RoentDek DLD40 User manual

RoentDek
HandelsGmbH
Supersonic Gas Jets
Detection Techniques
Data Acquisition Systems
Multifragment Imaging Systems
MCP Delay Line
Detector Manual
(Version 6.2.90.5)

Page 2 of 80 MCP Delay Line (Version 6.2.90.5)
Mail Addresses:
Headquarter
RoentDek Handels GmbH
Im Vogelshaag 8
D-65779 Kelkheim-Ruppertshain
Germany
Frankfurt branch
RoentDek Handels GmbH
c/o Institut für Kernphysik
Max-von-Laue-Str. 1
D-60438 Frankfurt am Main
Germany
Web-Site:
www.roentdek.com

MCP Delay Line (Version 6.2.90.5) Page 3 of 80
Table of Contents
1DETECTOR SYSTEM - COMPONENTS...............................................................................................................5
2THE MICROCHANNEL PLATE DETECTOR .....................................................................................................7
2.1 CHARACTERISTICS................................................................................................................................................. 7
2.1.1 Physical Characteristics of the Detector - Specification ........................................................................7
2.1.2 Physical Characteristics of MCPs................................................................................................................7
2.1.3 Electrical Characteristics of the Detector ....................................................................................................7
2.2 GENERAL DESCRIPTION......................................................................................................................................... 8
2.3 POSITION ENCODING ............................................................................................................................................. 8
2.4 ASSEMBLY OF THE MCP-DETECTOR ................................................................................................................... 10
2.4.1 List of Detector Assembly Parts..................................................................................................................10
2.4.2 Preparation.................................................................................................................................................11
2.4.3 Now the detector can be finally assembled.................................................................................................12
2.4.3.1 Connecting the Wires to the Delay-line Anode.........................................................................................................12
2.4.3.2 Assembly of the MCP-stack for the DLD40, DLD80 and HEX80 ...........................................................................13
2.4.3.3 Assembly of the MCP-stack for the DLD120 and HEX120 .....................................................................................16
2.4.4 Mounting the Detector an experimental setup............................................................................................18
2.4.5 Connecting the Signal Cables to the Feedtrough Flange ...........................................................................19
2.4.6 Operation of the Delay-line Detector – General Description.....................................................................21
2.5 THE FT12(16)-TP................................................................................................................................................ 22
2.6 THE ATR19 AMPLIFIER &CFD MODULE ........................................................................................................... 23
2.6.1 Signal inputs and amplification ..................................................................................................................24
2.6.2 The DLATR board.......................................................................................................................................27
2.6.3 CFD controls and outputs...........................................................................................................................27
2.6.4 Connecting and operating the ATR19.........................................................................................................29
2.6.5 Opening the ATR19 module........................................................................................................................30
3DATA ACQUISITION HARD- AND SOFTWARE..............................................................................................33
3.1 THE TIME-TO-DIGITAL-CONVERTERS (TDC) FOR PC.......................................................................................... 33
3.1.1 The HM1 / HM1-B......................................................................................................................................33
3.1.2 The TDC8....................................................................................................................................................34
For details of the TDC8 module versions please refer to the separate manual.................................................................................35
3.1.3 The CCC1 ...................................................................................................................................................36
3.2 HARD-AND SOFTWARE INSTALLATION ............................................................................................................... 36
3.2.1 HM1 / HM1-B.............................................................................................................................................36
3.2.2 TDC8...........................................................................................................................................................38
3.3 CONNECTING THE ATR19 WITH THE TDC........................................................................................................... 39
3.3.1 HM1 / HM1-B.............................................................................................................................................39
3.3.2 TDC8 (or other TDCs, e.g. via CCC1) .......................................................................................................39
3.3.3 CCC1 ..........................................................................................................................................................39
3.4 STARTING THE COBOLDPC SOFTWARE: ............................................................................................................ 40
3.5 THE “XXX STANDARD.CCF”................................................................................................................................. 41
3.5.1 DAQ parameters (here for TDC8PCI2 as an Example) .............................................................................42
3.5.2 DAQ coordinates ........................................................................................................................................43
3.5.3 DAN parameters and coordinates: .............................................................................................................43
3.5.3.1 DAN parameters (here for TDC8PCI2 as an Example) ............................................................................................43
3.5.3.2 DAN coordinates, primary........................................................................................................................................46
3.5.3.3 DAN coordinates, secondary, for DLD detectors......................................................................................................47
3.5.4 Spectra and conditions................................................................................................................................47
4THE DETECTOR POWER SUPPLIES HV2/4 AND BIASET2 WITH BATTERY BOX BAT2 ...................49
4.1 THE HV2/4:......................................................................................................................................................... 49
4.2 THE BIASET2..................................................................................................................................................... 50
4.2.1 ECH 114 –K(BIASET2 CRATE).................................................................................................................... 52
4.2.2 EHQ 104M_AIO(HV1/4) OPERATORS MANUAL ........................................................................................... 53
4.2.2.1 General information....................................................................................................................................54

Page 4 of 80 MCP Delay Line (Version 6.2.90.5)
4.2.2.2 Technical data.............................................................................................................................................54
4.2.2.3 EHQ Description ........................................................................................................................................55
4.2.2.4 Front panel .................................................................................................................................................56
4.2.2.5 Handling .....................................................................................................................................................57
4.2.2.6 Analogue I/O...............................................................................................................................................58
4.2.2.7 Block diagram EHQ....................................................................................................................................59
4.2.2.8 EHQ side cover...........................................................................................................................................60
Changing the Polarity.................................................................................................................................................60
4.3 BAT2 BOX ............................................................................................................................................................61
4.4 BAT3 BOX ............................................................................................................................................................62
5GETTING STARTED..............................................................................................................................................63
5.1 CHECKING THE NOISE LEVEL .............................................................................................................................. 63
5.2 VERIFICATION OF THE HIGH VOLTAGE SAFETY................................................................................................... 63
5.3 INITIAL START-UP PROCEDURE............................................................................................................................ 65
5.4 FINAL ADJUSTMENT ............................................................................................................................................ 66
6PERFORMANCE.....................................................................................................................................................69
7TROUBLE SHOOTING/FAQ.................................................................................................................................71
APPENDIX A. (MCP’S):............................................................................................................................................77
LIST OF FIGURES..........................................................................................................................................................79
LIST OF TABLES............................................................................................................................................................80

MCP Delay Line (Version 6.2.90.5) Page 5 of 80
1Detector System - Components
This manual describes all components of the RoentDek delay-line detector system as it can be delivered for the DLD40,
DLD80, HEX80 and DLD120 and HEX120 detector. Even if you have not purchased the complete system you will find
valuable information in the chapters describing the different components about the link between the components and the
operation. However, you might have received only the relevant parts of this manual.
If you have received special detector components, i.e. a detector of different size or type, or other electronic modules you will
find a separate manual commenting on peculiarities of your special system. In this case the information given here is mostly
relevant for your system but you might need extra information.
•DLD or HEX microchannel plate detector with delay-line anode
•ATR19 module: 6 or 8-channel fast (differential) amplifier with integrated constant-fraction-discriminator (NIM or
ECL-output)
•FT12(16)-TP 12-pin CF35 (and fourfold MHV) UHV-feedthrough flange(s) and CF100/CF150/CF200-CF35-
adapter (optional)
for Hexanode: additional 3 signal decouplers
•TDC8 or HM1 (optional)
•HV2/4 BIASET2 and BA2 or similar 4kV High Voltage Supplies (optional)
•Data acquisition and data analyzing software CoboldPC (optional)

Page 6 of 80 MCP Delay Line (Version 6.2.90.5)

MCP Delay Line (Version 6.2.90.5) Page 7 of 80
2The Microchannel Plate Detector
Typical performance:
position resolution < 0.1mm
overall linearity 0.2mm
rate capability 1MHz
multi-hit dead time 20ns (with ATR19, intrinsic detector signal dead time 5ns)
2.1 Characteristics
2.1.1 Physical Characteristics of the Detector - Specification
Mounting Flange Size: CF 100/CF 150/CF 200
Height above Flange: ≈100mm (adjustable)
Mounting Diameter: 94/144/196/246mm
Baking Temperature: 150°C Maximum
2.1.2 Physical Characteristics of MCPs
# of MCPs in Chevron stack 2
Outer Diameter: 50*/86.6/127mm
Active Diameter: 47*/83/120mm
L/D 60:1*
Thickness 1.5mm*
Pore size 25μm*
Center-to-center spacing: 32μm*
Bias Angle: 7° ±2°
Open Area Ratio: >50%
Operating Temperature Range: -50 to 70°C
Operating Pressure: < 2 ×10-6mbar
* for Photonis MCP: 46mm OD (42mm active), L/D 80:1 , 1mm thickness, 12.5μm pore size
2.1.3 Electrical Characteristics of the Detector
Chevron (2 MCPs)
Electron Gain @ 2400Volts: 1×107Minimum*
Operating Voltage: 2400V typical*
* for Photonis MCP: about 300V higher voltages are to be applied.
It is possible to further increase the gain by using triple stacks of these MCP. Please contact RoentDek for advice.
If you have chosen a detector set with central hole the hole size in the MCP is usually 6.4mm and the minimum active
diameter 9mm.

Page 8 of 80 MCP Delay Line (Version 6.2.90.5)
2.2 General Description
The RoentDek MCP detector with delay-line anode is a high resolution 2D-imaging and timing device for charged particle
or photon detection at high rates with multi-hit capability. The linear active diameter is at least 40mm for the DLD40, 80mm
for the DLD80 and about 120mm for the DLD120. The RoentDek Hexanode has a third delay-line layer that gives
redundant detection opportunities either to improve the multi-hit performance or to allow the construction of a MCP setup
with central hole and minimised blind detection area. In its usual version (HEX80) it has about 75mm redundant detection
area (hexagonal) and covers at least 80mm linear total detection area with at least two layers (HEX120: 100mm redundant,
115mm linear, 120mm total). For detectors with central hole (HEX40/o and HEX80/o) most of the descriptions in this
manual are relevant too.
The detector consists of a pair of selected rimless MCPs in chevron configuration, or sometimes of a triple stack (Z-stack)
and a helical wire delay-line anode for two-dimensional position readout. The MCPs are supported by a pair of partially
metallized ceramic rings (1.5/2mm thick, 65/105mm outer diameter for DLD40/DLD80/HEX80) and a 2D-position
sensitive delay-line anode (helical wire pair). The metallization of the ceramic rings is Nickel (for DLD80/HEX80 covered
with Gold). The metal contacts on the ceramic rings are suitable for soldering, clamping or spot welding. For the DLD120
and HEX120 the MCP stack is mounted between a metal front ring and the holder plate.
For the 40 and 80 mm MCP, the MCP stack is mounted independently so that different anode types can be implemented (e.g.
UHV-compatible Wedge-and-Strip anodes or timing anodes without position resolution, also available from RoentDek).
The MCP-holder system itself measures 66 ×6mm or 105 ×7mm.
The operation requires two DC voltages for MCP front and back contacts and three voltages for the support plate (“holder”)
and the wires. All voltages can be supplied by separate HV-supplies or a resistor chain. It is recommended to use individual
power supplies for biasing of the MCP stack and the delay-line anode.
The baking limit for UHV applications is specified as 150°C.
2.3 Position Encoding
The position of the detected particle/photon is encoded by the signal arrival time difference at both ends for each parallel
pair delay-line, for each dimension independently. While the signal speed along the delay line is close to speed of light in
vacuum, one can define a perpendicular signal speed v given by the pitch of one wire loop (typically 1mm) and the time,
which a signal needs to propagate though this loop. This defines the single path propagation “time” 1/v, given in ns/mm.
The corresponding ends of the delay-lined for each dimension are located on the opposite corners of the array (rear side).
The electrical resistance of each wire is between 5 and 100Ωend-to-end, depending on the size of the delay-line and the wire
type used. Corresponding ends of wires can such be identified. The four (or six) wire pairs from the delay-line ends of each
layer have to be connected from the corner contacts of the anode to vacuum feedthroughs by a twisted-pair wire
configuration (both wires of a pair must have equal lengths, within 5mm). From the feedthroughs the signals must be
transmitted (after DC-decoupling) to a differential amplifier or signal transformer via twisted pairs.
The difference between the signal arriving times at the adjacent ends of each delay-line is proportional to the position on the
MCP in the respective dimension. The sum of these arrival times is constant (within the time resolution of about one ns) for
each event. The time sequence of the signals can be measured by two time-to-amplitude converters (TAC) or an n-fold time-
to-digital converter (TDC). n is at least 4 or up to 7 (Hexanode with separate timing channel). As time reference (start of the
TDC) the signal on the MCP back or front side can be used.
For the DLD detectors, the digital encoding to receive a 2d digital image (X/Y) is
X = x1 – x2 and Y = y1 - y2 Equation 2.1
with x1, x2, y1 and y2 denominating the TDC channel number for each event (see next chapter).
The fast timing signal picked up from an MCP contact or, in the case of a pulsed particle/photon source, a “machine trigger”
signal can serve as time reference. The single path signal propagation time on the delay line is about 0.71ns/mm for DLD40,
0.98ns per mm for DLD80 and 1.25ns per mm for DLD120. Thus the correspondence between position and time in the 2d
image is twice this value: about 1.42ns/mm, 1.96ns/mm or 2.5ns/mm, respectively. Note that these numbers are only
accurate within 5% and are slightly different for each dimension. In order to calculate the position in mm from the digital X
and Y values you have to take into account the bin width of your TDC and the single path propagation time 1/v for the
respective layer.

MCP Delay Line (Version 6.2.90.5) Page 9 of 80
Figure 2.1: Operation principle of the delay-line-anode
The Hexanode has an additional layer. It is possible to calculate the two-dimensional particle position from the signals of
any two layers. The signals from a third layer serve as a redundant source of information for cases where signals are “lost”
due to electronic dead-time (multiple hit events), non-continuous winding schemes (anode with central holes) or non-perfect
electronic threshold conditions/damping on special very large delay-line anodes.
If you mount the anode to your MCP set with the wires of the innermost layer aligned with respect to the desired up/down
direction in your digital screen image (i.e. Y-direction) and if you follow the connection scheme in the next section, the
position calculation can be done with following codes:
The position in a hexagonal coordinate frame is coded by the arriving time differences from signals in opposite corners of the
anode.
u = (x1 – x2) * d1
v = (y1 – y2) * d2
w = (z1 – z2) * d3 + o
Equation 2.2
If 1/viis the single path signal propagation speed for a delay line layer I (viis slightly different for each layer) then diis given
by
1/di= 2 vi* ΔtEquation 2.3
Δt is the TDC channel width. dimust be precisely known to make the images obtained via different layer combination
coherent. o is an offset value that shall unify the “time difference zero” of all three layers, i.e. it must be chosen so that
geometrically the position lines for calculated u, v, w have a common crossing point, e.g w must be zero when u and v are
zero.
For the HEX80 approximate values for viare 0.737, 0.706 and 0.684mm/ns, from inner to outer layer (u, v, w). o differs
from anode to anode and is close to zero unless the connection cables have varying length.
To achieve optimal results v1, v2, v3and o must be calibrated for each delay-line by using acquired data (off-line).
The hexagonal frame can be transformed into a Cartesian coordinate system by the following equations using only two of the
hexagonal coordinates respectively:
Xuv =
Oxu +
()
Oyvu +− 2
3
1
Yuv =
Xuw = Xuv
Equation 2.4
()
Oyuw +−2
3
1
Yuw =
Xvw =
()
Ox++ wv
()
Oyvw +−
3
1
Yvw =
Ox and Oy are offsets.
For detectors with central hole, the gaps in the wiring have to be taken into account. Please contact RoentDek for the
program codes appropriate for your detector.

Page 10 of 80 MCP Delay Line (Version 6.2.90.5)
The X and Y positions can be calculated from any combination of these equations. If for a given event more signals than
from the minimum of two layers are available, it is recommended to choose signals from those two layers where the positions
are most distant from the respective delay line ends (and gaps).
Timing information:
In order to determine the time difference between an outer time marker and the particle impact, the signal at the MCP
contact can be used. But it is also possible to deduce the particle impact time from the delay-line signals:
If the MCP signal is used as the start of the TDCs, the “time sum” values
sumx = x1 + x2
sumy = y1 + y2 Equation 2.5
sumz = z1 + z2
are constant within the time resolution (less than one ns) for all positions. Thus it is also possible to deduce the particle
impact time from these time sum values. In order to achieve a high resolution one should take into account that the time sum
value on a layer varies slightly with the position on this layer in a fixed pattern. Please contact RoentDek for advice how to
incorporate that into the code.
Even if the particle timing is not of interest, the time sum values can be used to verify a proper detector function.
2.4 Assembly of the MCP-Detector
The assembly should take place under clean and dry conditions.
2.4.1 List of Detector Assembly Parts
•ceramic rings, partially metal coated (for DLD40, DLD80 and HEX80)
•two multi-channel plates, selected for chevron configuration, matched in resistance
•metal spring clamps (for DLD40, DLD80 and HEX80)
•plastic screws M3 with nuts (for DLD40, DLD80 and HEX80 only during assembly of the MCP holder)
*
•1 delay-line anode
•Assorted small parts for cable connections
You will usually receive the detectors pre-assembled. For DLD40, DLD80 and HEX80 the MCP holder with rear ceramic
ring is placed on the delay-line anode, it is fixed by the retractable “shields” in a position that should be resumed after
assembly of the MCP stack. Please observe the relative angle of the metallization structure and remount the MCP stack, after
assembly, so that the rear ceramic ring is in about the same orientation as before (shown in Figure 2.2).
Figure 2.2: Orientation of the rear ceramic ring on the Delay-line assembly (DLD40, DLD80 and HEX80)
*For DLD120 and HEX120: 6 Vespel M3 screws and 3 plastic M3 rods (only during assembly of the MCP holder)