Nuclear Physics Research and Education with GlueX

University Of Connecticut, Storrs CT

Investigators

Abstract

Researchers at the University of Connecticut are building key components for a new particle beam to be installed at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia. The beam consists of the same kind of particles that comprise ordinary light, called photons, except that their wavelength is ten billion times shorter than that of visible light. Such short wavelengths enable researchers to look into the interior of the nucleus and search for new kinds of nuclear particles that are believed to exist in the nuclear environment. The short-wavelength light beam is produced by passing a beam of electrons from a particle accelerator through a diamond crystal. If the diamond crystal is sufficiently perfect then the short-wavelength light it produces is polarized when it emerges from the crystal. The polarization gives experimenters enhanced selectivity in the search for new particles inside the nucleus. A team of physicists residing at Jefferson Lab and about a dozen universities, including both US and foreign partners, are responsible for the design and construction of both the photon beam and the experimental apparatus that uses it, and is known collectively as the GlueX Collaboration. In order to achieve the desired beam intensity and polarization for the GlueX experiment, the Connecticut group faces a challenge in fabricating and mounting diamonds with the required shape and quality. Taking advantage of recent advances in diamond crystal growth within the gem industry, and also the excellent diagnostic tools available at the Cornell CHESS X-ray source, the group seeks to produce ultra-thin diamond crystals of large area and mount them in such a way that they are stable when exposed to an intense electron beam from the accelerator. The group is also working together with partners to produce detectors to be used to measure the precise wavelength of each of the photons produced in the crystal, and to monitor the beam polarization during the experiment. All of this work is carried out by students at the University of Connecticut, under the supervision of the Principal Investigator. The team includes one graduate student and two or three undergraduate students who are active on the project both during the academic year, and more intensely, during the summer. One highlight of the group's schedule during the month of July is to welcome 2-4 gifted high school students from the UConn Mentor Connection program to work alongside the group leader and other team members for three weeks on aspects of the project adapted to their level of experience. These activities amplify the long-term impact of the nuclear physics research program at the University of Connecticut, both in terms of the enriched educational experiences that it provides to students across a broad range of levels, and in the cutting-edge basic science that it produces.