ISNAP Accelerators

FN 10MV Tandem Accelerator

Notre Dame’s FN Tandem Van de Graaff accelerator was installed into what is now the Nuclear Science Laboratory in 1968.  This machine, built by High Voltage Engineering, used an insulating belt to create the electrical potentials used to accelerate both positive ion and electron beams.  The electron beam capability was removed in the mid 1970’s and the charging system was upgraded to a pelletron built by National Electrostatics Corporation in 2000 when the belt was replaced with a chain of electrically isolated pellets (see NEC’s website for details at www.pelletron.com/charging.htm).   Negatively charged ions from the ion source are attracted to the positive voltage of the terminal (10 MV maximum).  Inside the terminal, these ions travel through a thin carbon foil which strips electrons from the beam particles and these positive ions are accelerated away from the terminal and towards a 90 degree dipole magnet which directs the desired beam towards the first of two target rooms.

Sta. ANA - 5U 5MV Single-Ended Accelerator

Notre Dame’s Sta. ANA (Stable ion Accelerator for Nuclear Astrophysics) or 5U accelerator, installed in 2012, is a single ended vertical pelletron built by National Electrostatics Corporation.  The system uses 4 charging chains to reach a maximum terminal voltage of 5MV.  An ECR source with 4 source gas bottles inside the terminal allows for a wide range of beams and charge states to be accelerated away from the terminal.  The beam is sent through a 90 degree dipole magnet towards a target room that includes a variety of different experimental stations.

St. Andre 3 MV Tandem Accelerator

Notre Dame’s St. Andre accelerator is a 3MV tandem pelletron accelerator built by National Electrostatics Corporation, and installed in the Nuclear Science Laboratory in 2017. This machine, the newest accelerator to the lab, uses two chains of insulating links (pellets) to create the electrical potential used to accelerate light ion beams (H and He). Negatively charged ions from the Alphatross ion source are attracted to the positive voltage of the terminal (3 MV maximum). Inside the terminal, these ions travel through a region of nitrogen gas which strips electrons from the beam particles and these positive ions are accelerated away from the terminal and towards a series of 45-degree dipole magnets which directs the beam towards the nuclear applications target room. This machine is used primarily to perform ion beam analyses (Particle Induced X-ray Emission, Particle Induced Gamma-ray Emission, Rutherford Backscattering, etc.) on a variety of targets.