Antrag/first_sentences.txt

complex beam dynamics at accelerator towards application in advanced radiation therapy

phase space....

complex dynamics of structured beams for advanced radiation therapy


The present advances in accelerator based RT, like FLASH RT or microbeam RT,
lead to operation parameters of the accelerator that can not anymore be described
by simple linear optics and beam dynamics. Instead, the consideration of nonlinear
and complex optics as well as beam dynamics influenced by collective effects becomes
necessary due to the development towards higher charge and energy combined with shorter
pulse lengths and transverse modulations.

my experience in longitudinal as well as transverse collective effects and instabilities
influencing the electron bunch shape in all dimensions....
at rings but focus on single bunch effects can be transferred to linac..
simulations as well as experimental studies...
also diagnostics, used electron-beam based as well as synchrotron-radiation based and improved and developed further diagnostic methods ...
Much data analysis... and investigating new phenomena occurring in extreme operation modes...

bridge gap between accelerator science and medical physics

study from accelerator point of view all the beam dynamics effects relevant in the generation
of such beams as well as the diagnostic to reliably deliver the predicted conditions.
Furthermore, extent the simulations of the beam dynamics beyond the end of the accelerator
all the way into the target, by including the transport in air and water/matter.
This will allow the prediction of the temporal and spacial shape (shape and length) of
the radiation/electron pulse not only at the exit of the accelerator but also at any diagnostic
on the way and finally also at the target inside the patient.

beam-matter interaction have been described in the past by covariance matrices...(based on e.g. average scattering angles,...)
which was applied e.g. for thin foils in the beam path.
This can be applied and adapted to calculating the impact of the beam-matter interaction
on the beam properties during the transport all the way to the target.
Therefore, the feasibility and the accuracy of predicting the beam properties on target can be improved.

In case, the spacial structuring of the beam on target is of importance,
it is critical to know how the spacial distribution changes along the way from generation to the target.
To this end the beam-matter interaction out side the accelerator will be included in the simulations.
On top of this, calculations of the collective effects occurring within the high intensity beam
will be added by extending established theoretical descriptions usually applied
to beam dynamics calculations within the accelerator, to the beam transport outside the accelerator.
The hope is that, by extending the calculation of these effects beyond the accelerator, as a first step,
it becomes possible to predict the resulting spatial distribution on target.
And as a second step, it might allow to consider effects of the beam transport already during the generation.
Ideally, this would allow the generation of a spacial distribution which preemptively compensates for the expected changes.

TEST with experiment and iteratively improve model....by testing impact and relevance of different effects
(for example space charge, MORE effects?) in general and depending on the beam properties (energy, charge, custom(?) temporal and spacial pattern)
in simulations as well as crosscheck with measurements



-rewrite with more focus on the FLASH und less on microbeams, but more as second schwerpunkt

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TODO:
- What about longitudinal modulation which is transformed in spatial modulation by fast sweep in the end? similar to TDC or split ring resonator?
- or what about energy modulation which is transformed to spatial modulation by spectrometer bend?

-for microbeams first start with mask close before target? in case structuring from gun does not survive
-use SLM to change spot on cathode shot by shot, and therefore, change (e.g.) scan e beam. is this simpler, than scanning with a magnet?

!- https://doi.org/10.1016/S0958-3947(02)00086-9 shows electron beam through mask, but beamlets combine again after some 10 mmm. what if e beam directly micro structured, investigate how this would propagate through accelerator and later through air, water and matter

Dose-Volume Effect, where the tolerance of normal tissue to radiation
damage increases dramatically as the radiation field size decreases, ???
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develop predictions/simulations as well as select correct diagnostics
test both with measurements

flash, short pulses but how short when arriving

micro-structured beams
spatial light modulator -> structuring possible but what arrives at target due to scattering and space charge effects (between beamlets)?!!

pulse charakteristik bunch strukture, mikro beams
probleme auch pulse längen messung nicht nur charge

tests possible at different energies

flute as rf-based accelerator and maybe ATHENA as laser based accelerator as (preliminary) source of short electron pulses
THz/x-ray from KARA?

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these studies will define an optimal set...
these studies will provide simulation tools(?)/simulations for ...(pulse customarily shaped in space and time) ( transport through accelerator to target supported by specialized(?) diagnostics)


the research aims to greatly extend/improve/....

have been developed and ready to be adapted.
will be investigated as required

pave the way towards....

beam modalities

an unmet challenge