Home > United States of America > Connecticut > New London County > Groton > Smith Lake Cemetery > Frederic Harley Coensgen

Frederic Harley Coensgen

View larger map

1 / 1

❮ ❯

Frederic Harley Coensgen

Birth	:	10 Feb 1919 Great Falls, Cascade County, Montana, USA
Death	:	18 Nov 2007 Pleasanton, Alameda County, California, USA
Burial	:	Smith Lake Cemetery, Groton, New London County, USA
Coordinate	:	41.3488700, -72.0413300
Description	:	The following provided by Find a Grave contributor, Carol Lorang: Frederic H. Coensgen, a pioneer of magnetic fusion research, passed away November 18, 2007, age 88, following a short illness. During a forty-five year career at the Lawrence Livermore National Laboratory, Fred served as group leader and scientific inspiration for a succession of experiments employing the magnetic mirror principle to confine hot plasmas. In the mid 1970 s, he led the 2XIIB experiment that established the principles for stabilizing mirror-confined plasmas that inspired the invention of the tandem mirror at Livermore and Novosibirsk. Based on intense energetic neutral beams... Read More	The following provided by Find a Grave contributor, Carol Lorang: Frederic H. Coensgen, a pioneer of magnetic fusion research, passed away November 18, 2007, age 88, following a short illness. During a forty-five year career at the Lawrence Livermore National Laboratory, Fred served as group leader and scientific inspiration for a succession of experiments employing the magnetic mirror principle to confine hot plasmas. In the mid 1970 s, he led the 2XIIB experiment that established the principles for stabilizing mirror-confined plasmas that inspired the invention of the tandem mirror at Livermore and Novosibirsk. Based on intense energetic neutral beams to heat the plasma, the launching of 2XIIB in the early 1970's also led to the development at Lawrence Berkeley Laboratory of the 50 ampere neutral beam sources used to heat the DIIID tokamak at General Atomics and the TFTR at Princeton that achieved the world's first definitive demonstration of controlled fusion energy in the mid 1990's. Fred was a superb experimental physicist, greatly admired by colleagues for his leadership, dry humor and boldness in tackling new technologies needed for progress. Novel magnetic coils to achieve compressional heating of plasmas led to his first success, culminating in the achievement of temperatures of 3.6 KeV in the Toy Top II device, reported at an international conference at Salzburg in 1961. However, in that same experiment it was found that, following compression, the plasma was terminated by MHD modes of instability. Characteristically, Fred took this setback in stride, and moved on by modifying the shape of the magnetic fields to create a stable magnetic well, a new technique demonstrated by the Soviet plasma physicist Ioffe. By the early 1970 s, Fred again shifted course, to add neutral beam heating to replace compression. This led to the pace-setting 2XIIB experiment mentioned above. Again, technological innovation played a vital role. As the target plasma for injection, 2XIIB employed the washer stack plasma gun previously used as the starting point for compression. Again, there was first a setback with the occurrence of loss cone instabilities peculiar to mirror machines. Then news arrived from Ioffe in Russia that he had also stabilized these modes, using a principle developed theoretically by Post at Livermore, wherein a supply of cold ions partially fills the loss cone. Realizing at once that improving the vacuum removed cold ions, Fred set out to modify his plasma gun to provide a continuous stream of cold plasma to fill the loss cone during neutral beam injection. The stream-stabilized 2XIIB was an instant success, yielding in 1975 ion temperatures approaching 20 KeV. This was the highest temperature yet achieved in a controlled fusion experiment of any kind, preceding by three years a similar achievement in the PLT tokamak at Princeton, also using neutral beam injection. Even more impressive was the fact that the combination of a magnetic well to stabilize low frequency MHD instabilities and the plasma stream to stabilize loss cone instabilities led to plasmas stable in every sense. It was these results, together with an analysis of how the stream gun worked, that led Dimov in Novosibirsk and, independently, Fowler and Logan in Livermore, to propose the tandem mirror. By 1976, the remarkable stability of the 2XIIB plasma led to the achievement of plasma pressures in the magnetic well at the ultimate theoretical limit with plasma pressure comparable to magnetic pressure. This inspired a different idea, called the Field Reversed Mirror. In the 1970's and 1980 s, the U. S. magnetic fusion program exploited successes in 2XIIB to pursue Field Reversed Mirrors in a device called Beta II, and a succession of Tandem Mirror devices beginning with the highly successful TMX experiment at Livermore and the TARA at MIT; the TMX-U employing thermal barriers to enhance confinement; and the large MFTF-B tandem mirror completed in 1986. Coensgen was physics leader for all of those projects that were carried out at Livermore. Though mirror experiments on this scale are no longer pursued in the U. S., tandem mirror programs in Japan and Russia continue Coensgen's legacy. Fred Coensgen was born in Great Falls, Montana, February 10, 1919. He received his Ph.D. in physics from the University of California, Berkeley. He spent his entire career at the Lawrence Livermore National Laboratory, retiring in 1994. After retirement, he became an accomplished photographer, and enjoyed hiking and family. He is survived by his wife Charlene of Pleasanton, California, 6 children and 9 grandchildren.

frequently asked questions (FAQ):

Where is Frederic Harley Coensgen's memorial?
Frederic Harley Coensgen's memorial is located at: Smith Lake Cemetery, Groton, New London County, USA.
When did Frederic Harley Coensgen death?
Frederic Harley Coensgen death on 18 Nov 2007 in Pleasanton, Alameda County, California, USA
Where are the coordinates of the Frederic Harley Coensgen's memorial?
Latitude: 41.3488700
Longitude: -72.0413300

Family Members:

Parent

Helen A Jones Thompson

(1899 - 1972)

Spouse

Charlene Marie Thompson Coensgen

(1932 - 2009)

Flowers:

Nearby Cemetories:

1. Smith Lake Cemetery
Groton, New London County, USA
Coordinate: 41.3488700, -72.0413300

2. Avery-Morgan Burial Ground
Groton, New London County, USA
Coordinate: 41.3486000, -72.0419100

3. Binks Cemetery
Groton, New London County, USA
Coordinate: 41.3684044, -72.0264511

4. Old Town Hill Cemetery
Groton, New London County, USA
Coordinate: 41.3479805, -72.0110397

5. Benjamin Burrows Cemetery
Groton, New London County, USA
Coordinate: 41.3457489, -72.0111847

6. Potters Field
Groton, New London County, USA
Coordinate: 41.3417290, -72.0116500

7. Colonel Ledyard Cemetery
Groton, New London County, USA
Coordinate: 41.3502998, -72.0749969

8. Knowles Cemetery
Groton, New London County, USA
Coordinate: 41.3734741, -72.0499573

9. Fish Cemetery #02
Groton, New London County, USA
Coordinate: 41.3377419, -72.0066986

10. Chester Cemetery
Groton, New London County, USA
Coordinate: 41.3322906, -72.0105743

11. Wallsworth Cemetery
Mystic, New London County, USA
Coordinate: 41.3601050, -72.0056010

12. Bill Cemetery
Groton, New London County, USA
Coordinate: 41.3557180, -72.0794190

13. Palmer Cemetery
Groton, New London County, USA
Coordinate: 41.3340230, -72.0021090

14. Beth-El Cemetery
Groton, New London County, USA
Coordinate: 41.3711014, -72.0768967

15. Starr Burying Ground Cemetery
Groton, New London County, USA
Coordinate: 41.3731003, -72.0772018

16. Lower Mystic Cemetery
West Mystic, New London County, USA
Coordinate: 41.3539009, -71.9927979

17. Coast Guard Mascot Burial Site
Groton, New London County, USA
Coordinate: 41.3168030, -72.0666809

18. Baley Burial Ground
Groton, New London County, USA
Coordinate: 41.3132920, -72.0580280

19. Odd Fellows Cemetery
Groton, New London County, USA
Coordinate: 41.3734000, -72.0814000

20. Niles Family Cemetery
Groton, New London County, USA
Coordinate: 41.3784904, -72.0040817

21. Packer Cemetery #2
Groton, New London County, USA
Coordinate: 41.3457909, -71.9856415

22. Noank Valley Cemetery
Noank, New London County, USA
Coordinate: 41.3280487, -71.9910507

23. Packer Cemetery
West Mystic, New London County, USA
Coordinate: 41.3532982, -71.9832993

24. Wood Cemetery
Groton, New London County, USA
Coordinate: 41.3844920, -72.0757730