From: Hans Schneider
Sent: Monday, August 29, 2005 4:11 PM
To: Hans Schneider; Lawrence E. Dudek; Geoffrey J. Gettelfinger
Cc: William R. Blanchard; Alfred von Halle; Wayne T. Reiersen; Hutch
Neilson; Allen J. Patterson; Raymond C. Gernhardt; John Lawson; Gene
Baker; Bradley E. Nelson
Subject: RE: Coil Testing Progress

CORRECTION:

NCSX Coil currents were in fact nearly 600 amps and NOT 300 amps as indicated in my last e-mail.

Corrections to the Word and Excel documents to follow.

Sorry.

Hans

-----Original Message-----
From: Hans Schneider 
Sent: Monday, August 29, 2005 2:27 PM
To: Lawrence E. Dudek; Geoffrey J. Gettelfinger
Cc: William R. Blanchard; Alfred von Halle; Wayne T. Reiersen; Hutch Neilson; Allen J. Patterson; Raymond C. Gernhardt; John Lawson; Gene Baker; Bradley E. Nelson
Subject: RE: Coil Testing Progress

All:

Coil Voltage data from shots 118085 to 118107 was reviewed in detail. While there were some errors in the 'Record' and 'Playback' software (which have been corrected), all Raw Data was collected and stored properly.

The attached Word document and Excel Spreadsheet data are from Shot 118103. The other 4 shots with current are similar.

Brief Summary:

Coil Current approx. 300 Amps
Coil Resistance approx. 13 mOhms
Coil Voltage Peak approx. -74 volts
Voltage Rise time approx 1.5 mSec

Please let me know if there are specific data requests.

Hans 

-----Original Message-----
From: Lawrence E. Dudek 
Sent: Saturday, August 27, 2005 1:05 PM
To: Geoffrey J. Gettelfinger
Cc: William R. Blanchard; Alfred von Halle; Wayne T. Reiersen; Hutch Neilson; Allen J. Patterson; Raymond C. Gernhardt; John Lawson; Hans Schneider; Gene Baker; Bradley E. Nelson
Subject: Re: Coil Testing Progress

Geoff & TRC test team,
Congratulations! Sounds like a productive run.
Larry


On Aug 27, 2005, at 11:36 AM, Geoffrey J. Gettelfinger wrote:

> The twisted racetrack coil (TRC) was cooled down to operating
> temperature (<85K) and single phase LN2 flow was established with the
> pump circuit.
>
> A set of warm and cold insulation checks were made and good results  
> were
> obtained.
>
> A campaign of power testing commenced on Friday, 8/26 with some  
> success:
>
> 1)  The DC power supplies were connected to the TRC without difficulty
> and numerous 200 amp pulses were run for controls troubleshooting.
>
> 2)  The "pulse overtime" circuit was challenged resulting in both the
> trip being issued and the rectifiers responding appropriately.
>
> 3)  The current difference circuit operated correctly on an attempt to
> operate at increased levels.  The cause was traced to a faulty current
> transducer that could not be repaired in the available time.
>
> 4)  The resistance inference utility suggested a coil resistance of  
> 0.7
> milliohms during a pulse which strongly agreed with low-resistance
> ohmmeter measurements made prior to the run.
>
> 4)  Finally and importantly, the design of the protective circuitry  
> and
> its operation (planned and unplanned) has been shown to have no effect
> on NSTX activity.
>