Professor Gaitskell leads a research team hunting for direct evidence of particle dark matter, one of physics' greatest unclaimed prizes. His group is working on an experiment that has a detector located in the underground laboratories in the Sanford Lab, South Dakota, (LUX Experiment). The LUX experiment which started running in 2013 is the world's most sensitive dark matter detector.

For further details of our research please see http://particleastro.brown.edu

A wealth of observations, dating back 70 years [1], show that the universe is composed of >96% invisible matter and energy [see 2, and refs. therein]. The nature of these missing components is one of the most fundamental questions in physics, and has attracted broad attention from the public. The leading candidate for the invisible "dark matter" is subatomic particles left over from the big bang known as Weakly Interacting Massive Particles (WIMPs). Such particles are also predicted by supersymmetry, a favored class of new particle models [3]. If WIMPs exist, they are also the dominant mass in our own Milky Way, and, though they only very rarely interact with conventional matter, should nonetheless be detectable by sufficiently sensitive detectors on Earth. The primary challenge in detecting them is reducing natural radioactivity. If no effort is made to reduce this background radioactivity, it would mask the dark matter signal by some 10 or more, orders of magnitude. The primary techniques for reducing this radioactive background are placing detectors in a suitable deep underground location, of which there are only a handful worldwide, and using a sophisticated shield against ambient radioactivity from the rock and cavern infrastructure.

Gaitskell's group is actively involved in the development and operation of detectors that are capable of detecting dark matter particle interactions. The current main focus is on a detector based around liquid xenon (LXe). When a particle interaction occurs in LXe both scintillation light and ionization (electron-ion) signals are created. These signals can be detected using arrays of photomultipliers (PMTs). The LUX experiment, which recently began operations at the Sanford Underground Laboratory, South Dakota, has a 1/3 tonne LXe target observed by some 120 PMTs.

The research group continues to work on alternative photodetection techniques to replace PMTs, in order to provide better quantum efficiency for the light detection, and lower intrinsic radioactivity.

Gaitskell has had extensive experience of dark matter deployment and operation at underground labs being a PI on the CDMS II (Soudan, MN), which he is now winding down his involvement on, the XENON1- (Gran Sasso, Italy) experiments, which is over, and the LUX Experiment. He has also constructed and operated a low background gamma screening facility (SOLO) at the Soudan Mine.

References

[1] F. Zwicky, Helv. Phys. Acta, 6 (1933), 110.

[2] R. J. Gaitskell, Ann. Rev. Nucl. Part. Sci. 54 (2004) 315.

[3] W. Freedman and M Turner, Rev. Mod. Phys. 75 (2003) 1433.; C. Munoz, Int. J. Mod. Phys. A19 (2004) 3093.; J. Feng, hep-ph/0405215 (2004).

[4] LUX Collaboration, 2013. (Phys. Rev. Lett. 112, 091303 – Published 4 March 2014, arXiv:1310.8214) First results from the LUX dark matter experiment at the Sanford Underground Research Facility.

(details on application)

D. Akerib et al,LUX Collaboration: First results from the LUX dark matter experiment at the Sanford Underground Research Facility, Phys. Rev. Lett. 112, 091303 / arXiv:1310.8214

D. C. Malling, S. Fiorucci, M. Pangilinan, J. J. Chapman, C. H. Faham, J. R. Verbus, R. J. Gaitskell, “Dark Matter Search Backgrounds from Primordial Radionuclide Chain Disequilibrium” , accepted by Astroparticle Physics, arXiv: 1305.5183

D. Akerib et al, (LUX Collaboration). “Technical Results from the Surface Run of the LUX Dark Matter Experiment” Astroparticle Physics (2013) 10.1016/j.astropartphys.2013.02.001, arXiv: 1210.4569

D. Akerib et al, (LUX Collaboration). “The LUX Dark Matter Experiment” Nucl. Instr. Meth. A 704 111 (2013) ; arXiv: 1211.3788

D. Akerib, et al, (LUX Collaboration). “The LUX prototype detector: heat exchanger development” arXiv:1207.3665, Nucl. Instr. Meth. A, January 24 (2013)

D. Akerib, et al, (LUX Collaboration/K. Kazkaz). “LUXSim: A Component-Centric Approach to Low-Background Simulations.” arXiv:1111.2074, Nucl. Instr. Meth. A 675 63 (2012)

J. Angle et al., (XENON10 Collaboration), “A search for light dark matter in XENON10 data”, Phys. Rev. Lett. 107:051301 (2011) arxiv:1104.3088.

D. Akerib et al, (LUX Collaboration/D. Malling). “An Ultra-Low Background PMT for Liquid Xenon Detectors”, arxiv:1205.2272, NIM A 703 1 (2012)

D. Akerib, et al, (LUX Collaboration/J. Chapman). “Data Acquisition and Readout System for the LUX Dark Matter Experiment.” NIM A668:1-8 (2012)

D.S. Akerib et al. (CDMS Collaboration), "Limits on spin-independent WIMP-nucleon interactions from the two-tower run of the Cryogenic Dark Matter Search", Phys. Rev. Lett. 96 (2006) 011302, astro-ph/0509259.

D.S. Akerib et al. (CDMS Collaboration), "Limits on spin-dependent WIMP-nucleon interactions from the Cryogenic Dark Matter Search", Phys. Rev. D73 (2006) 011102, astro-ph/0509269.

D. S. Akerib, et al. (CDMS Collaboration), "Exclusion Limits on the WIMP-Nucleon Cross-Section from the First Run of the Cryogenic Dark Matter Search in the Soudan Underground Lab", Phys. Rev. D72 (2005) 052009, astro-ph/0507190.

M. Attisha, L. De Viveiros, R. Gaitskell, J-P. Thompson, "Soudan Low Background Counting Facility (SOLO)", AIP Conf. Proc. 785, p75 (2005).

E. Aprile ,C. E. Dahl, L. DeViveiros, R. Gaitskell, K. L. Giboni, J. Kwong, P. Ma jewski, K. Ni, T. Shutt and M. Yamashita, "Simultaneous Measurement of Ionization and Scintillation from Nuclear Recoils in Liquid Xenon as Target for a Dark Matter Experiment", Phys. Rev. Lett., submitted Dec 2005. (astro-ph/0601552).

E. Aprile et al., "The XENON Dark Matter Search Experiment", Proc. of the 6th UCLA Symposium on Sources and Detection of Dark Matter, Santa Monica Feb 2004, astro-ph/0407575.

R.J.Gaitskell, "Direct Detection of Dark Matter'', Annu. Rev. Nucl. and Part. Sci. 54 (2004) 315-359.

G. Eigen, R.J. Gaitskell, G.D. Kribs and K.T. Matchev, Indirect Investigations of Supersymmetry, Report of the "Indirect Investigations of SUSY" subgroup of the P3 Physics Group at Snowmass 2001 (hep-ph/0112312)

R J Gaitskell, Toward One Tonne Direct WIMP Detectors: Have We Got What It Takes? , 3rd International Workshop on Identification of Dark Matter (World Scientific, submitted, to be published September 2001). (Preprint available at http://xxx.lanl.gov/abs/astro-ph/0106200.)

D. Tovey, R. Gaitskell, P. Gondolo, Y. Ramachers, and L. Roszkowski, A New Method for Presenting Model-Independent Spin-Dependent Cross-Section Limits from Dark Matter Searches, Phys. Lett. B 488 (2000) 17

2011 Elected Fellow of American Physical Society

2003- Outstanding Junior Investigator, Department of Energy, High Energy Physics

1995-00 Center Fellowship, Center for Particle Astrophysics, UC Berkeley, 301 LeConte Hall, Berkeley, CA 94720, USA

1995 Lindemann Fellowship, The Lindemann Trust Committee, Dartmouth House, 37 Charles Street, London W1X 8AB, UK (stipend not taken up)

1993-95 Fellowship by Examination, Magdalen College, Oxford, OX1 4AU, UK

1993-95 Post Doctoral Research Fellowship, PPARC (Particle Physics and Astronomy Research Council) Polaris House, North Star Avenue, Swindon, Wilts SN2 1SZ, UK

1993 D.Phil. in Physics, St John's College, Oxford University, UK

1989 Graduate Studentship, SERC (Science and Engineering Research Council), UK (address as PPARC above)

1989 Corporate Finance Evening Course Graduate, London Business School, London, UK

1987 Qualified Registered Representative, London Stock Exchange, London, UK

1985 BA Hons. Degree in Physics, St John's College, Oxford University, UK 2nd(1)

1981 Open Scholarship, St John's College, Oxford University, UK

1981 Scholarship, Worshipful Company of Scientific Instrument Makers, London, UK

Fellow of American Physical Society

In Spring 2014 PHYS1250 (Stellar Structure and the Interstellar Medium).Intermediate/advanced course for astrophysics/physics undergraduates.

In Fall 2013 Coordinating PHYS0030, 0050, 0070 undergraduate teaching experimental lab program

In Spring 2013 Developed new experiments for PHYS2010 (Graduate Introduction to Experimental Physics) – Bell’s Inequality/Aspect Experiment. Test of QM coherence. This is a new experiment being included in our future graduate teaching.

In Fall 2012 I taught PHYS1280 (Introductory Cosmology), 15 students in class. Advance intermediate class for astrophysics/physics undergraduates.

In Spring 2012 I conducted a group study for the development of iOS applications for physics outreach/teaching at Brown Physics Dept.

In Fall 2011 I was on teaching relief through a research award by Dept. of Energy.

In Spring 2011 I taught PHYS0060 (Electromagnetism and Fundamental Physics), 35 in class