New 1π sr acceptance angle display-type ellipsoidal mesh analyzer for electron energy and two-dimensional angular distribution as well as imaging analysis

We propose a Display-type Ellipsoidal Mesh Analyzer (DELMA) using a newly developed 1 pi sr wide acceptance angle electrostatic lens (WAAEL), energy aperture and some other electrostatic lenses [1-5]. It can display two-dimensional angular distributions of charged particles within the acceptance angle of +/- 60 degrees, which is much larger than the largest acceptance angle range so far and comparable to the display-type spherical mirror analyzer (DIANA) developed by Daimon et al. [6,8-11]. It also has a focusing capability with 5 times magnification and similar to 30 mu M lateral resolution. The relative energy resolution is typically from 2 to 5 x 10(-3) depending on the emission area of the sample, as well as on the diameter of energy aperture. Because this new analyzer has a function of low-magnification photoemission electron microscope, this instrument will be extended and applied as a new type Stereo-PEEM [7] in near future. (c) 2011 Elsevier B.V. All rights reserved.