J. Feikes

Status of the IR and THz beamlines at the Metrology Light Source

The low-energy electron storage ring Metrology Light Source (MLS), a dedicated synchrotron radiation source, is in user operation since April 2008 at operating energies ranging from 105 MeV up to 630 MeV. It provides coherent THz radiation when it is operated in a low alpha mode with short electron bunches. At the MLS, two bending magnet beamlines optimized for the MIR and the THz spectral range are operational. We report the status of these two beamlines and present first results of the IR and THz measurements at the MLS.

IR and THz Beamlines at the Metrology Light Source of the PTB

The low‐energy electron storage ring Metrology Light Source (MLS), a dedicated synchrotron radiation source, is in user operation since April 2008. As a special option it provides coherent synchrotron radiation (CSR) in the THz range when it is operated in a low‐α mode with short electron bunches. At the MLS three beamlines dedicated to the use of IR and THz radiation were designed, built and commissioned.

Enhancing the sensitivity of nano-FTIR spectroscopy

Synchrotron radiation-based nano-FTIR spectroscopy utilizes the highly brilliant and ultra-broadband infrared (IR) radiation provided by electron storage rings for the infrared spectroscopic characterization of samples at the nanoscale. In order to exploit the full potential of this approach we investigated the influence of the properties of the radiation source, such as the electron bunch shape and spectral bandwidth of the emitted radiation, on near-field infrared spectra of silicon-carbide (SiC). The adapted configuration of the storage ring optics enables a modification of the transverse electron bunch profile allowing an increase of the measured near-field signal amplitude. Additionally, the decay of the signal amplitude due to the decreasing storage ring current is also eliminated. Further options for improving the sensitivity of nano-FTIR spectroscopy, which can also be applied to other broadband radiation sources, are the adaption of the spectral bandwidth to the wavelength range of interest or the use of polarization optics. The sensitivity enhancement emerging from these options is verified by comparing near-field spectra collected from crystalline SiC samples. The improvement in sensitivity by combining these approaches is demonstrated by acquiring nano-FTIR spectra from thin organic films, which show weak resonances in the IR-regime.

First measurements at the new dedicated THz beamline at the MLS

The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin (HZB). The MLS is designed and prepared for a low-α machine optics mode based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the far-IR and THz region. We present first results obtained from the new dedicated THz beamline at MLS.

Status of the THz activities at the MLS

We report the status of the MLS as a source of powerful, stable, and pulsed THz radiation. Additionally we show results from the commissioning of the experimental stations and first measurements in the THz spectral range.

Status of the Metrology Light Source

The Physikalisch‐Technische Bundesanstalt (PTB), the German national metrology institute, has set up the low‐energy electron storage ring Metrology Light Source (MLS) in close cooperation with the Helmholtz‐Zentrum Berlin (HZB, formerly BESSY). This new storage ring has been in regular user operation since April 2008 and is dedicated to synchrotron‐radiation‐based metrology and technological developments in the far‐IR/THz, IR, UV, VUV and EUV spectral range. The MLS has a double‐bend‐achromate lattice structure, injection is from a 105 MeV racetrack microtron. The electron energy can be ramped to any value from 105 MeV up to 630 MeV and the electron beam current covers the range from one stored electron (1 pA) up to 200 mA. The MLS is the first electron storage ring optimized for the generation of coherent synchrotron radiation, based on an electron bunch shortening mode. In this mode, MLS delivers coherent radiation in the far‐IR/THz spectral range with enhanced intensity as compared to the normal mode o...

First commissioning results in the IR/THz range at the electron storage ring Metrology Light Source

The Physikalisch-Technische Bundesanstalt (PTB) has set up a low-energy electron storage ring in Berlin-Adlershof in close cooperation with the BESSY GmbH. The Metrology Light Source (MLS) is the first machine designed and prepared for a special machine optics mode (low-alpha operation mode) based on an octupole correction scheme, for the production of short bunches and coherent synchrotron radiation (CSR) in the FIR/THz spectral range. In our contribution we present first commissioning results which clearly indicate that the MLS in combination with dedicated beamlines offers intense, stable, and well focussed THz radiation.

IR and THz radiation from the metrology light source of the PTB

The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has set up a low-energy electron storage ring in close cooperation with the BESSY GmbH in Berlin-Adlershof. The new storage ring, named Metrology Light Source (MLS), will be mainly dedicated to metrology and technological developments in the EUV, VUV, and IR spectral range. The design of three infrared beamlines will take advantage of the high brightness, the high flux, and the broadband behavior of the synchrotron radiation source. Additionally the MLS will be the first dedicated storage ring designed und prepared for the production of coherent synchrotron radiation (CSR) in the FIR and THz region.

THz based shape analysis of sub-ps electron bunches at BESSY

Short electron bunches in storage rings emit strong THz and sub-THz radiation if the length of the bunches is lower than the wavelength of the radiation. Two strong broad band THz sources have been established at the BESSY storage ring: 1. Coherent THz generation by compressed bunches at 500 MHz repetition rate gained by up to 10/sup 7/ in average power compared to incoherent sources. 2. Recently, ultrashort THz radiation emitted by the interaction of a femtosecond laser at a repetition rate of 1 kHz and the electron bunch in an undulator was detected. Experimental results on bunch length measurement using THz radiation are presented.