manualshive.com logo in svg

RoentDek DLD120, Руководство пользователя

Поделиться
Скачать
RoentDek DLD120 Скачать руководство пользователя страница 65

 

 

 

MCP Delay Line (Version 6.2.90.5) 

Page 65 of 80 

 

In rare cases it happened that after shipping either the connection cable or the 

DLATR6(8)

 box underwent damage and the 

reason for a discharge can actually be found in the cable or the 

DLATR6(8)

 box. In order to check this, remove the cables 

from the feedthrough and repeat the procedure. No discharge should occur now. Otherwise contact 

RoentDek

.  

 

Whenever you make changes to the detector hardware or the cable connections you should repeat this procedure. 

5.3

 

Initial Start-up Procedure 

If you apply voltage across the MCP stack for the first time this must be done very slowly and in a very controlled way, also if 
you increase the voltage further after operating formerly at lower voltage. Please also refer to the separate manual for MCP 

handling. 
Even after you have verified that there was no discharge when applying voltages to the detector, you could not yet verify a 

possible discharge problem between “MCP front” and “MCP back” contact. Usually the risk for that is very small. Although 
there is a minimum chance for amplifier damage by such a connection problem you should from now on operate with 

amplifiers active to verify the MCP stack during the startup procedure.  
If you want to apply voltages in the 

electron detection mode

, connect the MCP front output (#1) of the 

FT12(16)-TP

 plug to the 

ATR19/NDLATR6(8)

 channel 1 or 2 and terminate the MCP back output (#2) with an adjustable lemo terminator. In case 

of the 

DLATR6(8)

 use the A1 output to verify the signal from the MCP stack (front side). The switch for channel 2 on the  

DLATR6(8) 

front panel

 

should be set to “poti”. This is the safest way for the electronics in the event of a discharge. It is 

recommended, however, to start the MCP operation for the first time in 

ion detection mode

. 

If you want to apply voltages in the 

ion detection mode

, connect the MCP back output (#2) of the 

FT12(16)-TP

 plug to the 

ATR19/NDLATR6(8)

 channel 1 or 2 and terminate the MCP front output (#1) with an adjustable lemo terminator. In case 

of the 

DLATR6(8)

 use the A2 output to verify the signal from the MCP stack (back side). The switch for channel 1 on the  

DLATR6(8) 

front panel should be set to “poti”. This is the safest way for the electronics in the event of a discharge. 

 
The 

ion detection mode

 will generally be easier for the following start-up procedure as in this case the anode potential can be kept 

constant and only one potential (“MCP front”) must slowly be increased, when putting operation voltage to the MCP stack. 
Therefore this mode is strongly recommended for the following procedure, even if you plan to run the detector in 

electron 

detection mode

 later. 

 

1.

 

Turn off all ion gauges and any sources emitting a high rate of charged particles (ion pumps?) or high energetic 
photons (UV and higher) in the vicinity of the detector. All detector potentials are on ground potential or close to 

that. 

 

2.

 

Set the potentials for the anode (holder, signal wire, reference wire) to the voltages for 

ion detection mode

 as 

recommended in the “operation” sub-section. 

 
Now the voltage across the MCP stack must be increased. For 

ion detection mode

 you only need to increase “MCP front”, 

leaving “MCP back” at ground potential. For 

electron detection mode

 you should leave “MCP front” at or close to ground 

potential while you increase “MCP back” and consequently also the anode potential to proper voltages between the anode 

and “MCP back”. In this case also verify that the “MCP front” or “MCP back” potential, whichever you expect to stay near 
ground potential really does so while you increase the potential on the other side of the MCP stack (see section 2.4.6). In the 

following only the relative voltage across the MCP stack will be referred to and the other potentials must be adjusted in 

electron detection mode

 to maintain proper operation condition. Please refer to section 2.4.6 about these relative voltage limits. 

 

3.

 

Increase the voltage across the MCP stack (bias) to 1000V. From now on verify the signals from the MCP on 

Outputs A1 or A2 (monitor). Any real MCP signals (i.e. some “dark” counts) will not appear before 1500V MCP 
bias. In the following you will increase the MCP bias in steps of 100V about every 10 minutes. If you see other 

signals on the oscilloscope than electronic noise, or if you experience a discharge then reduce the bias to zero and 
start again. In case of discharge verify that the amplifier still gives the “normal” noise level, otherwise it could have 

been damaged (contact 

RoentDek

). If the discharge problem persists or if a high rate of dark counts appears you 

have some connection problem inside or the MCP stack is damaged. Check if you can rule out the presence of any 

real particle sources (note, that a sharp tip like on a damaged mesh can emit electrons in the presence of a strong 
field). If you can not find the reason for the malfunction please contact 

RoentDek

. 

 

4.

 

At a certain MCP bias (around 2000V) you should see a few dark counts (usually less than 50/s for the 

DLD40

 and 

< 200/s for the DLD80). MCP signals from particle counts or dark counts at the An (monitor) outputs are fast 
negative signals of a few ns rise time. They have amplitudes between noise level and about 400mV (on 50

Ω

 input). 

Before you reach 2500V MCP bias you should stop the procedure.  

Содержание DLD120

Страница 1: ...RoentDek Handels GmbH Supersonic Gas Jets Detection Techniques Data Acquisition Systems Multifragment Imaging Systems MCP Delay Line Detector Manual Version 6 2 90 5 ...

Страница 2: ...ail 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 ...

Страница 3: ...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 3 DATA 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 SO...

Страница 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 5 GETTING 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 6 PERFORMANCE 69 7 TROUBLE SHOOTING FAQ 71 APPENDIX A MCP S 77 LIST OF FIGURES 79 LIST OF TABLES 80 ...

Страница 5: ... 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 cons...

Страница 6: ...Page 6 of 80 MCP Delay Line Version 6 2 90 5 ...

Страница 7: ...er 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 1 107 Mi...

Страница 8: ... 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 correspondin...

Страница 9: ...h signal propagation speed for a delay line layer I vi is slightly different for each layer then di is given by 1 di 2 vi Δt Equation 2 3 Δt is the TDC channel width di must 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 positio...

Страница 10: ... 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 configurat...

Страница 11: ... ring from the delay line Two of the shields can be retracted to liberate the stack after the M2 screws are loosened Note that the shields must not touch any contacts on the ceramic rings and that the spring clamps that hold the stack together are mounted with about 45 angle with respect to the delay line so that they are not touching any metal part This orientation has to be resumed when re assem...

Страница 12: ...ly 2 4 3 Now the detector can be finally assembled Preferably under clean room conditions 2 4 3 1 Connecting the Wires to the Delay line Anode You need the set of 4 6 twisted pair cables to connect the anode wires In the four corners of the anode back side each pair must be connected to the M2 rods preferably with the connector pins provided Mounting the cable in a different way i e by M2 nuts is ...

Страница 13: ... you have to decide if you want to solder the cables for the MCP contacts directly to the contacts pads on the ceramic ring This is recommended Even for UHV environment a small amount of lead free solder flux is usually tolerable In this case remove the screw from the front ring and solder a cable to a pad on each ring After soldering the parts should be cleaned If you prefer not to solder the cab...

Страница 14: ...MCPs There is no need for a special tilt angle orientation Figure 2 10 Assembly of MCP stack Stage 2b DLD40 DLD80 HEX80 It is especially important to avoid that dust particles settle between the MCP during assembly Dust particles can usually be blown away be spraying dry air on the MCP Touch MCPs only with care along the rim preferably with gloves After the stack is piled you may check if it is we...

Страница 15: ...lder the wire to the MCP back side contact a special spring clamp is provided that can be inserted between the rings at a position with a contact pad on a hole on the back side ring Make sure again that there is no such contact pad on the upper ring at this position Figure 2 15 MCP stack with spring ring for MCP back cable DLD40 DLD80 HEX80 4 Now the MCP stack can be mounted to the anode by insert...

Страница 16: ...MCP stack for the DLD120 and HEX120 A cartoon about the mounting of the MCP stack for the DLD120 and HEX120 can be found on our Web Site in the MOVIES section For the 120mm MCP size the mounting is different than for the 40 or 80mm MCP sizes no ceramic rings are used Instead the MCPs are fitted between a metal square shaped rear plate which mates to the delay anode and a metal front ring The rear ...

Страница 17: ...ell centered adjustments can be done by carefully moving the MCPs on the ring If the MCPs need replacement mount a set with matching electrical resistance only 3 Place front metal ring with the indented side facing downward on the MCP The guide pins will help in the alignment Figure 2 21 Assembly of MCP stack Stage 3 1 DLD120 and HEX120 Now fix the stack with three plastic screws very carefully an...

Страница 18: ...product option for each detector type to mount it to a flange of Conflat norm The size of the flange is given by the detector dimension If you are not using this option you may instead use the outermost threaded holes in the holder to mount the detector to your experimental setup Please note that the holder plate will usually carry a much different potential than the mating part of your experiment...

Страница 19: ...d twisted pair cables of sufficient lengths as described before in this section The cables should only be as long as necessary Especially the quality amount of ringing of the MCP signal is usually better if the connection cable is very short For the DLD connect all 8 signal cables from the delay line and the other 3 or 4 high voltage cables MCP front MCP back anode holder plate and optional mesh f...

Страница 20: ... reference No 3 No 3 No 9 y1 signal No 5 No 5 3 No 10 y1 reference No 5 No 5 No 11 y2 signal No 6 No 6 4 No 12 y2 reference No 6 No 6 Table 2 2 FT12 TP pin description for HEX detectors If a connector pin is too close to the chamber wall or a neighboring pin this may result in a discharge during detector operation with further consequences to the electronics Please give special attention to pins 1...

Страница 21: ...ons For UV photon detection the MCP front side potential is arbitrary The wire array consists of two double delay line helical propagation lines Lecher line For each dimension a wire pair is formed by a collection signal wire and a reference wire A potential difference of about 20V to 50V of the signal wire with respect to the reference wire ensures that the electron cloud emerging from the MCP is...

Страница 22: ...pin feedthrough FT12 for the in vacuum cables and the airside connector plug The plug provides adequate RC decoupling circuits and special transformer circuits to turn the differential delay line signals into single line signals with 50Ω line impedance on Lemosa type Euro norm output connectors The detector voltages are supplied via input cables SHV UReference Reference wires USignal Signal wires ...

Страница 23: ...setting for differential amplification Attention Although the outputs of the FT12 16 TP are delivered with DC coupling to ground potential a discharge on a detector can damage the electronics which is used to analyze or amplify the signals 2 6 The ATR19 Amplifier CFD Module This is Version 6 2 90 5 Please look for updates of this manual at http roentdek com mitte doppel links fuer_manu detect_manu...

Страница 24: ...ive signals have to be connected via the non inverting input To ensure a proper 50Ω termination of single polarity signals the other side of the internal amplifier input must be terminated to ground see chapter 2 6 1 The recommended readout version of the RoentDek delay line detectors involves the FT12 16 TP plug with internal signal transformers for the delay line signals When the ATR19 is delive...

Страница 25: ... each individual channel inside the ATR19 i e the position of the termination jumpers JP5 JP6 odd channel numbers of the ATR front panel JP8 and JP9 even channel numbers a no jumpers inputs and are active differential with 100Ω impedance Please observe the polarity b jumper on JP6 JP9 input inverting 50Ω impedance to ground can be used for positive input signals c jumper on JP5 JP8 input non inver...

Страница 26: ...put settings for differential input no input jumpers set Figure 2 33 ATR19 base board with input jumper settings for signal input through the LEMO input 50Ω impedance to ground non inverting for negative signal input The level control board was removed here for better view ...

Страница 27: ... on a board 2 6 3 CFD controls and outputs The ATR19 has the following inputs outputs and controls for each channel 2 LEMO connectors In and In for signal input see chapter 2 6 1 3 LEMO connectors for signal outputs Mon analog output signal i e the amplified signal before the CFD stage ECL Timing signal output from the CFD circuit differential ECL Only for the ECL version of the ATR19 NIM For the ...

Страница 28: ...2 on the level control board inside the ATR19 see chapter 2 6 5 enables the threshold control by the poti default setting In this mode jumper JP11 JP12 set the LEMO output carries the DC voltage for control with an Ohm meter If the jumper is removed the poti is disabled and the LEMO connector serves as input for the DC voltage from an external source A DC voltage of 5V corresponds to a threshold l...

Страница 29: ...power adapter please follow the steps in chapter 2 6 5 for opening the ATR19 and remove the inside cable end from the mains adapter to the external input If you have ordered the ATR19 for use without AC mains adapter the cable is already connected in the correct way For operating the ATR19 you need to supply DC voltages between 6V to pin 5 and between 6V to pin 8 2A each pin 1 and 2 must be ground...

Страница 30: ...om its guide slots 4 Retract the top lid 5 Fix the rear panel to the housing again It is sufficient to fix the rear panel only provisionally by a couple of screws When reinserting the screws make sure that they are entering the thread correctly Warning when the lid is open you should not connect the mains cable to the socket There is a severe risk of electroshock which might be fatal The ATR19 sha...

Страница 31: ...ector as standard differential ECL levels The ECL level is found at the pin near the red dot and the ECL at the lower pin Additionally the ECL level is supplied via a 50Ω resistor in line to the NIM LEMO connector for control see chapter 2 6 3 If JP2 JP4 is set and JP22 JP23 is left open the ECL level is directly present on the NIM LEMO connector without in line resistor Please inquire before you ...

Страница 32: ...Page 32 of 80 MCP Delay Line Version 6 2 90 5 ...

Страница 33: ... It has a common start input and 4 channels of stop inputs all differential ECL The resolution is 133ps or better adjustable the range is 14bit or up to 30bit in a special long range mode resolution and pulse pair separation ability reduced It can be operated in three modes a In the standard mode transparent mode it can detect up to 3 or 4 hits per channel with a pulse pair resolution of about 15n...

Страница 34: ...ip production discontinued It has an input for common start or common stop operation and 8 channels It operates only in transparent mode list mode and can collect up to 16 hits per channel The resolution is 500 psec and the range is 16 bit The input level is NIM Up to three TDC8 can be combined Especially two of the TDC8 can be coupled to an effective 15 ISA or 16 PCI channel single start stop TDC...

Страница 35: ...MCP Delay Line Version 6 2 90 5 Page 35 of 80 Figure 3 4 TDC8 PCI board Figure 3 5 TDC8PCI2 board For details of the TDC8 module versions please refer to the separate manual ...

Страница 36: ...ctors with commercial CAMAC TDCs providing favorable features not found in the TDC8 or the HM1 HM1 B Please refer to the separate manual Figure 3 6 CCC1 IO Card with CCC Module 3 2 Hard and Software Installation 3 2 1 HM1 HM1 B Shut down your computer For your devices safety turn off the power to your computer and all peripheral devices Drain static electricity from your body by touching the metal...

Страница 37: ...ard Inserting the card into any other type of slot can damage your card your computer or both Firmly secure the adapter with a screw or clip to ensure that the adapter is properly grounded to the computer s chassis Replace the cover of the computer as described in your computer s manual Connect the HM1 module with the I O card using the connection cable The three green LED on the HM1 module should...

Страница 38: ...he PCI Version set this parameter to 0 Locate a free ISA or PCI slot in your computer and firmly insert the card into the selected slot To avoid damaging your hardware insert the card only into a slot with the same bus type as the card Inserting the card into any other type of slot can damage your card your computer or both The TDC8PCI needs two PCI slots even though it connects only to one PCI sl...

Страница 39: ...an be used for other signals to be correlated i e from a second detector or a TOF trigger For some multi hit measurements it can be advisable to additionally connect the MCP signal to a free channel For coincidence experiments it is often of advantage to operate the TDC8 in common stop mode and supply a delayed trigger signal to the common input to arrive after the last significant signal in chann...

Страница 40: ... you have purchased the HM1 with histogramming option please refer also to the HM1 TDC manual The following procedure is mainly describing the start up in the standard transparent mode which is recommended for first use of the detector system Now you can start the CoboldPC program In this state the program has linked the proper program parts and waits for input from the command line type the comma...

Страница 41: ...rograms that define parameters and coordinates which are attributed to the data acquisition part and the data analysis part of the event handling Finally it defines spectra and conditions Due to this modular construction it is possible to use almost the same data analysis sequences for different hardware i e TDC types Some users find this sequenced structure of the xxx Standard ccf file not adequa...

Страница 42: ...rt time of list mode file internally set Parameter 8 DAQ ID internal parameter DAQ_ID_RAW 0x000000 for RAW no Data DAQ_ID_TDC8 0x000002 for TDC8 ISA PCI DAQ_ID_2TDC8 0x000005 for 2 TDC8 Advanced Burst Mode Parameter 9 LMF version number internal parameter Parameter 14 Defines whether common start or common stop mode is used Default is 0 common start If the common stop mode 1 is used the TDC output...

Страница 43: ...by computed coordinates such as the position or time sum TOF derived from the raw data It also comprises some correction shifting and rotation computations and coordinate system transformations so that the basic computations for experiments with a position and time sensitive detector are already available without changing the DAN dll supplied here The computations yield in an additional set of coo...

Страница 44: ...ber is the number of resolution bins i e LSB If it is set to 1 the unit is transformed to ns using the TDC resolution value parameter 20 If the parameter is 2 a position in mm is calculated using the values of parameters 110 and 111 and 112 The time sum values are in ns unless the parameter is 0 Parameter 102 Hexanode calculations 0 no Hexanode 1 Hexanode If a Hexanode is used additional calculati...

Страница 45: ...e exchange the values for X and Y only for DLD and try again to sort the data possibly the physical dimensions of the anode have been exchanged during mounting Parameter 112 pTPCalW Time to Position calibration factor for w 1 v in mm ns only for Hexanode 1 4620 for HEX80 Parameter 120 pCOx Rotation Offset Center for PosX Parameter 121 pCOy Rotation Offset Center for PosY These parameters define th...

Страница 46: ...bsolute time of event from the start of data acquisition in µs only if enabled see parameter 2 DeltaEventTime time between an event and the previous event in µs only if time stamp recording is enabled see parameter 2 This spectrum can be used to determine the average event rate use the fit exp CoboldPC command on the acquired spectrum EventCounter number of event from the start of data acquisition...

Страница 47: ...y pOSum PosX x position PosX x pOPx PosY y position PosY y pOPy If hex flag not set PosY Yuv If hex flag set r r coordinate after transformation in r phi coordinates from PosX PosY phi phi coordinate after transformation in r phi coordinates from PosX PosY xRot x position after rotation yRot y position after rotation The following coordinates are only filled with valid information for the Hexanode...

Страница 48: ...fferent conditions e g by an AND to allow the analysis of even higher dimensional coordinate correlations For details about the definition of spectra and conditions for spectrum manipulation options and data I O to other programs please refer to the CoboldPC manual In the spectra ccf you find some pre defined conditions as an example and spectra that will allow you to view the most important coord...

Страница 49: ...e maximum voltage is 4kV Both can be restricted in 10 steps from 0 3mA 400 V to 3mA 4000V which is 100 Please set the maximum current to 10 i e 0 3mA when using it with a RoentDek MCP detector unless otherwise directed If the trip protection switch is set to enable kill the voltage will be turned off in case of over current or over voltage according to the settings of Vmax and Imax Otherwise the m...

Страница 50: ...rear panel Changing the Polarity of Channel A and or B To change the polarity of either channel A or B locate the red knobs on the left side panel see Figure 4 2 and place the module flat on a table showing the side panel Gently adjust the slit of the red knob to the desired polarity using either an adequate screwdriver or a coin Please make sure that the screwdriver is not tilted Do not press on ...

Страница 51: ...MCP Delay Line Version 6 2 90 5 Page 51 of 80 Figure 4 4 BIASET2 Crate with four HV1 4 ...

Страница 52: ...d Crates mounted into racks or several crates mounted in stack must be cooled by fans The analogue set voltages per channel are available on the rear side of the crate The state of readiness will be achieved with the main switch POWER on the rear Technical Data ECH 114 K Supply voltage AC 230 V 10 15 fused with 2 1 6 A T on the main plug Supply voltage DC 24 V 2 5 A 24 V 2 5 A Power max 120 W Hous...

Страница 53: ...side cover 4 2 2 9 Changing the Polarity Attention It is not allowed to use the unit if the covers have been removed We decline all responsibility for damages and injuries caused by an improper use of the mo dule It is highly recommended to read the operators manual before any kind of operation Note The information in this manual is subject to change without notice We take no responsibility whatso...

Страница 54: ...e measurement 1 V Accuracy current measurement 0 05 IO 0 02 IO max 1 digit for one year voltage measurement 0 05 VO 0 02 VO max 1 digit for one year LCD display 4 digits with sign switch controlled voltage display in V current display in µA Stability Δ VO no load load 5 10 5 Δ VO VINPUT 5 10 5 Temperature coefficient 5 10 5 K Voltage control CONTROL switch in position manual 10 turn potentiometer ...

Страница 55: ...s prevent exceeding the front panel switch settings for the current Imax and voltage Vmax limits A monitoring circuit prevents malfunction caused by low supply voltage The internal error detection logic evaluates the corresponding error signals and the external INHIBIT signal It allows the detection of short overcurrent due to single flashovers in addition Digital control unit A micro controller h...

Страница 56: ... panel 1 4 digit LCD display 2 Error indicator 3 Measuring switch 4 10 turn potentiometer 5 HV ON switch 6 CONTROL switch 7 KILL switch 8 INHIBIT input 9 HV ON indicator 10 HV output 11 Polarity indicator Figure 4 6 Front Panel of the EHQ 104M_AIO HV1 4 Module ...

Страница 57: ...ometer 4 in a range from 0 to the set maximal voltage If the CONTROL switch 6 is switched over to analogue I O control DAC high voltage will be activated only after setting the analogue set voltage in a range from 0 to the maximal set voltage Maximum output voltage and current can be selected in 10 steps with the rotary switches Vmax and Imax switch dialled to 10 corresponds to 100 on the cover si...

Страница 58: ...ng analogue set and monitor voltages These voltages are dependent on the max output voltage of the unit for 2kV VOmax 4kV is 0 VSET MON VO 400 and for VOmax 4kV is 0 VSET MON VO 1000 Pin assignment 96 pin connector on the flip side A3 B3 C3 24V A5 B5 C5 GND A7 B7 C7 24V B15 VSET internal connected to GND with 1 MΩ ...

Страница 59: ...ont panel Operating elements Resonance Converter HV Transformer Rectifier Polarity switch HV Filter HV OUTPUT Channel A rectifier AGC amplifier Precision V monitoring max I monitoring max Error logic Inhibit Supply voltage monitoring Hardware voltage ramp Filter 96 pin connector according to DIN 41612 24V Filter Figure 4 7 Block diagram EHQ HV1 4 ...

Страница 60: ... Polarity To change the polarity of either channel A or B locate the red knobs on the left side panel see Figure 4 8 and place the module flat on a table showing the side panel Gently adjust the slit of the red knob to the desired polarity using either an adequate screwdriver or a coin Please make sure that the screwdriver is not tilted Do not press on the knob Do not use force The channel is adju...

Страница 61: ...uts of the FT12 TP plug The desired potential for the reference wire Uref must then be supplied to the Uin reverse connector of the BAT2 with the special cable Note that the battery is not discharged during normal operation as no current is flowing between Uref and Uin Even in the presence of a short on the delay line anode there is still a 1MΩ resistance between the plus and minus pole of the int...

Страница 62: ... the single SHV input on the opposite side HV input of the BAT3 Note that the battery is not discharged during normal operation as no current is flowing between Uref and Uin Even in the presence of a short on the delay line anode there is still a 1MΩ resistance between the plus and minus pole of the internal battery pack The lifetime of the battery pack is therefore very long several years The ind...

Страница 63: ...t dust particle settles on the delay line and produces a short Note that there are several 1 MΩ in line resistors in the DLATR6 8 and FT12TP that will not allow to measure precisely any erroneous resistance on the anode 5 1 Checking the Noise Level When all cables including those to the high voltage power supplies voltages still down and the TDCs are connected you may switch on the N DLATR6 8 ATR1...

Страница 64: ...e noise levels again You may continue with section 5 3 For electron detection mode continue with step 7 If a discharge occurs you must verify all your connections inside the chamber again Verify that there is sufficient distance to any part close to the detector which carries different potentials than the detector parts After sufficient pumping time resume the test procedure from the beginning If ...

Страница 65: ...de is strongly recommended for the following procedure even if you plan to run the detector in electron detection mode later 1 Turn off all ion gauges and any sources emitting a high rate of charged particles ion pumps or high energetic photons UV and higher in the vicinity of the detector All detector potentials are on ground potential or close to that 2 Set the potentials for the anode holder si...

Страница 66: ...the MCP and the noise level Assuming all wire connections are correct and all detector potentials are applied you should see similarly shaped analog output signals on MCPfront back and the delay line A1 2 A3 8 monitor The outputs from the delay line should have similar signal heights If not the amplification factors on the DLATR boards should be adjusted see chapter 2 6 The analog signal height on...

Страница 67: ... data acquisition you should not supply signals to the ECL TTL converter A walk adjust of the N DLATR6 8 ATR19 is usually not needed If you press the walk button follow the instructions in section 2 6 The potis on the front panel of the DLATR6 8 or of the FT12 16 TP can be used to reduce ringing and reflections of the analog signals This is of importance for multi hit detection tasks When you opti...

Страница 68: ...Page 68 of 80 MCP Delay Line Version 6 2 90 5 ...

Страница 69: ... detector was irradiated by α particles with about 6 MeV kinetic energy Figure 6 2 Time sum peak for one dimension at fixed position Note that the apparent time sum integrated over all positions in the respective dimension will usually show a broader time sum spectrum due to slight variations of the absolute time sum as function of the respective position Wherever a narrow time sum is required thi...

Страница 70: ... Version 6 2 90 5 Figure 6 3 Enlargement from of a shadow mask image obtained by a DLD80 detector that was read out with HM1 The hexagons are 3 mm wide the obstacles have 0 2mm width One channel corresponds to approximately 0 08mm ...

Страница 71: ...oldPC directory Make sure that you have installed the CoboldPC program properly In case of WinNT Win2000 WinXP OS did you log on as ADMINISTRATOR for the installation procedure Were there any error or warning messages during installation Does your PC meet the hardware specification US compatible b although the event count rate seems to make sense I don t get a satisfactorily detector image at leas...

Страница 72: ...for the N DLATR6 strong enough sufficient current correct voltage PROBLEM The analog output from the MCP front back channels1 2 looks ok but not all of the delay line signals channels 3 8 a all are missing Make sure that the potentials on holder signal and reference on are correct Is there a wiring error Remove signal and reference SHV inputs on the DLATR6 8 rear panel or FT12 TP and verify the ab...

Страница 73: ...er down and open the box for that Is the power source for the N DLATR6 strong enough sufficient current correct voltage PROBLEM I have increased all CFD thresholds to maximum but there is still too high noise on channel 1 2 outputs Turn off the high voltage and remove the high voltage cables on the DLATR6 rear side If the noise has disappeared a power supply or power supply cable connection might ...

Страница 74: ...t all the cables on the DLATR boards inside the N DLATR6 8 are connected you need to power down and open the box for that Is the vacuum ok Is there any source of charged particles UV light ion gauge in the vacuum that can produce an excessive particle rate to the detector this may look like no signals Verify the detector wiring again First check if there is the current through the MCP stack from f...

Страница 75: ...ers a repair exchange service at reasonable costs If the analog output is missing after a discharge it is worth to try an easy and often successful repair because very likely only a pair of SMD double diode BAV99 and two pairs of SMD resistors 56Ω and 47Ω need to be replaced These are located close to the amplifier input When you have replaced all marked parts try to operate the channel again If t...

Страница 76: ...ine wire will be bent and will not touch other wires One way to do this is firmly gripping the anode with the fingers on the ceramic edges so that the loose wire can not become even looser on the turns that are still straight With the other hand then one or several turns of the broken wires can be unwound In order to fix it again on the connection screw there are two options If the screw is still ...

Страница 77: ...in their containers with the ion barrier facing down The MCP should be protected from exposure to particle contamination Particles which become affixed to the plate can be removed by using a single hair brush and an ionized dry nitrogen gun The MCP should be mounted only in fixtures designed for this purpose Careful note should be taken of electrical potentials involved CAUTION Voltages must not b...

Страница 78: ...Page 78 of 80 MCP Delay Line Version 6 2 90 5 ...

Страница 79: ...GURE 2 24 ASSEMBLY OF MCP STACK STAGE 4 DLD120 AND HEX120 18 FIGURE 2 25 SKETCH OF THE DETECTOR FLANGE MOUNTING OPTION 19 FIGURE 2 26 CF35 12 PIN FEEDTHROUGH FLANGE VACUUM SIDE THE SLIT IN THE SHIELDING ON THE AIR SIDE OF THE CONNECTOR HAS TO POINT UP 20 FIGURE 2 27 FT12 TP PLUG 22 FIGURE 2 28 FT12 TP PLUG HEX VERSION 22 FIGURE 2 29 SINGLE HF SIGNAL DE COUPLER PLUGS WITH TERMINATOR LEFT WITH LEMO ...

Страница 80: ...R6 8 AN OR ATR19 MONITOR OUTPUT 66 FIGURE 6 1 IMAGING OF A SHADOW MASK ON DLD40 DETECTOR THE DETECTOR WAS IRRADIATED BY Α PARTICLES WITH ABOUT 6 MEV KINETIC ENERGY 69 FIGURE 6 2 TIME SUM PEAK FOR ONE DIMENSION AT FIXED POSITION 69 FIGURE 6 3 ENLARGEMENT FROM OF A SHADOW MASK IMAGE OBTAINED BY A DLD80 DETECTOR THAT WAS READ OUT WITH HM1 THE HEXAGONS ARE 3 MM WIDE THE OBSTACLES HAVE 0 2MM WIDTH ONE ...

Отзывы:

Нет отзывов

Бренды по названию

Популярные бренды

Загрузить еще бренды