Erik Wallén

Description of the new I1011 beamline for magnetic measurements using synchrotron radiation at MAX-lab

We report on the characterization of the new I1011 beamline at the MAX-II storage ring, in the MAX-lab synchrotron radiation laboratory and give examples of first results. This beamline is using an Elliptically Polarizing Undulator source, producing soft x-rays of a variable polarization state. It delivers high flux and high brightness circularly polarized x-rays in the energy range 0.2 to 1.7 keV, covering the L-edges of the late 3d elements. The new beamline will operate with an octupole magnet endstation. It is specially engineered to solve the problem of the limited optical access typically associated with magnetic fields and synchrotron radiation endstations. Eight water-cooled magnets allow the application of the magnetic field of up to 1 T in any direction. X-ray absorption spectroscopy, X-ray resonant reflectivity and the corresponding magnetic variants, i.e., XMCD, XMLD and XRMS experiments are possible also under an applied magnetic field. The high flux allows working with dilute magnetic systems such as ultra-thin films and nano structures.

Aperture and lifetime measurements with moveable scrapers at MAX II

A set of measurement with moveable aperture restrictions, also called scrapers, has been carried out at MAX II (Nucl. Instr. and Meth. A 343 (1994) 644), the 1.5GeV electron storage ring at MAX-lab, Lund, Sweden. The measurements with scrapers in MAX 11 have shown to give a number of useful results, such as the vertical and horizontal acceptance, which are 7.4 x 10(-6) and 9.6 x 10-6 m, respectively, the lifetime limitations due to scattering on residual gas in the vacuum system, the Touschek effect and the quantum effect. The vertical acceptance of MAX 11 corresponds to a total vertical aperture of 10.04 mm and a total horizontal aperture of 22.4 mm at the position of the scraper, i.e. in the straight sections. The lifetime in MAX II at the measurement with 180mA of stored beam at full energy, 1.5GeV, was 23.8h. The 23.8h of lifetime is the total lifetime which is determined by the following lifetime limiting effects: Touschek effect 37 h, quantum effect >>100 h, elastic scattering on the residual gas 134 h, and inelastic scattering on the residual gas 132 h. It has shown possible to inject into and ramp the MAX II storage ring with a total vertical aperture in the straight sections as small as 9.34 mm. The measurements have shown that it is possible to install an insertion device in MAX II with a 10mm aperture without decreasing the beam lifetime, provided that the insertion devices do not deteriorate the vacuum situation. The gas mixture of the residual gas in the MAX II storage ring at operation has been measured and the absolute gas pressure is given by the results from the scraper measurements. In MAX II, as in most accelerators, the residual gas is dominated by hydrogen. The residual gas pressure in MAX II with 180 mA of stored beam at 1.5 GeV was 5.24 x 10(-9) Torr and it consists of 96.5% H-2, 1.1% H2O, 1.8% CO, and 0.6% CO2

The SPECIES beamline at the MAX IV Laboratory: A facility for soft X-ray RIXS and APXPS

SPECIES, the soft X-ray beamline for resonant inelastic scattering and ambient-pressure photoelectron spectroscopy at MAX IV, is described.

Commissioning of a 6.4T superconducting wavelength shifter at MAX-lab

The 6.4 T wavelength shifter at MAX-lab is a three pole superconducting planar wiggler with a warm bore, i.e. the vacuum tube passing through the wavelength shifter is at ambient temperature. The wavelength shifter, including surrounding systems such as power supply and He liquifier, has been assembled, tested, and commissioned at MAX-lab. The wavelength shifter has been installed into the 1.5 GeV MAX II electron storage ring. A field of 6.4 T in the central pole has been obtained and a consumption of 4.3 1/h of liquid helium has been measured under nominal working conditions. The influence on the stored electron beam in the MAX II ring has been measured and the measurements have shown that the wavelength shifter will not degrade the performance of MAX II. The wavelength shifter is however not in use at present and it has been taken out of the MAX II storage ring. (Less)

The MAX IV Facility

The MAX IV facility is a planned successor of the existing MAX facility. The planned facility is described below. It consists of two new synchrotron storage rings operated at different electron energies to cover a broad spectral region and one linac injector. The linac injector is also meant to be operated as a FEL electron source. The two rings have similar low emittance lattices and are placed on top of each other to save space. A third UV light source, MAX III, is planned to be transferred to the new facility.

The max-IV design: Pushing the envelope

The proposed MAX IV facility is meant as a successor to the existing MAX-lab. The accelerator part will consist of three storage rings, two new ones operated at 3 and 1.5 GeV respectively and the existing 700 MeV MAX III ring. The two new rings have identical lattices and are placed on top of each other. Both these rings have a very small emittance, 0.86 and 0.4 nm rad respectively, and offer synchrotron radiation of very high mean brilliance. As an injector, a 3 GeV linear accelerator is planned. The design philosophy and the special technical solutions called for are presented in this paper.

BioMAX: The Future Macromolecular Crystallography Beamline at MAX IV

This paper describes the preliminary design of the BioMAX beamline at the 3 GeV ring of the MAX IV facility, focusing on the optics and x-ray beam performance. The MAX IV facility will include two storage rings with 1.5 GeV and 3.0 GeV electron energy and a linac serving both as injector for the two rings and feeding a short pulse facility. BioMAX is one of the first seven beamlines funded at the MAX IV facility. It is a multipurpose high-throughput beamline for macromolecular crystallography. The beamline aims to be robust and simple to operate with a beam benefiting from the properties of the MAX IV 3 GeV ring. However it does not aim at the smallest beam or crystal sizes since it is foreseen that it will be complemented with a microfocus beamline aiming at a beam size of 1 mu m. The beamline experiment setup will be highly automated, both in terms of sample handling hardware and data analysis, including feedback to the data collection. The BioMAX beamline is planned to be in operation in 2016. (Less)

COLDDIAG: A Cold Vacuum Chamber for Diagnostics

One of the still open issues for the development of superconducting insertion devices is the understanding of the heat load induced by the beam passage. With the aim of measuring the beam heat load to a cold bore and in order to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. We plan to have access with the same set-up to a number of different diagnostics, so we are implementing: i) retarding field analysers to measure the electron flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. COLDDIAG is built to fit in a short straight section at ANKA, but we are proposing its installation in different synchrotron light sources with different energies and beam characteristics. A first installation in DIAMOND is planned in June 2011. Here we describe the technical design report of this device and the planned measurements with beam.

A cascaded optical klystron on an energy recovery linac – race track microtron

We are currently investigating a device capable of generating continuous, coherent radiation down in the Angstrom region in sub-ps pulses in a relatively compact set-up. By placing a cascaded optical klystron (OK) in the return path of a 3 GeV Race Track Microtron operating in Energy Recovery mode Harmonic Generation can be performed in several stages in parallel. A four stage OK can generate Angstrom radiation from a 266 nm seed. The demands on the electron optics are severe, but the requirements on the electron beam are not extreme. The layout of a possible facility is presented and the basic concepts are discussed below

Status of the MAX IV light source project

The MAX IV light source project is presented. The MAX IV light source will consist of three low emittance storage rings and a 3 GeV injector linac. The three storage rings will be operated at 700 MeV, 1.5 GeV, and 3.0 GeV, which make it possible to cover a large spectral range from IR to hard X-rays with high brilliance undulator radiation from insertion devices optimised for each storage ring. The preparation of the injector linac to serve as a short pulse source and the major sub-systems of the facility are also presented.