How to see the invisible?

The Billotron

The Billotron is a device designed and built by LPC Caen to illustrate the methods with which physicists of the infinitely small (nuclear in particular) are able to study the elementary structures of matter, here the nucleus of the atom.


The logotron is based on the principle of the Rutherford experiment, carried out in 1911 by the English physicist Ernest Rutherford. It consists of sending alpha particles (helium nuclei) from a uranium source onto a thin gold leaf. Detectors were placed all around the sheet in order to measure the particles deflected at different angles. It is by analyzing the deflection of these alpha particles that Rutherford was able to reveal the structure of the atom, formed of an extremely compact core with a small center, which will prove to be the nucleus of the atom. This experiment thus marked the beginning of nuclear physics 100 years ago…

Expérience de Rutherford. Le Billotron.


The Billotron is in the form of a circular plate of 1m diameter on which is placed a molded shape representing the object to be probed (potential). This shape can be variable, in the form of a hollow (attractive potential) or a bump (repellent potential) for example. At the 2 ends are placed the launching ramp for the balls and the collector. The balls deflected by the central shape are collected on the periphery of the plate by a series of 15 collectors, covering the whole angular range from 0 to 360 degrees around the object analyzed.


Several actions of communication of Billotron are proposed by the laboratory (Fête de la science, Forum des métiers, Colleges, High Schools, visits and internships at the laboratory.


The first winner of the Schlumberger Museum Award is the Laboratory of Corpuscular Physics with the Billotron. Based on the principle of the Rutherford experiment (1911), the father of nuclear physics, the Billotron presents the research work by illustrating the approach of scientists to access the infinitely small and observe the invisible.

Schlumberger Foundation: one family, one museum, one award

The "Têtes chercheuses" competition is organized in partnership with Relais d'Sciences. Open to all scientific and/or technical teams in Basse-Normandie, this competition aims to encourage innovative approaches to scientific mediation. It awards the Schlumberger Museum Prize, endowed with 10,000 euros by the Schlumberger Museum Foundation, and allows the realization of a project illustrating a research problem and the initiation of a dialogue with the public. The winning project is presented each year during the Fête de la Science before being distributed regionally and nationally.

Prix Musée Schlumberger. Concours Têtes chercheuses. Billotron (2010), Muoscope (2015).

Schlumberger Museum Award. Researchers’ heads competition. Billotron (2010), Muoscope (2015).

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