1. Beam Ion Profiles with the SSNPA Diagnostic Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U Niigata U Tsukuba U U Tokyo JAERI Ioffe Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching U Quebec Deyong Liu, W. W. Heidbrink University of California, Irvine, CA 92697 D. S. Darrow, A.L. Roquemore and S.S. Medley Princeton Plasma Physics Laboratory, Princeton, NJ 08543 NSTX 2005 Research Forum Supported by

2. Four SSNPA Sightlines provide simultaneous measurements of the fast-ion profile

3. Improved Noise Rejection using Fast Digitizer and Analysis Software Raw Data threshold 100KeV threshold Pulse peak that PHA programs found Pulse Height Analysis (PHA)  s) Shot 118186 0.300~0.302s pulse model assumed from true signal pulses Noise

4. Reasonable Signals Obtained on SSNPA Rtan=60cm SSNPA E//B NPA Rtan=60cm 46.3keV 89.6KeV 52.5keV 62.5keV 69.8keV 93.9KeV 81.4KeV Energy Spectrum EbEb E b /2 E b /3 ? Gas-filled torus shot 118186 A@90KeV In plasma shots (as shown in the left graph), similar temporal evolution has been obtained on SSNPA and E//B NPA. In gas-filled torus shots (as shown in the above graph), full energy (E b ) and half energy(E b /2) components are clearly seen in the energy spectrum. Energy resolution of ~10keV has been achieved.

5. Contaminants to the Spectra are Understood shot 117983 Experimental data Rtan=90cm Empirical estimation Pile-up contribution Neutron contribution Unphysical counts above the injection energy are sometimes observed. These are caused by neutron radiation and by pulse pile-up. Corrections to the spectra to remove these contaminants are under development.

6. Beam Ion Redistribution Observed on SSNPA Rtan=60cm Rtan=80cm Rtan=90cm Rtan=120cm 43~49 KeV 50~58 keV 66~75 KeV 83~ 91KeV 59~65 keV 76~82 KeV shot 117895

7. Beam Ions Move Outward in Radius Rtan=100cm Rtan=120cm Rtan=60cm Rtan=90cm 271ms 349ms Shot 117895

8. The SSNPA Diagnostic provides useful data on the fast-ion profile The noise of SSNPA has been decreased to 1/4 of that in 2004 and reasonable signals are obtained. Energy resolution of ~10 keV and temporal resolution of ~2 ms have been achieved. The redistribution and loss of beam ions during MHD activity have been observed. The system is ready for extensive studies of the effects of instabilities on the fast-ion profile.

9. Parameters and MHD Spectrum of Shot 117895 Strong MHD activity happened in the time period of 0.271~0.349s. 0.271s 0.349s