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A mid-infrared oscillator FEL has been commissioned at the Fritz-Haber-Institut. The accelerator consists of a thermionic gridded gun, a subharmonic buncher and two S-band standing-wave copper structures [1,2]. It provides a final electron energy adjustable from 15 to 50 MeV, low longitudinal (

A method has been developed to differentiate between non-muscle tissues such as liver, kidney and heart and that of muscle in meat samples using tissue specific DNA detection. Only muscle tissue is considered meat from the point of view of labelling (Food Labelling [Amendment] (England) Regulations 2003) and Quantitative Ingredient Declaration (QUID), and also certain parts of the carcass are prohibited to be used in raw meat products (Meat Products [England] Regulations 2003). Included in the prohibited offal are brain and spinal cord. The described methodology has therefore been developed primarily to enforce labelling rules but also to contribute to the enforcement of BSE legislation on the detection of Central Nervous System (CNS) tissue. The latter requires the removal of Specified Risk Material (SRM), such as bovine and ovine brain and spinal cord, from the food chain. Current methodologies for detection of CNS tissue include histological examination, analysis of cholesterol content and immunodetection. These can potentially be time consuming, less applicable to processed samples and may not be readily adapted to high throughput sample analysis. The objective of this work was therefore to develop a DNAbased detection assay that exploits the sensitivity and specificity of PCR and is potentially applicable to more highly processed food samples. For neuronal tissue, the DNA target selected was the promoter for Glial Fibrillary Acidic Protein (GFAP), a gene whose expression is restricted to astroglial cells within CNS tissue. The promoter fragments from both cattle and sheep have been isolated and key differences in the methylation patterns of certain CpG dinucleotides in the sequences from bovine and sheep brain and spinal cord and the corresponding skeletal muscle identified. These have been used to design a PCR assay exploiting Methylation Specific PCR (MSP) to specifically amplify the neuronal tissue derived sequence and therefore identify the presence of CNS tissue in an assay sample.

A mid-infrared oscillator FEL has been commissioned at the Fritz-Haber-Institut. The accelerator consists of a thermionic gridded gun, a subharmonic buncher and two S-band standing-wave copper structures. It provides a final electron energy adjustable from 15 to 50 MeV, low longitudinal (

An electron accelerator and beamline for an IR and THz FEL with a design wavelength range from 4 to 500 μm has been commissioned by Advanced Energy Systems at the Fritz-Haber-Institut (FHI) [1] in Berlin, Germany, for applications in molecular and cluster spectroscopy as well as surface science. The linac comprises two S-band standing-wave copper structures and was designed to meet challenging specifications, including a final energy adjustable in the range of 15 to 50 MeV, low longitudinal emittance (< 50 keV-psec) and transverse emittance (< 20 π mm-mrad), at more than 200 pC bunch charge with a micro pulse repetition rate of 1 GHz. First lasing was achieved February 2012.

A mid-infrared oscillator FEL with a design wavelength range from 4 to 50 μm has been commissioned at the Fritz-Haber-Institut in Berlin, Germany, for applications in molecular and cluster spectroscopy as well as surface science. The accelerator consists of a thermionic gridded electron gun, a subharmonic buncher and two S-band standing-wave copper structures. The device was designed to meet challenging specifications, including a final energy adjustable in the range of 15 to 50 MeV, low longitudinal emittance (< 50 keV-psec) and transverse emittance (< 20 Pi mm-mrad), at more than 200 pC bunch charge with a micro pulse repetition rate of 1 GHz and a macro pulse length of up to 15 μs. Two isochronous achromatic 180 degree bends deliver the beam to the undulators, only one of which is presently installed, and to the beam dumps. Calculations of the FEL gain and IR-cavity losses predict that lasing will be possible in the wavelength range from less than 4 to more than 50 μm. First lasing was achieved at a wavelength of 16 μm in 2012*. We will describe the FEL system design and performance, provide examples of lasing, and touch on the first anticipated user experiments. *W. Schoellkopf et al., MOOB01, Proc. FEL 2012

An IR and THz FEL with a design wavelength range from 4 to 500 µm has been commissioned at the Fritz-Haber-Institut (FHI) in Berlin, Germany, for applications in, i.a., molecular and cluster spectroscopy as well as surface science. The linac comprises two S-band standingwave copper structures. The first one operates at near fixed field to accelerate the electrons to 20 MeV, while the second one is designed to accelerate (or decelerate) to any final energy between 15 and 50 MeV. A key aspect of the system is low longitudinal emittance, < 50 keVpsec, at more than 200 pC bunch charge with a max. micro pulse rep. rate of 1 GHz. The up to 15 µs long macro pulses come at a rate of up to 20 Hz. The electrons are steered through either one of two FELs. A single-plane-focusing, 40 mm period hybrid magnet undulator combined with a 5.4 m long cavity has been commissioned for the mid-IR (< 50 µm). In addition, a two-plane- focusing undulator in combination with a 7.2 m long cavity with a 1-d waveguide for the optical mode is planned for the far-IR. In February 2012 we observed 'first lasing' at 28 MeV and a wavelength of 18 µm. We will present first results characterizing the system.

An IR and THz free-electron laser for applications in, i.a., molecular and cluster spectroscopy as well as surface science has been installed at the Fritz-Haber-Institut in Berlin. Commissioning has started at the end of July 2011. On February 14th ‘first lasing’ was observed at a wavelength of about 18 µm. The normal-conducting electron linac together with a gun-to-dump electron beam line has been designed, fabricated, and installed by Advanced Energy Systems, Inc. It comprises two S-band (2.99 GHz) standing-wave copper structures. The first one is designed to accelerate the electron bunches to a fixed energy of 20 MeV, while the second one shall accelerate or decelerate the electrons to any final energy between 15 and 50 MeV. Electron bunches of up to 300 pC charge are accelerated at a maximum rate of 1 GHz. A chicane between the two structures allows for variable bunch-compression down to 1 ps. Further, the design length of the electron macro-pulses is as long as 15 µs with a maximum repetition rate of 20 Hz. The electrons will, eventually, be steered through either one of two oscillator FELs, So far, the first FEL has been installed. It includes a 2-m-long planar hybrid-magnet undulator made by STI Optronics, Inc. with a period of 40 mm, which is enclosed within a 5.4 m long IR cavity. At a minimum gap of 16.5 mm a maximum undulator parameter of more than 1.6 is reached. As a result, it is expected that MIR radiation in the range from 4 µm up to almost 50 µm can be produced with this system. Hole-outcoupling is used to extract a beam from the IR cavity. The cavity length will be stabilized using the feedback signal from a HeNe-laser interferometer. The design of the FIR FEL, so far, has been outlined. It shall employ a 7.2 m long cavity containing a full-length 1-dimensional waveguide and a more than 4 m long undulator with a period of 11 cm. The design wavelength range covers the FIR from about 30 µm all the way to the THz regime up to about 500 µm. We will present the status of commissioning and design of the MIR and FIR FEL, respectively.

The free electron laser (FEL) at the Fritz Haber Institute (FHI) in Berlin is designed to deliver radiation from 4 to 400 microns. A single-plane-focusing undulator combined with a 5.4 m long optical cavity is used for the generation of mid-infrared (MIR) radiation up to 50 microns. A two-plane-focusing undulator, in combination with a 7.2 m long cavity with a 1-D waveguide for the optical mode, is planned for the far-infrared (FIR). Beam was delivered to the MIR beam dump in October 2011 and first light at 18 microns was achieved on Valentine’s Day, 2012. We describe progress to date and plans to complete the commissioning of the MIR beamline and the installation of the FIR beamline.

The THz Free-Electron Laser (FEL) at the Fritz Haber Institute (FHI) of the Max Planck Society in Berlin is designed to deliver radiation from 3 to 300 microns using a single-plane-focusing mid-IR undulator and a two-plane-focusing far-IR undulator that acts as a waveguide for the optical mode. A key aspect of the accelerator performance is the low longitudinal emittance, < 50 keV-psec, that is specified to be delivered at 200 pC bunch charge and 50 MeV from a gridded thermionic electron source. We utilize twin accelerating structures separated by a chicane to deliver the required performance over the < 20 - 50 MeV energy range. The first structure operates at near fixed field while the second structure controls the output energy, which, under some conditions, requires running in a decelerating mode. "First Light" is targeted for the centennial of the sponsor in October 2011 and we will describe progress in the commissioning of this device to achieve this goal. Specifically, the measured performance of the accelerated electron beam will be compared to design simulations and the observed matching of the beam to the mid-IR wiggler will be described.

The THz FEL at the Fritz Haber Institute (FHI) in Berlin is designed to deliver radiation from 4 to 400 microns. A single-plane-focusing undulator combined with a 5.4 m long cavity is used is the mid-IR (< 50 micron), while a two-plane-focusing undulator in combination with a 7.2 m long cavity with a 1-d waveguide for the optical mode is used for the far-IR. A key aspect of the accelerator performance is low longitudinal emittance, < 50 keV-psec, at 200 pC bunch charge and 50 MeV from a gridded thermionic electron source. We utilize twin accelerating structures separated by a chicane to deliver the required performance over the < 20 - 50 MeV energy range. The first structure operates at near fixed field while the second structure controls the output energy, which, under some conditions, requires running in a decelerating mode. "First Light" is targeted for the centennial of the FHI in October 2011 and we will describe progress in the commissioning of this device. Specifically, the measured performance of the accelerated electron beam will be compared to design simulations and the observed matching of the beam to the mid-IR wiggler will be described.

SPIRE, the Spectral and Photometric Imaging REceiver, is the Herschel Space Observatory's submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier-transform spectrometer (FTS) covering 194–671 μm (447-1550 GHz). In this paper we describe the initial approach taken to the absolute calibration of the SPIRE instrument using a combination of the emission from the Herschel telescope itself and the modelled continuum emission from solar system objects and other astronomical targets. We present the photometric, spectroscopic and spatial accuracy that is obtainable in data processed through the “standard” pipelines. The overall photometric accuracy at this stage of the mission is estimated as 15% for the photometer and between 15 and 50% for the spectrometer. However, there remain issues with the photometric accuracy of the spectra of low flux sources in the longest wavelength part of the SPIRE spectrometer band. The spectrometer wavelength accuracy is determined to be better than 1/10th of the line FWHM. The astrometric accuracy in SPIRE maps is found to be 2 arcsec when the latest calibration data are used. The photometric calibration of the SPIRE instrument is currently determined by a combination of uncertainties in the model spectra of the astronomical standards and the data processing methods employed for map and spectrum calibration. Improvements in processing techniques and a better understanding of the instrument performance will lead to the final calibration accuracy of SPIRE being determined only by uncertainties in the models of astronomical standards.

The Fritz Haber Institute of the Max Planck Society in Berlin, Germany will celebrate its Centennial in 2011. Coincident with this event, they will christen a THz Free Electron Laser (FEL) that will operate from 3 to 300 microns. A linac with a gridded thermionic gun is required to operate from 15 to 50 MeV at 200 pC while delivering a transverse rms emittance of 20 mm-mrad in a 1 psec rms, 50 keV rms energy spread bunch at the wigglers. Mid-IR and far-IR wigglers enable this electron beam to deliver the required radiation spectrum. In addition to the longitudinal emittance, a key design requirement is the minimization of the micropulse and macropulse jitter to ensure radiation wavelength stability and timing consistency for pump probe experiments. We present the completed physics and engineering design that delivers the required performance for this device. Shipment is scheduled for the end of the calendar year and the status of fabrication will be summarized.