Lucid, the student cosmic-ray detector going into space

British high school students will send the Lucid, the Langton Ultimate Cosmic-ray Intensity Detector, cosmic-ray observatory to orbit in 2014. Adapting sensors from the Large Hadron Collider to detect intense photons, subatomic particles, and cosmic-ray particles, the student-designed experiment will mark the first time this technology has been used in open space and will produce science that nobody has seen before.

The Simon Langton Grammar School for Boys and the Simon Langton Girls’ Grammar School are middle and high schools in the United Kingdom that emphasize science and mathematics education. The students often participate in cutting-edge research. On a school visit to the site of the Large Hadron Collider in 2007, students met with the Cern scientists at the Medipix Collaborative. These scientists developed the supercollider’s particle detectors using an innovative technology that combines the capabilities of several instruments to measure particle energy, spectra, motion, and other properties in one package. 

After returning home, the students learned of a contest to send an experiment into space. UK-based small satellite pioneer Surrey Satellite Technology, challenged schools to propose experiments that could ride on an upcoming satellite. The guidelines warned students that their experiments could be damaged by cosmic rays, extremely energetic atomic nuclei accelerate to near the speed of light by supernova explosions. One of the students wondered whether the Medipix sensors could measure those cosmic rays. With help from scientists at Cern and the University of Houston the students designed an instrument and submitted their proposal for the Lucid experiment.

Lucid's design consists of five Medipix-based particle detectors mounted onto five sides of an open cube. When a particle passes through one of the sensors, it creates electrons and electron holes in the semiconductor layers. The electrons migrate to the CMOS sensor where the pixels capture the electric charges. The nature of the sensor and their arrangement gives Lucid unique capabilities. The amount of charge and the pattern they make in the sensor’s image lets the students identify the kind of particle and its energy. The data will let students distinguish between subatomic particles, energetic photons, and different kinds of cosmic-ray particles. They will calculate the particle’s energy, mass, and velocity. The timing and location of the particle’s passage through the different sensors, combined with telemetry from the satellite, will let the students estimate the particle’s origins. The students will analyze these measurements to study the South Atlantic Anomaly where Earth’s radiation belts dip down towards the surface, the solar energetic particles unleashed by space weather, and the cosmic-rays from supernovae throughout the Milky Way. Director of the Langton Star Centre, Dr. Becky Parker, told People & Science Magazine 

We are not sure exactly what we will see because we haven’t monitored cosmic rays at the level of individual particle energies before.  Isn’t that scary ? Yes, but the students say it’s great to be working on a project where the answers are not known. 

Lucid didn’t win the original contest.In a 2013 interview with Surrey Satellite’s blog the project’s then student project manager Matt Harrison explained that certifying the sensors for use in space would have exceeded the contest’s £100,000 budget. The team at Surrey Satellite were impressed with the design, however, and told the students they could still go into space if they raised the extra £60,000 needed to test the sensors. Lucid is now part of Surrey Satellite’s TechDemoSat-1 mission and will ride into orbit on a Russian Soyuz rocket in mid-2014. Simon Langton’s students will command the instrument and receive its data at the Langton Star Centre, the school’s STEM education center. They will share the data with schools who join the CERN@school program, a science education program organized by Simon Langton and Cern that places Medipix-based educational cosmic-ray detectors in high schools in the United Kingdom and Ireland.

 

The following paywalled journal articles provide more information about the sensor technology:

Application of the Medipix2 technology to space radiation dosimetry and hadron therapy beam monitoring” Pinsky, L

Timepix, a 65k programmable pixel readout chip for arrival time, energy and/or photon counting measurements” Llopart, X

Preparing for the first Medipix detectors in space” Pinsky, L