From 9b4f33c4a069b0c70588bfdd7da635329812b9a5 Mon Sep 17 00:00:00 2001 From: kuehl Date: Tue, 30 Jul 2024 08:24:29 +0000 Subject: [PATCH 1/5] Update on Overleaf. --- cau-ath-er_i1-0/report.tex | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index f205a0a..c9645d5 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -227,7 +227,7 @@ Summary \begin{figure}[ht] \includegraphics[width=\columnwidth]{../cau-ath-spc-0005_i1-0/figures/TRLtable.png} \end{figure} -{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit Ca} +{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOs} We have assessed the \acs{TRL} of the critical subsystems of \acs{AHEPaM} in Tab.~\ref{tab:TRL}. While the average TRL is high (see document \cite{ahepam-heritage}, the overall, wrapped-up \acs{TRL} is defined by the lowest \acs{TRL} and thus driven by the large \acs{SSD}s needed for the current design of \acs{AHEPaM}. A dedicated qualification process for these large detectors would improve that assessment but could not be performed in the course of this work on the development of the \acs{AHEPaM} conceptual study. All other critical subsystems have heritage from previous space missions (detailed in \cite{ahepam-heritage}) or from the \acs{CHAOS}/\acs{BEXUS} project which is currently undergoing environmental tests and will be launched in October 2024. This experiment can be considered as a simplified \acs{AHEPaM} which comprises all measurement principles relevant for \acs{AHEPaM} but uses smaller detectors (\acs{SSD}s). It is a high-fidelity demo-model of \acs{AHEPaM} measurement principles. The \acs{CHAOS} \acs{BGO} scintillator is identical to the one foreseen for \acs{AHEPaM}, as is its Cherenkov detector. Thus all critical subsystems of \acs{AHEPaM} have been tested with \acs{CHAOS} except for the large (and expensive) \acs{SSD}s. The \acs{DORN} instrument for Chang'E 6 was developed by \acs{IRAP} in Toulouse but uses our front-end electronics (\acs{FEE}) for the detector read out, as it is foreseen for \acs{AHEPaM}. \begin{table}[h] From 736c49e3bdf86ba42a7d1b12f1ae587715009980 Mon Sep 17 00:00:00 2001 From: kuehl Date: Tue, 30 Jul 2024 08:24:40 +0000 Subject: [PATCH 2/5] Update on Overleaf. --- cau-ath-er_i1-0/report.tex | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index c9645d5..3eb200e 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -227,7 +227,7 @@ Summary \begin{figure}[ht] \includegraphics[width=\columnwidth]{../cau-ath-spc-0005_i1-0/figures/TRLtable.png} \end{figure} -{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOs} +{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut} We have assessed the \acs{TRL} of the critical subsystems of \acs{AHEPaM} in Tab.~\ref{tab:TRL}. While the average TRL is high (see document \cite{ahepam-heritage}, the overall, wrapped-up \acs{TRL} is defined by the lowest \acs{TRL} and thus driven by the large \acs{SSD}s needed for the current design of \acs{AHEPaM}. A dedicated qualification process for these large detectors would improve that assessment but could not be performed in the course of this work on the development of the \acs{AHEPaM} conceptual study. All other critical subsystems have heritage from previous space missions (detailed in \cite{ahepam-heritage}) or from the \acs{CHAOS}/\acs{BEXUS} project which is currently undergoing environmental tests and will be launched in October 2024. This experiment can be considered as a simplified \acs{AHEPaM} which comprises all measurement principles relevant for \acs{AHEPaM} but uses smaller detectors (\acs{SSD}s). It is a high-fidelity demo-model of \acs{AHEPaM} measurement principles. The \acs{CHAOS} \acs{BGO} scintillator is identical to the one foreseen for \acs{AHEPaM}, as is its Cherenkov detector. Thus all critical subsystems of \acs{AHEPaM} have been tested with \acs{CHAOS} except for the large (and expensive) \acs{SSD}s. The \acs{DORN} instrument for Chang'E 6 was developed by \acs{IRAP} in Toulouse but uses our front-end electronics (\acs{FEE}) for the detector read out, as it is foreseen for \acs{AHEPaM}. \begin{table}[h] From 6899c55c423d4f881d7f5999ac264b57823fe7a0 Mon Sep 17 00:00:00 2001 From: kuehl Date: Tue, 30 Jul 2024 08:24:42 +0000 Subject: [PATCH 3/5] Update on Overleaf. --- cau-ath-er_i1-0/report.tex | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index 3eb200e..8145196 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -227,7 +227,7 @@ Summary \begin{figure}[ht] \includegraphics[width=\columnwidth]{../cau-ath-spc-0005_i1-0/figures/TRLtable.png} \end{figure} -{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut} +{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut. Müssten wir nur erkl} We have assessed the \acs{TRL} of the critical subsystems of \acs{AHEPaM} in Tab.~\ref{tab:TRL}. While the average TRL is high (see document \cite{ahepam-heritage}, the overall, wrapped-up \acs{TRL} is defined by the lowest \acs{TRL} and thus driven by the large \acs{SSD}s needed for the current design of \acs{AHEPaM}. A dedicated qualification process for these large detectors would improve that assessment but could not be performed in the course of this work on the development of the \acs{AHEPaM} conceptual study. All other critical subsystems have heritage from previous space missions (detailed in \cite{ahepam-heritage}) or from the \acs{CHAOS}/\acs{BEXUS} project which is currently undergoing environmental tests and will be launched in October 2024. This experiment can be considered as a simplified \acs{AHEPaM} which comprises all measurement principles relevant for \acs{AHEPaM} but uses smaller detectors (\acs{SSD}s). It is a high-fidelity demo-model of \acs{AHEPaM} measurement principles. The \acs{CHAOS} \acs{BGO} scintillator is identical to the one foreseen for \acs{AHEPaM}, as is its Cherenkov detector. Thus all critical subsystems of \acs{AHEPaM} have been tested with \acs{CHAOS} except for the large (and expensive) \acs{SSD}s. The \acs{DORN} instrument for Chang'E 6 was developed by \acs{IRAP} in Toulouse but uses our front-end electronics (\acs{FEE}) for the detector read out, as it is foreseen for \acs{AHEPaM}. \begin{table}[h] From cca5ceca5bb16c9f398231427886919b7a83926c Mon Sep 17 00:00:00 2001 From: kuehl Date: Tue, 30 Jul 2024 08:24:46 +0000 Subject: [PATCH 4/5] Update on Overleaf. --- cau-ath-er_i1-0/report.tex | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index 8145196..3068900 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -227,7 +227,7 @@ Summary \begin{figure}[ht] \includegraphics[width=\columnwidth]{../cau-ath-spc-0005_i1-0/figures/TRLtable.png} \end{figure} -{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut. Müssten wir nur erkl} +{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut. Müssten wir nur erklären} We have assessed the \acs{TRL} of the critical subsystems of \acs{AHEPaM} in Tab.~\ref{tab:TRL}. While the average TRL is high (see document \cite{ahepam-heritage}, the overall, wrapped-up \acs{TRL} is defined by the lowest \acs{TRL} and thus driven by the large \acs{SSD}s needed for the current design of \acs{AHEPaM}. A dedicated qualification process for these large detectors would improve that assessment but could not be performed in the course of this work on the development of the \acs{AHEPaM} conceptual study. All other critical subsystems have heritage from previous space missions (detailed in \cite{ahepam-heritage}) or from the \acs{CHAOS}/\acs{BEXUS} project which is currently undergoing environmental tests and will be launched in October 2024. This experiment can be considered as a simplified \acs{AHEPaM} which comprises all measurement principles relevant for \acs{AHEPaM} but uses smaller detectors (\acs{SSD}s). It is a high-fidelity demo-model of \acs{AHEPaM} measurement principles. The \acs{CHAOS} \acs{BGO} scintillator is identical to the one foreseen for \acs{AHEPaM}, as is its Cherenkov detector. Thus all critical subsystems of \acs{AHEPaM} have been tested with \acs{CHAOS} except for the large (and expensive) \acs{SSD}s. The \acs{DORN} instrument for Chang'E 6 was developed by \acs{IRAP} in Toulouse but uses our front-end electronics (\acs{FEE}) for the detector read out, as it is foreseen for \acs{AHEPaM}. \begin{table}[h] From 1cf2a986ad7d2e8ae71fc661bd08bfcbad751dab Mon Sep 17 00:00:00 2001 From: kuehl Date: Tue, 30 Jul 2024 08:31:30 +0000 Subject: [PATCH 5/5] Update on Overleaf. --- cau-ath-er_i1-0/report.tex | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index 3068900..40366a0 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -173,7 +173,7 @@ The design of \acs{AHEPaM} that resulted from this study is shown in Fig.~\ref{f \section{Expected Performance} \label{sec:performance} -Detailed simulations were performed with \acs{GEANT4} \cite{agostinelli-etal-2003} to determine the geometry factors of different combinations of detectors in \acs{AHEPaM} which are key to understanding the expected performance of \acs{AHEPaM}. The required discrimination between electrons and protons was achieved by selecting a refractive index $n$ of the Cherenkov detector which is close to that of vacuum, i.e., 1 {\bf bitte den richtigen Wert geben, das soll ja ein exec. summary sein.}. Thus this detector only triggers to protons with kinetic energies above $\sim 3$ GeV {\bf und sonst steht überall 2 GeV...?}, which lies well beyond the maximum of the \acs{GCR} flux. That means that most protons are correctly separated from electrons by this technique alone. Additional measurements in \acs{AHEPaM} further improve this discrimination. The main challenge for \acs{AHEPaM}, however, is to meet the required statistical accuracy, i.e., to acquire sufficient counting statistics to meet the requirements given in Tab.~\ref{tab:orig-meas-req}. To increase counting statistics only particles from one hemisphere were simulated, exploiting the symmetry of \acs{AHEPaM} (see Fig.~\ref{fig:AHEPaM-concept}). Therefore, only results from one hemisphere (i.e., $2\pi$ sr) are reported here. During solar quiet times, i.e., in the absence of a solar particle event, the \acs{GCR} particle radiation background is essentially isotropic. This, however, is also the situation when the count rates are small, in other words, it is the limiting case for determining \acs{AHEPaM}s measuring capabilities. This also means that the $2\pi$-sr results reported here can effectively be doubled, i.e., their uncertainties divided by the appropriate factor, $\sqrt{2}$. We do not correct for this geometric factor in this report because solar particle events can be very an-isotropic during their onset times, i.e., in the first hours of the event. +Detailed simulations were performed with \acs{GEANT4} \cite{agostinelli-etal-2003} to determine the geometry factors of different combinations of detectors in \acs{AHEPaM} which are key to understanding the expected performance of \acs{AHEPaM}. The required discrimination between electrons and protons was achieved by selecting a refractive index $n$=1.05 of the Cherenkov detector which is close to that of vacuum. Thus this detector only triggers to protons with kinetic energies above $\sim 2$ GeV, which lies well beyond the maximum of the \acs{GCR} flux. That means that most protons are correctly separated from electrons by this technique alone. Additional measurements in \acs{AHEPaM} further improve this discrimination. The main challenge for \acs{AHEPaM}, however, is to meet the required statistical accuracy, i.e., to acquire sufficient counting statistics to meet the requirements given in Tab.~\ref{tab:orig-meas-req}. To increase counting statistics only particles from one hemisphere were simulated, exploiting the symmetry of \acs{AHEPaM} (see Fig.~\ref{fig:AHEPaM-concept}). Therefore, only results from one hemisphere (i.e., $2\pi$ sr) are reported here. During solar quiet times, i.e., in the absence of a solar particle event, the \acs{GCR} particle radiation background is essentially isotropic. This, however, is also the situation when the count rates are small, in other words, it is the limiting case for determining \acs{AHEPaM}s measuring capabilities. This also means that the $2\pi$-sr results reported here can effectively be doubled, i.e., their uncertainties divided by the appropriate factor, $\sqrt{2}$. We do not correct for this geometric factor in this report because solar particle events can be very an-isotropic during their onset times, i.e., in the first hours of the event. The concept for \acs{AHEPaM} which was developed in this contract continuously provides two classes of data products, high resolution and high statistics. The high-resolution data product is much better at discriminating between protons and electrons than the high-statistics data product. It requires particles to traverse the entire \acs{AHEPaM} particle telescope, i.e., to hit the front-most and rear-most detectors in Fig.~\ref{fig:AHEPaM-concept}. The field of view for this data product is narrow and consequently its geometric factor ("gathering power") is limited, and hence only a fraction of all particles is measured. The high-statistics data product, on the other hand, provides data at high counting statistics, but at the cost of reduced discrimination between electrons and protons. This is achieved by relaxing the requirement that all detectors of the \acs{AHEPaM} telescope are triggered which results in a larger geometric factor. The measurement capabilities of both data products are summarized in Tab.~\ref{tab:AHEPaM-data-products}. Note that the instruments hard- and software can be designed such that both, the high species-resolution and high statistic mode are performed in parallel. Comparison with the requirements listed in Tab.~\ref{tab:orig-meas-req} shows that \acs{AHEPaM} is close to meeting the measurement requirements for protons. In fact, accounting for the $2\pi$-sr simulation, the high-statistics data products meet the original requirement. It has been also shown that the Helium requirements can be fulfilled as long as the proton requirements are met. However, those for electrons can not be met, primarily because their flux is much lower than the proton flux (see Fig.~\ref{fig:GCR-spec}). The flux of electrons in the energy range below about 50 MeV is dominated by solar and Jovian electrons \cite{vogt-etal-2018, eraker-and-simpson-1981}. Solar energetic electron events at energies above 1 MeV were measured already in the 1970's and 1980's by the MEH experiment on ISEE 3 and showed only a few events exceeding energies of 50 MeV (for details see \cite{moses-etal-1989}). Thus, the flux of electrons above 50 MeV is dominated by the slowly varying galactic contribution. Therefore, we propose to relax the requirement on the temporal resolution of the electron flux. Possible time-scales for such re-defined requirements should be linked to physical processes such as Forbush decreases (1 day time resolution) or Carrington rotations (28 days). @@ -211,7 +211,7 @@ How could AHEPaM be simplified Since \acs{AHEPaM} is a scientific instrument, the development of the telescope and the front-end electronics had the highest priority for long time during the concept design phase. While the detector/ telescope design matured, the detailed mechanical design did not move forward with the same pace. This later led to a situation where the structural design needed to include a finalized detector arrangement. Since the simulation results were all based on the fixed telescope geometry, a late stage change in the cherenkov detector's mechanical support concept was very complex to include, mainly due to lack of available space between the detectors. So, in retrospective it would have been beneficial for some design aspects to detail the mechanical design parallel to the telescope design. The simulations detailed in section 1 of \cite{ahepam-djf} have been performed individually with and without a Cherenkov detector in order to investigate whether or not the \ac{AHEPaM} requirements can be fulfilled with both setups. The requirement regarding the electron uncertainties has proven to be the most difficult one to achieve due to the contribution of protons to the electron channels. This contamination is significant due to the higher proton flux compared to the electrons expected for the \ac{GCR} (see fig. \ref{fig:GCR-spec}).\newline -While the methods introduced in \cite{ahepam-djf} utilizing thresholds in the different detectors of the instrument have reduced the contamination already significantly even without a Cherenkov detector, this improvement has proven to be insufficient in order to fulfill the given requirements. Introducing the Cherenkov to the setup allowed for a further suppression of the proton contamination and hence significant lower electron uncertainties. Additionally, the Cherenkov allows to separate protons above and below 2~GeV {\bf woanders ist von 3 Gev die Rede} allowing for better energy resolutions up to 2~GeV as well as providing an integral channel for protons above 2~GeV. Hence, from a measurement technique perspective the Cherenkov detector is highly preferred.\newline +While the methods introduced in \cite{ahepam-djf} utilizing thresholds in the different detectors of the instrument have reduced the contamination already significantly even without a Cherenkov detector, this improvement has proven to be insufficient in order to fulfill the given requirements. Introducing the Cherenkov to the setup allowed for a further suppression of the proton contamination and hence significant lower electron uncertainties. Additionally, the Cherenkov allows to separate protons above and below 2~GeV allowing for better energy resolutions up to 2~GeV as well as providing an integral channel for protons above 2~GeV. Hence, from a measurement technique perspective the Cherenkov detector is highly preferred.\newline From a technical point of view, the Cherenkov detector increases the complexity of the instrument. Especially the high voltage that is necessary in order operate the \ac{PMT} of the Cherenkov detector has to be considered. Furthermore, the Cherenkov detector has to be connected to its \acs{PMT} and the rest of the instrument mechanically and thermally. The technical details are further described in section 5 in \cite{ahepam-djf}. It is important to note that Cherenkov detectors have been already used successfully for space mission in the past (including instruments built in Kiel \cite{ahepam-heritage}). \newline Based on the analysis we have decided that a Cherenkov is recommended in order to fulfill the measurement requirements and that the additional technical efforts are both manageable and appropriate for the benefits. However, a de-scoped version of \ac{AHEPaM} without the Cherenkov detectors has been proven to provide the capabilities of separating electrons from protons utilizing the methods described in \cite{ahepam-djf} based on sufficient statistics which could be achieved by integrating over longer time periods. Given the small temporal variations of electrons in the energy range above 50~MeV this de-scoped version is expected to provide electron fluxes within the required systematical and statistical uncertainty range if the requirements on the integration period for electrons would be relaxed. @@ -223,11 +223,11 @@ Furthermore, it has been shown that as a simplified design concept, discarding t Summary -{\bf Paddy: Wir haben nirgendwo anders TRL zahlen gegeben. Evtl. lohn es sich hier irgendwo unser heritage document zu zitieren?:\cite{ahepam-heritage}.\\ rfws: Was geben wir dort für TRLs an? \\ Erwähnt werden EPHIN, EPD/HET, KET und die diversen BEXUS missionen. Ich hab nochmal reingeschaut und wir geben dort doch TRL Zahlen an, allerdigns nur für die einzelnen Methoden: } \newline +{\bf Erwähnt werden im Heritage doc \cite{ahepam-heritage} EPHIN, EPD/HET, KET, RAD und die diversen BEXUS missionen. Ich hab nochmal reingeschaut und wir geben dort doch TRL Zahlen an, allerdigns nur für die einzelnen Methoden (siehe die Tabelle unten): } \newline \begin{figure}[ht] \includegraphics[width=\columnwidth]{../cau-ath-spc-0005_i1-0/figures/TRLtable.png} \end{figure} -{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut. Müssten wir nur erklären} +{\bf Bzgl Ableitung auf deine Tabelle unten: i) dE/dx-C haben wir im Heritage auf 3-4, mit CHAOS finde ich die Erhöhung auf 5 gut. Müssten wir nur erklären, ii) da wir bei dE/dx ein TRL von 7 (u.a. auch bei HET und RAD) haben könnten wir BGO in deiner Tablle auf 7 setzen? Wie und ob sich dieses auch auf die Large SSDs umsetzt bin ich skeptisch. Ist vom Engineering her doch deutlich schwieriger? } We have assessed the \acs{TRL} of the critical subsystems of \acs{AHEPaM} in Tab.~\ref{tab:TRL}. While the average TRL is high (see document \cite{ahepam-heritage}, the overall, wrapped-up \acs{TRL} is defined by the lowest \acs{TRL} and thus driven by the large \acs{SSD}s needed for the current design of \acs{AHEPaM}. A dedicated qualification process for these large detectors would improve that assessment but could not be performed in the course of this work on the development of the \acs{AHEPaM} conceptual study. All other critical subsystems have heritage from previous space missions (detailed in \cite{ahepam-heritage}) or from the \acs{CHAOS}/\acs{BEXUS} project which is currently undergoing environmental tests and will be launched in October 2024. This experiment can be considered as a simplified \acs{AHEPaM} which comprises all measurement principles relevant for \acs{AHEPaM} but uses smaller detectors (\acs{SSD}s). It is a high-fidelity demo-model of \acs{AHEPaM} measurement principles. The \acs{CHAOS} \acs{BGO} scintillator is identical to the one foreseen for \acs{AHEPaM}, as is its Cherenkov detector. Thus all critical subsystems of \acs{AHEPaM} have been tested with \acs{CHAOS} except for the large (and expensive) \acs{SSD}s. The \acs{DORN} instrument for Chang'E 6 was developed by \acs{IRAP} in Toulouse but uses our front-end electronics (\acs{FEE}) for the detector read out, as it is foreseen for \acs{AHEPaM}. \begin{table}[h]