5 papers
| title: | Short wavelength FELs using the SLAC linac |
| format: | journal article |
| year: | 1994 |
| 30 authors: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | We have studied the use of the SLAC linac to drive FELs at wavelengths down to a few angstroms. Lasing would be achieved in a single pass of a low emittance, high peak current, high energy eelctron beam through a long undulator by Self-Amplified-Spontaneous-Emissin (SASE). About 10(13) photons per pulse can be produced in 100 fs pulses at a 120 Hz rate, corresponding to brightness levels of about 10(22) average and 10(32) peak. Peak power levels are tens of GW. Electron energies of 10-20 GeV are required. Signifcant imporvement of FEL performance seems possible using harmonic generation techniques according to results from numerical simulations. |
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| title: | Short wavelength FELs using the SLAC linac |
| format: | conference procceeding |
| conference: | 8th National Conference on Synchrotron Radiation Instrumentation |
| year: | 1994 |
| 6 authors: | | | | | | |
| abstract: | Recent technological developments have opened the possibility to construct a device which we call a linac coherent light source (LCLS) (C. Pellegrini et al., Nucl. Instr. and Meth. A 331 (1993) 223; H. Winick et al., Proc. IEEE 1993 Particle Accelerator Conf., Washington, DC, May 1993; C. Pellegrini, Nucl. Instr. and Meth. A 341 (1994) 326; J. Seeman, SPIE Meet. on Electron Beam Sources of High Brightness Radiation, San Diego, CA, July 1993 [1?4]); it would be a fourth-generation light source, with brightness, coherence, and peak power far exceeding other sources. Operating on the principle of the free electron laser (FEL), the LCLS would extend the range of FEL operation to much shorter wavelength than the 240 nm that has so far been reached. We report the results of studies of the use of the SLAC linac to drive an LCLS at wavelengths from about 3 to 100 nm initially and possibly even shorter wavelengths in the future. Lasing would be achieved in a single pass of a low emittance, high peak current, high-energy electron beam through a long undulator. Most present FELs use an optical cavity to build up the intensity of the light to achieve lasing action in a low-gain oscillator configuration. By eliminating the optical cavity, which is difficult to make at short wavelengths, laser action can be extended to shorter wavelengths by self-amplified-spontaneous-emission (SASE), or by harmonic generation from a longer wavelength seed laser. Short wavelength, single pass lasers have been extensively studied at several laboratories and at recent workshops (M. Cornacchia and H. Winick (eds.), SLAC Report 92/02; I. Ben-Zvi and H. Winick (eds.), BNL report 49651 [5,6]). The required low-emittance electron beam can be achieved with recently-developed rf photocathode electron guns (B.E. Carlsten, Nucl. Instr. and Meth. A 285 (1989) 313; J. Rosenzweig and L. Serafini, Proc. IEEE 1993 Particle Accelerator Conf., Washington, DC, 1993 [7,8]). The peak current is increased by about an order of magnitude by compressing the bunch to a lenght of about 0.2 ps (rms). Techniques for beam transport, acceleration, and compression without emittance dilution have been developed at SLAC as part of the linear-collider project (J. Seeman, Advances of Accelerator Physics and Technologies, ed. H. Schopper (World Scientific, Singapore, 1993 [9]). The undulator length required to saturate the laser varies from about 15 m for a 100 nm FEL to about 60 m at 3 nm. Initial experiments, at wavelengths down to about 50 nm are planned using the 25-m long Paladin undulator now located at LLNL. In a proposed future LCLS R&D facility the short wavelength light pulses are distributed to multiple end stations using grazing-incidence mirrors. About 1014 photons per pulse can be produced at a 120 Hz rate, corresponding to average brightness levels of about 1021 photons/s/mm(2)/mrad(2) within 0.1% BW and peak brightness levels of about 1031 photons/s/mm(2)/mrad(2) within 0.1% BW. Peak power levels are several hundred megawatts to several gigawatts. Electron energies required range from about 500 MeV for the 100 nm FEL to about 7 GeV for 3 nm. |
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| title: | The SLAC soft X-ray high power FEL |
| format: | conference procceeding |
| conference: | 15th International Free Electron Laser Conference |
| year: | 1994 |
| 23 authors: | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | We discuss the design and performance of a 2 to 4 nm FEL operating in self-amplified spontaneous emission (SASE), using a photoinjector to produce the electron beam, and the SLAC linac to accelerate it to an energy of about 7 GeV. Longitudinal bunch compression is used to increase the peak current to 2.5 kA, while reducing the bunch length to about 40 mu m. The FEL field gain length is about 6 m, and the saturation length is about 60 m. The saturated output power is about 10 GW, corresponding to about 10/sup 14/ photons in a single pulse in a bandwidth of about 0.1%, with a pulse duration of 0.16 ps. Length compression, emittance control, phase stability, FEL design criteria, and parameter tolerances are discussed. (15 References). |
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| title: | A 2-4 nm Linac Coherent Light Source (LCLS) using the SLAC linac |
| format: | conference procceeding |
| conference: | 1993 Particle Accelerator Conference |
| year: | 1993 |
| 20 authors: | | | | | | | | | | | | | | | | | | | | |
| abstract: | We describe the use of the SLAC linac to drive a unique, powerful, short wavelength Linac Coherent Light Source (LCLS). Operating as an FEL, lasing would be achieved in a single pass of a high peak current electron beam through a long undulator by self-amplified spontaneous emission. The main components are a high-brightness rf photocathode electron gun; pulse compressors; about 1/5 of the SLAC linac; and a long undulator with a FODO quadrupole focusing system. Using electrons below 8 GeV, the system would operate at wavelengths down to about 3 nm, producing [right angle bracket]or=10 GW of peak power in sub-ps pulses. At a 120 Hz rate the average power is approximately=1 W. (6 References). |
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| title: | A 2 to 4 nm high power FEL on the SLAC linac |
| format: | conference procceeding |
| conference: | 14th International Free Electron Laser Conference |
| year: | 1993 |
| 13 authors: | | | | | | | | | | | | | |
| abstract: | The authors report the results of preliminary studies of a 2 to 4 nm SASE FEL, using a photoinjector to produce the electron beam, and the SLAC linac to accelerate it to an energy up to 10 GeV. Longitudinal bunch compression is used to increase ten fold the peak current to 2.5 kA, while reducing the bunch length to the subpicosecond range. The saturated output power is in the multi-gigawatt range, producing about 10/sup 14/ coherent photons within a bandwidth of about 0.2% r.m.s., in a pulse of several millijoules. At 120 Hz repetition rate the average power is about 1 W. The system is optimized for X-ray microscopy in the water window around 2 to 4 nm, and will permit imaging a biological sample in a single subpicosecond pulse. (21 References). |
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