holger kollmus - vbe-uhv 1 sis100_1 erda measurements erda – measurements: understanding of ion...
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Holger Kollmus - VBE-UHV 1
SIS100_1 ERDA Measurements
ERDA – Measurements: Understanding of
Ion Beam-Loss Induced Desorption
Holger Kollmus - VBE-UHV 2
Prospects
elemet specific depth profiling of samples by detection of elastically scattered recoil ions
surface - bulk information
characterization of sample properties and
possible modification under ion irradiation
time resolved monitoring of sample evolution
in situ cleaning of target using Xe-sputter gun
access to physics of ion induced desorption
Ion beam loss induced desorption is a serious luminosity limitation for SIS18
Holger Kollmus - VBE-UHV 3
Work Plan
1st quarter 2nd quarter 3rd quarter 4th quarter 1st quarter 2nd quarter 2nd half 1st half 2nd half
Task1:
ERDA measurements
Set- up of ERDA experiment at HLI of GSI, first experiments with different stainless steel targetsExperiments with pumping surfaces (NEG, Pd, Ti,...), Implementation of energy dispersive electron detectorExperiments with layered targets, diffusion barriers, measurements on electronic desorption yields
ERDA as standard tool for quality control
2005 2006 2007
Holger Kollmus - VBE-UHV 4
Milestones and Deliverables
Milestones:
01-Jun-2005 Influence of oxide layer on stainless steel determined02-Jan-2006 Desorption rates of activated and saturated getter materials measured02-Jan-2007 Decision on adequate chamber and/or collimator material and in situ
cleaning methodes
Deliverables:
01-Jun-2005 Report on the influence of the oxide layer on the desorption yieldof stainless steel targets
01-Jan-2006 Summary result of ERD Analysis of pumping and saturated surfaces31-Dec-2007 Selection of adequate chamber and collimator materials based on
ERDA measurements
Holger Kollmus - VBE-UHV 5
Status of ERDA-Experiment 01-2006 (a)
Residual GasAnalyser
Detector
Xe Sputter Gun
Beam
Target HolderFeedthrough
Faraday Cup
•
static vacuum 10-11 mbar, only UHV-ERDA worldwide
Holger Kollmus - VBE-UHV 6
Status of ERDA-Experiment 01-2006 (b)
beam times Ca10+ (III/2005): commissioning, desorption of silicon, influence of
surface contaminations Xe18+ (III/2005): influence of oxide layer on stainless steel today Xe18+: desorption of high purity copper, influence of oxide
layer, desorption of gold terminated copper, secondary electron emission
NiFeCr
Si
ONC
Holger Kollmus - VBE-UHV 7
ERDA Results Silicon
clear correlation between desorption yield and target modification clean Si in UHV no desorption, only sputtering
0 2000 4000 6000 800010-13
10-12
10-11
3x10-9
4x10-9
5x10-9
pre
ssu
re
tota
l[m
bar
]pa
rtia
l[A
]
time [s]
2 12 14 15 28 29 32 44 total
Holger Kollmus - VBE-UHV 8
ERDA Results Stainless Steel
clear correlation between oxide layer and desorption desorption can be only reduced to the bulk contamination level
Holger Kollmus - VBE-UHV 9
ERDA New Time Schedule
Nr. Task 1 2 3 4 1 2 3 4 1 2 3 4
1 ERDA Measurements
2 Set-up of UHV-ERDA at the HLI, Commissioning
3Measurements with stainless steel targets and silicon
influence of oxide layer
4Measurements with Copper and Gold coated Copper
5 Desorption yield contribution of
secondary electrons
6 Desorption yield of pump. and satur. surfaces
7 Exp. with layered targets, diff. barriers
8Desc. on adequate chamber and or collimator material
Holger Kollmus - VBE-UHV 10
ERDA Milestones
today we can report on: influence of surface contamination of silicon wafer influence of oxide layer on stainless steel (preliminary)
soon we can report on: desorption yield of OFHC copper, influence of oxide layer on
copper desorption yield of gold coated copper first test on the influence of secondary electron emission
we are slightly out of the time schedule, but we have reasonable progresswe have slightly changed the scientific program due to recent results
Holger Kollmus - VBE-UHV 11
First Publication – GSI Scientific Report
Holger Kollmus - VBE-UHV 12
Personal an Financial Situation
EU OC EU OC EU OCplanned (PM) 18 43.2 0 2.2 0 18presently spent (PM) 0 17 0 0.7 0 0investment (€) 30.0
0068.10
08.300 0 5.00
00
presently spent (€) 60.000 2.800 0
GSI LMU TUD
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