The detailed
time chart of all work package (WP) activities is given in summary
in the Gantt chart
Timetable. This is seen to be separated into three distinct
but overlapping phases:
Construction phase (WP1-7, months 1-24),
Measurements phase (WP8, months 19-48),
Data analysis and Dissemination of results phase (WP9-10,
months 19-48),
Administration (WP11, months 1-48),
Evaluation (WP12, months 46-48),
The work packages are explained
next in more detail. Additionally, in Table I (at the very end
of this proposal), the names of the researchers, their expertise,
their assigned tasks and their estimated effort are listed for
convenience.
A. Construction
phase (WP1-WP7, 24 months)
Work packages 1-7 relate to the construction phase
in which the entire experiment composed of beam line, ion strippers, vacuum
chamber, gas cell, spectrometer, position sensitive detectors and data
acquisition system will need to be designed, constructed, tested and/or put
into operation.
Work Package
1
Start:
Month 1
Finish:
Month 15
Cost:
Title:
WP1:
Beam
line design and construction
Description:
Research Teams:
RT1, RT2, RT3
1.1 Optics design of complete
beam line
The optics of the entire accelerator will be checked with
the CPO code TRANSPORT and compared to real beam conditions.Then the optics of the new beam line will be designed
starting from the switching magnet port L45. This will
determine exactly what and where to place steerers, quadrupoles,
beam monitors, slits and the optimal length to the target
for highest transmission.
1.2 Beamline constructionUsing the optics design the new beam line will then
be constructed. This includes the beam tubing, support
stands, placing the focusing elements at the right place,
adding gate valves, pumping ports, vacuum gauges, etc.The machine shop will be used for many of the required
constructions. Materials needed for beam line and optical
elements already exist, but might need repairs.
1.3 Optical alignment
of new beam lineWill be performed with a telescope whose stand has
to be built and aligned with alignment mark at accelerator
switching magnet
1.4 Vacuum test of new
beam lineA turbo pump with fore line pump will be needed to
bring the beam line to a vacuum of 5Χ10-7 Torr
or better. If pumps not available they will have to be
ordered and bought.
1.5 Test new beam line
transmission with ions from TANDEMOnce under vacuum fluorine
or oxygen beams will be used to test beam line transmission
through slits by recording ion current at the end of the
beam line and comparing to current at switching magnet
and expectations of CPO TRANSPORT code.
Deliverables:
1
Report and possibly part of BS, MS or PhD thesis
Work Package
2
Start:
Month 1
Finish:
Month 15
Cost:
Title:
WP2:
Design
and Construction of Ion beam strippers
Description:
Research Teams:
RT1, RT2, RT3
2.1 Foil post stripper
design and construction: A
self-supporting multiple foil stripper will be designed, build in the shop
and placed between analyzing and switching magnet for post-stripping of the
beam.
2.2 Tandem terminal gas
stripper design and construction: The TANDEM tank will be
opened and a differentially pumped gas canal will be positioned with turbo
pump, pressure monitor and leak valve.
2.3 TRANSPORT study of
beam transmission through strippers:
Code TRANSPORT will be used for the optimization of the
low energy TANDEM beam for optimal transmission through
the terminal stripper
2.4 Implementation of charge state analysis code for optimal charge
selection:.
Charge state analysis code CHARGE implemented for the
TANDEM parameters to predict charge distributions after
stripping.
2.5 Test of strippers
and ion transmission to new beam line: Test beams run to measure the efficiency of gas and post
stripping and get a better idea of the actual beam currents of highly charged
ion beams
Deliverables:
1
Report and possibly part of BS, MS or PhD thesis
Work Package
3
Start:
Month 1
Finish:
Month 9
Cost:
Title:
WP3:
00
Auger projectile spectroscopy - Design of experimental apparatus
Description:
Research Teams:
RT1, RT2, RT3
3.1 Design of full
experimental setup inside collision chamber:Details of
electron optics, gas cell and spectrometer input lens geometries will be
reconsidered and partially redesigned to further improve Kansas apparatus. TRANSPORT code used to
optimize ion beam transmission through the target gas cell.
3.2 Market research,
ordering and receiving all required components: The
apparatus from Kansas
came without electronics such as signal processing amps, HV power supplies
and data acquisition which have to be bought. New spectrometer support will
be designed and constructed in the machine shop.
Deliverables:
2
Reports and part of BS, MS or PhD thesis
Work Package
4
Start:
Month 4
Finish:
Month 15
Cost:
Title:
WP4:
Collision
chamber preparation
Description:
Research Teams:
RT1, RT2, RT3
4.1 Preparation of high
vacuum collision chamber:Careful study of best usage of two
collision chambers brought from Kansas.
The 2nd chamber is bigger than the original with more space for
gas cell and spectrometer and has better mu-metal shielding advantages that
need to be considered. High voltage cabling considerations. Electrical signal
and noise pick-up considerations. Pumping speed analysis, selection of turbo
pumps and ultimate vacuum considerations. Typically, a central turbo pump
(350-500 lt/s) is needed for the chamber with a second smaller one (100 lt/s)
for the target gas cell. All pumps will have to be bought.
4.2 Faraday cup
construction: The Faraday cup has to be designed, built and
carefully installed on the chamber. It is used to stop the beam and measure
its current for monitoring and spectrum normalization.
4.3 Connection of
chamber to beam line and final tests with ion beam from TANDEM: The whole chamber and Faraday cup will be tested
for vacuum to about 1 x 10-7 Torr. Then it will be connected to
the beam line and aligned to the beam axis on a special support stand that
will be built in the machine shop. Check of transmission and current
integration with ion beam from the accelerator.
Deliverables:
1
Report and possibly part of BS, MS or PhD thesis
Work Package
5
Start:
Month 7
Finish:
Month 15
Cost:
Title:
WP5:
Differentially
pumped gas cell - design and construction
Description:
Research Teams:
RT1, RT2, RT3
A low chamber (2-4Χ10-7 Torr) pressure with fully
loaded (10-20 mTorr) target gas cell is crucial for obtaining high quality,
low background electron spectra, particularly with position sensitive
detection since it also reduces the dead time of the entire data acquisition
This necessitates the use of a doubly differentially pumped gas cell with its
own independent pumping system a concept first used with great success in
Kansas.
5.1 Design of doubly
differentially pumped gas cell:calls for a voltage floatable target gas
cell enclosed in an outer cell and directly pumped by an independent turbo
pump with μm XYZ alignment capabilities.
Supporting the gas cell at the correct focusing distance is very important
and will be studied in simulation using SIMION
CPO software in conjunction with the input lens settings of the hemispherical
analyzer. A 50-100 lt/s turbo pump with back up pump will have to be ordered
and installed.
5.2 Gas cell
construction and placement in collision chamber: Gas
cell manifold, aperture assembly, pumping system and support will be built
according to the design in the shop and positioned.
5.3 Connection to gas
feed through and pressure stabilization unit: The gas pressure will be stabilized and monitored
by a feedback system, typically a capacitive manometer, which will also have
to be bought.
5.4 Gas cell alignment and support: involves the crucial optical alignment of the gas
cell with the optical axis and is first performed in air with a telescope.
Final micro adjustment to minimize electron background from slit edge
scattering is performed by taking electron spectra with ion beam on target
(WP8.1).
Deliverables:
1
Report and part of BS, MS or PhD thesis
Work Package
6
Start:
Month 1
Finish:
Month 18
Cost:
Title:
WP6:
Electronics
and Data Acquisition system -design and implementation
Description:
Research Teams:
RT1, RT2, RT3
6.1 Detectors
electronics: Design, purchase, and assembly: The pulses from the electron detectors of the
spectrometers are processed through a system of preamps, shaping amps,
logical gates and ADCs which will have to be redesigned and whose components
must be bought. Spectrometer electrode voltages are delivered by programmable
precision high voltage power supplies and coordinated with the detector
signals through the data acquisition system (DAQ) centrally controlled by a
PC. Both DAQ and power supplies must also be bought as well as related high
voltage vacuum feedthroughs, SHV and MHV connectors, HV cabling etc.
6.2 Design and development
of data acquisition (DAQ) systems for channeltron and PSD: DAQ
software must be written for the purchased DAQ. Two different types of DAQ
programs will be used either to scan the spectrometer voltages with the
channeltron detector or keep the voltages fixed when used with spectrograph’s
position sensitive detector (PSD). Eventually both will be combined in one
program.
6.3 Tests of complete
electronics and DAQ with pulsers:
Tests of the electronics will be performed with pulsers, Eventually, improvements
in the counting rate capabilities of the Kansas system [Ben99b] and dead time
minimization will be sought using histogramming memory electronics or
delay-line electronics
Deliverables:
2
Reports and part of BS, MS or PhD thesis, DAQ software programs
Work Package
7
Start:
Month 7
Finish:
Month 18
Cost:
Title:
WP7:
Electron
spectrometers - preparation, setup and operation
Description:
Research Teams:
RT1, RT2, RT3
7.1 Hemispherical
Deflector Analyzer (HDA) - preparation and tests of operation:
7.2 Two-stage 450
parallel plate Analyzer (PPA) - preparation and tests of operation:
Existing HDA [Ben99a, b,
Zou02a] and PPA [Zou97a] spectrometers brought from Kansas must be prepared for use, cleaned, resurfaced
with conducting graphite coating (Aquadag) and tested for electrical high
voltage break down to 5kV. Special positioning stands for both systems
allowing for sensitive alignment must be built. Both MCP plates, found to
develop dead spots or hot spots after heavy and channeltron detector,
deteriorate over time will be replaced as needed, the cost included under
consumables.
7.3 Final test of
spectrometers -high voltage control and DAQ: Finally, the entire spectroscopy apparatus
connected to the DAQ (WP6) will be tested first with an e-gun and later with
collisional electrons.Further
improvement of the optics of deceleration stage in either type of
spectrometer is also planned using the simulation software SIMION for maximum
transmission optimization and improved energy resolution.
Deliverables:
1
Report and part of BS, MS or PhD thesis, DAQ software programs
B. Measurement
phase (WP8)
With
the end of phase A, we can finally start in WP8 with the proposed measurements
using the He-like ions, the installed post strippers, the new beam line and the
electron spectroscopy setup. The measurements will be performed using the
zero-degree Auger projectile spectroscopy technique [Zou97a], which records the
Auger electrons emitted from the projectile ions excited in the collision with
the gas target with high resolution in the direction of the beam (00
– zero-degrees).
Work Package
8
Start:
Month 19
Finish:
Month 48
Cost:
Title:
WP8:
Measurements of electron spectra using ions from the TANDEM
Description:
Research Teams:
RT1, RT2, RT3, RT4
For
the specific isoelectronic sequence measurements proposed here we shall
follow the procedures presented in Strohschein et al [Stro08a] used for the
measured C4+ spectra shown in Figs. 1 and 2. The same procedures
will be repeated for every single different ion species used until we cover
all the ions with atomic number between Lithium and Fluorine.These are described below:
8.1 Start up of negative ion source
- tuning the beam at the required energy for optimal transmission:
This
is the first part of every beam time and includes the startup of the ion source,
tuning the selected ion species through the accelerator with the required
energy, selecting the right charge state at the analyzing magnet, post
stripping if necessary prior to switching the beam to the right beam line by
setting the switching magnet. Depending on whether beam in the ground state
or mixed state is required, the tank gas stripper or the post-stripper is
activated. The selected beam is eventually tuned through the target gas cell
and the 00 spectrometer and optimized in the final Faraday cup.
Electron spectra are then accumulated and final beam tuning to minimize
background from slits etc. is performed.
8.2 Absolute energy calibration of
electron spectra
Before
projectile electron spectra can be taken an overall electron energy calibration
of the entire apparatus is required usually performed with known target Auger
lines as for example obtained in 3 MeV p + Ne/Ar [Zou97a]. Also required is
the accurate knowledge of the beam velocity which is usually obtained by
measuring the energy of the “cusp” electrons which are known to move at the
projectile speed. Finally, once this is known, projectile electron spectra
can be safely accumulated since the Auger energies in the lab frame are now
well specified and particular states/lines can be accurately identified.
8.3. Absolute calibration of
electron double differential cross sections (DDCS)
This
is an important calibration of the counts scale of an electron spectrum
related to the electron DDCS and the overall absolute efficiency of the
apparatus. It is typically performed by a procedure well established by
Zouros and his collaborators in Kansas.
It involves a measurement of the so called Binary Encounter peak electrons
using bare ions which correspond to elastically scattered electrons for which
the absolute DDCS are very well established from theory. This calibration is
usually performed with a strong completely stripped ion beam typically F9+,
O8+ or B5+ around 1 MeV/u [Zou97a].
8.4. Measurements of electron
spectra and conversion to DDCS
Once
the precise energy range of the spectrum to be recorded as well as the target
gas pressure are specified after a few standard tests requiring short runs of
spectra accumulation, the final high resolution spectra (under electron
pre-deceleration)are accumulated
consisting of (a) A spectrum with loaded gas cell, (b) A spectrum with no gas
(background spectrum). The subtraction of (b) from (a) will give the
necessary “clean” or background subtracted spectrum.
This
procedure is repeated for all required spectra for both types of He-like
beams, i.e. the “pure” ground state beams taken using the terminal gas
stripper and the mixed 1s2/1s2s 3S beams taken using a
foil post-stripper. Such spectra will be taken for both H2 and He
targets and possibly for other gas targets such as CH4, Ne or Ar,
having more than 2 electrons to be captured, as an extra test. Total high
statistics accumulation time for each spectrum can vary between 1 and 4 hours
depending on beam intensity.
8.5. Servicing of experimental
components after use
The
electron spectrometers with their detectors are normally kept in the
collision chamber under vacuum even when not used for measurements since this
preserves them in a clean environment and extends the life time of the MCP
plates and channeltron detectors. However, after some use the MCPs eventually
deteriorate and need to be replaced about once a year, depending on use.
Similarly, for channeltrons, which however being more rugged, need
replacement only once every 2 years. Spectrometers also sometimes, especially
if a vacuum accident occurs, need meticulous cleaning and even high voltage
conditioning. Graphite coating must also be refreshed every so often,
especially if the spectrometer needs to be taken apart for cleaning which is
a major operation. Both Prof. Benis and Zouros have done this procedure many
times.
8.6. Back-up of all data on special
storage media
In
a typical run many different spectra are collected. Especially the
two-dimensional images of the 2-D PSD require a lot more disk space on the
PC. The data of each run will be backed up onto a special hard disk, labeled
and logged so it can be readily accessed for future offline data analysis.
Deliverables:
2
Reports, part of BS, MS or PhD thesis
C. Data analysis
and dissemination phase (WP9-WP10)
After
the first few measurements we shall start the data analysis and the
dissemination of the results first within the local groups and then on a more
international scale.
Work Package
9
Start:
Month 19
Finish:
Month 48
Cost:
Title:
WP9:
Analysis and presentation of new results
Description:
Research Teams:
RT1, RT2, RT3, RT4
9.1 Homebuilt Software
for data analysis: Typical data
analysis has to do with fitting Auger lines (with specialized peak fitting
software) and extracting the absolute single and double differential cross sections
as a function of collision energy. The technique of 00Auger
projectile spectroscopy is well known for its ability to obtain such results
for each state, as long as the observed states are well resolved in the
spectra. This allows for very stringent tests of theory
9.2 Analysis of all
data: Total production cross sections will also be
determined using theoretical structure information (usually Hartree-Fock
codes like Cowan’s etc. [Zou08a]) for the Auger yield and the angular
distribution probability.
9.3 Presentation of new
results within research groups:
From the determined cross sections for the 4P and the 2P
lines we shall eventually extract a value for the ratio R as a function of
collision energy. Cascade contributions will be computed using various codes
already developed by Zouros and Sulik [Zou08a].
9.4 Discussions of new
results - reevaluation of what to measure: We also have extensive contact with theorists who
will be interested to compare their calculations to our new data.
Deliverables:
1
Report and part of BS, MS or PhD thesis, software data analysis programs
Work Package
10
Start:
Month 22
Finish:
Month 48
Cost:
Title:
WP10:
Dissemination of new results worldwide
Description:
Research Teams:
RT1, RT2, RT3, RT4
10.1Final technical reports with summary of
measurements and results:
10.2 Publications in
international scientific journals of the field: The
dissemination of our new results will be accomplished primarily by scientific
publications in well known international journals of high impact factor such
as Physical Review (Letters, A: Rapid Communications, Α: Papers), Journal of Physics B (Letters, Papers),
Journal of Electron Spectroscopy and Related Phenomena, Nuclear Instruments
and Methods in Physics Research A και
B, Physica Scripta, Review of Scientific Instruments, International Journal
of Mass Spectrometry etc..
10.3 Participation in international
conferences - presentations:
Also by presentations at meetings, seminars and international conferences such
as:
ICPEAC (Int. Conf.
on the Physics of Photonic, Electronic and Atomic Collisions) (2013,2015)
ISIAC
(International Symposium on Ion Atom Collisions) (2013,2015)
HCI (international
conference on the physics of Highly Charged Ions) (2012,2014,2016)
CAARI (Int.
Conference on the Applications of Accelerators in Research and Industry)
(2012,2014)
Over the entire 48 month duration the project coordinator
will be in charge of:
11.1 Organization, advertising, interviewing, monitoring,
coordination, report and paper writing:
11.2 Website administration
Deliverables:
3
Reports, Website
E.
Project Evaluation (WP12)
Work Package
12
Start:
Month 1
Finish:
Month 48
Cost:
Title:
WP12:
Project Evaluation
Description:
Research Teams:
RT1, RT2, RT3, RT4
12.1
To be clarified - Η Δράση Αξιολόγησης Πράξης προστέθηκε
πρόσφατα στις εργασίες των εγκεκριμμένων προτάσεων και επομένως
ο τρόπος υλοποίησης δεν έχει καταστεί ακόμα σαφής. Αναμένονται
οι σχετικές διευκρινίσεις ώστε να έχουμε μια καλύτερη εικόνα
του πως θα διεξαχθεί.