Cosmic Ray Spark Chambers at the University of Cambridge

In every minute of our lives, we are bathed in a "cosmic rays" -- a rain of sub-atomic particles that pass through us, through our houses, through our bodies, and pass down deep into the earth. The sources of these cosmic rays are enormously energetic processes in distant parts of our galaxy, such as the death of stars. Ordinarily these rays are invisible --- but with a spark chamber they can be seen.

A spark-chamber is a device that makes cosmic rays visible. It does so by creating a string of sparks along the path of the cosmic ray.

In the 1930s, 40s and 50s, cosmic-ray spark-chambers were cutting edge science. These days, they are mainly used for educational purposes. Chambers installed in museums and science-centres can be used to show people that cosmic rays and sub-atomic particles are real, and exist in a tangible way. Visually, the sparks are stunning. The simplicity of the design (from the point of view of the viewer) adds to the effectiveness of the demonstration -- there are no "computers" or "screens" between the viewer and the cosmic ray. The the experience is tantamount to seeing the cosmic ray directly. This leads to a notable "wow factor" when the devices exhibited to the public. Typical comments are

"What? You mean I'm actually seeing the path of a real cosmic ray? It's in this room? It came from across the galaxy? They're going through me too? That's amazing!"

Who we are, and why we are building Spark Chambers:

We are researches from the High Energy Physics Group of the University of Cambridge. In our daily life we conduct scientific research in sub-atomic particle physics, some of which involves the Large Hadron Collider in CERN. We have a particle physics "ourtreach" programme, which seeks to connect our work on particle physics to the public. As part of this work, we have designed and built museum-quality spark-chambers. We exhibit these chambers in free events staged for members of the public whenever we can. These include science-week, lab open days, physics at work events, and other parts of the outreach programme of the Cavendish Laboratory. This page contains information concerning these "Spark Chambers for the East of England". Please enjoy.


If you have any question regarding the spark chambers we have made at the University of Cambridge, please email Dr Christopher Lester using the address:

putting "Spark-chamber" prominently in the subject line of your email. We are happy to receive contact/questions from museums, schools, and other educational bodies interested in creating spark chambers of their own.

News: Mark III(b) Cambridge Spark Chamber exhibited in The Royal Society, Summer Science Festival

July 2011

Every summer the The Royal Society (the oldest scientific academy in continuous existence) hosts a public festival to showcase UK science from all areas. The particle physics groups of the universities of Cambridge and Birmingham were selected to exhibit the Mark III(b) Cambridge spark chamber in the 2011 Summer Science Exhibition. Pictured above are Dr Lazzeroni of the University of Birmingham (grinning) showing a small boy and his mother their first cosmic ray. You may read some of the web-pages we set up to describe the way the spark-chamber works.

News: Mark III(a) Cambridge Spark Chamber sees its first Cosmic Rays

January 2011


Above is a picture of our Mark III(a) museum-quality chamber. (Click on it for a higher resolution photo.) We built it for an exhibition in a science centre in Poland, and it has just seen its first cosmic rays.

News: Mark II Cambridge Spark Chamber sees Cosmic Rays.

October 2009

News: Mark I (prototype) Chamber sees first cosmic rays!

12th August 2009.


A higher definition mp4 file may be downloaded here.

Further information.