Author Archives: Rafael Lang

The neutron background of the XENON100 dark matter search experiment

In order to search for dark matter, it is imperative that background signals in particular from neutrons are well under control. We describe the successful techniques and leading results from our efforts in a dedicated publications:

E. Aprile et al. (XENON100), The neutron background of the XENON100 dark matter search experiment, arXiv:1306.2303. The paper is also published in Journal of Physics G 40 (2013), 115201.

Response of the XENON100 Dark Matter Detector to Nuclear Recoils

Dark matter is expected to induce nuclear recoils in our detector. We have demonstrated that we have an excellent matching of our expectation and the measured response of the XENON100 detector to such nuclear recoils, with an agreement at the percent level:

E. Aprile et al. (XENON100), Response of the XENON100 Dark Matter Detector to Nuclear Recoils, arXiv:1304.1427. The paper is also published in Physical Review D88 (2013), 012006.

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data

Using data from the year-long search for dark matter with XENON100, we could derive world-leading limits on spin-dependent interactions of dark matter:

E. Aprile et al. (XENON100), Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data, arXiv:1301.6620. The paper is also published in Physical Review Letters 111 (2013), 021301.

The distributed Slow Control System of the XENON100 Experiment

In order to operate the XENON100 detector in a stable way over the course of years, we require a thorough control of various operation parameters. The corresponding system is described in a publication:

J. M. Cardoso et al. (XENON100), The distributed Slow Control System of the XENON100 Experiment, arXiv:1211.0836. The paper is also published in Journal of Instrumentation 7 (2012), T12001.

Measurement of the Scintillation Yield of Low-Energy Electrons in Liquid Xenon

Our detector is so sensitive that we can detect individual photons and individual electrons. A description of the response of the detector to the latter is published here:

E. Aprile et al. (XENON100), Measurement of the Scintillation Yield of Low-Energy Electrons in Liquid Xenon, arXiv:1209.3658. The paper is also published in Physical Review D86 (2012), 112004.

Analysis of the XENON100 Dark Matter Search Data

Analyzing terabytes of background and calibration data in the search for just a couple of dark matter-induced events is a difficult process that we published in a dedicated paper:

E. Aprile et al. (XENON100), Analysis of the XENON100 Dark Matter Search Data, arXiv:1207.3458. The paper is also published in Astroparticle Physics 54 (2014), 11–24.

Implications on Inelastic Dark Matter from 100 Live Days of XENON100 Data

Given the extreme sensitivity of the XENON100 detector, we could rule out the most common scenarios that are envisioned in the so-called inelastic dark matter scenario:

E. Aprile et al. (XENON100), Implications on Inelastic Dark Matter from 100 Live Days of XENON100 Data, arXiv:1104.3121. The paper is also published in Physical Review D84 (2011), 061101.

Construction Started

The XENON1T experiment has been approved by the INFN executive committee to be built in Hall B of the underground laboratory Laboratori Nazionali del Gran Sasso (LNGS) near Assergi, Italy. The experiment is designed to perform a search for Dark Matter with a sensitivity that is more than two orders of magnitude better than the current best sensitivities in the field.

XENON at Gran Sasso

Drawing of the XENON experiment at the Gran Sasso underground laboratory. Left the water shielding with the cryostat, on the right the service building with the electronics and xenon handling systems.

XENON1T will contain more than 3000kg of liquid xenon that are instrumented as a two-phase (liquid/gas) time projection chamber. The cryostat is housed in a water tank ten meters high and ten meters in diameter, shown on the left in the picture. This water tank shields the experiment from ambient radioactivity. A three-story service building, shown on the right in the picture, houses the systems required for handling, cooling and purification of the xenon as well as electronics and computing required for data taking. First filling with liquid xenon is expected in 2014.