P65 - High-Energy X-ray Absorption Spectroscopy

 

First EXAFS spectra measured at P65


On September 16th the main beamshutter of beamline P65 was opened for the first time. The beamline is now in commissioning until the begin of the winter shutdown. After the winter shutdown the beamline will step by step go into regular user operation. For the next user run 28 proposals were already submitted by future P65 user groups.

If you plan to submit a proposal for the next user run period please contact the beamline scientist to check the availability of certain experimental equipment and the feasibility of your planned experiment before you write your proposal!


The first XAFS spectra were measured on 9th of October 2015, just 4 days after the monochromatic beam reached the experimental hutch for the first time and we received the radiation protection clearance for this hutch.

The commisioning of P65 is making good progress while the experimental hall still has the appearance of a building side

3D model of beamline P65, (1) optics hutch, (2) experimental hutch, (3) control hutch, (4) sample preparation lab, (5) gas cabinets for problematic gases.

P65 is desigend to be the successor of DESY's three bending magnet EXAFS beamlines at the shutdown DORIS III storage ring. It will provide a realtivly large beam (1x1 mm2) and a moderate photon flux density. The 11 period undulator delivers a monochromatic photon flux of about 1011 s-1. Two plane mirrors with variable angle of incidence and three different surface coatings are installed in front of the water cooled double crystal mocnochromator. They will reduce the power load density on the first DCM crystal and effectivly suppress the contamination of the monochromatic X-ray beam with higher harmonics radiation.

The experimental hutch will have a size of approximately 4 x 6 m2, this is comparable to the hutch of beamline C at DORIS III. The height of the ceiling in the hutch is 4 m, this is high enough to mount for instance a He-transfer tube in the standard dewar bottles for liquid helium. Access to the hutch is possible via a large sliding door at the end of the hutch. In the lateral direction the distance between the beam and the wall of the experimental hutch will be about 0.6 m on the left hand side (looking downstream) and 3 m on the right hand
side.

 

Beamline Stats

 

Source:

Mini-undulator (11 periods)

Energy Range:

4 - 44 keV

Accessible Elements:

K-edges: Ca - Nd
L-edges: Sb - Uuo

Monochromator:

C-type Mono (fixed exit)
Crystals: Si(111), Si(311)

Mirrors:

2 plane mirrors for higher harmonic rejection, variable incidence angle (1.5 - 4.5 mrad)
Coatings: Both mirrors: 3 optical surfaces (Si, Rh, Pt). 1st mirror (water cooled) in front of DCM

Beamsize at Sample:

1 x 1 mm2 (vert x hor)

Flux at Sample

>1011 Photons/sec

Bandwidth

10-4

Methods

X-ray absorption spectroscopy in transmission and fluorescence mode.
Equipment for in-situ investigations with toxic and other problematic gases and liquids.

Detectors

Ionisation Chambers

Energy dispersive 7 pixel HPGe detector

Energy dispersive multipixel SDD detector

Si-PIPS diodes

 
 
 
Assembly of C-type DCM
Assembly of the DCM for beamline P65 in the clean room.
One of the first XAFS spectra of a Cu-foil. Continuous and synchronised scan of undulator gap and DCM, 300 s scan time