Luca Grandi

Assistant Professor

Ph.D., Universita degli Studi di Pavia, Italia, 2005
Contact Information
Phone: (773) 834-7659
Location: ERC 485
Email: lgrandiuchicago.edu
WWW: Web Site

Picture: Research
XENON building
I have always been fascinated by fundamental physics, the kind of physics that is able to change our way of looking at the surrounding world and can provide a deeper understanding of how nature works. At the same time I have always been attracted by small scale experiments, those human-sized experiments where you can understand the entire experimental setup, in all its small details. Moreover I enjoy designing detectors, operating them and analyzing the collected data. These interests naturally brought me towards the field of rare events physics and, more specifically, toward Dark Matter direct searches. This area of research has a huge potential for discovery and the capability of providing experimental results that affect the foundation of our physics theories.

My activities, until now, have been focused on the development of two-phase noble liquids Time Projection Chamber (TPC) technology for Dark Matter direct detection. During my Ph.D. I was involved in the design, construction and operation of the WArP-2.3kg prototype, the first argon detector to have set a limit on the WIMP (Weakly Interacting Massive Particles) interaction rate.

From 2008 to 2015, I have worked on the <a target='_blank' href='http://darkside.lngs.infn.it/'>DarkSide</a> project, of which I am a co-founder. DarkSide combines argon two-phase and liquid scintillator technology: the use of depleted argon as a target in a two-phase argon TPC, coupled with a powerful neutron veto based on the Borexino experiment results in a unique detector for Dark Matter search, sensitive to extremely rare and low-energy nuclear recoils possibly induced by WIMPs and capable of achieving background-free conditions. DarkSide-50, the first physics detector of the DarkSide family, has been deployed at Gran Sasso Underground Laboratory in Italy during the last quarter of 2014. The detector has been used to demonstrate the performance and background suppression capabilities of argon and set a competitive limit on dark matter properties. The DarkSide-50 experiment has set a solid foundation for the possible extension of argon technology to future multi-ton scale detectors.

In 2015 I joined the <a target='_blank' href='http://xenon1t.org/'>XENON-1T</a> project. The experiment features a 3500kg liquid xenon detector surrounded by a large water tank to suppress the background. The two-phase xenon TPC is presently under construction and its commissioning at Gran Sasso Underground Laboratory is scheduled for the last quarter of 2015. The XENON-1T experiment, thanks to its design, large fiducial mass, and increased sensitivity to WIMPs, will probe properties of dark matter in yet unexplored regions and will “open” a second phase of dark matter searches with multi-ton noble liquid detectors. University of Chicago contributions to the XENON program span from activities related to the assembly and preparation of the TPC detector, to simulations and data analysis. The group is managing the US data-processing/analysis hub, hosted by the UChicago Research Computing Center. The activity of the group within XENON-1T is also complemented by the operation of small noble liquid detectors in our laboratory at the university, which we use to test new ideas and perform measurements that will inform the analysis and interpretation of ongoing dark matter searches.

<span class='decor'><b>Selected Publications:</b></span>
"First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso", Phys.Lett. B743 (2015) 456-466.

"Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon", Phys.Rev. D91 (2015) 092007.

"Observation of the dependence on drift field of scintillation from nuclear recoils in liquid argon", Phys.Rev. D88 (2013) 9, 092006.

"Light yield in DarkSide-10: A prototype two-phase argon TPC for dark matter searches", Astropart.Phys. 49 (2013) 44-51.

"Precision measurement of the 7Be solar neutrino interaction rate in Borexino", Phys.Rev.Lett. 107 (2011) 141302.

"Effects of Nitrogen and Oxygen contamination in liquid Argon", Nucl.Phys.Proc.Suppl. 197 (2009) 70-73.

"First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory", Astropart.Phys. 28 (2008) 495-507.

"Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors", Nucl.Instrum.Meth. A587 (2008) 46-51.

"Measurement of the specific activity of 39Ar in natural argon", Nucl.Instrum.Meth. A574 (2007) 83-88.

Ongoing Scientific Projects:

Past Scientific Projects: Depleted Argon cryogenic Scintillation and Ionization Detection (DarkSide)

Past Students

GRADUATE: Michael Hank (2018), Katrina Miller (2018)

UNDERGRADUATE: Thomas Wester (2017)

KICP Publications
2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012

Latest Journal Publications
  1. "The XENON1T data acquisition system", Journal of Instrumentation, Volume 14, Issue 07, pp. P07016 (2019) (Jul 2019)
  2. "Light Dark Matter Search with Ionization Signals in XENON1T", arXiv:1907.11485 (Jul 2019)
  3. "A Search for Light Dark Matter Interactions Enhanced by the Migdal effect or Bremsstrahlung in XENON1T", arXiv:1907.12771 (Jul 2019)
  4. "XENON1T dark matter data analysis: Signal and background models and statistical inference", Physical Review D, Volume 99, Issue 11, id.112009 (Jun 2019)
  5. "The XENON1T Data Acquisition System", arXiv:1906.00819 (Jun 2019)
  6. "XENON1T Dark Matter Data Analysis: Signal Reconstruction, Calibration and Event Selection", arXiv:1906.04717 (Jun 2019)
  7. "Constraining the Spin-Dependent WIMP-Nucleon Cross Sections with XENON1T", Physical Review Letters, Volume 122, Issue 14, id.141301 (Apr 2019)
  8. "First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment", Physical Review Letters, Volume 122, Issue 7, id.071301 (Feb 2019)
  9. "Dark Matter Search Results from a One Ton-Year Exposure of XENON1T", Physical Review Letters, Volume 121, Issue 11, id.111302 (Sep 2018)
  10. "Signal yields of keV electronic recoils and their discrimination from nuclear recoils in liquid xenon", Physical Review D, Volume 97, Issue 9, id.092007 (May 2018)
  11. "Characterization of photomultiplier tubes with a realistic model through GPU-boosted simulation", Journal of Instrumentation, Volume 13, Issue 02, pp. T02011 (2018) (Feb 2018)
  12. "The XENON1T dark matter experiment", The European Physical Journal C, Volume 77, Issue 12, article id.881, 23 pp (Dec 2017)
  13. "The electronics, trigger and data acquisition system for the liquid argon time projection chamber of the DarkSide-50 search for dark matter", Journal of Instrumentation, Volume 12, Issue 12, pp. P12011 (2017) (Dec 2017)
  14. "Material radioassay and selection for the XENON1T dark matter experiment", The European Physical Journal C, Volume 77, Issue 12, article id.890, 15 pp (Dec 2017)
  15. "First Dark Matter Search Results from the XENON1T Experiment", Physical Review Letters, Volume 119, Issue 18, id.181301 (Nov 2017)
  16. "Model independent approach to the single photoelectron calibration of photomultiplier tubes", Nuclear Inst. and Methods in Physics Research, A, Volume 863, p. 35-46 (Aug 2017)
  17. "Online $^{222}$Rn removal by cryogenic distillation in the XENON100 experiment", arXiv:1702.06942 (Feb 2017)
  18. "The electronics and data acquisition system for the DarkSide-50 veto detectors", Journal of Instrumentation, Volume 11, Issue 12, pp. P12007 (2016) (Dec 2016)
  19. "Removing krypton from xenon by cryogenic distillation to the ppq level", arXiv:1612.04284 (Dec 2016)
  20. "DARWIN: towards the ultimate dark matter detector", Journal of Cosmology and Astroparticle Physics, Issue 11, article id. 017 (2016) (Nov 2016)

Latest Conference Proceedings
  1. "The DarkSide Program", Roma International Conference on Astroparticle Physics 2014 (RICAP-14), Noto, Italy, Edited by P. Piattelli; A. Capone; R. Coniglione; G. De Bonis; M. De Vincenzi; C. Distefano; A. Morselli; P. Sapienza; EPJ Web of Conferences, Volume 121, id.06010 (Jul 2
  2. "The DarkSide-50 outer detectors", Journal of Physics: Conference Series, Volume 718, Issue 4, article id. 042062 (2016) (May 2016)
  3. "The DarkSide awakens", Journal of Physics: Conference Series, Volume 718, Issue 4, article id. 042016 (2016) (May 2016)
  4. "Measurement of Scintillation Efficiency of Low Energy Nuclear Recoils in Liquid Argon", American Physical Society, APS April Meeting 2013, April 13-16, 2013, abstract #T12.002 (Apr 2013)

Past Visitors:
  1. Luke Goetzke, Columbia University (2016)
  2. Ashlea Monti, King College Prep HS (2016)
  3. Nora Wengerski, King College Prep (2016)
  4. Aprile Elena, University of Columbia (2015)
  5. Montuschi Michele, INFN - Ferrara (Italy) (2015)
  6. Daniel Akerib, Case Western Reserve University (2014)
  7. Daniel Akerib, SLAC (2014)
  8. Michael Foxe, Pacific Northwest National Lab (2014)
  9. Guangyong Koh, Princeton University (2014)