### Abstract

We investigate the quantum regime of a high-gain free-electron laser starting from noise. In the first part, we neglect the radiation propagation and we formulate a quantum linear theory of the N-particle free-electron laser Hamiltonian model, quantizing both the radiation field and the electron motion. Quantum effects such as frequency shift, line narrowing, quantum limitation for bunching and energy spread, and minimum uncertainty states are described. Using a second-quantization formalism, we demonstrate quantum entanglement between the recoiling electrons and the radiation field. In the second part, we describe the field classically but we include propagation effects (i.e. slippage) and we demonstrate the novel regime of quantum SASE with high temporal coherence and discrete spectrum. Furthermore, we describe "quantum purification'' of SASE: the classical chaotic spiking behavior disappears and the spectrum becomes a series of discrete very narrow lines which correspond to transitions between discrete momentum eigenstates ( which originate high temporal coherence).

Original language | English |
---|---|

Article number | 090701 |

Number of pages | 9 |

Journal | Physical Review Special Topics: Accelerators and Beams |

Volume | 9 |

Issue number | 9 |

DOIs | |

Publication status | Published - Sep 2006 |

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### Keywords

- free electron lasers
- noise
- electron motion

### Cite this

*Physical Review Special Topics: Accelerators and Beams*,

*9*(9), [090701]. https://doi.org/10.1103/PhysRevSTAB.9.090701

}

*Physical Review Special Topics: Accelerators and Beams*, vol. 9, no. 9, 090701. https://doi.org/10.1103/PhysRevSTAB.9.090701

**Quantum regime of free electron lasers starting from noise.** / Bonifacio, R.; Piovella, N.; Robb, G.R.M.; Schiavi, A.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Quantum regime of free electron lasers starting from noise

AU - Bonifacio, R.

AU - Piovella, N.

AU - Robb, G.R.M.

AU - Schiavi, A.

PY - 2006/9

Y1 - 2006/9

N2 - We investigate the quantum regime of a high-gain free-electron laser starting from noise. In the first part, we neglect the radiation propagation and we formulate a quantum linear theory of the N-particle free-electron laser Hamiltonian model, quantizing both the radiation field and the electron motion. Quantum effects such as frequency shift, line narrowing, quantum limitation for bunching and energy spread, and minimum uncertainty states are described. Using a second-quantization formalism, we demonstrate quantum entanglement between the recoiling electrons and the radiation field. In the second part, we describe the field classically but we include propagation effects (i.e. slippage) and we demonstrate the novel regime of quantum SASE with high temporal coherence and discrete spectrum. Furthermore, we describe "quantum purification'' of SASE: the classical chaotic spiking behavior disappears and the spectrum becomes a series of discrete very narrow lines which correspond to transitions between discrete momentum eigenstates ( which originate high temporal coherence).

AB - We investigate the quantum regime of a high-gain free-electron laser starting from noise. In the first part, we neglect the radiation propagation and we formulate a quantum linear theory of the N-particle free-electron laser Hamiltonian model, quantizing both the radiation field and the electron motion. Quantum effects such as frequency shift, line narrowing, quantum limitation for bunching and energy spread, and minimum uncertainty states are described. Using a second-quantization formalism, we demonstrate quantum entanglement between the recoiling electrons and the radiation field. In the second part, we describe the field classically but we include propagation effects (i.e. slippage) and we demonstrate the novel regime of quantum SASE with high temporal coherence and discrete spectrum. Furthermore, we describe "quantum purification'' of SASE: the classical chaotic spiking behavior disappears and the spectrum becomes a series of discrete very narrow lines which correspond to transitions between discrete momentum eigenstates ( which originate high temporal coherence).

KW - free electron lasers

KW - noise

KW - electron motion

U2 - 10.1103/PhysRevSTAB.9.090701

DO - 10.1103/PhysRevSTAB.9.090701

M3 - Article

VL - 9

JO - Physical Review Special Topics: Accelerators and Beams

JF - Physical Review Special Topics: Accelerators and Beams

SN - 1098-4402

IS - 9

M1 - 090701

ER -