K. D., Dow P., Shroyer J. E., Groh J. C., Dober B., Spisak J., Galitzki N., Bhandarkar T., Devlin M. J., Dicker S., Gallardo P. A., Harrington K., Iuliano J., Johnson B. R., Johnson D., Kofman A. M., Kusaka A., Lee A., Limon M., Nati F., Orlowski-Scherer J., Page L., Randall M., Teply G., Tsan T., Wollack E. J., Xu Z., and Zhu N.

Abstract

We present the design and measured performance of a new carbon fiber strut design that is used in a cryogenically cooled truss for the Simons Observatory small aperture telescope. The truss consists of two aluminum 6061 rings separated by 24 struts. Each strut consists of a central carbon fiber tube fitted with two aluminum end caps. We tested the performance of the strut and truss by (i) cryogenically cycling and destructively pull-Testing strut samples, (ii) non-destructively pull-Testing the final truss, and (iii) measuring the thermal conductivity of the carbon fiber tubes. We found that the strut strength is limited by the mounting fasteners and the strut end caps, not the epoxy adhesive or the carbon fiber tube. This result is consistent with our numerical predictions. Our thermal measurements suggest that the conductive heat load through the struts (from 4 to 1 K) will be less than 1 mW. This strut design may be a promising candidate for use in other cryogenic support structures.

Published
2022

6. Constraints on axionlike polarization oscillations in the cosmic microwave background with POLARBEAR

Author

Adachi, S, Adkins, T, Arnold, K, Baccigalupi, C, Barron, D, Cheung, K, Chinone, Y, Crowley, KT, Errard, J, Fabbian, G, Feng, C, Flauger, R, Fujino, T, Green, D, Hasegawa, M, Hazumi, M, Kaneko, D, Katayama, N, Keating, B, Kusaka, A, Lee, AT, Minami, Y, Nishino, H, Reichardt, CL, Siritanasak, P, Spisak, J, Tajima, O, Takakura, S, Takatori, S, Teply, GP, Yamada, K, Adachi, S, Adkins, T, Arnold, K, Baccigalupi, C, Barron, D, Cheung, K, Chinone, Y, Crowley, KT, Errard, J, Fabbian, G, Feng, C, Flauger, R, Fujino, T, Green, D, Hasegawa, M, Hazumi, M, Kaneko, D, Katayama, N, Keating, B, Kusaka, A, Lee, AT, Minami, Y, Nishino, H, Reichardt, CL, Siritanasak, P, Spisak, J, Tajima, O, Takakura, S, Takatori, S, Teply, GP, and Yamada, K

Published
2023

7. Erratum: The Simons Observatory Large Aperture Telescope Receiver (ApJS (2021) 256: 23 DOI: 10.3847/1538-4365/ac0db7)

Author

Zhu N., Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dunner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keating, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Zhu N., Bhandarkar T., Coppi G., Kofman A. M., Orlowski-Scherer J. L., Xu Z., Adachi S., Ade P., Aiola S., Austermann J., Bazarko A. O., Beall J. A., Bhimani S., Bond J. R., Chesmore G. E., Choi S. K., Connors J., Cothard N. F., Devlin M., Dicker S., Dober B., Duell C. J., Duff S. M., Dunner R., Fabbian G., Galitzki N., Gallardo P. A., Golec J. E., Haridas S. K., Harrington K., Healy E., Patty Ho S. -P., Huber Z. B., Hubmayr J., Iuliano J., Johnson B. R., Keating B., Kiuchi K., Koopman B. J., Lashner J., Lee A. T., Li Y., Limon M., Link M., Lucas T. J., McCarrick H., Moore J., Nati F., Newburgh L. B., Niemack M. D., Pierpaoli E., Randall M. J., Sarmiento K. P., Saunders L. J., Seibert J., Sierra C., Sonka R., Spisak J., Sutariya S., Tajima O., Teply G. P., Thornton R. J., Tsan T., Tucker C., Ullom J., Vavagiakis E. M., Vissers M. R., Walker S., Westbrook B., Wollack E. J., Zannoni M., Zhu N., Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dunner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keating, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Zhu N., Bhandarkar T., Coppi G., Kofman A. M., Orlowski-Scherer J. L., Xu Z., Adachi S., Ade P., Aiola S., Austermann J., Bazarko A. O., Beall J. A., Bhimani S., Bond J. R., Chesmore G. E., Choi S. K., Connors J., Cothard N. F., Devlin M., Dicker S., Dober B., Duell C. J., Duff S. M., Dunner R., Fabbian G., Galitzki N., Gallardo P. A., Golec J. E., Haridas S. K., Harrington K., Healy E., Patty Ho S. -P., Huber Z. B., Hubmayr J., Iuliano J., Johnson B. R., Keating B., Kiuchi K., Koopman B. J., Lashner J., Lee A. T., Li Y., Limon M., Link M., Lucas T. J., McCarrick H., Moore J., Nati F., Newburgh L. B., Niemack M. D., Pierpaoli E., Randall M. J., Sarmiento K. P., Saunders L. J., Seibert J., Sierra C., Sonka R., Spisak J., Sutariya S., Tajima O., Teply G. P., Thornton R. J., Tsan T., Tucker C., Ullom J., Vavagiakis E. M., Vissers M. R., Walker S., Westbrook B., Wollack E. J., and Zannoni M.

Abstract

After the publication of the article, it was brought to our attention that the description of Equation (1) may cause potential confusion. Thus, we have decided to provide a newer reference and added a unit for qtot in the description. The updated paragraph should read as the following:.

Published
2021

8. The effects of inclination on a two stage pulse tube cryocooler for use with a ground based observatory

Author

Tsan, T, Galitzki, N, Ali, A, Arnold, K, Coppi, G, Ervin, T, Foote, L, Keating, B, Lashner, J, Orlowski-Scherer, J, Randall, M, Seibert, J, Spisak, J, Teply, G, Xu, Z, Zhu, N, Tsan T., Galitzki N., Ali A. M., Arnold K., Coppi G., Ervin T., Foote L., Keating B., Lashner J., Orlowski-Scherer J., Randall M. J., Seibert J., Spisak J., Teply G. P., Xu Z., Zhu N., Tsan, T, Galitzki, N, Ali, A, Arnold, K, Coppi, G, Ervin, T, Foote, L, Keating, B, Lashner, J, Orlowski-Scherer, J, Randall, M, Seibert, J, Spisak, J, Teply, G, Xu, Z, Zhu, N, Tsan T., Galitzki N., Ali A. M., Arnold K., Coppi G., Ervin T., Foote L., Keating B., Lashner J., Orlowski-Scherer J., Randall M. J., Seibert J., Spisak J., Teply G. P., Xu Z., and Zhu N.

Abstract

Ground-based observatories across a wide range of wavelengths implement cryogenic cooling techniques to increase the sensitivity of instruments and enable low temperature detector technologies. Commercial pulse tube cryocoolers (PTCs) are frequently used to provide 40 K and 4 K stages as thermal shells in scientific instruments. However, PTC operation is dependent on gravity, giving rise to changes in cooling capacity over the operational tilt range of pointed telescopes. We present a study of the performance of a two stage PTC with a cooling capacity of 1.8 W at 4.2 K and 50 W at 45 K (Cryomech PT420-RM) from 0-55° away from vertical to probe capacity as a function of angle over a set of realistic thermal loading conditions. Our study provides a method to extract temperature estimates given predicted thermal loading conditions across the angular range sampled. We then discuss the design implications for current and future tilted cryogenic systems.

Published
2021

10. A family of experiments on test-driven development

Author

Santos, A. (Adrian), Vegas, S. (Sira), Dieste, O. (Oscar), Uyaguari, F. (Fernando), Tosun, A. (Ayşe), Fucci, D. (Davide), Turhan, B. (Burak), Scanniello, G. (Giuseppe), Romano, S. (Simone), Karac, I. (Itir), Kuhrmann, M. (Marco), Mandić, V. (Vladimir), Ramač, R. (Robert), Pfahl, D. (Dietmar), Engblom, C. (Christian), Kyykka, J. (Jarno), Rungi, K. (Kerli), Palomeque, C. (Carolina), Spisak, J. (Jaroslav), Oivo, M. (Markku), Juristo, N. (Natalia), Santos, A. (Adrian), Vegas, S. (Sira), Dieste, O. (Oscar), Uyaguari, F. (Fernando), Tosun, A. (Ayşe), Fucci, D. (Davide), Turhan, B. (Burak), Scanniello, G. (Giuseppe), Romano, S. (Simone), Karac, I. (Itir), Kuhrmann, M. (Marco), Mandić, V. (Vladimir), Ramač, R. (Robert), Pfahl, D. (Dietmar), Engblom, C. (Christian), Kyykka, J. (Jarno), Rungi, K. (Kerli), Palomeque, C. (Carolina), Spisak, J. (Jaroslav), Oivo, M. (Markku), and Juristo, N. (Natalia)

Abstract

Context: Test-driven development (TDD) is an agile software development approach that has been widely claimed to improve software quality. However, the extent to which TDD improves quality appears to be largely dependent upon the characteristics of the study in which it is evaluated (e.g., the research method, participant type, programming environment, etc.). The particularities of each study make the aggregation of results untenable. Objectives: The goal of this paper is to: increase the accuracy and generalizability of the results achieved in isolated experiments on TDD, provide joint conclusions on the performance of TDD across different industrial and academic settings, and assess the extent to which the characteristics of the experiments affect the quality-related performance of TDD. Method: We conduct a family of 12 experiments on TDD in academia and industry. We aggregate their results by means of meta-analysis. We perform exploratory analyses to identify variables impacting the quality-related performance of TDD. Results: TDD novices achieve a slightly higher code quality with iterative test-last development (i.e., ITL, the reverse approach of TDD) than with TDD. The task being developed largely determines quality. The programming environment, the order in which TDD and ITL are applied, or the learning effects from one development approach to another do not appear to affect quality. The quality-related performance of professionals using TDD drops more than for students. We hypothesize that this may be due to their being more resistant to change and potentially less motivated than students. Conclusion: Previous studies seem to provide conflicting results on TDD performance (i.e., positive vs. negative, respectively). We hypothesize that these conflicting results may be due to different study durations, experiment participants being unfamiliar with the TDD process, or case studies comparing the performance achieved by TDD vs. the control approach (e.g

Published
2021

11. The Simons Observatory Large Aperture Telescope Receiver

Author

Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Richard Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dünner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keatin, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, J Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Perez Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Ningfeng Zhu, Tanay Bhandarkar, Gabriele Coppi, Anna M. Kofman, John L. Orlowski-Scherer, Zhilei Xu, Shunsuke Adachi, Peter Ade, Simone Aiola, Jason Austermann, Andrew O. Bazarko, James A. Beall, Sanah Bhimani, J. Richard Bond, Grace E. Chesmore, Steve K. Choi, Jake Connors, Nicholas F. Cothard, Mark Devlin, Simon Dicker, Bradley Dober, Cody J. Duell, Shannon M. Duff, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Patricio A. Gallardo, Joseph E. Golec, Saianeesh K. Haridas, Kathleen Harrington, Erin Healy, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Jeffrey Iuliano, Bradley R. Johnson, Brian Keatin, Kenji Kiuchi, Brian J. Koopman, Jack Lashner, Adrian T. Lee, Yaqiong Li, Michele Limon, Michael Link, Tammy J Lucas, Heather McCarrick, Jenna Moore, Federico Nati, Laura B. Newburgh, Michael D. Niemack, Elena Pierpaoli, Michael J. Randall, Karen Perez Sarmiento, Lauren J. Saunders, Joseph Seibert, Carlos Sierra, Rita Sonka, Jacob Spisak, Shreya Sutariya, Osamu Tajima, Grant P. Teply, Robert J. Thornton, Tran Tsan, Carole Tucker, Joel Ullom, Eve M. Vavagiakis, Michael R. Vissers, Samantha Walker, Benjamin Westbrook, Edward J. Wollack, Mario Zannoni, Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Richard Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dünner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keatin, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, J Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Perez Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Ningfeng Zhu, Tanay Bhandarkar, Gabriele Coppi, Anna M. Kofman, John L. Orlowski-Scherer, Zhilei Xu, Shunsuke Adachi, Peter Ade, Simone Aiola, Jason Austermann, Andrew O. Bazarko, James A. Beall, Sanah Bhimani, J. Richard Bond, Grace E. Chesmore, Steve K. Choi, Jake Connors, Nicholas F. Cothard, Mark Devlin, Simon Dicker, Bradley Dober, Cody J. Duell, Shannon M. Duff, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Patricio A. Gallardo, Joseph E. Golec, Saianeesh K. Haridas, Kathleen Harrington, Erin Healy, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Jeffrey Iuliano, Bradley R. Johnson, Brian Keatin, Kenji Kiuchi, Brian J. Koopman, Jack Lashner, Adrian T. Lee, Yaqiong Li, Michele Limon, Michael Link, Tammy J Lucas, Heather McCarrick, Jenna Moore, Federico Nati, Laura B. Newburgh, Michael D. Niemack, Elena Pierpaoli, Michael J. Randall, Karen Perez Sarmiento, Lauren J. Saunders, Joseph Seibert, Carlos Sierra, Rita Sonka, Jacob Spisak, Shreya Sutariya, Osamu Tajima, Grant P. Teply, Robert J. Thornton, Tran Tsan, Carole Tucker, Joel Ullom, Eve M. Vavagiakis, Michael R. Vissers, Samantha Walker, Benjamin Westbrook, Edward J. Wollack, and Mario Zannoni

Abstract

The Simons Observatory is a ground-based cosmic microwave background experiment that consists of three 0.4 m small-aperture telescopes and one 6 m Large Aperture Telescope, located at an elevation of 5300 m on Cerro Toco in Chile. The Simons Observatory Large Aperture Telescope Receiver (LATR) is the cryogenic camera that will be coupled to the Large Aperture Telescope. The resulting instrument will produce arcminute-resolution millimeter-wave maps of half the sky with unprecedented precision. The LATR is the largest cryogenic millimeter-wave camera built to date, with a diameter of 2.4 m and a length of 2.6 m. The coldest stage of the camera is cooled to 100 mK, the operating temperature of the bolometric detectors with bands centered around 27, 39, 93, 145, 225, and 280 GHz. Ultimately, the LATR will accommodate 13 40 cm diameter optics tubes, each with three detector wafers and a total of 62,000 detectors. The LATR design must simultaneously maintain the optical alignment of the system, control stray light, provide cryogenic isolation, limit thermal gradients, and minimize the time to cool the system from room temperature to 100 mK. The interplay between these competing factors poses unique challenges. We discuss the trade studies involved with the design, the final optimization, the construction, and ultimate performance of the system.

Published
2021

12. The Simons Observatory: Overview of data acquisition, control, monitoring, and computer infrastructure

Author

Koopman, BJ, Lashner, J, Saunders, LJ, Hasselfield, M, Bhandarkar, T, Bhimani, S, Choi, SK, Duell, CJ, Galitzki, N, Harrington, K, Hincks, AD, Ho, S-PP, Newburgh, L, Reichardt, CL, Seibert, J, Spisak, J, Westbrook, B, Xu, Z, Zhu, N, Koopman, BJ, Lashner, J, Saunders, LJ, Hasselfield, M, Bhandarkar, T, Bhimani, S, Choi, SK, Duell, CJ, Galitzki, N, Harrington, K, Hincks, AD, Ho, S-PP, Newburgh, L, Reichardt, CL, Seibert, J, Spisak, J, Westbrook, B, Xu, Z, and Zhu, N

Abstract

The Simons Observatory (SO) is an upcoming polarized cosmic microwave background (CMB) survey experiment with three small-aperture telescopes and one large-aperture telescope that will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz to achieve the sensitivity necessary to measure or constrain numerous cosmological parameters, including the tensor-to-scalar ratio, effective number of relativistic species, and sum of the neutrino masses. The SO scientific goals require coordination and control of the hardware distributed among the four telescopes on site. To meet this need, we have designed and built an open-sourced platform for distributed system management, called the Observatory Control System (ocs). This control system interfaces with all subsystems including the telescope control units, the microwave multiplexing readout electronics, and the cryogenic thermometry. We have also developed a system for live monitoring of housekeeping data and alerting, both of which are critical for remote observation. We take advantage of existing open source projects, such as crossbar for RPC and PubSub, twisted for asynchronous events, grafana for online remote monitoring, and docker for containerization. We provide an overview of the SO software and computer infrastructure, including the integration of SO-developed code with open source resources and lessons learned while testing at SO labs developing hardware systems as we prepare for deployment.

Published
2020

13. Simons Observatory Small Aperture Telescope overview

Author

Marshall, HK, Spyromilio, J, Usuda, T, Kiuchi, K, Adachi, S, Ali, AM, Arnold, K, Ashton, P, Austermann, JE, Bazako, A, Beall, JA, Chinone, Y, Coppi, G, Crowley, KD, Crowley, KT, Dicker, S, Dober, B, Duff, SM, Fabbian, G, Galitzki, N, Golec, JE, Gudmundsson, JE, Harrington, K, Hasegawa, M, Hattori, M, Hill, CA, Ho, SPP, Hubmayr, J, Johnson, BR, Kaneko, D, Katayama, N, Keating, B, Kusaka, A, Lashner, J, Lee, AT, Matsuda, F, McCarrick, H, Murata, M, Nati, F, Nishinomiya, Y, Page, L, Sathyanarayana Rao, M, Reichardt, CL, Sakaguri, K, Sakurai, Y, Sibert, J, Spisak, J, Tajima, O, Teply, GP, Terasaki, T, Tsan, T, Walker, S, Wollack, EJ, Xu, Z, Yamada, K, Zannoni, M, Zhu, N, Marshall, HK, Spyromilio, J, Usuda, T, Kiuchi, K, Adachi, S, Ali, AM, Arnold, K, Ashton, P, Austermann, JE, Bazako, A, Beall, JA, Chinone, Y, Coppi, G, Crowley, KD, Crowley, KT, Dicker, S, Dober, B, Duff, SM, Fabbian, G, Galitzki, N, Golec, JE, Gudmundsson, JE, Harrington, K, Hasegawa, M, Hattori, M, Hill, CA, Ho, SPP, Hubmayr, J, Johnson, BR, Kaneko, D, Katayama, N, Keating, B, Kusaka, A, Lashner, J, Lee, AT, Matsuda, F, McCarrick, H, Murata, M, Nati, F, Nishinomiya, Y, Page, L, Sathyanarayana Rao, M, Reichardt, CL, Sakaguri, K, Sakurai, Y, Sibert, J, Spisak, J, Tajima, O, Teply, GP, Terasaki, T, Tsan, T, Walker, S, Wollack, EJ, Xu, Z, Yamada, K, Zannoni, M, and Zhu, N

Abstract

The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with three small-aperture telescopes (SATs) and one large-aperture telescope (LAT), which will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz in order to achieve the sensitivity necessary to measure or constrain numerous cosmological quantities. The SATs are optimized for a primordial gravitational wave signal in a parity odd polarization power spectrum at a large angular scale. We will present the latest status of the SAT development.

Published
2020

14. The Simons Observatory: Overview of data acquisition, control, monitoring, and computer infrastructure

Author

Guzman, JC, Ibsen, J, Koopman, BJ, Lashner, J, Saunders, LJ, Hasselfield, M, Bhandarkar, T, Bhimani, S, Choi, SK, Duell, CJ, Galitzki, N, Harrington, K, Hincks, AD, Ho, SPP, Newburgh, L, Reichardt, CL, Seibert, J, Spisak, J, Westbrook, B, Xu, Z, Zhu, N, Guzman, JC, Ibsen, J, Koopman, BJ, Lashner, J, Saunders, LJ, Hasselfield, M, Bhandarkar, T, Bhimani, S, Choi, SK, Duell, CJ, Galitzki, N, Harrington, K, Hincks, AD, Ho, SPP, Newburgh, L, Reichardt, CL, Seibert, J, Spisak, J, Westbrook, B, Xu, Z, and Zhu, N

Abstract

The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with three small-aperture telescopes and one large-aperture telescope, which will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz in order to achieve the sensitivity necessary to measure or constrain numerous cosmological quantities, as outlined in The Simons Observatory Collaboration et al. (2019). To achieve these goals we have built an open-sourced platform, called OCS (Observatory Control System), which orchestrates distributed hardware systems. We provide an overview of the SO software and computer infrastructure.

Published
2020

16. Improving development practices through experimentation:an industrial TDD case

Author

Santos, A. (Adrian), Spisak, J. (Jaroslav), Oivo, M. (Markku), Juristo, N. (Natalia), Santos, A. (Adrian), Spisak, J. (Jaroslav), Oivo, M. (Markku), and Juristo, N. (Natalia)

Abstract

Test-Driven Development (TDD), an agile development approach that enforces the construction of software systems by means of successive micro-iterative testing coding cycles, has been widely claimed to increase external software quality. In view of this, some managers at Paf—a Nordic gaming entertainment company—were interested in knowing how would TDD perform at their premises. Eventually, if TDD outperformed their traditional way of coding (i.e., YW, short for Your Way), it would be possible to switch to TDD considering the empirical evidence achieved at the company level. We conduct an experiment at Paf to evaluate the performance of TDD, YW and the reverse approach of TDD (i.e., ITL, short for IterativeTest Last) on external quality. TDD outperforms YW and ITLat Paf. Despite the encouraging results, we cannot recommend Paf to immediately adopt TDD as the difference in performance between YW and TDD is small. However, as TDD looks promising at Paf, we suggest to move some developers to TDD and to run a future experiment to compare the performance of TDD and YW. TDD slightly outperforms ITL in controlled experiments for TDD novices. However, more industrial experiments are still needed to evaluate the performance of TDD in real-life contexts.

Published
2018

17. Cornell University Life Sciences Core Laboratories Center

Author

VanEe, J., Schweitzer, P., Zhang, S., Williams, R., Pillardy, J., Sun, Q., Wang, W., Li, Y., Betel, D., Stelick, T., Spisak, J., Cote, L., Cameron, R., Wroblewski, H., Hover, B., Zhang, L., Mosher, J., Xin, Y., Westby, G., Busuttil, J., Monni, S., Sherwood, R., Ptak, A.C., Chen, W., McCardle, J., Bayles, C., Dela Cruz, J., Riccio, M., Bukowski, R., Ponnala, L., Myers, C., Singh, H., Howard, M., Flaherty, J., Manocchia, A., Dodge, E., Smith, K., Aquadro, C., Melnick, A., Brenna, T., Zipfel, W., Clark, A., Siepel, A., Carr, L., Rose, J.K.C., and Grills, G.

Subjects
Poster Session Abstracts
Abstract

The Cornell University Life Sciences Core Laboratories Center (CLC) provides an array of genomics, proteomics, imaging and informatics shared research resources and services to the university community and to outside investigators. The CLC includes fee-for-service research, technology testing and development, and educational components. The Center has seven core facilities, including genomics (DNA sequencing, genotyping, and microarrays), epigenomics, proteomics and mass spectrometry, microscopy and imaging, bioinformatics, bio-IT, and advanced technology assessment. The CLC is part of a New York State designated Center for Advanced Technology in Life Science Enterprise. The mission of the CLC is to promote research in the life sciences with advanced technologies in a shared resource environment. Use of the CLC resources and services is steadily increasing due to the growth in the number and types of cores in the center, to the expansion of existing services and the implementation of new core technologies, and to the coordinated integration and synergy of services between the CLC cores. Multidisciplinary support for multi-functional instrument platforms is implemented by integrated operations of the CLC core facilities. Investigators are offered coordinated project consultations with the directors and staff of all relevant cores during the design, data production and analysis phases of their projects. The CLC is involved in establishing and supporting multidisciplinary research projects that involve both intercampus initiatives and multi-institutional collaborations. With a concentration of advanced instrumentation and expertise in their applications, the CLC is a key resource for life sciences research.

Published
2011

19. Cornell University Life Sciences Core Laboratories Center

Author

VanEe, J., Schweitzer, P., Wang, W., Li, Y., Zhang, S., Williams, R., Deng, K.Y., Pillardy, J., Sun, Q., Stelick, T., Spisak, J., Paronett, E., Cote, L., Cameron, R., Zhao, J., Hover, B., Kresovich, J., Xin, Y., Figueroa, M., Shaknovich, R., Monni, S., Unnsteinsdottir, U., Sherwood, R., Ptak, C., Yan, H., Bayles, C., Xia, G., Doran, R., Bukowski, R., Myers, C., Ponnala, L., Stefanov, S., Howard, M., Flaherty, J., Manocchia, A., Dodge, E., Smith, K., Aquadro, C., Lin, D., Melnick, A., Zipfel, W., Soloway, P., Jin, M., Clark, A., Siepel, A., Rose, J.K.C., and Grills, G.S.

Subjects
Poster Session Abstracts
Abstract

CF-13

Published
2010

20. Telemetry system of biological parameters

Author

Spisak, J. and Marek Penhaker

Subjects
biological parameters, data transfer, mobile telemetry, stress, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

The mobile telemetry system of biological parameters serves for reading and wireless data transfer of measured values of selected biological parameters to an outlying computer. It concerns basically long time monitoring of vital function of car pilot.The goal of this projects is to propose mobile telemetry system for reading, wireless transfer and processing of biological parameters of car pilot during physical and psychical stress. It has to be made with respect to minimal consumption, weight and maximal device mobility. This system has to eliminate signal noise, which is created by biological artifacts and disturbances during the data transfer.

Published
2005

27. Solvent Extraction of Cobalt From Nickel in Sulfate Leach Liquors

Author

Spisak, J. F., Peterson, H. D., and Butts, G. E.

Abstract

In 1978, Anschutz Mining Corp. began efforts to develop the Madison Cobalt Project in southeast Missouri. Preliminary metallurgical studies indicated that intermediate grade cobalt products, suitable for shipment to existing refineries, could be recovered from the sulfide mineralization of the ore body. However, tolling and freight charges were significant, as the refineries were located outside the US. These refineries would not satisfy the goal of strategically insulated production of superalloy-grade cobalt.

Published
1984
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28. The Simons Observatory: Bandpass and polarization-angle calibration requirements for B-mode searches

Author

Abitbol, M, Alonso, D, Simon, S, Lashner, J, Crowley, K, Ali, A, Azzoni, S, Baccigalupi, C, Barron, D, Brown, M, Calabrese, E, Carron, J, Chinone, Y, Chluba, J, Coppi, G, Devlin, M, Dunkley, J, Errard, J, Fanfani, V, Galitzki, N, Gerbino, M, Colin Hill, J, Johnson, B, Jost, B, Keating, B, Krachmalnicoff, N, Kusaka, A, Lee, A, Louis, T, Madhavacheril, M, McCarrick, H, McMahon, J, Daniel Meerburg, P, Nati, F, Nishino, H, Page, L, Poletti, D, Puglisi, G, Randall, M, Rotti, A, Spisak, J, Suzuki, A, Teply, G, Vergès, C, Wollack, E, Xu, Z, Zannoni, M, Abitbol, M, Alonso, D, Simon, S, Lashner, J, Crowley, K, Ali, A, Azzoni, S, Baccigalupi, C, Barron, D, Brown, M, Calabrese, E, Carron, J, Chinone, Y, Chluba, J, Coppi, G, Devlin, M, Dunkley, J, Errard, J, Fanfani, V, Galitzki, N, Gerbino, M, Colin Hill, J, Johnson, B, Jost, B, Keating, B, Krachmalnicoff, N, Kusaka, A, Lee, A, Louis, T, Madhavacheril, M, McCarrick, H, McMahon, J, Daniel Meerburg, P, Nati, F, Nishino, H, Page, L, Poletti, D, Puglisi, G, Randall, M, Rotti, A, Spisak, J, Suzuki, A, Teply, G, Vergès, C, Wollack, E, Xu, Z, and Zannoni, M

Abstract

We quantify the calibration requirements for systematic uncertainties on bandpasses and polarization angles for next-generation ground-based observatories targeting the large-angle $B$-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on bandpass gain calibration, center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that bandpass calibration factors and center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio $r$ on the order of $Delta rsim10^{-3}$, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to ${cal O}(10)$ degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on $r$ if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on $r$ significantly, broadening the error bar by ${cal O}(10%)$ at most. We validate these results by reanalyzing the latest publicly available data from the BICEP2 / Keck Array collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO.

29. Possibilities of using a magnesite fines waste as an important mineral resource.

Author

Spisak J., Kostial I., Lisuch J., Mikula J., Nascak D., Repisky R., Spisak J., Kostial I., Lisuch J., Mikula J., Nascak D., and Repisky R.

Abstract

Magnesite is a valuable material with applications in refractories for the metallurgical and cement industries. Large amounts of high-grade fines are lost during the mining, beneficiation and thermal treatment of magnesite, and the upgrading of the fines using heavy media washing is not possible. Thermal treatment of fines in shaft furnaces can produce dusts in amounts equivalent to 15%-20% and in rotary furnaces to 30%-35% of the feed material. A basic solution to the problem is to increase the thermal efficiency of the furnaces. In the case of shaft furnaces this can be achieved by re-designing the combustion system to provide a constant sintering temperature through the furnace cross-section. Two new thermal treatment furnaces are described. The microfluid furnace is based on a hydromechanical fluidisation process. The furnace has a number of chambers in which material is successively dried, heated, calcined and cooled. Mathematical modelling has been used to design a full-scale furnace with 11 vertical chambers, with the burner located in the seventh chamber. The high-speed rotary furnace is based on mechanical fluidisation and the process involves the formation of a dispersed layer which allows perfect contact between the gaseous media and the surface of the particles being processed. Experimental data were used to develop a mathematical model which was used for the design of a pilot-scale furnace., Magnesite is a valuable material with applications in refractories for the metallurgical and cement industries. Large amounts of high-grade fines are lost during the mining, beneficiation and thermal treatment of magnesite, and the upgrading of the fines using heavy media washing is not possible. Thermal treatment of fines in shaft furnaces can produce dusts in amounts equivalent to 15%-20% and in rotary furnaces to 30%-35% of the feed material. A basic solution to the problem is to increase the thermal efficiency of the furnaces. In the case of shaft furnaces this can be achieved by re-designing the combustion system to provide a constant sintering temperature through the furnace cross-section. Two new thermal treatment furnaces are described. The microfluid furnace is based on a hydromechanical fluidisation process. The furnace has a number of chambers in which material is successively dried, heated, calcined and cooled. Mathematical modelling has been used to design a full-scale furnace with 11 vertical chambers, with the burner located in the seventh chamber. The high-speed rotary furnace is based on mechanical fluidisation and the process involves the formation of a dispersed layer which allows perfect contact between the gaseous media and the surface of the particles being processed. Experimental data were used to develop a mathematical model which was used for the design of a pilot-scale furnace.

32. Simons Observatory Small Aperture Telescope overview

Author

Heather McCarrick, Osamu Tajima, Yuji Chinone, Jon E. Gudmundsson, Nicholas Galitzki, Federico Nati, Gabriele Coppi, Andrew Bazako, Joseph Seibert, Kevin D. Crowley, Jason E. Austermann, Masaya Hasegawa, Grant Teply, Jacob Spisak, Tran Tsan, Bradley R. Johnson, Edward J. Wollack, Giulio Fabbian, Brian Keating, Simon Dicker, Mario Zannoni, Mayuri Sathyanarayana Rao, Yume Nishinomiya, Frederick Matsuda, Kam Arnold, Shunsuke Adachi, Ningfeng Zhu, Charles A. Hill, James A. Beall, Tomoki Terasaki, D. Kaneko, Akito Kusaka, Kevin T. Crowley, Bradley Dober, Samantha Walker, Lyman A. Page, Adrian T. Lee, Kenji Kiuchi, Kathleen Harrington, Shuay-Pwu Patty Ho, Nobuhiko Katayama, Makoto Hattori, Peter Ashton, Johannes Hubmayr, Joseph E. Golec, Kana Sakaguri, Masaaki Murata, Shannon M. Duff, Kyohei Yamada, Zhilei Xu, Yuki Sakurai, Jack Lashner, Christian L. Reichardt, Aamir Ali, Marshall, HK, Spyromilio, J, Usuda, T, Kiuchi, K, Adachi, S, Ali, A, Arnold, K, Ashton, P, Austermann, J, Bazako, A, Beall, J, Chinone, Y, Coppi, G, Crowley, K, Dicker, S, Dober, B, Duff, S, Fabbian, G, Galitzki, N, Golec, J, Gudmundsson, J, Harrington, K, Hasegawa, M, Hattori, M, Hill, C, Ho, S, Hubmayr, J, Johnson, B, Kaneko, D, Katayama, N, Keating, B, Kusaka, A, Lashner, J, Lee, A, Matsuda, F, Mccarrick, H, Murata, M, Nati, F, Nishinomiya, Y, Page, L, Rao, M, Reichardt, C, Sakaguri, K, Sakurai, Y, Sibert, J, Spisak, J, Tajima, O, Teply, G, Terasaki, T, Tsan, T, Walker, S, Wollack, E, Xu, Z, Yamada, K, Zannoni, M, and Zhu, N

Subjects
Aperture, Cosmic microwave background, FOS: Physical sciences, Field of view, Astrophysics::Cosmology and Extragalactic Astrophysics, CMB, law.invention, Telescope, FIS/05 - ASTRONOMIA E ASTROFISICA, Optics, law, Observatory, Cosmic Microwave Background, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, business.industry, Gravitational wave, Stray light, Bolometer, Astrophysics::Instrumentation and Methods for Astrophysics, Radio, Primordial gravitational wave, B-mode, Ground-Based Telescope, business, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Simons Observatory (SO) is a cosmic microwave background (CMB) experiment from the Atacama Desert in Chile comprising three small-aperture telescopes (SATs) and one large-aperture telescope (LAT). In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz in order to achieve the sensitivity necessary to measure or constrain numerous cosmological quantities. In this work, we focus on the SATs which are optimized to search for primordial gravitational waves that are detected as parity-odd polarization patterns called a B-modes on degree scales in the CMB. Each SAT employs a single optics tube with TES arrays operating at 100 mK. The high throughput optics system has a 42 cm aperture and a 35-degree field of view coupled to a 36 cm diameter focal plane. The optics consist of three metamaterial anti-re ection coated silicon lenses. Cryogenic ring baffles with engineered blackbody absorbers are installed in the optics tube to minimize the stray light. The entire optics tube is cooled to 1 K. A cryogenic continuously rotating half-wave plate near the sky side of the aperture stop helps to minimize the effect of atmospheric uctuations. The telescope warm baffling consists of a forebaffle, an elevation stage mounted co-moving shield, and a fixed ground shield that together control the far side-lobes and mitigates ground-synchronous systematics. We present the status of the SAT development., Comment: 8 pages, 6 figures

Published
2021
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33. The Simons Observatory: A large-diameter truss for a refracting telescope cooled to 1 K

Author

Kevin D. Crowley, Peter Dow, Jordan E. Shroyer, John C. Groh, Bradley Dober, Jacob Spisak, Nicholas Galitzki, Tanay Bhandarkar, Mark J. Devlin, Simon Dicker, Patricio A. Gallardo, Kathleen Harrington, Jeffrey Iuliano, Bradley R. Johnson, Delwin Johnson, Anna M. Kofman, Akito Kusaka, Adrian Lee, Michele Limon, Federico Nati, John Orlowski-Scherer, Lyman Page, Michael Randall, Grant Teply, Tran Tsan, Edward J. Wollack, Zhilei Xu, Ningfeng Zhu, Crowley, K, Dow, P, Shroyer, J, Groh, J, Dober, B, Spisak, J, Galitzki, N, Bhandarkar, T, Devlin, M, Dicker, S, Gallardo, P, Harrington, K, Iuliano, J, Johnson, B, Johnson, D, Kofman, A, Kusaka, A, Lee, A, Limon, M, Nati, F, Orlowski-Scherer, J, Page, L, Randall, M, Teply, G, Tsan, T, Wollack, E, Xu, Z, and Zhu, N

Subjects
Instrumentation, CMB, cosmology, telescopes
Abstract

We present the design and measured performance of a new carbon fiber strut design that is used in a cryogenically cooled truss for the Simons Observatory small aperture telescope. The truss consists of two aluminum 6061 rings separated by 24 struts. Each strut consists of a central carbon fiber tube fitted with two aluminum end caps. We tested the performance of the strut and truss by (i) cryogenically cycling and destructively pull-testing strut samples, (ii) non-destructively pull-testing the final truss, and (iii) measuring the thermal conductivity of the carbon fiber tubes. We found that the strut strength is limited by the mounting fasteners and the strut end caps, not the epoxy adhesive or the carbon fiber tube. This result is consistent with our numerical predictions. Our thermal measurements suggest that the conductive heat load through the struts (from 4 to 1 K) will be less than 1 mW. This strut design may be a promising candidate for use in other cryogenic support structures.

Published
2022

34. Small Aperture Telescopes for the Simons Observatory

Author

Osamu Tajima, Johannes Hubmayr, Suzanne T. Staggs, Aamir Ali, Bejamin Westbrook, Kam Arnold, Trevor Sasse, Charles A. Hill, Frederick Matsuda, Tran Tsan, Kenji Kiuchi, Grant Teply, Andrew Bazarko, Federico Nati, Yuji Chinone, Joseph Seibert, Carlos Sierra, Nicholas Galitzki, Zhilei Xu, Peter Ashton, Ningfeng Zhu, Erin Healy, Haruki Nishino, Sara M. Simon, Shannon M. Duff, Kevin D. Crowley, Mario Zannoni, Edward J. Wollack, Jacob Spisak, Michael D. Niemack, John Orlowski-Scherer, Christopher Raum, Lance Corbett, Adrian T. Lee, Aashrita Mangu, Kathleen Harrington, Michael Ludlam, Yuki Sakurai, Shunsuke Adachi, Gabriele Coppi, Maria Salatino, Neil Goeckner-Wald, Mayuri Sathyanarayana Rao, Maximiliano Silva-Feaver, Mark J. Devlin, Christopher G. Ellis, Heather McCarrick, Kevin T. Crowley, Shuay-Pwu Patty Ho, Akito Kusaka, Brian Keating, Simon Dicker, Ali, A, Adachi, S, Arnold, K, Ashton, P, Bazarko, A, Chinone, Y, Coppi, G, Corbett, L, Crowley, K, Devlin, M, Dicker, S, Duff, S, Ellis, C, Galitzki, N, Goeckner-Wald, N, Harrington, K, Healy, E, Hill, C, Ho, S, Hubmayr, J, Keating, B, Kiuchi, K, Kusaka, A, Lee, A, Ludlam, M, Mangu, A, Matsuda, F, Mccarrick, H, Nati, F, Niemack, M, Nishino, H, Orlowski-Scherer, J, Sathyanarayana Rao, M, Raum, C, Sakurai, Y, Salatino, M, Sasse, T, Seibert, J, Sierra, C, Silva-Feaver, M, Spisak, J, Simon, S, Staggs, S, Tajima, O, Teply, G, Tsan, T, Wollack, E, Westbrook, B, Xu, Z, Zannoni, M, and Zhu, N

Subjects
Small aperture telescope, TES, Refractor, Simons Observatory, Cosmic microwave background, CMB, Inflation, Cosmology, media_common.quotation_subject, Cosmic microwave background, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Cosmology, Radio spectrum, 010305 fluids & plasmas, law.invention, Telescope, FIS/05 - ASTRONOMIA E ASTROFISICA, law, Observatory, 0103 physical sciences, General Materials Science, 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, media_common, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, Condensed Matter Physics, Polarization (waves), Atomic and Molecular Physics, and Optics, Sky, Refracting telescope, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Simons Observatory (SO) is an upcoming cosmic microwave background (CMB) experiment located on Cerro Toco, Chile, that will map the microwave sky in temperature and polarization in six frequency bands spanning 27 to 285 GHz. SO will consist of one 6-m large aperture telescope fielding $$\sim$$ 30,000 detectors and an array of three 0.42-m small aperture telescopes (SATs) fielding an additional 30,000 detectors. This synergy will allow for the extremely sensitive characterization of the CMB over angular scales ranging from an arcmin to tens of degrees, enabling a wide range of scientific output. Here we focus on the SATs targeting degree angular scales with successive dichroic instruments observing at mid-frequency (MF: 93/145 GHz), ultra-high-frequency (UHF: 225/285 GHz), and low-frequency (LF: 27/39 GHz). The three SATs will be able to map $$\sim$$ 10% of the sky to a noise level of $$\sim$$ $$2\,\upmu {\hbox {K}}$$ -arcmin when combining 93 and 145 GHz. The multiple frequency bands will allow the CMB to be separated from galactic foregrounds (primarily synchrotron and dust), with the primary science goal of characterizing the primordial tensor-to-scalar ratio, r, at a target level of $$\sigma (r) \approx 0.003$$ .

Published
2020

35. The effects of inclination on a two stage pulse tube cryocooler for use with a ground based observatory

Author

Nicholas Galitzki, Ningfeng Zhu, John Orlowski-Scherer, Kam Arnold, Brian Keating, Michael J. Randall, Grant Teply, Logan Foote, Tamar Ervin, Zhilei Xu, Jack Lashner, Aamir Ali, Gabriele Coppi, Joseph Seibert, Jacob Spisak, Tran Tsan, Tsan, T, Galitzki, N, Ali, A, Arnold, K, Coppi, G, Ervin, T, Foote, L, Keating, B, Lashner, J, Orlowski-Scherer, J, Randall, M, Seibert, J, Spisak, J, Teply, G, Xu, Z, and Zhu, N

Subjects
Materials science, business.industry, Cryogenic, Detector, General Physics and Astronomy, Cryocooler, Cooling capacity, Angular dependence, Wavelength, Optics, Tilt (optics), Observatory, Thermal, General Materials Science, business, Pulse tube refrigerator, Pulse Tube Cryocooler
Abstract

Ground-based observatories across a wide range of wavelengths implement cryogenic cooling techniques to increase the sensitivity of instruments and enable low temperature detector technologies. Commercial pulse tube cryocoolers (PTCs) are frequently used to provide 40 K and 4 K stages as thermal shells in scientific instruments. However, PTC operation is dependent on gravity, giving rise to changes in cooling capacity over the operational tilt range of pointed telescopes. We present a study of the performance of a two stage PTC with a cooling capacity of 1.8 W at 4.2 K and 50 W at 45 K (Cryomech PT420-RM) from 0 - 55 ° away from vertical to probe capacity as a function of angle over a set of realistic thermal loading conditions. Our study provides a method to extract temperature estimates given predicted thermal loading conditions across the angular range sampled. We then discuss the design implications for current and future tilted cryogenic systems.

Published
2021

36. The Simons Observatory: gain, bandpass and polarization-angle calibration requirements for B-mode searches

Author

Valentina Fanfani, Mario Zannoni, Mark J. Devlin, J. Colin Hill, Josquin Errard, Aritoki Suzuki, Gabriele Coppi, Edward J. Wollack, Julien Carron, Adrian T. Lee, Thibaut Louis, Davide Poletti, Mathew S. Madhavacheril, Michael L. Brown, Baptiste Jost, Brian Keating, Federico Nati, P. Daniel Meerburg, S. Azzoni, Maximilian H. Abitbol, Haruki Nishino, Sara M. Simon, Michael J. Randall, Jacob Spisak, Lyman A. Page, Bradley R. Johnson, Jo Dunkley, Yuji Chinone, Aamir Ali, David Alonso, Grant Teply, Jeff McMahon, Carlo Baccigalupi, Clara Vergès, Jens Chluba, Aditya Rotti, Giuseppe Puglisi, Nicholas Galitzki, Kevin D. Crowley, Martina Gerbino, Zhilei Xu, Jack Lashner, Erminia Calabrese, Kevin T. Crowley, Darcy Barron, Akito Kusaka, Nicoletta Krachmalnicoff, Heather McCarrick, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Van Swinderen Institute for Particle Physics and G, High-Energy Frontier, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), APC - Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE31-0022,BxB,Champs B interstellaires et modes B de l'inflation(2017), ANR-17-CE23-0002,B3DCMB,Big Bang à partir de Big Data (du fond diffus cosmologique)(2017), Abitbol, M, Alonso, D, Simon, S, Lashner, J, Crowley, K, Ali, A, Azzoni, S, Baccigalupi, C, Barron, D, Brown, M, Calabrese, E, Carron, J, Chinone, Y, Chluba, J, Coppi, G, Devlin, M, Dunkley, J, Errard, J, Fanfani, V, Galitzki, N, Gerbino, M, Colin Hill, J, Johnson, B, Jost, B, Keating, B, Krachmalnicoff, N, Kusaka, A, Lee, A, Louis, T, Madhavacheril, M, Mccarrick, H, Mcmahon, J, Daniel Meerburg, P, Nati, F, Nishino, H, Page, L, Poletti, D, Puglisi, G, Randall, M, Rotti, A, Spisak, J, Suzuki, A, Teply, G, Vergès, C, Wollack, E, Xu, Z, and Zannoni, M

Subjects
CMBR polarisation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Calibration (statistics), Cosmic microwave background, FOS: Physical sciences, Parameter space, Residual, Atomic, 01 natural sciences, Particle and Plasma Physics, Settore FIS/05 - Astronomia e Astrofisica, Band-pass filter, Observatory, 0103 physical sciences, CMBR experiments, Nuclear, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, CMBR polarization, Physics, Settore FIS/05, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, cosmological parameters from CMBR, Molecular, Astronomy and Astrophysics, Polarization (waves), Nuclear & Particles Physics, gravitational waves and CMBR polarization, Computational physics, astro-ph.CO, CMBR experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Instrumentation and Methods for Astrophysics, Focus (optics), Astronomical and Space Sciences, astro-ph.IM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We quantify the calibration requirements for systematic uncertainties for next-generation ground-based observatories targeting the large-angle $B$-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on gain calibration, bandpass center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that gain calibration and bandpass center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio $r$ on the order of $\Delta r\sim10^{-3}$, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to ${\cal O}(10)$ degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on $r$ if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on $r$ significantly, broadening the error bar by ${\cal O}(10\%)$ at most. We validate these results by reanalyzing the latest publicly available data from the BICEP2/Keck collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO., Comment: 41 pages, 18 figures

Published
2021

37. Dark Population Transfer Mechanism for Sterile Neutrino Dark Matter.

Author

Fuller GM, Gráf L, Patwardhan AV, and Spisak J

Abstract

We present a mechanism for producing a cosmologically significant relic density of one or more sterile neutrinos. This scheme invokes two steps: First, a population of "heavy" sterile neutrinos is created by scattering-induced decoherence of active neutrinos. Second, this population is transferred, via sterile neutrino self-interaction-mediated scatterings and decays, to one or more lighter mass (∼10  keV to ∼1  GeV) sterile neutrinos that are far more weakly (or not at all) mixed with active species and could constitute dark matter. Dark matter produced this way can evade current electromagnetic and structure-based bounds, but may nevertheless be probed by future observations.

Published
2024
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38. Human-level play in the game of Diplomacy by combining language models with strategic reasoning.

Author

Bakhtin A, Brown N, Dinan E, Farina G, Flaherty C, Fried D, Goff A, Gray J, Hu H, Jacob AP, Komeili M, Konath K, Kwon M, Lerer A, Lewis M, Miller AH, Mitts S, Renduchintala A, Roller S, Rowe D, Shi W, Spisak J, Wei A, Wu D, Zhang H, and Zijlstra M

Subjects
Humans, Diplomacy, Software, Video Games, Artificial Intelligence, Language
Abstract

Despite much progress in training artificial intelligence (AI) systems to imitate human language, building agents that use language to communicate intentionally with humans in interactive environments remains a major challenge. We introduce Cicero, the first AI agent to achieve human-level performance in Diplomacy , a strategy game involving both cooperation and competition that emphasizes natural language negotiation and tactical coordination between seven players. Cicero integrates a language model with planning and reinforcement learning algorithms by inferring players' beliefs and intentions from its conversations and generating dialogue in pursuit of its plans. Across 40 games of an anonymous online Diplomacy league, Cicero achieved more than double the average score of the human players and ranked in the top 10% of participants who played more than one game.

Published
2022
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39. Psychedelic Prophets : The Letters of Aldous Huxley and Humphry Osmond

Author

Huxley, Aldous, Osmond, Humphry, BISBEE, CYNTHIA CARSON, BISBEE, PAUL, DYCK, ERIKA, FARRELL, PATRICK, SEXTON, JAMES, SPISAK, JAMES W., Huxley, Aldous, Osmond, Humphry, BISBEE, CYNTHIA CARSON, BISBEE, PAUL, DYCK, ERIKA, FARRELL, PATRICK, SEXTON, JAMES, and SPISAK, JAMES W.

Published
2018

40. The Simons Observatory: A large-diameter truss for a refracting telescope cooled to 1 K.

Author

Crowley KD, Dow P, Shroyer JE, Groh JC, Dober B, Spisak J, Galitzki N, Bhandarkar T, Devlin MJ, Dicker S, Gallardo PA, Harrington K, Iuliano J, Johnson BR, Johnson D, Kofman AM, Kusaka A, Lee A, Limon M, Nati F, Orlowski-Scherer J, Page L, Randall M, Teply G, Tsan T, Wollack EJ, Xu Z, and Zhu N

Abstract

We present the design and measured performance of a new carbon fiber strut design that is used in a cryogenically cooled truss for the Simons Observatory small aperture telescope. The truss consists of two aluminum 6061 rings separated by 24 struts. Each strut consists of a central carbon fiber tube fitted with two aluminum end caps. We tested the performance of the strut and truss by (i) cryogenically cycling and destructively pull-testing strut samples, (ii) non-destructively pull-testing the final truss, and (iii) measuring the thermal conductivity of the carbon fiber tubes. We found that the strut strength is limited by the mounting fasteners and the strut end caps, not the epoxy adhesive or the carbon fiber tube. This result is consistent with our numerical predictions. Our thermal measurements suggest that the conductive heat load through the struts (from 4 to 1 K) will be less than 1 mW. This strut design may be a promising candidate for use in other cryogenic support structures.

Published
2022
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41. Synthesis of amide and sulfonamide substituted N-aryl 6-aminoquinoxalines as PFKFB3 inhibitors with improved physicochemical properties.

Author

Boutard N, Białas A, Sabiniarz A, Guzik P, Banaszak K, Biela A, Bień M, Buda A, Bugaj B, Cieluch E, Cierpich A, Dudek Ł, Eggenweiler HM, Fogt J, Gaik M, Gondela A, Jakubiec K, Jurzak M, Kitlińska A, Kowalczyk P, Kujawa M, Kwiecińska K, Leś M, Lindemann R, Maciuszek M, Mikulski M, Niedziejko P, Obara A, Pawlik H, Rzymski T, Sieprawska-Lupa M, Sowińska M, Szeremeta-Spisak J, Stachowicz A, Tomczyk MM, Wiklik K, Włoszczak Ł, Ziemiańska S, Zarębski A, Brzózka K, Nowak M, and Fabritius CH

Subjects
HCT116 Cells, Humans, Kinetics, Solubility, Amides chemistry, Phosphofructokinase-2 antagonists & inhibitors, Quinoxalines chemistry, Quinoxalines pharmacology, Sulfonamides chemistry
Abstract

In oncology, the "Warburg effect" describes the elevated production of energy by glycolysis in cancer cells. The ubiquitous and hypoxia-induced 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) plays a noteworthy role in the regulation of glycolysis by producing fructose-2,6-biphosphate (F-2,6-BP), a potent activator of the glycolysis rate-limiting phosphofructokinase PFK-1. Series of amides and sulfonamides derivatives based on a N-aryl 6-aminoquinoxaline scaffold were synthesized and tested for their inhibition of PFKFB3 in vitro in a biochemical assay as well as in HCT116 cells. The carboxamide series displayed satisfactory kinetic solubility and metabolic stability, and within this class, potent lead compounds with low nanomolar activity have been identified with a suitable profile for further in vivo evaluation., (Copyright © 2018. Published by Elsevier Ltd.)

Published
2019
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42. Discovery and Structure-Activity Relationships of N-Aryl 6-Aminoquinoxalines as Potent PFKFB3 Kinase Inhibitors.

Author

Boutard N, Białas A, Sabiniarz A, Guzik P, Banaszak K, Biela A, Bień M, Buda A, Bugaj B, Cieluch E, Cierpich A, Dudek Ł, Eggenweiler HM, Fogt J, Gaik M, Gondela A, Jakubiec K, Jurzak M, Kitlińska A, Kowalczyk P, Kujawa M, Kwiecińska K, Leś M, Lindemann R, Maciuszek M, Mikulski M, Niedziejko P, Obara A, Pawlik H, Rzymski T, Sieprawska-Lupa M, Sowińska M, Szeremeta-Spisak J, Stachowicz A, Tomczyk MM, Wiklik K, Włoszczak Ł, Ziemiańska S, Zarębski A, Brzózka K, Nowak M, and Fabritius CH

Subjects
Cell Survival drug effects, Crystallography, X-Ray, Dose-Response Relationship, Drug, Enzyme Inhibitors chemical synthesis, HCT116 Cells, Humans, Lactic Acid antagonists & inhibitors, Lactic Acid biosynthesis, Models, Molecular, Molecular Structure, Phosphofructokinase-2 metabolism, Quinoxalines chemical synthesis, Structure-Activity Relationship, Drug Discovery, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Phosphofructokinase-2 antagonists & inhibitors, Quinoxalines chemistry, Quinoxalines pharmacology
Abstract

Energy and biomass production in cancer cells are largely supported by aerobic glycolysis in what is called the Warburg effect. The process is regulated by key enzymes, among which phosphofructokinase PFK-2 plays a significant role by producing fructose-2,6-biphosphate; the most potent activator of the glycolysis rate-limiting step performed by phosphofructokinase PFK-1. Herein, the synthesis, biological evaluation and structure-activity relationship of novel inhibitors of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which is the ubiquitous and hypoxia-induced isoform of PFK-2, are reported. X-ray crystallography and docking were instrumental in the design and optimisation of a series of N-aryl 6-aminoquinoxalines. The most potent representative, N-(4-methanesulfonylpyridin-3-yl)-8-(3-methyl-1-benzothiophen-5-yl)quinoxalin-6-amine, displayed an IC 50 of 14 nm for the target and an IC 50 of 0.49 μm for fructose-2,6-biphosphate production in human colon carcinoma HCT116 cells. This work provides a new entry in the field of PFKFB3 inhibitors with potential for development in oncology., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2019
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43. 1-Sulfonyl-6-Piperazinyl-7-Azaindoles as potent and pseudo-selective 5-HT6 receptor antagonists.

Author

Fabritius CH, Pesonen U, Messinger J, Horvath R, Salo H, Gałęzowski M, Galek M, Stefańska K, Szeremeta-Spisak J, Olszak-Płachta M, Buda A, Adamczyk J, Król M, Prusis P, Sieprawska-Lupa M, Mikulski M, Kuokkanen K, Chapman H, Obuchowicz R, Korjamo T, Jalava N, and Nowak M

Subjects
Amnesia chemically induced, Animals, Behavior, Animal drug effects, Dose-Response Relationship, Drug, Humans, Indoles chemical synthesis, Indoles chemistry, Maze Learning drug effects, Mice, Models, Molecular, Molecular Structure, Piperazines chemical synthesis, Piperazines chemistry, Scopolamine, Serotonin Antagonists chemical synthesis, Serotonin Antagonists chemistry, Structure-Activity Relationship, Sulfones chemical synthesis, Sulfones chemistry, Amnesia drug therapy, Indoles pharmacology, Piperazines pharmacology, Receptors, Serotonin metabolism, Serotonin Antagonists pharmacology, Sulfones pharmacology
Abstract

A series of 1-Sulfonyl-6-Piperazinyl-7-Azaindoles, showing strong antagonistic activity to 5-HT6 receptor (5-HT6R) was synthesized and characterized. The series was optimized to reduce activity on D2 receptor. Based on the selectivity against this off-target and the analysis of the ADME-tox profile, compound 1c was selected for in vivo efficacy assessment, which demonstrated procognitive effects as shown in reversal of scopolamine induced amnesia in an elevated plus maze test in mice. Compound 3, the demethylated version of compound 1c, was profiled against a panel of 106 receptors, channels and transporters, indicating only D3 receptor as a major off-target. Compound 3 has been selected for this study over compound 1c because of the higher 5-HT6R/D2R binding ratio. These results have defined a new direction for the design of our pseudo-selective 5-HT6R antagonists., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Published
2016
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