@ grandilab.uchicago

Searching for Dark Matter with Noble Liquid Technologies

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery."
Enrico Fermi

What do we do?

To make it simple… we search for dark matter!

Does dark matter exist?

Well, the story is complicated. Observations of the cosmic microwave background fluctuation, large-scale galaxy surveys and studies of large-scale structure formation indicate that a huge fraction of the matter in the Universe is not visible. An exotic and not yet discovered species of elementary particle would explain all these observations. Several experiments have been built in last two decades to prove the existence of these elusive particles but their detection is challenging and we do not have yet a clear picture of what they are and if they really exist.

So, are you looking for something that might not exist?

You are right! That's what makes this field so fascinating, it is fundamental physics. Dark matter puzzle is a cutting edge science topic: 95% of the matter is dark and it is waiting for physicists to shed some light over it. Of course all this is risky but "nothing ventured, nothing gained!".

How do you search for it?

We build specialized, low-background detectors designed to identify rare and low-energy interactions, possibly induced by dark matter interacting with ordinary matter. We have been doing this by contributing to two major experimental efforts in the field: XENON1T (2015-now) and DarkSide-50 (2008-2015), respectively featuring ultrapure xenon and argon as targets for dark matter detection. Both detectors employ the so-called two-phase (gas/liquid) Time Projection Chamber (TPC) technology that allows to simultaneously detect ionization and excitation produced by even tiny energy depositions in the sensitive liquid volume.

Is it easy?

Absolutely not! It is really challenging since the dark matter signal is expected to be really wimpy and the experimental technologies should be pushed to their edges to reach the needed sensitivities. That's why, together with the main experiments, we are running a set of smaller scale detectors that we use to study in great detail the noble liquid properties and the detection technology we are developing. These studies will play a crucial role for the interpretation of data acquired from the actual dark matter detectors.


The XENON1T two-phase xenon Time Projection Chamber (TPC) is presently deployed at Laboratori Nazionali del Gran Sasso (LNGS) and expected to be commissioned during the first few months of 2016. Thanks to its design, large fiducial mass (1 tonne fiducial), and ultra-low background, the XENON1T experiment will soon after start probing properties of dark matter in yet unexplored regions and will “open” a second phase of dark matter searches with multi-ton noble liquid detectors.

The group activities within the XENON1T program have been initially focused on the preparation and assembly of the two-phase Time Projection Chamber and on the development of the US data-processing/analysis hub - a Tier 1 Center in LHC jargon - hosted by the UChicago Research Computing Center. The XENON1T detector is presently operating within the Water Cherenkov Detector in Hall B of LNGS. The focus of the group has now switched towards data analysis with major contributions to few papers in preparation.

"The XENON1T Dark Matter Experiment", E.Aprile et al., submitted to Eur. Phys. J. C (Sep 2017)
"First Dark Matter Search Results from the XENON1T Experiment ", E.Aprile et al., accepetd by PRL (Sep 2017)
"Material radioassay and selection for the XENON1T dark matter experiment", E.Aprile et al., submitted to Eur. Phys. J. C (2017)
"Removing krypton from xenon by cryogenic distillation to the ppq level", E.Aprile et al., Eur. Phys. J. C (2017) 77: 275.
"Online 222Rn removal by cryogenic distillation in the XENON100 experiment", E.Aprile et al., Eur.Phys.J. C77 (2017) 77: 358.
"Results from a Calibration of XENON100 Using a Source of Dissolved Radon-220", E.Aprile et al., Phys. Rev. D 95, 072008 (2017)

UChicago Noble Liquids R&D

Our research, focused on the development and operation of the dark matter detectors, is complemented by R&D activities and auxiliary measurements, designed to test new ideas for next generation detectors as well as inform analyses of presently running dark matter searches. This is accomplished by means of small experimental setups operated in our lab or on neutron beam facilities like ISNAP at Notre Dame University and TUNL at Duke University.

"Model Independent Approach to the Single Photoelectron Calibration of Photomultiplier Tubes", R.Saldanha et al., Nucl.Instrum.Meth. A863 (2017) 35-46.
"Measurement of scintillation and ionization yield and scintillation pulse shape from nuclear recoils in liquid argon", H.Cao et al., Phys.Rev. D91 (2015) 092007
"Observation of the dependence on drift field of scintillation from nuclear recoils in liquid argon", T.Alexander et al., Phys.Rev. D88 (2013) 9, 092006

DARKSIDE-50 (our past...)

We contributed to the design, operation and data analysis of the DarkSide-50 detector since its inception. DarkSide-50 is a two-phase argon Time Projection Chamber (TPC). The detector, filled with special low-radioactivity argon extracted from ancient underground gas-reservoir, has operated at LNGS since October 2013, setting strong foundations for the potential exploitation of the technique in future, large multi-ton detectors.

Phys.Rev. D93 (2016) 081101
JINST 11 (2016) P03016
Phys.Lett. B743 (2015) 456-466
Astropart.Phys. 49 (2013) 44-51
JINST 5 (2010) P05003
Nucl.Instrum.Meth. A587 (2008) 46-51
Astropart.Phys. 28 (2008) 495-507
Nucl.Instrum.Meth. A574 (2007) 83-88

The Group

Luca Grandi, xenon1t / XENON1T PI

Prof. Luca Grandi

Assistant Professor
@ Kavli Institute for Cosmological Physics,
@ Enrico Fermi Institute,
@ UChicago Physics Department

Jacques Pienaar, xenon1t / XENON1T member

Dr. Jacques Pienaar

Research Associate @ KICP
(XENON1T, Noble Liquid R&D)

Christopher Tunnell, xenon1t / XENON1T member

Dr. Christopher Tunnell

Fellow @ KICP

Evan Shockley, xenon1t / XENON1T member

Evan Shockley

UChicago Graduate Student

(XENON1T, Noble Liquid R&D)

Nickolas Upole, xenon1t / XENON1T member

Nickolas Upole

UChicago Graduate Student

(XENON1T, Noble Liquid R&D)

Katrina Miller, xenon1t / XENON1T member

Katrina Miller

UChicago Graduate Student

(XENON1T, Noble Liquid R&D)

Michael Hank xenon1t / XENON1T member

Michael Hank

UChicago Graduate Student

(XENON1T, Noble Liquid R&D)

Mark Lewis, xenon1t / XENON1T member

Mark Lewis

UChicago Graduate Student

(XENON1T, Noble Liquid R&D)

Alumni and Former Group Members

Richard Saldanha, xenon1t / XENON1T PI

Richard Saldanha

Senior Scientist at PNNL

Yann Guardincerri

Yann Guardincerri

Roger Roglans

Roger Roglans

Graduate Student

UC Berkley

Thomas Wester

Thomas Wester

Research Assistant



September 7, 2017

The first year graduate student Michael Hank joined our group.

October 4, 2016

The first year graduate student Katrina Miller joined our group.

September 1, 2016

Dr. Christopher Tunnel, KICP Center Fellow, is starting today his adventure with our group.

July 21, 2016

Prof. Grandi presented at iDM2016, Identification of Dark Matter 2016, early commissioning data from XENON1T .

June 14, 2016

An REU student, Analis Lawrence from Florida International University, has joined us for the summer.

Feb 16, 2016

The group is in Los Angeles attending DM2016, Sources and Detection of Dark Matter and Dark Energy in the Universe .

Feb 15, 2016

Three new KICP Postdoctoral Fellows have been hired! Christopher will join our group starting from September!

Jan 28, 2016

We moved our entire laboratory to LL1 of William Eckhardt Research Center . This brand new, gigantic lab space is amazing!

Nov 11, 2015

A big inaguration has been organize to celebrate the beginning of XENON1T commissioning. Look for it among the UChicago News and the Kavli Foundation news .

Oct 23, 2015

The entire group is presently at Gran Sasso National Laboratory to participate to the preparation and assembly of the XENON1T Time Projection Chamber. Check some of the updated pictures in the XENON1T slideshow.

Sep 27, 2015

We are succesfully running in our lab our first xenon detector, XCD2.0. It is a single-phase liquid xenon detector that will be used to study the response of liquid xenon to low-energy nuclear recoils as function of fields and energy. See pictures uploaded in the Noble Liquid R&D section.

Sep 23, 2015

Together with KICP colleagues we will be hosting the LOWECAL workshop on Calibration of low-energy particle detectors

Sep 11, 2015

The entire group, together with KICP and Astronomy, will move to the new William Eckhardt Research Center.

Aug 26, 2015

Opened a Postdoctoral Research position to work with the group on XENON1T experiment

Aug 15, 2015

We received a 3 years award from NSF to support the proposal submitted to the Astroparticle Physics Division centered on dark matter search with xenon-based technology.

Apr 1, 2015

We officially joined the XENON1T collaboration

Dec 19, 2014

Together with Dr. Pordes at FNAL we will be funded for the second year under the UChicago-FNAL Collaborative Seed Grant Program. The proposed research is focused on the study of the response of noble liquids to low energy interactions. The outcomes are expected to inform analysis for running dark matter experiments.

Feb 26, 2014

Luca is presenting today at DM2014 (UCLA's 11th Symposium on Sources and Detection of Dark Matter and Dark Energy in the Universe) the FIRST results from DarkSide-50 detector run with Atmospheric Argon. The presentation, titled “DarkSide-50: performance and results from the first atmospheric argon run”, is available here

Aug 6, 2013

"SCENE: SCintillation Efficiency of Noble Elements" has been selected for University of Chicago-Fermilab seed grant funding. The grant will partially cover construction costs and operations of a series of small scale detectors used to study in great details scintillation and ionization yield of liquid argon and xenon.

Interested to join the group?

If you are a graduate or undergraduate student check with the PI if we have an open position.

+1 (773) 834-7659

Eckhardt Research Center
Office 485

If you are looking for a Postdoctoral position with the group you should consider applying to the openings linked below.

2018 KICP Fellowships (opens in summer 2017)

2018 McCormick/Fermi Fellowships (opens in summer 2017)