The AGIPD Detector

for the European XFEL

Julian Becker (DESY), Roberto Dinapoli (PSI), Peter Goettlicher (DESY),

Heinz Graafsma (DESY), Dominic Greiffenberg (PSI), Marcus

Gronewald (U Bonn), Beat Henrich (PSI), Helmut Hirsemann (DESY),

Stefanie Jack (DESY), Robert Klanner (U Hamburg), Hans Krueger (U

Bonn), Alessandro Marras (DESY), Aldo Mozzanica (PSI), Bernd

Schmitt (PSI), Xintian Shi (PSI), Ulrich Trunk (DESY), Jiaguo Zhang (U

Hamburg)

XFEL -Detector Requirements

Unique time structure of the beam: • 600 µs long bunch trains at a repeatition rate of 10 Hz

• Each train consists of 2700 bunches with a separation of 220 ns

• (SASE) Each bunch consists of ~1012 photons arriving <100 fsOther specifications:

• 27000 X-ray flashes per sec

• Wavelength: 0.1 .. 6 nm (12.4 .. 0.2 keV)

• Peak Brilliance: 5.1033 ph/(s.mm2.rad2.

0,1% bandwidth)

XFEL -Detector Requirements

Beam provides

Simultaneous deposition of all photons

Challenges

Single photon counting not possible

Approach

Charge integration

High number of bunches

2700 bunches per train (600 µs)

Reading out of single frames impossible

Analog storage on >200 storage cells

Dynamic range of the detector: 0 … <104 ph/pixel

Dynamic gain switichng

3 gain stages

Single photon counting capability for highest gain

AGIPD - Design

The AGIPD Detector

64 x 64 pixels

2 chips

8 chips

4 modules

Specifications

• 1 Mpixel

• 16 modules (4 x 4)

1 module: 8 x 2 chips,

1 chip: 64 x 64 pixel

• Pixel size:

200 x 200 µm2

• Sensor:

500 µm thick Si

• Hole for direct beam

• Active cooling

AGIPD - Prototypes

AGIPD 0.1 AGIPD 0.2 AGIPD 0.3

• No pixels yet

• 3 readout blocks consisting of:

Readout chain (Preamp + CDS stage)3 different kinds of leakage current compensation

• 16 x 16 pixels

• 100 storage cells

• No leakage current compensation

• Different combinations of preamps and storage cell architechures

• 16 x 16 pixels

• 200 storage cells

• Radiation hard storage cell design

• High speed serial control logic

AGIPD – Characterization

AGIPD 0.1 AGIPD 0.2 AGIPD 0.3

• Linearity of the gain

• Stress-test of the input gate at the preamp

•Temporal behavior of the preamp and CDS stage

• Energy calibration

• Noise determination

• Pixel-to-Pixel variations

• Storage cells variations

• First imaging

• Radiation hardness of storage cells

• Test of the high speed serial control logic

AGIPD 0.1 - Linearity of the gain(before stress-test)

• Linearity test using a pulser applying voltage pulses on a 11 pF input capacitance:

A voltage pulse of 1 V corresponds to an equivalent charge of ~20000 x 12 keV photons

Pulsing with 1 kHz for 1 hour: 3.6 106 x 20k 12 keV photons

• Rise time of the pulse: 5 ns

AGIPD 0.1 - Linearity of the gain(before stress-test)

High gainstage:0.35 % (rms) 0.27 x 12 keV ph. (max)(range: 7 .. 51 x 12 keV ph.)

Medium gainstage:0.15 % (rms)2.6 x 12 keV ph. (max)(range: 360 .. 1500 x 12 keV ph.)

Low gainstage:0.13 % (rms)11.8 x 12 keV ph. (max)(range: 2000 .. 7000 x 12 keV ph)

AGIPD 0.1 - Linearity of the gain(before stress-test)

Linearity < 1% for whole dynamic range!

AGIPD 0.1 - Linearity of the gain

(after stress-test)

AGIPD 0.1 -Linearity of the gain

(after stress-test)

Are the pulses arriving fast enough? How does the switching look like?

Direct measurements (Preamp/CDS)High gainstage

Resumee:

• Risetime of pulser is 5 ns

• Preamp and CDS are properly working within ~50 ns

No switching

Direct measurements (Preamp/CDS)

Medium gainstage

1x switching

Direct measurements (Preamp/CDS)Low gainstage

2x switchings

Direct measurements (Preamp/CDS)Low gainstage

2x switchings

Resumee:

• Preamp and CDS are properly working within ~50 ns, also when gain switching 1x and 2x

AGIPD 0.2 – Energy calibration

• Energy calibration done using X-ray fluorescence from Ge (10 keV), Mo (17.5 keV) and Sn (25 keV)• Integration time was 1 s• Sensor voltage 120 V• 600000 frames investigated per photon energy Ge (10 keV) Mo (17.5 keV) Sn (25 keV)

Nonlog scale to demonstratelow number of fluorescence photons!

AGIPD 0.2 – Energy calibration / Noise

Noise measurements with an integration time of 100 ns reveal a value of (1.15 ± 0.11) keV, corresponding to an ENC of (318 ± 30) e-

AGIPD 0.2 – Pixel-to-Pixel variations

Pixel-to-pixel variations of the gain: ~ ± 1.9 % (rms)

AGIPD 0.2 – Imaging: the „A“

SummaryAGIPD 0.1

• Linearity better than 1 % for all gain stages

• Input gate stress-test revealed no degradation neither in gain nor in linearity after extensive pulsing with an equivalent of up to 7.108 x 1.1.105 12 keV photons

• Rise time of the preamp and CDS ~ 50 ns (within expectations)

AGIPD 0.2

• Noise: (1.15 ± 0.11) keV = ENC of (318 ± 30) e-

Single photon resolution demonstrated for high gain stage

• Pixel-to-Pixel variations: ± 1.9 % (rms)

• Storage Cell variations: ± 0.65 % (with simple correction algorithm): ± 0.01 %

• Imaging capability shown