| Paper |
Title |
Page |
| MOPCH016 |
Bunch Compression Monitor
|
86 |
| |
- H. Delsim-Hashemi, J. Rossbach, P. Schmüser
Uni HH, Hamburg
- O. Grimm, H. Schlarb, B. Schmidt
DESY, Hamburg
- A.F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
|
|
| |
An accelerated bunch of electrons radiates coherently at wavelengths longer than or comparable to the bunch length. The first generation Bunch Compression Monitor (BCM) that is installed at the VUV-FEL applies this principle by measuring the total radiation intensity. For a better control on the degree of the compression, the radiated intensity in different bandwidth can be used. Dependent on the changes in the structure of the bunch, its radiation spectrum changes correspondingly. A new generation BCM uses wavelength dependent diffracting devices and multi-channel sensors to measure the signal in different wavelength channels simultaneously. This paper describes the construction of the first prototypes and experimental results in different short wavelength bands measured at the linac of the VUV-FEL at DESY, Hamburg.
|
|
| TUPCH026 |
Single Shot Longitudinal Bunch Profile Measurements at FLASH using Electro-optic Techniques
|
1055 |
| |
- B. Steffen, E.-A. Knabbe, B. Schmidt
DESY, Hamburg
- G. Berden, A.F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
- W.A. Gillespie, P.J. Phillips
University of Dundee, Nethergate, Dundee, Scotland
- S.P. Jamison, A. MacLeod
UAD, Dundee
- P. Schmüser
Uni HH, Hamburg
|
|
| |
For the high-gain operation of a SASE FEL, extremly short electron bunches are essential to generate sufficiently high peak currents. At the superconducting linac of the VUV-FEL at DESY, we have installed an electro-optic experiment with temporal decoding and spectral decoding to probe the time structure of the electric field of single sub 200fs e-bunches. In this technique, the field-induced birefringence in an electro-optic crystal is encoded on a chirped ps laser pulse. The longitudinal electric field profile of the electron bunch is then obtained from the encoded optical pulse by a single-shot cross correlation with a 30 fs laser pulse using a second-harmonic crystal (temporal decoding) or by a single-shot measurement of its spectrum (spectral decoding). In the temporal decoding measurements an electro-optic signal of 230fs FWHM was observed, and is limited by the material properties of the particular electro-optic crystal used. Bunch profile and time jitter measurements were obtained simultaneously with VUV SASE operation.
|
|
| TUPCH027 |
Time Resolved Single-shot Measurements of Transition Radiation at the THz Beamline of FLASH using Electro-optic Spectral Decoding
|
1058 |
| |
- B. Steffen, E.-A. Knabbe, B. Schmidt
DESY, Hamburg
- G. Berden, A.F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
- W.A. Gillespie, P.J. Phillips
University of Dundee, Nethergate, Dundee, Scotland
- S.P. Jamison, A. MacLeod
UAD, Dundee
- P. Schmüser
Uni HH, Hamburg
|
|
| |
Single-shot electro-optic detection was used to measure the temporal profile of coherent transition radiation (CTR) pulses at the VUV-FEL at DESY. The CTR was generated from single bunches kicked to an off-axis screen, with the radiation transported through a 20m long transfer line imaging the CTR from a radiation screen to an experimental station outside the accelerator tunnel. Bipolar pulses with a FWHM less than 1ps have been measured and are consistent with simulations of the propagation of radiation through the transfer line.
|
|
| TUPCH042 |
The Optical System for a Smith-Purcell Experiment at 45MeV
|
1097 |
| |
- V. Blackmore, W.W.M. Allison, G. Doucas, C. Perry
OXFORDphysics, Oxford, Oxon
- P.G. Huggard
CCLRC/RAL, Chilton, Didcot, Oxon
- M.B. Johnston
University of Oxford, Clarendon Laboratory, Oxford
- B. Redlich, A.F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
|
|
| |
Smith-Purcell (SP) radiation has been used to investigate the longitudinal profile of a 45MeV, picosecond long bunched beam at the FELIX facility, FOM Institute. The three important optical elements that made this experiment possible were (i) high quality optical filters, (ii) nonimaging light concentrators, (iii) and a system to rapidly change between gratings.
|
|
| TUPCH043 |
Observations of the Longitudinal Electron Bunch Profile at 45MeV Using coherent Smith-Purcell radiation
|
1100 |
| |
- G. Doucas, V. Blackmore, B. Ottewell, C. Perry
OXFORDphysics, Oxford, Oxon
- P.G. Huggard
CCLRC/RAL, Chilton, Didcot, Oxon
- M.B. Johnston
University of Oxford, Clarendon Laboratory, Oxford
- M.F. Kimmitt
University of Essex, Physics Centre, Colchester
- B. Redlich, A.F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
|
|
| |
Coherent Smith-Purcell (SP) radiation has been used to determine the longitudinal profile of the electron bunch at the FELIX facility, FOM Institute. Far-infrared radiation was detected using a simple, compact arrangement of 11 pyroelectric detectors. Background radiation was suppressed through the use of high quality optical filters, and an efficient light collection system. The measured bunch profile was most closely in agreement with 90% of the particles contained within 5.5ps, with an approximately triangular temporal profile.
|
|