High-Energy Heavy Ion Nuclear Microprobe

 

Microprobe Beam Line
The major components of a high–energy, heavy ion, focused microprobe were purchased from MARC in Australia and the beam line, pumping system and analysis chamber were constructed at UNT. The microprobe began operating in September 1999. The nuclear microprobe beam line shares the 3.0 MV tandem accelerator with the 5 other beam lines. Currently, the major research projects are focused on the applications of Ion Beam Induced Charge Collection (IBICC), Ion Beam Induced Luminescence (IBIL) and Single Event Upset (SEU) techniques, which require a low beam current and a high spatial resolution (~ few mm).

 

 A source of negative ions by cesium sputtering (SNICS) provides a wide variety of ion species (H, Li, B, C, Si, etc.). The second ion source is a NEC Alphatross  for helium ions.

 

Old Microprobe Target Chamber

 

Data Acquisition and Controls

The microbeam line hardware consists of objective and aperture slits, probe-forming lens packages with a computerized focusing control system, a computerized beam scan unit, and a target chamber. The magnetic probe-forming lens system is the Russian-Quadruplet configuration, which gives a relatively high demagnification factor (~ 60). The advantage of higher demagnification means a larger size of the objective slits without sacrificing the spatial resolution; therefore, a larger beam current can be obtained.

 

 

In 2003 the target chamber was upgraded. The addition of better positioned ports allow for easier data acquisition. A turbo pump is used for the initial evacuation and an ion pump mounted at 90o is used when acquiring data. Analysis techniques and research include RBS, micro-PIXE, IBIC, IBIL and SEU.

 

 

New Lens Mounts

The addition of the new lense mounts makes alignment much easier

 

New Vibration Isolation System

Also in 2003, a new vibration isolation system was placed on the microprobe allowing it to easily achieve 1 micron beams.

 

 

 

 

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