# Free electron laser dynamics with a variable wiggler

## Abstract

Dynamics of a free electron laser with a variable wiggler are analyzed, patterned after the work of Bonifacio, Pellegrini, and Narducci (BPN) for the constant wiggler configuration. The electron energy, phase, and the field amplitude are expressed in terms of dimensionless scaled variables, and their equations of motion are derived. The dynamics is controlled completely only two quantities, the Pierce parameter and the detuning. This development suggests that the wiggler field be subject to the constraint lambda/sub w/B/sub w/ = constant. These equations are then solved numerically for a linearly varying wiggler wavelength for the cases of laser initiation from noise and amplification of an injected signal. For laser initiation from noise, the linearly decreasing wiggler wavelength severely damps the output intensity. It also displays perfect agreement with the BPN results for the special case of constant wiggler. For an injected signal, significant amplification is seen for percentage decreases of lambda/sub w/ up to 17% with a maximum near 13%. There is chaotic behavior of the bunching parameter up to 17%. A distinct transition occurs between 17% and 18%, wherein the output intensity is no longer amplified and the chaotic characteristics disappear.

- Authors:

- Publication Date:

- Research Org.:
- Drexel Univ., Philadelphia, PA (USA)

- OSTI Identifier:
- 6363628

- Resource Type:
- Thesis/Dissertation

- Resource Relation:
- Other Information: Thesis (Ph. D)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 42 ENGINEERING; FREE ELECTRON LASERS; DYNAMICS; AMPLIFICATION; DAMPING; NOISE; WIGGLER MAGNETS; ELECTRICAL EQUIPMENT; ELECTROMAGNETS; EQUIPMENT; LASERS; MAGNETS; MECHANICS; 420300* - Engineering- Lasers- (-1989)

### Citation Formats

```
Hartzell, Jr, K R.
```*Free electron laser dynamics with a variable wiggler*. United States: N. p., 1986.
Web.

```
Hartzell, Jr, K R.
```*Free electron laser dynamics with a variable wiggler*. United States.

```
Hartzell, Jr, K R. 1986.
"Free electron laser dynamics with a variable wiggler". United States.
```

```
@article{osti_6363628,
```

title = {Free electron laser dynamics with a variable wiggler},

author = {Hartzell, Jr, K R},

abstractNote = {Dynamics of a free electron laser with a variable wiggler are analyzed, patterned after the work of Bonifacio, Pellegrini, and Narducci (BPN) for the constant wiggler configuration. The electron energy, phase, and the field amplitude are expressed in terms of dimensionless scaled variables, and their equations of motion are derived. The dynamics is controlled completely only two quantities, the Pierce parameter and the detuning. This development suggests that the wiggler field be subject to the constraint lambda/sub w/B/sub w/ = constant. These equations are then solved numerically for a linearly varying wiggler wavelength for the cases of laser initiation from noise and amplification of an injected signal. For laser initiation from noise, the linearly decreasing wiggler wavelength severely damps the output intensity. It also displays perfect agreement with the BPN results for the special case of constant wiggler. For an injected signal, significant amplification is seen for percentage decreases of lambda/sub w/ up to 17% with a maximum near 13%. There is chaotic behavior of the bunching parameter up to 17%. A distinct transition occurs between 17% and 18%, wherein the output intensity is no longer amplified and the chaotic characteristics disappear.},

doi = {},

url = {https://www.osti.gov/biblio/6363628},
journal = {},

number = ,

volume = ,

place = {United States},

year = {1986},

month = {1}

}