120 likes | 228 Views
SWEA MAVEN Calibration Plan A. Fedorov. Outline:. New electron gun presentation. Electron beam properties Another calibration facilities and control system What and how to measure. Overview of the new e- gun.
E N D
SWEA MAVEN Calibration Plan A. Fedorov
Outline: • New electron gun presentation. • Electron beam properties • Another calibration facilities and control system • What and how to measure
Overview of the new e- gun The goal: To create a wide uniform e- beam as close to the sensor as possible. The total current of the beam and its cross-section distribution should be measured.
Overview of the new e- gun: external parts Hamamatsu Xenon lamp on the movable support Fused silica window
Overview of the new e- gun: internal parts Palladium photocathode and an acceleration system: 1. Energy up to 10keV 2. Strictly parallel e- beam 3. No disturbed e- trajectories at the beam perifery
Overview of the new e- gun: internal parts The photocathode at the end of the light tube. The beam current monitor. The beam monitor on the Y-Z axis stage. 1. Beam cross-section 2. Beam parallelism 3. Beam energy distribution
Overview of the new e- gun: beam cross-section Flux distribution for close lamp position. 20% of variation within 40mm circle. We know the absolute beam for each sensor position
Sensor positioning Y: 0.1mm Elevation (Thet) : +/- 90 deg, 0.1deg Azimuth (Phi) : +/- 170 deg, 0.1deg
Calibration plan: Main Variables Simulated (left) and measured (right) Elevation-K response For D = 0 Simulated (left) and measured (right) Elevation-K response For D = -0.59 K = E/Uan D = Udef/E Elevation, deg (mechanical) Virtual Elevation Azimuth, deg
Calibration plan: Elevation-D profile GF determination 1. Define D – Elevation profile 2. For Az = const, for Elevations (step = 3 deg) : K-D response 3. Calculate dGF/dAz for this point (each anode)
Calibration plan: GF azimuth profile Repeat the same for all Az (step = 2 deg) and all anodes