Thermostabilization system of VEPP-5 forinjector
Gespeichert in:
| Veröffentlicht in: | Вопросы атомной науки и техники |
|---|---|
| Datum: | 1999 |
| Hauptverfasser: | , , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
1999
|
| Online Zugang: | https://nasplib.isofts.kiev.ua/handle/123456789/81150 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | Thermostabilization system of VEPP-5 forinjector / K.V. Gubin, V.D. Hambikov, A.G. Igolkin, P.V. Martyshkin // Вопросы атомной науки и техники. — 1999. — № 3. — С. 35-37. — Бібліогр.: 3 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-81150 |
|---|---|
| record_format |
dspace |
| spelling |
Gubin, K.V. Hambiko, V.D. Igolkin, A.G. Martyshkin, P.V. 2015-05-11T18:27:43Z 2015-05-11T18:27:43Z 1999 Thermostabilization system of VEPP-5 forinjector / K.V. Gubin, V.D. Hambikov, A.G. Igolkin, P.V. Martyshkin // Вопросы атомной науки и техники. — 1999. — № 3. — С. 35-37. — Бібліогр.: 3 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/81150 en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Thermostabilization system of VEPP-5 forinjector Система термостабилизации форинжектора ВЭФФФ-5 Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Thermostabilization system of VEPP-5 forinjector |
| spellingShingle |
Thermostabilization system of VEPP-5 forinjector Gubin, K.V. Hambiko, V.D. Igolkin, A.G. Martyshkin, P.V. |
| title_short |
Thermostabilization system of VEPP-5 forinjector |
| title_full |
Thermostabilization system of VEPP-5 forinjector |
| title_fullStr |
Thermostabilization system of VEPP-5 forinjector |
| title_full_unstemmed |
Thermostabilization system of VEPP-5 forinjector |
| title_sort |
thermostabilization system of vepp-5 forinjector |
| author |
Gubin, K.V. Hambiko, V.D. Igolkin, A.G. Martyshkin, P.V. |
| author_facet |
Gubin, K.V. Hambiko, V.D. Igolkin, A.G. Martyshkin, P.V. |
| publishDate |
1999 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Система термостабилизации форинжектора ВЭФФФ-5 |
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/81150 |
| citation_txt |
Thermostabilization system of VEPP-5 forinjector / K.V. Gubin, V.D. Hambikov, A.G. Igolkin, P.V. Martyshkin // Вопросы атомной науки и техники. — 1999. — № 3. — С. 35-37. — Бібліогр.: 3 назв. — англ. |
| work_keys_str_mv |
AT gubinkv thermostabilizationsystemofvepp5forinjector AT hambikovd thermostabilizationsystemofvepp5forinjector AT igolkinag thermostabilizationsystemofvepp5forinjector AT martyshkinpv thermostabilizationsystemofvepp5forinjector AT gubinkv sistematermostabilizaciiforinžektoravéfff5 AT hambikovd sistematermostabilizaciiforinžektoravéfff5 AT igolkinag sistematermostabilizaciiforinžektoravéfff5 AT martyshkinpv sistematermostabilizaciiforinžektoravéfff5 |
| first_indexed |
2025-11-25T17:44:25Z |
| last_indexed |
2025-11-25T17:44:25Z |
| _version_ |
1850519071542476800 |
| fulltext |
THERMOSTABILIZATION SYSTEM OF VEPP-5 FORINJECTOR
K.V.Gubin, V.D.Hambikov, A.G.Igolkin, P.V.Martyshkin
BINP, Novosibirsk, Russia
HEATING EFFECTS AND ENERGY SPREAD IN
A BEAM
The temperature condition changes in an
accelerating structure influence on its RF
characteristics. This fact leads to the change in the beam
average energy as well as to the supplementary energy
spread in the structure.
Let's consider ultrarelativistic charged particles
in the field of the running RF wave with a phase
velocity βph = 1 + ∆βph. For the simplicity we shall
assume that there is no group effects in the beam and no
interaction between the beam and the accelerating
structure.
If we assume that ∆βph L/λ << 1 where L - the
length of the structure, λ - the length of the RF wave,
then the energy gained by the particle in the accelerating
structure will be
−
∆
−
∆
−=∆ 00 sinsin φ
βω
φ
βω
c
L
c
A
E phph
(1)
where A -- energy gradient of the structure, ω -
perashion frequency and φ0 - initial RF phase of particle.
For a beam of the phase length 2φ the part of
heating effects in the beam energy spread can be
estimated as
φβωδ sin
2max0
minmin0 L
cE
EE
ph∆=−= (2)
where E0min and E0max - minimum (φ0 = φ) and maximum
(φ0 = 0) energy gain when ∆β = 0, Emin - minimum
energy gain when ∆β ≠ 0 .
Relation between the change of resonant
frequency and the phase velocity of RF wave can be
written as [2]:
av
gr
ph
gr
ph
ph
ph T∆=∆=
∆
α
β
β
ω
ω
β
β
β
β
(3)
here α - the temperature expansion ratio of copper, ∆Tav
- the value of average temperature changing.
Equation (2) together with (3) determines the
maximum acceptable change of an average temperature
of the accelerating structure with a certain energy spread
limit caused by heating:
δ
φπ α β
βλ
sinph
gr
av L
T =∆ (4)
For the linear temperature distribution along the
maximum acceptable temperature gradient ∆ of the
structure T will be
δ
φπ α β
βλ
sin
6
ph
gr
L
T =∆ (5)
For the accelerating structure of VEPP-5
preinjector prototype the parameter βgr /βph is equal to
0.02. Taking the value of acceptable energy spread of
0.5% for a beam of RF-phase length about 20°, we
obtain that the system of thermostabilization should
ensure the average temperature of the accelerating
structure with the precision of ±0.1°C and the
temperature gradient along the structure not more than
1.2°C.
TEMPERATURE CONDITIONS OF
ACCELERATING STRUCTURE
Fig. 1 Acceleration section.
Accelerator section (Fig.1) is a cylindrical disk-loaded
waveguide placed inside the stainless steel coat for
better rigidness. The inner surface of the coat and outer
surface of structure form the channel with a ring-shaped
section of water cooling system. The main parameters
of section are listed in Table 1. Present construction of
the section determines the method of
thermostabilization: to stabilize the temperature and the
cooling water flow.
Table 1. Main parameters of acceleration section.
Length 280 m
Inner diameter of structure 84 mm
Outer diameter of structure 100 mm
Inner diameter of coat 108 mm
Outer diameter of coat 112 mm
Resonance frequency 2856 MHz
Repetition rate 50 Hz
RF pulse duration 0.5 µsec
Heating per one pulse up to 80 J
When the structure is filled with RF field, the
part of energy transforms into heat in the skin-layer on
the inner surface. The heating of the skin-layer can be
estimated using the nonstationary equation of thermal
conductivity ∆T ≈ (Pδ)/(αS), where P - pulse power of
heating, δ - depth of skin-layer, α - thermal conductivity
of copper, S - square of inner surface of accelerating
structure.
Assuming P=100 MW, δ = 10-6m, S=2m2, we
obtain that by the end of RF-pulse the heating of skin-
layer will be about 0.13°C. Taking into account that
without cooling the heating would be about 20°C we
suggest that even for the single pulse duration, and for
the time of several milliseconds between pulses as well,
all the heat will be distributed uniformly along the
radius of accelerating structure.
Present estimations illustrate that the distribution
of temperature along the radius of accelerating structure
and pulse nature of heating can be neglected. Thus, we
can analyze one-dimensional model with
quasistationary heating: long and thin rod of copper
(accelerating structure) with nonuniform heating along
it placed into cylindrical coat. In the ring channel
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 1999. №3.
Серия: Ядерно-физические исследования. (34), с. 35-37.
35
formed by the outer surface of structure and the inner
surface of coat, the cooling water is circulated. Thermal
contact with air and heat currents from butt-ends
supposed to be equal to zero.
Fig. 2. Numerically simulated corellation between input
(1) and output (2) cooling water versus time.
So, we should solve the system of three
nonstationary equations of thermal conductivity with
common boundary conditions of third kind. Analytical
solving of such a system in general case is rather
complicated. Due to this fact, numerical simulation
based on the method of finite differences was realized.
This model was experimentally tested on the prototype
of accelerator section and thermostabilization system of
VEPP-5 preinjector.
Fig. 3. Experimental corellation between temperature of
input (1) and output (2) cooling water versus time. The
scale of horisontal axis – 60 second per point. Water
flow is 0.27 lps.
In the experiment the temperature of cooling
water at the section entrance was changing and the
cooling water flow was constant. The dependence of the
input and output water temperature and its flow on the
time was measured and expected value of this
dependencies was numerically simulated with the same
parameters. Several series of measurements were done.
In Fig.2, 3 expected and measured data are
shown. The difference between it does not exceed 2%.
Thus we can calculate the temperature
distribution in structure and water along the axis of
section in any moment of time with any input
parameters such as flow and temperature of the water
and RF power in the section.
To determine the section sensitivity to the
disturbance of input water temperature, the following
model was tested: temperature disturbance was put over
the steady-state of section without RF power. (Tas(x,t) =
Tc(x,t) = Tw(x,t) = 0 )
>
<<
<
=
τ
τ
t
tT
t
tT distw
,0
0,
0,0
),0(
where Tas - temperature of accelerating structure, Tw -
temperature of water, Tc - temperature of coat, Tdist -
value of disturbance.
Fig. 4. Corellation between maximal deviation of
average accelerating structure temperature, relating to
amplitude of disturbance and the duration of
temperature disturbance of cooling water at the section
entrance.
The results of simulation are shown in Fig.4. As
one can see, with the present geometry of section
(Table 1) and the flow of water in certain bounds the
following correlation is observed:
Tdist τ Q ≤ 2 [l °C] (6)
Correlation (6) determines the quality of
thermostabilization of water at the entrance of the
section.
Fig. 5. Corellation between the average accelerating
structure temperature and the cooling water flow at
different power of RF-heating.
Next problem: how does the steady-state
condition of section sense influence the change of water
flow and RF power. Simulations were done for RF
power range from 500 up to 4000 W and the flow range
from 0.1 up to 1.0 lps. The main results are:
- over the whole range of RF-power the temperature
gradient along the section is not significant and with a
flow over 0.2 lps it does not exceed 0.6°C;
- knowing the heating power we can select the flow for
each section in order to compensate the tolerance of RF
36
parameters of different sections with the help of
calculated correlation between the average temperature
of section and the flow of water (Fig.5), the mentioned
correlation is
Q T / P ≈ 0.5 [l °C / kJ ] (7)
It allows to determine the section sensitivity to
disturbances of heating and water flow.
TECHNICAL REALIZATION AND PRESENT
STATUS
Technically the system of thermostabilization
supposed to be performed by two-contour water scheme
(Fig.6). All elements to be stabilized are connected in
parallel to the inner closed water contour. The
temperature stabilization is realized as a controlled
heating of input water by the heating unit, individual for
each element. Dumping of heat surplus is produced by
the heat exchanger.
Fig. 6. Sheme of two-contour thermostabilisation
system.
This construction allows to stabilize the cooling
water flow through elements, to decrease the power
consumption, to change the individual heating
conditions for each element of accelerator, to
compensate the tolerance in RF parameters during the
adjusting process.
Main characteristics of the system are shown in
Table 2. At the present time the assembly of water
contours is in progress. The heating unit that consists of
heater, controlled power supply, flow meter, thermistors
and control device, has been completely designed,
tested on preinjector prototype and now is in serial
production.
Table 2. Main parameters of thermostabilization system.
Number of elemets/branches 20
Flow of water per branch 0.5..1.0 lps
Total flow 15..20 lps
Operating temperature of elements 40±3°C
Precision of temperature stabilization 0.1..0.2°C
Peak power consumption 300 kWt
Nominal power consumption 50..100 kWt
Capacity of water in the system 10 m3
REFERENCES
1. A.V.Alexandrov and others. Test of prototype of
preinjector for VEPP-5. Preprint INP 97-64,
Novosibirsk, 1997.
2. O.A.Waldner and others. Disk-loaded waveguides
references guide. Moscow, Atomizdat, 1977. (in
Russian).
3. S.S.Kutateladze. Heat transfer and hydrodynamical
resistance. Moscow, Energoatomizdat, 1990. (in
Russian).
36
|