Summary of Medipix Technology's 3-Years in Space…and ...

VCI-2016 – Medipix In Space Pinsky – Feb. 17, 2016 – Vienna

1

Summary of Medipix Technology’s 3-Years in Space…and

Plans for Future Developments Lawrence Pinsky

Physics Department University of Houston


The Full Author List…

A. Bahadori2,4, T. Campbell-Ricketts1, A. Empl1, R. Garza2,3, M. Kroupa2,3, R. Moore2, R. Rios2,3,

D. Fry2, E. J. Semones2, H. M. Son1, N. Stoffle2,3, D. Turecek1,6, S. A. Wheeler2, J. Jakubek5,6,

S. George1, Z. Vykydal5, S. Pospisil5 & L. S. Pinsky1

1 Physics Department, University of Houston, Houston, TX, USA

<[email protected]> 2 NASA Johnson Space Center, Houston, TX, USA 3 Lockheed-Martin Aerospace, Houston, TX, USA 4 Current address: Kansas State University, Manhattan, KS, USA 5 Institute for Experimental and Applied Physics, Czech Technical

University in Prague, Czech Republic 6 Current address: Advacam/Czech, Prague, Czech Republic.

2


3

All Medipix Devices are Hybrid Pixel Detectors

Detector and electronics readout are optimized separately !


4

Schematic Cross Section of a Hybrid Pixel Detector for

Penetrating Charged Particles


5

Charge Clusters

TimePix!

Incident!Particle!

The electron-hole pairs liberated by traversing charged particles drift in the bias voltage, and also diffuse laterally during the process, including effects from d-ray energies and Coulomb repulsion, creating a multi-pixel cluster.!

“PIXELMAN”!Image!


Medipix Genealogy

  There are currently 3 “generations” of Medipix Collaborations, and a 4th is currently forming…

  Medipix2 and Medipix3 have produced 2 distinct types of devices, Multi-Threshold Counting Chips, and Multi-Mode Encoding Chips. The latter chips are all called “Timepixes.”

  This talk will focus on the TImepix class of chips.

  All Timepix class chips can separately encode in each pixel the accumulated charge using the Time-Over-Threshold (TOT) and/or the time of arrival (TOA), as well as having counting modes.

6


Medipix 2 Timepix Architectures

  The Medipix2 Collaboration’s Timepixes:   The “Timepix” chip (~2007) IBM 250 nm technology

  Frame-Based Readout Only   Either 14-bit (pseudorandom) TOT or TOA (10 ns max resolution) or Hit

counts   1 Threshold (w/4-bit per pixel Equalization Offset)   “Bias-Agnostic” FEE.   256 x 256 55 µm square pixels   Wire-bond pad shelf on one edge

  The “Timepix2” chip (~2017) TSMC 130 nm technology (Design in Progress…)

  Close to “Plug-n-Play” control compatibility with Timepix…   Frame-based Readout Only, but with re-designed FEE & zero suppression   1 Threshold (w/4-bit per pixel Equalization Offset)   256 x 256 55 µm square pixels   Simultaneous TOT and TOA in each pixel w/1.6 ns time resolution.   TSV capable or wire-bond pad shelf on one edge.   TOT “Ghost” track suppression and post-frame-closing continuation. First-

hit only or “Summing ADC” Modes 7


800 MeV/A Si @ 85 degree Tracks (Data taken at HIMAC in Chiba, Japan

  The tracks are from particles diving downward from left to right.

  As they pass though the solder-bumps and into the underlying chip after leaving the Si detector layer.

  Some of the high energy δ-rays from the chip enter the overlying detector layer…

8!


Medipix3 and Medipix4 TImepix Architectures

  The Medipix3 Collaboration’s Timepix3:   The Timepix3 chip (~2014) IBM 130nm DM 4-1 Technology

  BOTH Continuous DATA-DRIVEN “SuperPixel” readout and Frame-Based Readout…

  Simultaneous (10-bit) TOT and (14+4+… bit) TOA (~1.6 ns max resolution)

  1 Threshold (w/4-bit per pixel Equalization Offset)   256 x 256 55 µm square pixels   High-charge input “clamping” FEE.   TSV capable or wire-bond pad shelf on one edge.

  The (“Projected”) Forming Medipix4 Collaboration’s TImepix4 capabilities;

  The TImepix4 chip (!2018-2020) TSMC 65 nm Technology   Larger size and Smaller Pixels   Both Data-Driven and Frame-based readouts   >> 1 ns time resolution   Fungible output registers w/zero suppression

9


Data-Driven Readout Works Very Well

10


Radiation Environment Monitor (“REM”) NASA ISS SDTO Flight Hardware!

11 Interfaces supplied by IEAP/CTU Prague!

All Space Applications To Date Use!Medipix2 Timepixes!


S/N 1007 On ISS since 2012

12


REM Dose Rate Data (µG/min) Corrected Track-By-Track from Si to H2O

13 South Atlantic Anomaly!


Trapped Radiation AND the South Atlantic Anomaly (SAA)

14


REM v. TEPC Dose Equivalent Rates

15

TEPC Tissue-Equivalent Proportional Counter!


16


17


18


EFT-1 Mission December 5, 2014

19

1.1.1 Exploration Flight Test 1

The EFT-1 mission was the first opportunity to fly a Timepix-based detec-tion system on the Orion MPCV. The Orion MPCV was launched from theKennedy Space Center (KSC) atop a Delta IV Heavy rocket on 5 December2014. The EFT-1 trajectory (shown in Figure 2) included two orbits: one lowaltitude orbit, and one highly eccentric orbit with an apogee of almost 6000km. Although the primary mission objectives were to test the thermal protec-tion system, hardware separation events, and the parachute system [17], theOrion MPCV passed through trapped electron regions and encountered intenseregions of the trapped proton belts as a result of this flight profile. Radiationmeasurements in these regions are key to understanding astronaut radiation ex-posure in the Orion MPCV during trapped proton belt transit and comparingthe trapped proton belt models with measurements.

Figure 2: EFT-1 Overview [18]

5


20

4 Hours & 36 Minutes Later!


“BIRD”

  The Timepix device (BIRD—Battery-powered Independent Radiation Detector) on the Orion test flight (EFT-1) appears to be totally successful.

  Both independent detectors onboard turned on as planned with the accelerometer switches…

  AND… the data looks ~ to the simulations using AE9 & AP9 Model inputs…

21

Timepix!


BIRD inside EFT-1 Orion

22

During EFT-1, the BIRD operated as a stand-alone device. The measure-ments began after the BIRD accelerometer registered the required number ofsamples above a pre-defined acceleration value [19, 20]. The power was pro-vided by internal batteries, and data were stored on the BIRD SD cards.

2.1.3 Integration with Orion

The AES RadWorks REM Team was engaged with the NASA Orion Programand Lockheed Martin throughout the design, testing, installation, flight, and de-installation of BIRD. The BIRD was officially accepted, having met all leviedrequirements, by Lockheed Martin on October 21, 2013 [21]. Procedures andassociated NASA Task Performance Sheets (TPS) were delivered to LockheedMartin to ensure a smooth integration process.

The BIRD S/N 1001 and S/N 1002 units were delivered to KSC on Oc-tober 7, 2014. The pre-flight functional check-out at KSC was performed onBIRD S/N 1001 on November 26, 2014, at which time the BIRD was placedin sleep mode. The RAMs were installed on the BIRD and then the BIRD wasinstalled in the Orion MPCV on November 28, 2014, as shown in Figure 5. Forreference, a CAD image of the installation is shown in Figure 6.

Figure 5: Image of BIRD installation.

8


BIRD (Stand-Alone) Hardware

23

The two identical subsystems are separated by an aluminum partition andfunctioned similarly throughout the EFT-1 mission. Each instrument containsa battery assembly, a processor board, a power board and a Timepix carrierboard. The processor board consists of a digital signal processor, a SecureDigital (SD) memory card, an accelerometer, and other supporting electronicsrequired to receive and store the radiation data from the Timepix assembly. TheTimepix assembly is mounted permanently to the carrier board and connects tothe processor board through a small connector. The serial peripheral bus pro-vides primary communication between the signal processor and the Timepixassembly. The power board consists of a voltage boosting regulator and diodeprotection circuitry. The regulator receives the dynamic voltage input from thebattery assembly and converts it into a steady and stable power source for allthe other electronics. The carrier board is the interface to the Timepix. It hasa small rear mount connector that plugs into the processor board. This boardallows for easy installation and removal of the Timepix assemblies and servesas a test interface board, allowing for integration with a Fitpix (a previously-developed Timepix data acquisition system). Each instrument is equipped witha Military Specification (MIL spec) circular connector that can be used to inter-face with the outside world in order to perform system health and status checksbefore the flight. An exploded model of the device is shown in Figure 4.

Figure 4: BIRD schematics

7


Accelerometer Data

24 Figure 7: Acceleration as measured by BIRD

14

Launch!Delta-IV Heavy!

Upper Stage!Burns!

RCS!Maneuverings!

Reentry!

Parachutes!In the water (waves)!

Zero g!(Rotating)!


25

(a) Dose rate in water for the left detector.

(b) Dose rate in water for the right detector.

Figure 12: Dose rate in silicon and water (H2O) for each frame (dots) andcomputed using equation 3, where the sum is over a one minute period (solidline).

19

Dose!Rates!

(Si & H2O)!µGy/min!

Preliminary!


26

(a) Dose equivalent rate in water for the left detector.

(b) Dose equivalent rate in water for the right detector.

Figure 13: Dose equivalent rate for each frame (dots) and computed usingequation 3, where the sum is over a one minute period (solid line).

20

Dose!Equivalent!

Rates!µSv/min!

!(Based on!NCRP 132)!

Preliminary!

1 mSv/min!

16.6 Hours = 1 Sv!

Current Estimates suggest that corrections might cause reductions of ~5-10%!


27

4.6 LET Spectra

Linear Energy Transfer (LET) spectra are generated for each BIRD subunitbased on calculation of individual ion energy deposition and track length throughthe detector. Because these calculations rely on the ability to separate individ-ual ion tracks, the results below exclude portions of the trajectory where thepixel occupancy exceeds 8 percent, corresponding to removal of frames with alarge number of overlapping tracks.

The results, shown in Figure 22 for both BIRD units for the full missionduration but excluding the high occupancy frames, display characteristics andoverall shapes consistent with one another, and similar to spectra generated byRadiation Environment Monitor units aboard ISS. This includes a small peakat approximately 14 keV/µm which corresponds to protons with energies lowenough to stop within the detector volume.

Figure 22: Number of particles as a function of LET.

29

Stopping Protons!

Electrons from X-Rays?!


Time Dependence in the Azimuthal

Distribution in the φ Direction During the

First Peak

28

(a) Azimuthal angle - f distributions as a function of time in the left detector.

(b) Azimuthal angle - f distributions during the first peak in dose for the leftdetector.

(c) Azimuthal angle - f distributions before the second peak in dose for theleft detector.

Figure 25: Azimuthal angle - f distributions during different periods of EFT-1for the left detector.

33

4.7.1 Directionality

The BIRD coordinate system is illustrated in Figure 23. The azimuthal angle -f and polar angle - q respectively correspond to the angle between the X andY axes (e.g. in the sensor plane) and Z and X axes (normal to the sensor plane).

Figure 23: BIRD coordinate system.

31

in the Left Detector !


29

AP9 & AE9 Trapped Radiation Model Comparisons

(Charged Particle Tracks) For various shielding Assumptions…

4.2.3 Model Comparisons

The AP (energetic proton) and AE (energetic electron) models have been de-veloped to specify the radiation environment for modern spacecraft design ap-plications. The latest generations of these models - AP9 and AE9 - offer un-precedented coverage in particles and energies which address the major spaceenvironmental hazards and include uncertainties and dynamics that have neverbeen available for use in design [32]. Figure 14 shows data-model compar-isons between BIRD and AP9/AE9. Initial comparisons between BIRD dataand AP9/AE9 (AX9) show very good agreement for an estimated shieldingthickness of 10 g/cm2 of aluminum. In the future, we will use the as-flowntrajectory to account for Orion’s rotation along its flight path. We will alsoray trace the detector locations to fully characterize the surrounding vehicularshielding distribution. These modifications will lead to more informative dataanalyses and model comparisons.

Figure 14: BIRD dose rates and AX9 mean dose rates at varying thicknesses.

21


Photons From Electrons (Analysis From Martin Kroupa)

30

PRELIMINARY!


Photons v. Dose & AE Flux Analysis by Martin Kroupa

31

PRELIMINARY!


Timepix-Based HERA on Future Orion Manned Spacecraft

(Hybrid Energetic Radiation Assessor)

32

HERA is composed of a!HERA Power Unit (HPU)!

and!Several HERA Sensor Units (HSU)!

Future Evolution into Timepix2 Use…!


Some Issues and Observations

&

Recent Results

33


“Skirts”   For high dE/dx tracks

that create high charge concentrations in the sensors, one sees a “skirt” of low TOT counts surrounding the central cluster.

  The “skirts” lie beyond the charge drift radius, and are caused by “Induced” charges on the pickup pads…

  The net strength of the skirts is proportional to the total charge deposited

34

An Fe track at 400 MeV/A!


The Origin of the “Skirt”

  What the Front-End Electronics sees is NOT a current from the physical collection of the drifting charge in the sensor…

  RATHER, it is an Induced Current in the Front-End that is due to the formation of the Image Charge in the conducting surface on the bottom edge of the Sensor…

  In fact, the Image Charge can extend beyond the range of the drifting charges that are actually collected… Those pixels form the “Skirt” (Why are they are not “0”?)

35

+!-!


Timepix & Timepix3 “Volcanos”   When operated with “p-

on-n” sensors (i.e. collecting “holes”) & with very high charge inputs cause very low TOT responses.

  This discharge of the FEE input capacitance occurs for holes when the input charge build-up reaches the point where the charge is rapidly dumped, resulting in a low TOT. The cause is still being investigated…

36

B09-W005 (p on n) - IKrum 5, 0 DegreesAverage Clustershape x Projection Through y = 0

y Projection Through x = 0 x,y Projection (Log Scale)


Timepix3’s Input Charge v. TOT Design Plateau Response

37

Region 2

40

0 100 200 300 400 500 600 700 8000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1x 10-6

Qin (ke-)

ToT

(s)

1 2 3 4


Timepix3 P-on-N v. N-on-P

38

Collecting HOLES!

Collecting!ELECTRONS!


Overlaps – Timepix v. Timepix3

  a

39

Timepix3 peak offset for comparison!


Up v. Down in the Timepix3

40

Track Enters top of the sensor…!

…and, Exits at the bottom of the sensor.!

Note: Direction of Motion along the track is not determined by TOA…!


TOT v. TOA in Timepix3

41

~210 MeV/A O ion…!

δ-ray!δ-rays are more easily seen in TOA!

δ-ray!

Statistically the co-moving δ-rays should predominate!(This is from a “downward” moving particle…) !


Timepix3 Data Rates

  2 interfaces are currently available:   FitPix3 (USB 2.0) Advacam/Czech

(Prague)  Vertical proton tracks up to 2 x 105 cm2 s

with negligible losses (Tested up to 5 x 105 /cm2 s.

  SPYDR (10Gig E or Fiber) NIKHEF (Amsterdam)

  Theoretically up to 8.1 x 107 Pixels/s (Random hits)

42


Summary and Future Plans   Since 2012 we have continuously flown Timepix

Based Detectors on the ISS, and will do so for the foreseeable future…

  Single REM units will be used to evaluate the BEAM Inflatable module starting later this year…

  New USB2.0 devises are being prepared for deployment.   Timepix “Stacks” and “Cubes” are being designed for both

external and internal use…

  Following on the BIRD project, NASA is designing the next generation Radiation Monitor for baseline use in Orion as part of the HERA project.

  Initial HERA Flight hardware (w/4 Timepix sensors) will be delivered For the 2020 EM-1 trans-lunar mission in 2017.

  Timepix2, Timepix3 and eventually Timepix4 are all slated to play crucial roles in NASA’s future active radiation monitoring for manned space flight…

43


44

Thank You for Your Attention


Timepix3 TOArt

45


Timepix3 TOArt

46


Direct Dose (Track-by-Track) Calculation Issues…

47

!

!

“Stopping Power” (dE/dx) of Human Tissue with respect to Silicon…!

Dose Equivalent = Dose x Quality Factor!(Dose = Energy Deposited per gm of tissue)!

NCRP 142!Quality Factors!


Frame Rate & Pixel Occupancy

48

4.2 Rates

4.2.1 Frame Occupancy and Rate

Figure 11 provides the frame occupancy and recorded frame rate per minute.Note that around 15:20 UTC, the frame rate rapidly increases and saturates ataround 180 frames/minute while the frame occupancy sextuples3. This demon-strates the instrument’s ability to accurately sample complex environments withmany particles. Here, occupancy is defined as the number of pixels with en-ergy deposition normalized by the number of pixels in the sensor. The largestoccupancy spike (c.f. Figure 11) occurs between 15:40 and 16:00 UTC andcontains a high number of overlapping particle tracks.

(a) Occupancy and frame rate for the left detector.

(b) Occupancy and frame rate for the right detector.

Figure 11: Frame occupancy and the number of recorded frames per minutefor BIRD during EFT-1

3The observed saturation is driven by the speed of the SD-card used to store data.

17

The Frame-Length Adjustment algorithm was set to allow a minimum frame duration of 100 ms. That value was too conservative. The effect is that the algorithm was unable to keep the pixel occupancy to < 5%.!The decrease in number of frames for the highest fluences is due to the increased dead-time processing the larger data buffers incurred.!!

Note that, a frame duration of 10 ms was possible, and would have fully accommodated the < 5% limit for the highest rates experienced.!


Left v. Right Dose Rate and Dose Equivalent Dose Rate Comprisons

49

4.2.4 Dosimetry Comparisons in BIRD

Dosimetry rate comparisons between the left and right detectors of BIRD areshown in Figure 15. The agreement between the absorbed and equivalent dosesis nearly linear; some deviation is expected since each detector sees a slightlydifferent radiation environment. For example, one side may observe heavy ionsor interactions, while the other may not. This is also evident in Table 1, whichpresents the total dose accumulated by the BIRD and RAM instruments duringEFT-1.

(a) Absorbed dose rate comparison (b) Dose equivalent rate comparison

Figure 15: Absorbed dose rate and dose equivalent rate comparisons betweenthe Left and Right BIRD subunits

22


Cumulative Absorbed Dose

50

4.3 Accumulated Dose

Cumulative absorbed dose during EFT-1 is provided in Figure 16; the totals forthe mission are located in Table 1.

Figure 16: Cumulative absorbed dose (in water) for BIRD during EFT-1

4.3.1 Total Dose Comparisons

The total absorbed dose for EFT-1 as measured by BIRD subunits and the as-sociated RAMs are located in Table 1. The RAM absorbed doses representthe average for the individual TL/OSL dosimeters corresponding to each of thetwo RAM flight units, together with the standard error of the mean. The LeftRAM and Right RAM TL/OSL dosimeter individual absorbed dose values hadstandard deviations of 5% and 4%, respectively.

Table 1: Total absorbed dose for BIRD and RAMs aboard Orion MPCV andISS-TEPC during EFT-1 on December 5, 2014 between 12:07 and 16:30 UTC.

BIRD [mGy] RAM [mGy] ISS-TEPC [mGy]Left 17.9 15.1 ± 0.3 0.015Right 15.7 13.5 ± 0.2

23


Lest We Forget The GCR is Still there in the BIRD Data…

51

(a) Frame from the left detectorcorresponding to tag A in Figure27.

(b) Frame from the right detectorcorresponding to tag B in Figure27.

Figure 28: Example frames from the BIRD prior to the first increase in doserates.

(a) Frame from the left detectorcorresponding to tag C in Figure27.

(b) Frame from the left detectorcorresponding to tag D in Figure27.

(c) Frame from the left detectorcorresponding to tag E in Figure27.

Figure 29: Example frames from the left detector during the first increase indose rates.

36


Landau-Vavilov v. Timepix3 Energy Loss Distributions

52

“Grazing” Incidence (Thick Target)!Vertical Incidence (Thin Target)!

Expected “Thin Target” Deviation!


One SAA Pass, April 1st, 2014 Illustrating the Directionality of

the Trapped Radiation

Altitude (Deg)!

Azu

mith

(Deg

)!

Altitude (Deg)!

Azu

mith

(Deg

)!D

ose

Rat

e (u

Sv/h

r)!

Latit

ude!

Longitude (Deg)!

From Stuart George!


Altitude (Deg)!

Azu

mith

(Deg

)!

Altitude (Deg)!

Azu

mith

(Deg

)!D

ose

Rat

e (u

Sv/h

r)!

Latit

ude!

Longitude (Deg)!

From Stuart George!

One SAA Pass, April 1st, 2014 Illustrating the Directionality of

the Trapped Radiation


The SAA

61


However, “Skirts” Appear Around High Charge Deposition Clusters That

Cannot Be Due to Charge Collection

62 An Fe track at 400 MeV/A!


63

EFT-1 Dose-Rate (µG/min) Along the Trajectory!

Courtesy of Ryan Rios, NASA, JSC!Space Radiation Analysis Group!


64

Altitude!In Km!

(Log Scale)!

4.4 Altitude and Time Profiles

In this subsection, dosimetric quantities are presented as a function of altitudeand time. The highest observed dose rates did not occur at the peak altitude,but instead occurred before and just after the peak altitude. This observation isexplained by the changes in the spectral characteristics of the trapped radiationfield along the trajectory; while still within the trapped belt region, the spectrumwas comprised of lower-energy protons in the lower dose region between thetwo dose rate peaks.

(a) Absorbed dose rate as a function of altitude and time for the left detector of BIRD

(b) Absorbed dose rate as a function of altitude and time for the right detector of BIRD

Figure 17: Altitude as a function of time, weighted by the measured dose ratein EFT-1 trajectory.

24

10!

100!

1,000!

10,000!

10!

100!

1,000!

10,000!

Mission Elapsed Time!

Left!

Right!


65


66


Monte Carlo Simulation of the Detector Response

  We cannot simulate actual frames at accelerators…

  We need to validate our analysis codes on realistic simulations…

  We need to separate the sensor effects from the electronic response characteristics of the detector chips…

  See talk from Dec. 2014 FLUKA Collaboration Mtg.

  We need to measure the light fragment cross sections for transport simulation…

  We need to be able to simulate the shielding of the spacecraft in detail to select monitoring locations intelligently…

67


Initial FLUKA Results

  Fe beam at normal incidence.   Several Fe beam events per 'time frame' - X and Y

axis here give the pixel coordinate system.

68

DATA! FLUKA Simulation!

From Toni Empl!


Initial FLUKA Results

  400 MeV/A Fe beam at 60 degree incidence   Similar agreement is found for inclined Fe tracks

through the Timepix-3 sensor.   The approach seems to work rather well given the

extremely naive ansatz. 69

DATA! FLUKA!Simulation!

From Toni Empl!


A Nuclear Interaction In A Solder-Bump From An Upward-Moving Primary

70

Interaction!Fragments!Seen in the!

ISS REM!


Cross Section Measurement Configurations

71

Tilted Quad!

Simple In Line!


Double Differential Nuclear Interaction Cross Section

Measurements   Place a thin target ~ 1 cm in front of a Timepix

centered on a small incident heavy ion beam spot.   One would see all of the non-interacting beam

particles to determine the absolute incident flux.   Using the angular information in the cluster images

caused by the fragments from interacting incident beam particles, one can estimate the vertex location.

  From that, it is possible to determine the emitted angle of each fragment.

  Since the “projectile” fragments typically have velocities close to that if the incident beam, one can determined the individual charges of each fragment…

72


https://dl.dropboxusercontent.com/u/46291346/SAA_20_4_2013.mp4!

From Stuart George!


Using Timepix To Measure Absolute Double Differential

Interaction Cross Sections

74

Interaction!Fragments!Seen in the!

ISS REM!


LET∞ Conversion (Track-by-Track) From Si to Water (or soft tissue…)

75

!“Stopping Power” (dE/dx) of tissue with respect to Silicon…!

FROM SRIM!


76

Solder Bumps – Close Up


77

Solder Bumps on Both the Chip and the Sensor…


TOT Calibration in the Timepix3

78

Seems to work OK!


79

Energy

TOT

Timepix and its TOT mode (A Wilkinson-Type ADC)

  Input charge is discharged with a constant current source, giving rise to a triangular voltage pulse shape.

  If the pulse shape is triangular then Time over Threshold is proportional to collected charge i.e. to energy.

  Due to limited bandwidth the pulse can be NEVER perfectly triangular.

  Non-linear TOT to energy dependence Threshold

Time

Ener

gy

Calibration curve

Counter in each pixel can be used as " Timer to measure detection time => TOF experiments, TPC detectors, … " Wilkinson type ADC to measure energy of each particle detected.

Time"


Another Image…

80 ~210 MeV/A O ion…!

TOT! TOA!

δ-ray!

…However, electrons scatter and can be produced at any point

along the track…!

…But they are still easier to see in TOA!


Lower Bias Voltage Elongated Clusters

  a

81

230 MeV/u O with 40 V Bias Voltage w/ 500 um sensor…!The effect goes away at a 100 V Bias Voltage…!


EFT-1 Launch (As Seen by my iPad @ 10 km)

82 > 800,000 Kg at Launch!

Summary of Medipix Technology's 3-Years in Space…and ...

Documents

Transcript of Summary of Medipix Technology's 3-Years in Space…and ...